National Cancer Institute

CCR connections v OLUME 1, n O .1 | 2007

Preventing Cervical Cancer:

The HPV Vaccine

CENTER FOR CANCER RESEARCH ccr.cancer.gov

U.S. DEPARTMENT 

OF HEALTH AND 

HUMAN SERVICES

National Institute 

of Health
Center for Cancer Research

National Cancer Institute | National Institutes of Health | Building 31 – Room 3A11 | 31 Center Drive | Bethesda, MD 20892
ccr connections | v OLUME 1, N O .1 | 2007 1

Table of Contents

03 Editorial: Our Passion and Our Mandate

NEWS

04 Rapamycin: An FDA-approved agent that may prevent lung cancer?

President Bush Visits CCR

05 Cutting in: Getting between HIV and Chromosomes

06 Silent No More

Newly Tenured CCR Scientists

07 2007 Fellows & Young Investigators Retreat

08 Probing the Workings of an Ancient Antiviral Weapon

09 Uncovering Cancer’s Molecular Switches

10 Re-educating Stem Cells

11 New Recruits at CCR

FEATURES

12 A Victory Against Cancer: 25 Years in the Making 

16 Viral Deception: The Promise of Adenovirus as an HIV Vaccine

20 A War on Kidney Cancer

COMMENTARY

26 A CCR in Belfast

IN THE CLINIC

28 CCR Team Tackles Neurofibromatosis

v OLUME 1, N

O . 1 | 2007

12 20 16

FEATURE

Viral Deception

FEATURE

A War on Kidney Cancer

28

IN THE CLINIC

Tackling Neurofibromatosis

FEATURE

A Victory against Cancer
2 ccr connections | v OLUME 1, N O .1 | 2007

The mission of the CCR is:

To inform and empower the

entire cancer research community by 

making breakthrough discoveries

in basic and clinical cancer research

and by developing them into novel

therapeutic interventions for adults

and children afflicted with cancer or

infected with HIV

Contributors:

L.M. Bennett, Ph.D.

D. Kerrigan, M.S.

M. Randazzo, M.A., M.A.

S. Fox, B.A., B.S.W.

Baer Photography

Palladian Partners

SPG&M, SAIC-Frederick, Inc.

Vanchieri Communications

Designed and Produced by:

Feinstein Kean Healthcare
ccr connections | v OLUME 1, N O .1 | 2007 3

The Center for Cancer Research (CCR) 

provides such a unique environment. As

the basic and clinical research arm of 

NCI’s intramural program, CCR is a distinctive organization of scientists, physicians,

trainees, and support staff dedicated to

informing and empowering the entire 

biomedical community by making fundamental discoveries in cancer and HIV/AIDS

and rapidly translating those findings into

novel therapies for patients suffering from

those diseases. In addition, as part of the

NIH, CCR has a mandate to confront the

special challenges pre-sented by relatively

rare, but devastating cancers, as well as

cancers that may be predominant in medically underserved populations.

CCR has prodigious strengths in

both cutting-edge basic science and 

clinical research. The deep integration of

our basic and clinical efforts drives and

contributes to our success. Our unique

position within NCI enables us to be innovative and agile in our explorations, allowing us to commit resources for longer-term

and relatively high-risk studies that—

despite their potentially high impact

—would be difficult for other research

institutions to undertake. Furthermore, our

researchers collaborate not only with their

CCR colleagues, but also with many external researchers in both the private and

public arenas. We draw on their expertise,

and they on ours, to make the fastest

progress possible, and to ensure that 

innovative findings and technologies are

rapidly dispersed throughout the cancer

research community.

Everything we do at CCR begins and

ends with our patients. We recognize them

as full partners in our work, and we seek to

offer them an unsurpassed level of care. As

active participants in our research efforts,

in the flow of information from bench to

bedside and back, they often learn as much

about their disease as we do! This close

collaboration is deeply embedded in our

culture, is empowering for both patient and

physician, and adds to the unique richness

of the CCR environment.

It is one thing to describe the

uniqueness of CCR, and another to show it.

To that end, you hold in your hands the

first issue of CCR Connections. Here you will

find information about our basic and clinical research, our patients and scientists,

and our alumni. Within the pages of each

issue are only a few of the hundreds of CCR

“stories” we could tell that support our

vision and mission. Although each story is

distinct, each one also shares with all the

others the underlying passion for our work

and our mandate, derived from the founding mission of NCI 70 years ago, to understand, diagnose, treat, and prevent cancer

and HIV/AIDS.

We hope you find CCR Connections

interesting, informative, and even challenging, and we welcome your thoughts

and comments.

Robert H. Wiltrout, Ph.D.

Director, Center for Cancer Research

Our Passion and Our Mandate

For the first time in human history, we have the

fundamental biological knowledge we need to 

fight devastating diseases such as cancer and

HIV/AIDS within our reach. This knowledge is

important, but it is not enough: it also needs to be

tested and translated from basic scientific insight

to treatment and even prevention. This Herculean

feat can only come about in a scientific environment

that encompasses a diversity of talent, open sharing

of results and insights, and a united passion to

understand, treat, and prevent disease.

editorial

(Photo: R. Baer)
4 ccr connections | v OLUME 1, N O .1 | 2007

One attractive chemoprevention target is

mTOR, a protein linked to cell proliferation

and the synthesis of new proteins. The 

cellular pathways connected to mTOR are

stimulated by tobacco components such as

nicotine and one of its byproducts, a potent

tobacco-specific carcinogen called NNK.

However, mTOR’s relative importance in

tumor development and progression has

been unclear, clouding its potential as a 

prevention target for lung cancer.

After examining the interplay of

mTOR, NNK, and rapamycin (a well-known

mTOR-blocking drug that is FDA-approved

as an immunosuppressant), a collaborative

effort led by CCR’s Phillip A. Dennis, M.D.,

Ph.D., Senior Investigator, Medical Oncology

Branch, has established mTOR’s critical role 

in the formation of tobacco carcinogeninduced lung tumors. In addition, the

researchers also showed that rapamycin

might be an effective agent for preventing

lung cancer. The results were published 

in the April 1, 2007, issue of Clinical Cancer

Research, in a paper by lead author 

Courtney Granville, a doctoral student in 

Dennis’ laboratory.

Mice given rapamycin shortly after

exposure to NNK and kept on the drug 

continuously for several weeks had 90 

percent fewer tumors than untreated mice,

and the tumors that did develop were 74

percent smaller, highlighting mTOR’s importance in NNK-induced lung tumors. In a different experiment, tumors that developed

after NNK administration withered in size,

but not in number, when treated with

rapamycin, verifying their dependence on

mTOR to maintain growth, even after they

are formed. The team also found an everyother-day dosage schedule—as opposed to

five-days-on/two-days-off—to be the most

effective at quenching mTOR activity.

Importantly, the levels of rapamycin using

this schedule were comparable to what is

achieved when humans take rapamycin as

an immunosuppressant.

But can rapamycin’s effectiveness in

mice translate into a new intervention for

people at risk for lung cancer? That question

remains open. Dennis and his team point

out that while rapamycin was profoundly

effective, well-tolerated, and reached levels

in the mouse that are achievable in people,

the drug’s immunosuppressive effects in

humans could limit its use as a lung 

cancer intervention. For these reasons, the

researchers are currently studying the effects

of this schedule of rapamycin on immune

function in this mouse model system. If profound immunosuppression is not observed,

the Dennis team will translate these findings

into a clinical trial focused on rapamycin’s

effectiveness at eliminating premalignant

lesions in smokers with the highest lung

cancer risk, such as those carrying cancerpredisposing polymorphisms or having the

greatest exposure to tobacco carcinogens. 

President Bush

Visits CCR

On January 17, 2007, U.S. President George

W. Bush paid a visit to CCR’s patients and

staff as part of a day-long trip to the NIH to

participate in an NCI roundtable on cancer

prevention. The visit, which was the

President’s fifth to the NIH since taking

office in 2001, included a tour of the laboratories of CCR's Urologic Oncology Branch. 

Moderated by U. S. Department of

Health and Human Services Secretary

Michael O. Leavitt, the roundtable—which

included NIH Director Elias Zerhouni, M.D.,

National Human Genome Research Institute

Director Francis Collins, M.D., Ph.D., NCI

Director John Niederhuber, M.D., and cancer

survivors and advocates Grace Buler, M.D.,

and Becky Fisher—coincided with the

American Cancer Society’s announcement

that cancer deaths in the U.S. had fallen for

the second year in a row (and only the second time ever). The President, addressing

the gathering, said “I love coming to the

NIH; it is an amazing place. It is an amazing

place because it is full of decent, caring,

smart people, all aiming to save lives. And I

truly believe the NIH is one of America's

greatest assets.” 

Rapamycin:

An FDA-approved agent that may

prevent lung cancer?

(Photo: White House)

Even though smokers who quit

reduce their chances of developing

lung cancer, their risk will always

remain higher than that of the 

general population. To reduce that

risk, clinicians and researchers are

on the hunt for effective interventions

capable of countering tobacco’s 

lingering carcinogenic effects.

NEWS

Urologic Oncology Branch Chief 

W. Marston Linehan, M.D., talks with

President Bush during the President’s

visit to the NIH in January. 

(Graphic: Wikipedia)
ccr connections | v OLUME 1, N O .1 | 2007 5

While integrase inhibitors—which are effective in patients who have become resistant

to the current front-line anti-AIDS therapies—can interfere with integrase-cDNA

interactions (or crosslinking), their mechanisms of action are still unknown, and their

effectiveness is variable. Before devising an

effective therapy, researchers need to fully

understand how integrase and cDNA interact.

To elucidate this process, an international

team led by CCR’s Yves Pommier, M.D.,

Ph.D., Chief, Laboratory of Molecular

Pharmacology—who in 1993 published the

first study of HIV integrase inhibition—used

a pair of biochemical assays (the disulfide

and Schiff base assays, which probe interactions at different sites on integrase and

cDNA) to identify how eight integraseblocking drugs obstruct the protein’s function.

The results, published in a paper

authored by visiting fellow Allison

Johnson, Ph.D., in the March, 2007, issue

of Molecular Pharmacology, showed that a

family of integrase inhibitors called 3’-P

inhibitors—which insert themselves

directly between cDNA and integrase—are

significantly more potent than another

family of drugs known as ST-selectives—

which hamper the binding of integrase to

the host chromosome. The Pommier team

also found that drugs that interfere with

integrase in multiple ways are effective in

overcoming resistance to ST-selective

integrase inhibitors. 

Because of HIV’s quick mutation rate,

clinicians must block multiple viral pathways simultaneously to hold the virus at bay.

However, given that resistance to antiretroviral

therapy frequently arises, an understanding of

additional pathways is critical. Thus, by

highlighting the structural mechanisms

underlying current integrase inhibitors and

illuminating novel targets in the integraseviral cDNA complex, Pommier and his team

have provided additional evidence for these

drugs’ promise as potent retroviral agents. 

Cutting in:

Getting between HIV and Chromosomes

HIV’s life cycle could be cut short if the process of integration, by which

the virus inserts its genes into the host genome, were interrupted.

One of HIV’s tricks for spreading itself

throughout the body is to physically plug itself

into a person’s genome. It does so via integrase,

a viral protein that inserts the viral cDNA

transcribed from the virus’s RNA-based

genome into an infected host cell’s chromosomes.

This critical step in HIV’s life cycle, called 

integration, ensures the production of new,

progeny viruses; if this process is blocked, then

HIV infection cannot spread. 

NEWS

(Graphic: Y. Pommier, CCR)
6 ccr connections | v OLUME 1, N O .1 | 2007

For decades, it had been widely understood

that certain genetic mutations were silent.

Within genes, three-base blocks called

“codons” direct the addition of a specific

amino acid to a protein under construction.

The third base position in the codon can

sometimes change without affecting the

protein’s amino acid sequence in a socalled “synonymous” or “silent” mutation. In

other words, the gene can change, but the

protein and its function remain the same. In a

paper published in the January 26, 2007,

issue of Science, a CCR research team led by

Michael Gottesman, M.D., Chief of the

Laboratory of Cell Biology, revealed that

synonymous mutations may not be merely

“silent,” but can actually cause some proteins to

behave differently by changing how they fold.

The gene they studied, multidrug

resistance 1 (MDR1), codes for a protein

called P-glycoprotein (P-gp) that can pump

molecules—including anticancer drugs

—out of a cell. This protein pump can 

contribute to the drug resistance that arises

in a tumor over time. Such resistance 

can sometimes be reversed with P-gp 

inhibitors (e.g., cyclosporine A or verapamil).

Gottesman’s group found that a synonymous mutation, C3435T, when combined

with one or two other mutations, can interfere

with P-gp inhibitors and frees P-gp to expel

anticancer drugs from the cell. Experiments

showed that the change does not result

from chemical alterations or expression

changes in P-gp, but rather from changes in

the protein’s conformation. This phenomenon can occur if a synonymous mutation

like C3435T can substitute a rarer codon for

a more common one. This substitution can

affect the rate at which the P-gp is synthesized during translation of the mRNA into

protein, which in turn affects the dynamics

of how it folds.

The results of this study suggest that

researchers should take a harder look at the

large number of mutations that were once

assumed to be “silent.” Such mutations may

have renewed relevance to understanding

the origins and treatment of cancer.

Illustration showing potential effects of silent

SNP on protein translation. Ribosomes (blue)

“read” the mRNA (gray) and add amino acids

to the growing protein chain (red). The presence of a silent SNP (yellow) does not

change the amino acid sequence, but alters

the kinetics of the protein translation, changing the folding structure—and potentially the

function—of the resulting protein.

Silent No More

Newly Tenured CCR Scientists

Rémy Bosselut, M.D., Ph.D.

Laboratory of Immune Cell Biology (Nov/Dec 2006)

Ira O. Daar, Ph.D. 

Laboratory of Cell and Developmental Signaling (March 2007)

Carole A. Parent, Ph.D.

Laboratory of Cellular and Molecular Biology (Nov/Dec 2006)

Ying E. Zhang, Ph.D.

Laboratory of Cellular and Molecular Biology (March 2007)

NEWS

(Graphic: Feinstein Kean Healthcare)
ccr connections | v OLUME 1, N O .1 | 2007 7

This annual meeting provides the 1,000-plus

young scientists at CCR an opportunity to

meet, learn from each other, and develop a

sense of unity. Organized by CCR young

investigators for CCR young investigators,

the meeting is part career fair, part scientific

conference, and part networking event.

Eleven months of planning by four members

of the steering committee (Veronica Hall,

Ph.D.; Veronique Pascal, Pharm.D., Ph.D.;

Girish Patel, M.D.; and Gillian Whittaker,

Ph.D.) went into this event, though all 31

committee members participated in its execution. There was so much to do, and many

mailboxes remained overloaded throughout, prompting one committee member to

comment, “When you volunteer, you just

don’t realize how much work is involved!” 

The Career Fair—a first-time offering

for this retreat—was a major achievement

and success. Sixteen organizations from

academia, government, and industry came

searching for scientific talent, and a resume

critiquing service was available to help prepare fellows to take their next important

career steps. Many thanks are due to

Veronique Pascal for her hard work in organizing the fair, and we congratulate all who

left the fair with job offers in hand. 

Educationally, there were four fantastic keynote lecturers: Max Wicha, M.D.

(“Cancer Stem Cells: a New Paradigm in

Cancer Research”), Polly Matzinger, Ph.D.

(“Conversations between Tissues and 

T cells”), Lalage Wakefield, D.Phil (“TGF-ß‚ in

Cancer: From Bench to Bedside”), and

Steven Holland, M.D. (“From Immune

Deficiency to Immune Therapy”). Most

important was the celebration of research

conducted by CCR young scientists. There

were 35 oral presentations and over 100

poster presentations during the retreat; the

eight presenters judged the best received

travel awards. We also wish to congratulate

and thank Anurandha Budhu, Ph.D., of the

Laboratory of Human Carcinogenesis, who

delivered this year’s postdoctoral plenary

lecture, “Lessons Learned from Molecular

Profiling of Hepatocellular Carcinoma.” And

CCR Director Robert Wiltrout, Ph.D., was on

hand to answer questions and congratulate

the committee on a job well done!

What now for the CCR-FYI Steering

Committee? In addition to organizing next

year’s retreat, they will be busy helping

young investigators achieve their career

aspirations with variety of programs, including orientations, seminar series, networking

brunches, a newsletter, and a Web site. If 

you are interested in helping, join the 

CCR-FYI Steering Committee by emailing 

nciccrfyi@mail.nih.gov. 

Girish Patel, M.B.B.S., M.R.C.P., M.D.

Vice Chair & 2007 Retreat Chair

Fellows and Young Investigators Association

Center for Cancer Research

National Cancer Institute

NEWS

2007 Fellows & Young

(Graphic: CCR)

Investigators Retreat

The 7th annual CCR Fellows and Young Investigators (FYI) retreat was

held to much fanfare in Ocean City, Md., from February 27th to March

1st, 2007. Organized by the CCR-FYI Steering Committee and sponsored

by CCR’s offices of the Director and Training & Education, the event

brought more than 300 young CCR scientists together for 48 hours of 

scientific discussion, career exploration, and networking. 
8 ccr connections | v OLUME 1, N O .1 | 2007

The immune system is the evolutionary

result of an elaborate molecular sparring

contest: as the host develops new ways of

countering a pathogen, the pathogen

evolves new evasions and tactics. This interplay is well illustrated by the unfriendly

relationship of retroviruses like HIV or

HTLV-1 to the APOBEC3 family of antiviral

restriction proteins—components of what

has come to be called the “intrinsic”

immune response, a form of antiviral

defense possibly older than the innate or

adaptive responses—and, in particular,

APOBEC3G (hA3G). This host protein halts

retroviral replication by packing itself into

nascent virions and forcing hypermutation

of reversed-transcribed viral cDNA. 

Not to be outdone, HIV and HTLV-1

have both devised strategies for circumventing hA3G. HIV does so by producing Vif, a

viral protein that tags hA3G for degradation.

HTLV’s choice of strategy, however, has only

recently become clear.

In the February 20, 2007, issue of the

Proceedings of the National Academy of Sciences,

David Derse, Ph.D., Head of CCR’s Retrovirus

Gene Expression Section, and his colleagues

revealed that rather than actively eliminating its opponent, HTLV-1 (which can cause

adult T-cell leukemia) prevents hA3G from

being packaged into new virus particles. The

virus accomplishes this interference with 

a pair of highly conserved motifs located

near the C-terminus of the NC domain of

Gag, the viral structural protein that builds

HTLV’s shell. The Derse team found that 

the two motifs—a small cluster of acidic

amino acids followed by a leucine-rich

motif—together are required for HTLV to

keep hA3G (and other APOBEC3 proteins)

out of the virus. 

The work sheds light on an additional

mystery: how hA3G gets packaged into HTLV

(and other retroviruses) in the first place.

Current wisdom holds that both viral RNA

and NC are required for hA3G to gain entry,

but it is unclear whether the host protein

attaches to viral RNA alone or to NC-RNA

complexes. Derse’s work suggests the latter,

that hA3g binds to NC-RNA complexes. This

revelation opens the possibility of finding a

general—and potentially therapeutically

exploitable—mechanism by which hA3G

enters and interferes with all retroviruses.

The HTLV-1 virus (round objects with

a dense core) may thwart one of the

body’s ancient antiviral defenses by 

a novel mechanism.

The best known weapons of the

human immune system are its 

T cells and antibodies. However, its

arsenal also includes much more

ancient weapons, held over from 

our evolutionary ancestors. These

primordial agents of immunity 

lack the specificity of their more

advanced relatives, but provide a

powerful first line of defense against

whole classes of pathogens.

Probing the Workings

of an Ancient Antiviral Weapon

NEWS

(Photo: D. Derse, CCR)
ccr connections | v OLUME 1, N O .1 | 2007 9

As cells turn cancerous, the mechanisms

that control their growth and division go

awry. Thus-altered cells produce too many

proteins that signal growth, a build-up that

cells could reverse by breaking down the 

surplus. But cells also manufacture socalled chaperones which, under healthy

conditions, bind to and protect “client”

proteins from breakdown. This protection

is supposed to stabilize a healthy cell 

during stressful conditions. Unfortunately,

the clients of a chaperone called heatshock protein 90 (Hsp90) include signaling

proteins. Thus, Hsp90 inadvertently promotes undue cell growth and cancer by

protecting the excess proteins.

For this reason, researchers have

long sought not only an understanding 

of how the cell controls Hsp90 activation,

but also ways of stopping it early in tumor

formation. For example, a group of

researchers led by Leonard Neckers, Ph.D.,

Senior Investigator in CCR’s Urologic

Oncology Branch, identified geldanamycin,

a small molecule inhibitor of Hsp90, as

early as 1994; in 1998 they brought to the

clinic the first-in-class inhibitor called 

17-AAG (now being evaluated in more than

20 phase II human cancer trials). 

The Neckers team is now focusing

its efforts on Hsp90 acetylation—the

reversible addition of acetyl (-COCH3)

groups to specific amino acids. In a

Molecular Cell paper authored by Postdoctoral Fellow Bradley Scroggins, Ph.D.,

(released January 12, 2007) the investigators revealed that acetylation of a specific

lysine (K294) within the Hsp90 protein is

crucial for many of its binding and stabilizing properties. And in a yeast-based

model system, they showed that acetylation of K294 enhances Hsp90’s ability to

promote the same kind of aggressive

growth that marks renegade cancer cells in

humans—making the process an attractive

target for drug development studies.

Although acetylation of Hsp90 is not

known to be linked to cancer, these

results are highly suggestive that it plays

a role in the cancer process. “Acetylation

is another layer of control of Hsp90 

in response to environmental signals,”

Neckers said. “We want to further understand the role of this regulation.”

Instead of protecting cells

from damage, Hsp90 

(middle domain pictured)

may inadvertently help

them become cancerous;

understanding its control

mechanisms could help

put cells back on track. 

Uncovering Cancer’s

Molecular Switches

In many forms of cancer, the molecular machinery that is supposed to 

protect a cell from heading down the pathway to malignancy is subverted,

actually contributing to a process it is supposed to prevent. Of the many

different changes that can have this effect, most are poorly understood.

However, investigators at CCR have illuminated the ways in which one such

molecular guardian can unwittingly force healthy cells into malignancy,

thereby pointing to a potential new pathway for cancer drug development.

NEWS

(Graphic: National Center for Biotechnology Information)
1 0 ccr connections | v OLUME 1, N O .1 | 2007

NEWS

But to make this transformation with efficiency and specificity, researchers need a

deeper understanding of the fate of adult

stem cells and their progeny when placed

into a different environment. Do the stem

cells retain the ability to self renew? Do they

gain tissue-specific multipotency, developing into all of the constituent cell types of

their new host tissue? Can their progeny

react in the same way as native host tissue

cells to the normal hormonal or biochemical

changes in their new surroundings? 

In the March 6, 2007, issue of the

Proceedings of the National Academy of 

Sciences, senior research assistant Corinne 

Boulanger, of CCR’s Mammary Biology and

Tumorigenesis Laboratory, and Gilbert

Smith, Ph.D., Head of CCR’s Mammary Stem

Cell Biology Section, illustrate the extent to

which a cell’s microenvironment can influence its fate. The Smith lab showed that

mouse spermatogenic stem cells can be

introduced into the mammary microenvironment and take the place of parity-induced

mammary epithelial cells (PI-MECs): the

native progenitors of all cellular subtypes

found in mammary glands. 

When transplanted into PI-MECdepleted mammary fat pads in juvenile

mice, the spermatogenic cells produced

progeny that differentiated into several

mammary-specific cell types, helping generate chimeric, fully functional mammary

glands. The team also found that the transplanted male cells retained the ability to self

renew, and continued producing mammaryspecific progeny after experiencing the 

significant tissue remodeling seen in the

mammary gland caused by pregnancy and

lactation—just as PI-MECs do. 

The significance of this work lies in 

its definitive proof of the power of the 

microenvironment: that the signals specific

to the milieu in which a semi-differentiated

cell resides can override its previous 

programming. This outcome has obvious

implications for cancer research as well as

normal cell biology. However, the Smith

team, including Postdoctoral Fellows Brian

Booth, Ph.D., and David Mack, Ph.D., have

not yet identified the particular cellular cues

(other than pregnancy and lactation) that

mediated the interactions they observed;

that, they noted, is a subject for further study. 

The presence of X (red) and Y (green)

chromosomes in these chimeric mammary

glands shows that spermatogenic cells

transplanted into a mammary microenvironment can adopt characteristics

and produce progeny cells specific to

their new host tissue. 

Re-educating Stem Cells

Coaxing partially committed adult stem cells to transdifferentiate—to develop

into progeny cells and tissues other than those they are initially fated to

become—is the holy grail of adult stem cell research. Reprogramming a skin

stem cell to produce neurons and their supporting cells, for instance, would

be a boon for stroke and Parkinson’s disease patients. 

(Graphic: C. Boulanger and G. Smith, CCR)
ccr connections | v OLUME 1, N O .1 | 2007 1 1

Giuseppe Giaccone, M.D., Ph.D.

Dr. Giaccone was recently appointed

Chief of the Medical Oncology Branch.

He is the former Head of the

Department of Medical Oncology 

at the Free University Medical Center

in Amsterdam. His work at CCR will

focus on early drug development,

molecular targets that manipulate 

cellular processes, such as apoptosis, and how they relate to

lung cancer. “I am very excited about the opportunity to work 

in the NCI environment,” Giaccone said, “and about the great 

possibilities for having an impact on cancer research and 

treatment at this institution.”

Dennis M. Klinman, M.D.

Dr. Klinman is a Senior Investigator 

in the Laboratory of Experimental

Immunology and Chief of the

Immunoregulation Group. Previously,

he led the Section of Retroviral

Immunology at the U.S. Food and

Drug Administration’s Center for

Biologics Evaluation and Research. 

Klinman’s laboratory focuses on the mechanisms by which

immunomodulatory DNA sequences alter host susceptibility 

to cancer, inflammation, and infectious diseases. His work 

on immune-stimulating CpG and immune-suppressing TTAGGG

oligodeoxynucleotides is uncovering ways for clinicians to boost

vaccine responses or curb inflammatory or autoimmune reactions

by altering the host’s inflammatory and immune milieu.

Paul Meltzer, M.D., Ph.D.

Dr. Meltzer came to CCR from the

Cancer Genetics Branch of the

National Human Genome Research

Institute (NHGRI) in May 2006. He 

now serves as Chief of CCR’s Genetics

Branch, Head of the Clinical Molecular

Profiling Core (CMPC), and attending

physician in the Pediatric Oncology

Branch. At CCR, he is using genomic technologies, such as

microarrays, to profile the cancer genome in both clinical 

and laboratory-based investigations and basic research. Via 

the CMPC, he is also helping to bring the latest genomic 

technologies to clinical investigators both within his branch 

and throughout NCI. “I hope to have a stronger interaction 

with the NCI Intramural Research Program and to help bring

important genomic technologies to clinical and basic laboratory

investigators within the NCI,” Meltzer said.

Giorgio Trinchieri, M.D.

Dr. Trinchieri was most recently the

Director of the Schering Plough

Laboratory for Immunological

Research in Dardilly, France, and an

NIH Fogarty Scholar at the Laboratory

for Parasitic Diseases, National

Institute of Allergy and Infectious

Diseases. Since August 2006, he has

been the Director of the new Cancer and Inflammation Program

(CIP) and Chief of the Laboratory of Experimental Immunology.

Trinchieri discovered interleukin-12 (IL-12) in 1989 while at the

Wistar Institute, and he has since been characterizing the

molecular mechanisms underlying this cytokine’s production,

function, and activity. At CCR, he will continue his work on 

the interplay between inflammation/innate immunity and 

adaptive immunity, and on the roles played by IL-12 and other

pro-inflammatory cytokines in the regulation of carcinogenesis,

innate resistance, and anti-tumor immunity. “I am very optimistic

that the CIP will bring to CCR new lines of investigation,” said

Trinchieri, “that will allow investigators to shed light on 

mechanisms of carcinogenesis and tumor progression and 

to identify new targets for cancer therapy or prevention.”

New Recruits at CCR

(Photo: R. Baer)

NEWS

(Photo: SPG&M, SAIC-Frederick, Inc.)

(Photo: SPG&M, SAIC-Frederick, Inc.) (Photo: R. Baer)
1 2 ccr connections | v OLUME 1, N O .1 | 2007

A Victory 

against Cancer 

25 Years in the Making

In the early 1980s, CCR scientists heard the news that

researchers had established the link between human 

papillomavirus (HPV) and cervical cancer, including those in

NCI’s Division of Cancer Epidemiology and Genetics (DCEG).

This announcement set off a new quest: to craft a vaccine

against a form of cancer that, at the time, claimed the lives

of more than 5,000 American women each year. 

feature

Chondrus crispus, source 

of carrageenan.

(Graphic: E. Haeckel, via Wikipedia)

(Graphic: C. Buck, B. Trus, CCR)
ccr connections | v OLUME 1, N O .1 | 2007 1 3

Two decades of work by Douglas Lowy, M.D. (left), John Schiller, Ph.D. (right),

and their collaborators and students could help protect millions of women around

the world from HPV’s cancerous consequences. 

(Photo: R. Baer)

Apart from its significance as a landmark

event in women’s health, the FDA’s approval

also marked a victory for CCR scientists

Douglas Lowy, M.D., and John Schiller, Ph.D.,

who laid the biological foundation for the

HPV vaccine. Rather than rest on their laurels, these two lead scientists from CCR’s

Laboratory of Cellular Oncology and their

colleagues are already looking toward alternate ways of fighting or preventing cervical

cancer, including the next generation of HPV

vaccines and topical microbicides that might

address some of the significant challenges of

delivering a vaccine in the developing countries where it is most needed.

A Vaccine with Impact

HPV vaccines promise to make a big difference in women’s health. The American

Cancer Society estimates that 11,150

American women will be diagnosed with

invasive cervical cancer this year; nearly

3,700 will succumb to it.

A unique feature of HPV is the ability

of one of its component proteins, L1, to

assemble itself into empty shells called

virus-like particles (VLPs). Because they

contain no viral genomic material, these

particles cannot cause infection on their

own. What they can do, though, is mimic the

presence of a viable virus and trick the

immune system into mounting an anti-HPV

immune response. The pair found that

immunization of animals and even human

volunteers with these L1-based particles

could stimulate production of large numbers

of antibodies; serum taken from vaccinees

protected cultured cells from HPV infection

in the laboratory. 

NCI licensed the VLP technology to

two pharmaceutical companies, Merck and

GlaxoSmithKline (GSK), both of which 

subsequently developed HPV vaccines for

clinical use. Both vaccines protect against

HPV types 16 and 18, which cause up to 70

percent of all cervical cancer cases worldwide. Merck’s vaccine, marketed under the

name Gardasil®, also protects against HPV

types 6 and 11, which cause 90 percent of

genital warts. Both vaccines were remarkably

successful in Phase III clinical trials, showing

themselves to be 100 percent effective at

preventing the premalignant cellular

changes caused by the relevant virus types.

Thus far, protection has remained solid after

four years of follow-up. However, it appears

that the vaccine cannot clear HPV infections

that have already become established. 

The FDA approved Gardasil in June

2006 for women and girls ages nine to 26

years. The vaccine, which is given in a series

of three injections, was evaluated and

approved in six months under the FDA's 

priority review process, which is used for

products with potential to provide significant

health benefits. GSK is expected to apply for

approval of its vaccine, CervarixTM, in 2007. 

Taking it Further

The considerable public health impact of

this work has introduced NCI researchers to

issues that most basic scientists do not

face. How will the vaccine be delivered?

Will the people who need it be able to get

access to it? Those issues have spurred

them on ever since. 

HPV vaccines

promise to make

a big difference in

women’s health.

Nearly 25 years later, success: 

in 2006, the U.S. Food and Drug

Administration (FDA) approved

the first HPV-blocking vaccine to

protect against cervical cancer.

Approvals in Canada and Europe

soon followed. 
1 4 ccr connections | v OLUME 1 | 2007

“The vaccine is for the next generations of

women. But let’s not lose sight of the current

generation and the need to help them

reduce their incidence of cancer.”

Fighting two diseases with one 

vaccine is an efficient way of keeping costs

down. Schiller is working with Denise

Nardelli-Haefligher, Ph.D., at the Centre

Hospitalier Universitaire Vaudois in

Lausanne, Switzerland, to see if L1 can be

incorporated into the typhoid vaccine, which

is still used in developing countries. It may

also be possible to formulate the dualaction vaccine as a nasal spray, easing the

logistics of transport and administration.

Such a preparation elicited strong immune

responses in preclinical tests in mice. 

“We can easily grow liters and liters of

this. It doesn’t require high-tech production

methods,” Schiller said. “Plus, a small oral dose

for every villager would be much easier than

giving three intramuscular injections.” They

are moving forward with companies in India 

to conduct clinical trials of both vaccines.

“The current vaccine has implementation limitations that will make it difficult for

poor women to get it—and they’re the

women who need it most because they have

no Pap screening,” Schiller said. “It’s expensive to make and deliver this vaccine. We’re

trying to make better approaches that are

very simple to deliver.” 

A new approach can be highly complex

when developed in the laboratory, but has to

be simple to produce and distribute. Lowy

and Schiller are developing new therapeutic

technologies capable of meeting those goals

while still providing effective protection

against HPV (see “A Topical Option”). 

While the current Merck and GSK

vaccines are based on L1, the virus’s L2 

protein appears able to confer broad 

protection against more types of HPV.

However, it is less effective than L1 VLPs at

triggering virus-neutralizing antibody

responses. Lowy and Schiller are working

with Richard Roden, Ph.D., at the Johns

Hopkins University—a former fellow in the

Lowy lab—to improve the protein’s ability

to spur on these responses.

Helping This Generation

While preventing future HPV infections

remains a central goal, Lowy does not want to

abandon the millions of women who are

already infected. The Centers for Disease

Control and Prevention reported in February,

2007, that about one in four females ages 14 to

59—the equivalent of 25 million American

girls and women—are infected with HPV. 

“We need to recognize that the vaccine

is not going to do anything for the millions of

women who are already infected with HPV and

who remain at increased risk for cervical cancer,” Lowy warned. “The vaccine is for the next

generations of women. But let’s not lose sight

of the current generation and the need to help

them reduce their incidence of cancer.” 

He is hoping to see inexpensive DNAbased HPV tests made available to women

globally, along with appropriate follow-up

In their continued search for alternate and

easier ways to block human papillomavirus

(HPV) infection, John Schiller, Ph.D., and his

colleagues designed a high-throughput

screening assay to test a wide range of compounds in hopes of finding ones that can

prevent HPV infection. So far, a widely-used

thickening agent extract from seaweed,

called carrageenan—which can be applied as

a topical gel or cream—has shown the most

promise in laboratory tests. 

“The screen let us test lots of drugs and

other compounds very easily to see if they

can act as a topical microbicide,” Schiller

said. “Carrageenan popped out as something

that worked amazing well, and it’s already

[used] in some topical products.” 

The fact that carrageenan is inexpensive

and “generally recognized as safe” by the U.S.

Food and Drug Administration (FDA) for food

and topical, including vaginal, applications

increases its appeal to the scientists who are

eager to find products that are safe and effective

for humans. However, further studies are

needed to determine whether products containing carrageenan can inhibit HPV infection

and prevent sexual transmission of cancerassociated HPV in humans. 

In preclinical animal studies, Schiller’s

group tested carrageenan-based over-thecounter sexual lubicants in a mouse cervicovaginal infection model developed in his

laboratory. Even at a one million-fold dilution, these lubricants could prevent genital

HPV infection in these mice. As for human

studies, the Schiller lab has teamed with

Terri Cornelison, M.D., Ph.D., and colleagues

in the Division of Cancer Prevention to clinically test carrageenan’s ability to prevent

sexually transmitted HPV infections. 

Although a topical microbicide would

be a significant addition to the anti-HPV

arsenal, it does have some drawbacks. For

example, it would have to be used prior to

every occasion of sexual contact, as opposed

to a vaccine, which requires just a few injections. “I don’t see it as a replacement for the

vaccine,” Schiller said, “but it may be a complement to the vaccine to give coverage

against more types of HPV or where the vaccine

is not available.” 

Carrageenan may have other uses as well.

HPV can also be passed from mother to child

during birth and, in rare cases, lead to serious

diseases, including juvenile onset recurrent

respiratory papillomatosis. The relative safety

of carrageenan-containing infant formulas

suggests that a cervical gel containing carrageenan may be a viable option for preventing

HPV transmission during childbirth. 

A Topical Option

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ccr connections | v OLUME 1, N O .1 | 2007 1 5

feature

treatment. (To put the need in perspective,

more than half a million women worldwide

are currently stricken with invasive cervical

cancer each year, with a quarter million

deaths.) Thanks to work done by DCEG’s 

Mark Schiffman, M.D., M.P.H., and Diane

Solomon, M.D., HPV-DNA tests are known to

be cost effective when used in women with

inconclusive Pap test results. DNA-based

HPV testing is currently approved for screening of women over age 30, with some 

insurers now providing coverage. Digene

Corporation, which has partnered with the

Bill & Melinda Gates Foundation, is fieldtesting a new HPV-DNA test for use in

developing countries. If proven effective, it

will be available at a cost much lower than

current DNA-based tests, according to Lowy. 

Beyond Cancer

To capitalize on the fact that VLPs are “really

good at inducing antibody responses,”

Schiller is exploring their ability to fool the

immune system into making antibodies that

target “self” proteins—which the body normally tolerates—that play roles in chronic

diseases, such as Alzheimer’s disease or HIV

infection. For example, in the context of

Alzheimer’s, Schiller can imagine sopping up

the beta-amyloid protein that makes up

Alzheimer’s-causing plaques with antibodies

before it can coalesce in the brain.

In HIV, he is aiming at the CCR5 receptor. People lacking this receptor do not

The 2006 approval of the first human 

papillomavirus (HPV) vaccine ushered in a host

of awards for the NCI scientists who made 

possible development of the HPV vaccine. 

For their work on HPV, Douglas Lowy,

M.D., and John Schiller, Ph.D., of the

Laboratory of Cellular Oncology received a

2006 DHHS Secretary’s Award for Distinguished

Service. The award was shared with other

NCI investigators who made significant

contributions to HPV research including:

Allan Hildesheim, Ph.D., and Mark

Schiffman, M.D., M.P.H., in the Division of

Cancer Epidemiology and Genetics, and

Diane Solomon, M.D., in the Division of

Cancer Prevention.

Lowy and Schiller’s efforts also

earned them the 3rd Annual David Workman

Award from the Samuel Waxman Cancer

Research Foundation, the 2007 Dorothy P.

Landon-AACR Prize for Translational Cancer

Research, the 2007 Award for Excellence in

Technology Transfer from the Federal

Laboratory Consortium for Technology

Transfer, and the 2007 American Medical

Association Nathan Davis Award for Outstanding

Government Service. 

“We are simply symbols of the many

people who have made critical contributions to understanding the relationship

between papillomavirus infection and cervical cancer,” Lowy said. Both Lowy and

Schiller are quick to point out that the

recognition has been nice, but that they

remain humbled by the insightful research

done by so many of their colleagues. 

Recognition

John Schiller, Ph.D., encourages his trainees to follow their own paths.

“We try to set the postdocs up with broad, open-ended projects, where

we can build an enabling technology in an area that’s not fully

explored,” he said. He keeps his lab small enough to enable his postdocs to direct their projects and take them with them when they 

continue their careers at other institutions. He generally has three

postdocs, two technicians, and a staff scientist. A great deal of

responsibility falls to the postdocs. 

He can list several success stories. One fellow, Bryce Chackerian,

Ph.D., took work on virus-like particles (VLPs) and autoantibodies

with him to the University of New Mexico. Richard Roden, Ph.D., who

worked on the L2 vaccine in Schiller’s lab, took that technology with

him to the Johns Hopkins University. 

“The nice thing is we’re not competing for grants with my former

postdocs,” Schiller explained. “If we were in the extramural community, we’d be applying for the same research funds.” But being in the

intramural program, Schiller can let each fellow get a good head start

and expand on a technology that they launched in Schiller/Lowy lab. 

Leveraging CCR Progress 

through His Students

develop AIDS after infection with HIV, indicating that this receptor is necessary for the

virus to take hold. If the body could be

tricked into making autoantibodies that

compete for the receptor, perhaps HIV infection could be prevented or controlled.

VLPs may even work for contraceptive vaccines. With researchers in India,

Schiller is testing a vaccine that targets a

protein required for a fertilized egg to

implant in the uterine wall, preventing

pregnancy without affecting women’s hormone levels or menstruation. 

Right Place at the Right Time

Schiller, who began as a Postdoctoral

Fellow in Lowy’s lab, credits CCR’s research

environment for a lot of the progress they

have made. “I stayed because CCR is a very

good place to do research,” explained

Schiller. “We were studying the basic biology of a virus, but we had no experience

in vaccines or immunology. However, no

one said we couldn’t try to develop this

vaccine.” He is convinced that if he and

Lowy had been in the extramural program

at the beginning of their search, they would

have had to write a grant, which likely

would have been rejected because they did

not have the relevant track record in

immunology or virology. Within CCR, however, they had the freedom to operate with

confidence that they could justify their

work in the long-term. 
1 6 ccr connections | v OLUME 1, N O .1 | 2007

Despite advances in drug treatments, HIV prevalence continues to grow

at an alarming rate around the globe. The World Health Organization

estimated that 4.3 million more people worldwide were infected with 

HIV in 2006, bringing the number of those living with HIV/AIDS to 

a staggering 39.5 million people. This figure does not count the three 

million who lost their lives to the disease that same year. The human 

and societal cost of HIV is incalculable.

These numbers underline the need to both

treat HIV and prevent its further spread. To

that end, researchers in the Vaccine Branch

of the CCR are pooling knowledge of cancer

and retrovirus vaccines to understand not

only what immune system responses are

required to fight off infection with the virus,

but also how to develop a vaccine that will

elicit those responses. 

Researchers in the Immune Biology

of Retroviral Infection Section of CCR’s

Vaccine Branch, led by Marjorie RobertGuroff, Ph.D., have been pursuing these

goals for the last two decades, with a singular focus on developing an effective HIV

vaccine that can be easily delivered and

made widely available. For the fundamental

building block of their vaccine strategy,

they have turned to the adenovirus, a common human virus that can be genetically

altered to trick the immune system into

thinking it is seeing HIV and thus into

building robust HIV immune responses.

Theirs is a unique approach among many

other HIV vaccine efforts, and their recent

work in non-human primate models of HIV

suggests that it has a high potential for success. Given the positive results to date,

they have set the aggressive goal of beginning human testing of this adenovirusbased HIV vaccine within the next two

years. “It has become clear as we have studied the properties of this vaccine approach

that we have to move it along,” RobertGuroff said. “Other approaches were not

working, and the need is tremendous.”

Why No Vaccine Yet?

The lack of an HIV vaccine more than 25

years after the first cases of AIDS were

described is not due to a lack of research

effort. Indeed, developing an HIV vaccine

has been one of the largest—and thorniest—scientific problems of the last 20 years. 

Perhaps the biggest obstacle is the

nature of HIV itself. In addition to attacking

the very cells the body relies on for defense

against infection, HIV replicates rapidly and

inaccurately, allowing new strains to arise

quickly. This characteristic allows HIV to

evade the immune response by quickly

changing its protein makeup, a viral advantage that also explains the appearance of

drug-resistant strains of HIV following a

period of treatment. In other words, the virus

always manages to stay a few steps ahead of

the immune system or drug treatment

attempts to control it.

Thus, past HIV vaccine efforts had

two strikes against them: they were poorly

immunogenic and—because they targeted

only one or a few HIV proteins—too 

narrowly focused. 

Just as problematic for vaccine development efforts is an incomplete understanding

of what immune responses actually control

virus infection and replication, or the socalled “correlates of immunity.” Scientists

know that antibodies are important, as are

cell-killing or “cytotoxic” responses. They

also know that these immune responses

need to be present not only in blood, but

also at the mucosal surfaces where HIV most

often gains its entry. People naturally infected with HIV have great antibodies and fairly

robust cytotoxic immune responses against

the virus, yet these defenses still fail to control its devastating effects. It may be that the

initial burst of HIV replication following 

initial infection gives the virus enough of a

lead that the immune system is forever in

the futile position of playing “catch-up.”

The evidence for this viral “head start”

is strong, and the goal of many vaccine

efforts is to block this advantage. A live but

weakened (or “attenuated”) vaccine (i.e., one

that replicates slowly enough for the

immune system to establish a response and

survives long enough to make that response

Viral Deception: 

The Promise of Adenovirus 

as an HIV Vaccine

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ccr connections | v OLUME 1, N O .1 | 2007 1 7

lasting) has been the most successful vaccine tested in animals to date. This approach

to vaccine design has worked in humans

before, the best example being the Sabin

oral poliovirus vaccine. The immune

response triggered by such a vaccine may

not prevent infection, but may control the

initial infection enough to allow the immune

system to win the race.

Unfortunately, an attenuated HIV 

vaccine approach is far too dangerous to

attempt in people, as even an attenuated

virus can potentially regain its normal 

virulence. Thus, much research effort,

including that of the Robert-Guroff lab, 

has gone into investigating the notion of 

altering other infectious viruses to elicit the

right anti-HIV immune responses without

the risks of attenuated HIV. Adenovirus 

as an HIV “pretender” (see “Adenovirus

Reconstructed”) is a particularly attractive

basis for an HIV vaccine. It can readily be

engineered to express HIV-specific proteins

that elicit an immune response from the

host against native HIV, without the use of

actual live HIV. Also, adenovirus does not

insert itself into the host’s DNA, as HIV does,

but is content to pursue its lifecycle without

disrupting the host’s normal genes or

genome functions. 

Perhaps one of the most attractive

features of an adenovirus-based vaccine is

the virus' ability to infect many different cell

types without requiring that the cells be

dividing. These types include epithelial cells,

such as those that line the upper respiratory

tract and gut and which can engender the

mucosal immune responses necessary to

fight back against sexually transmitted infections such as HIV. This characteristic opens

the way to oral or inhaled delivery of the

primary vaccine—a critical element to 

consider when developing a vaccine that

would need to be distributed in remote parts

of the world where HIV is endemic.

Finally, adenovirus has been substantially studied for therapeutic purposes in

other settings, including its uses as a 

vaccine against adenovirus infection for 

millions of military personnel and as a gene

therapy vector. For these reasons, among

others, Robert-Guroff and her colleagues are

focusing on an adenovirus-based HIV vaccine.

Although others have also used an

adenovirus approach, they have concentrated on “replication-incompetent” adenoviral

vectors (adenovirus that cannot replicate

and is thus eliminated fairly quickly from the

host after its initial infection). The problem

with this approach is that it requires a high

dose of the replication-incompetent adenovirus in order to elicit an immune response.

Because this dose can cause a significant

inflammatory response, there is an upper

limit to the amount of replication-incompetent virus a person can be given. 

Thus, the researchers in the RobertGuroff lab have focused on replication-competent adenovirus, or adenovirus that is able

to replicate in the host. Replication-competent adenoviruses provide two significant

advantages. First, vaccine effectiveness is

improved because the virus is “real,” drawing

on all of the elements of immunity necessary

to fight infection. This method gives the

immune system greater exposure to the HIV

elements the virus is carrying and results in

more robust immune responses. The scientists in Robert-Guroff’s group demonstrated

this enhanced effectiveness convincingly in

studies that compared replicating and 

nonreplicating adenovirus-HIV vaccines in

nonhuman primates (the results were published in the August, 2005, issue of the

No other vaccine approach—except for live

attenuated HIV or SIV virus—has resulted 

in this level of protection to date.

(Graphic: © Russell Kightley, Russell Kightley Media, Canberra, Australia)

feature

Adenovirus
1 8 ccr connections | v OLUME 1, N O .1 | 2007

Journal of Virology), showing that replicating

adenovirus-based vaccines resulted in 

significantly more potent antibody and 

cytotoxic immune responses. 

The second, considerable advantage of

replicating adenovirus is that one can administer a much lower dose of the vaccine to get

sufficiently robust immune responses. This

fact will have a significant positive impact on

both manufacturing and cost issues.

In addition to administering the 

adenovirus-based HIV vaccine, the

researchers have found that a traditional

“boost” element a few weeks later of only the

HIV proteins encoded by the genes engineered into the original adenovirus vaccine

is necessary for strong antibody responses.

This “prime-boost” strategy is a common one

in many vaccine protocols, although it is not

ideal, given that the need for a follow-up

booster shot decreases the simplicity of 

providing effective vaccination.

From Non-Human Primates 

to People 

The real proof-of-principle for the replicating

adenovirus vaccine approach to controlling

HIV infection is described in papers published in the March, 2004, issue of the Journal

of Virology and in the September, 2006, issue

of Virology, both from Robert-Guroff’s group.

In the first paper, the team outlines a series

of studies in which rhesus macaque monkeys

were primed either orally or by inhalation

Adenoviruses are found in a wide range of 

animals and derive their name from human

adenoid tissues, from which they were first

isolated and described in 1953. The different

strains can cause significant diseases, yet only

about a third of the 50 or so known human

strains, or serotypes, are known to be diseaserelated. The majority of adenovirus infections

do not require clinical attention. 

The combination of its ability to infect

non-dividing cells and the opportunity to 

substitute non-adenovirus genes in its DNA

genome for carrying into host cells has made

adenovirus an attractive vector for gene therapy research. The size of the gene that can be

inserted is limited, due to the rigid structure

of the adenovirus vector and the requirement

for most of its own genes to remain intact.

Inserts of up to ten kilobases of DNA have

been successfully transferred, though socalled “gutless” adenovirus can accommodate

about 35 kilobases. (However, they require a

“helper” virus to infect host cells.) 

Gene therapy uses have focused on the

delivery of large viral doses in order to 

optimize expression of the therapeutic 

transgene. However, adenovirus can cause

significant inflammatory responses at higher doses, limiting its utility and safety in

most gene therapy approaches. This makes

adenovirus ideally suited for vaccine use,

where obtaining an immune response is the

goal. In particular, replication-competent

adenovirus (adenovirus that has had a

transgene added that does not disrupt its

ability to replicate after infection) can 

provoke sufficient immune responses even

at relatively low doses. In addition, the 

adenovirus predilection for epithelial cells,

such as those that line the gut and respiratory passages, allows it to be administered

orally or intranasally, routes that promote

the mucosal immune responses needed to

prevent HIV infection.

Adenovirus Reconstructed

Representation of the adenovirus

genome. Blue arrows represent 

transcribed adenoviral genes. The

red arrow represents the adenoviral

E3 genes, which can be removed

and replaced with HIV-related 

genes without interfering with the

ability of the adenovirus to replicate

in its host cells. 

with an adenovirus vaccine containing the

simian immunodeficiency virus (SIV, the

monkey equivalent of HIV) genes encoding

SIV core and coat proteins, followed by 

a booster shot of the actual proteins 

themselves. The vaccinated monkeys were

subsequently challenged with a high dose of

a particularly virulent form of SIV. The results

were striking: all of the monkeys showed

some degree of protection, with about 40

percent of them showing exceptionally

strong protection, including a complete lack

of viremia (virus in the blood stream) or levels of SIV viremia at the lower edges of

detection limits.

The 2006 Virology paper describes further the research where 11 of the same vaccinated monkeys were challenged again

intrarectally with a high dose of the same

pathogenic SIV. All of the vaccinated monkeys again showed some degree of protection, and eight of the 11 were still strongly

protected, demonstrating that not only was

this vaccine approach effective soon after

vaccination, but it also evoked a durable

immune response. No other vaccine

approach—except for live attenuated HIV or

SIV virus—has resulted in this level of protection to date.

There are significant challenges still

to be faced with moving this approach into

human trials. Robert-Guroff and her colleagues are currently addressing a host of

“traditional” drug development challenges—

such as choosing the right adenovirus and

HIV type (they are using “clade C,” the most

common strain of HIV worldwide, particularly

prevalent in Asia and southern Africa); determining which HIV proteins will elicit the best

response; making the adenovirus in sufficient quantity and purity according to strict

regulatory guidelines; and preparing it properly for oral, inhaled, or injected administration; toxicology testing, etc. They believe it

will take a year to make the vaccine properly

and another year to thoroughly test for toxicity. 

“My goal is to get this moving along

with strong enough data to interest a company

in developing it further,” said Robert-Guroff,

envisioning the need for extramural partnerships in the world of vaccine development.

“First it needs to be tested in humans.”

(Graphic: Feinstein Kean Healthcare)

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ccr connections | v OLUME 1, N O .1 | 2007 1 9

Ruth H. Florese, Ph.D., Visiting Fellow

Ruth Florese joined the Robert-Guroff lab

almost three years ago, coming from the

University of the Philippines, Manila, where she

was teaching microbiology to advanced students. “I’m here trying to learn as much as I can,”

she said. “I believe that doing cutting-edge

bench work will make me a better teacher,

because I can talk from experience,” she said.

“The NIH provides an unequalled environment

to do this kind of work.”

Although Florese is involved in the vaccine

work of the lab, her primary focus is on identifying the immune responses that are important

for controlling HIV infection. In particular, she is

studying whether an antibody-mediated form of

immunity called “antibody-dependent cellular

cytotoxicity," which does not prevent HIV from

entering the cells, may nevertheless play a critical role in limiting HIV’s spread in the body or

slowing the progression to AIDS. 

Florese received her doctoral degree from

Kobe University in Japan in 2002. 

Thorsten Demberg, Ph.D., Visiting Fellow

Thorsten Demberg joined the laboratory two

and a half years ago after completing his 

doctoral work at the Georg-August-Universität

of Göttingen in Lower Saxony, Germany. 

Demberg’s work in the lab touches on several projects, including a recent study published

in the Journal of Virology demonstrating the 

efficacy of a combination of two different 

adenovirus-HIV constructs (one with HIV-env

and one with HIV-tat), followed by boosts with

the related proteins, in rhesus macaques.

However, his main expertise is in technical

wizardry, developing and perfecting the assays

needed to understand immune responses to

vaccine regimens as well as the virus itself. 

Demberg is also excited about a state-ofthe-art fluorescence-activated cell-sorting

(FACS) facility soon to be installed at the lab.

“One of the major differences at CCR, compared

to other places, is the resources they provide to

help you do the science quickly and completely,”

he said. “This is a great work environment.”

Jean Patterson, Ph.D. and 

Ruth Florese, Ph.D. 

Thorsten Demberg, Ph.D.

Marjorie Robert-Guroff, Ph.D., Chief

Marjorie Robert-Guroff joined Robert Gallo’s

CCR lab in the early ‘70s, prior to the epidemic

appearance of HIV. At that time, the Gallo lab

was looking for retroviruses associated with

cancer. She joined the lab as an enzymologist

and was charged with looking for the telltale

biochemical “footprint” of reverse transcriptase, an enzyme specific to retroviruses. Using

the techniques of enzymology was difficult at

best, as other DNA polymerases had similar

properties. Thus, she and her colleagues set

out to make specific antibodies against the

different enzymes in order to more easily 

identify and characterize them in tumor tissue.

“An enzymologist basically became an immunologist by necessity,” said Robert-Guroff, a

transition which led naturally to her current

interest in retrovirus biology and immunology,

virus-cell interactions, and AIDS vaccine 

work. In 1989, she began a collaboration with

Wyeth on adenovirus vaccine protocols which

continues to today.

Robert-Guroff received her Ph.D. degree

from Georgetown University, and she was a

Postdoctoral Fellow of the Leukemia Society of

America at the NCI and of the Friedrich

Miescher-Institut, Basel, Switzerland.

Jean Patterson, Ph.D., Staff Scientist

Jean Patterson joined Robert-Guroff in 1996 as

a Postdoctoral Fellow, and she stayed on to

become a full research associate in 2000 and

then a staff scientist in 2004. “This work has

exciting potential to make a difference,” she

said, crediting the steadfast determination of

Robert-Guroff to pursue this approach even as

others were focusing elsewhere. Her doctoral

work in microbiology and immunology, at

Ohio State University, prepared her for the 

science, but she now focuses on translating

the science into clinical research and practice. 

“It has been incredibly interesting to 

see how the vaccine pipeline works,” Patterson

said. “I have been involved in the process since

its beginning, and I want to see where it will

go.” She is working on making the recombinant adenoviral vector that will be used in 

the clinical trial, as well as the background

work to identify appropriate cell lines to 

produce the virus. “Vaccine work integrates so

many diverse fields,” she said.

In addition to her laboratory work,

Patterson plays a major role in the teaching and

training of new scientists in the laboratory. 

(Photo: R. Baer) (Photo: R. Baer) (Photo: R. Baer)

Marjorie Robert-Guroff, Ph.D. 

The pill she is holding is a prototype

version of the adenovirus-based HIV

vaccine. 

Vaccine Hunters

The laboratories of CCR’s Immune Biology

of Retroviral Infection Section are tucked

away in one of the smaller buildings on the

edge of the NIH campus in Bethesda, Md.

In those laboratories are 11 researchers all

working together to move the adenovirusbased HIV vaccine from the laboratory 

into the clinic. Several of the scientists are

profiled briefly here.

feature

The Division of AIDS of the National

Institute of Allergy and Infectious Diseases

is contributing funds and collaborating with

CCR to produce and test the clinical-grade

adenovirus-based HIV vaccine in an NIH

clinical trial.
2 0 ccr connections | v OLUME 1, N O .1 | 2007

follicle cell prompt cell division in order for

a person to grow hair. But that same follicle cell has a restraining system to stop

cell division when inappropriate. (This is

why eyelashes stop growing at a certain

length, for example.) 

Every cell has many genes at its disposal, each capable of prompting division or

restraining it. Mutations in any single gene

or set of them can cause cells to go renegade. And because different genes might

become mutated in different, even adjacent,

cells, different tumors within the same 

tissue, and even different cells within the

same tumor, can be genetically different

from one another. Therefore, treatments that

target one person’s kidney cancer may not

affect that of another. 

Unraveling Kidney Cancer

Gene-by-Gene

Early on, Linehan’s group did not know the

extent of this genetic diversity. Thus, they

treated all kidney cancer as similar. But, after

partnering with Berton Zbar, M.D., Chief of

the Laboratory of Immunobiology, in 1983,

Linehan realized that the genetic knowledge

could now be transformed into a groundbreaking new weapon against cancer.

“We had hoped that if we understood

the genes that when mutated cause these

cancers,” Linehan said, “we might understand how they provide the foundation for

the development of targeted therapies.”

And the CCR researchers developed a

new logic: if one wants to find the genes that

cause kidney cancers, one must look for cancers that seem to be genetically inherited.

Although these malignancies may occur

rarely, one can extrapolate the information

gleaned from the rare cases to all patients

with more common forms of kidney cancer.

Embracing that strategy, Linehan’s

team began looking at patients with an illness called von Hippel-Lindau syndrome

(VHL). It predisposes individuals to nearly

600 types of tumors in multiple organs,

including a form of kidney cancer called

clear cell renal cell carcinoma (CCRCC). This

form of cancer accounts for 80 percent of

people with renal cell carcinomas, which in

turn represents more than 90 percent of all

malignant kidney tumors. The hope was that

any breakthrough in von Hippel-Lindau

would apply to CCRCC, which is not inherited.

After nearly ten years of performing

genetic analyses, the researchers in 1993

Linehan saw the devastation firsthand while

caring for patients at Duke University

Medical Center. Thus, by the time he

arrived at NCI in 1982, he was already compelled to take action. 

"I looked at these people with kidney

cancer, dying even after we had tried 300 different kinds of chemotherapy agents,” said

Linehan, who is now Chief of CCR’s Urologic

Oncology Branch (UOB). “We had to come

up with a better approach.”

And so began the 25-year story of a

group of CCR investigators who dedicated

their careers to doing just that. 

All Kidney Cancers 

Are Not Equal

All kidney tumors are not created equal.

Clinicians only began to understand this

concept when genetic analysis was applied

to kidney cancer. This new knowledge gave

scientists a map with which to track the

genetic roots for human disease. Whereas

oncologists used to classify cancers by the

tissue within which they first emerged, the

emphasis on genes revealed the relative

naiveté of this organ-based scheme. 

Tumors arise from once-normal

cells that begin dividing uncontrollably

because of alterations in their genes.

Many genes play a role in normal cell division. For example, certain genes in a skin

A decade after President Richard Nixon’s 1971 declaration of war on cancer, urological surgeon W. Marston

Linehan, M.D., at CCR, declared his own battle against kidney cancer. The disease afflicts nearly 40,000 adults in

the U.S. annually, a third of whom will die from the illness or its complications. Then, as now, the incidence of kidney

and similar renal pelvic cancers was rising by 2 percent each year. 

A War on Kidney Cancer

All kidney

tumors are not

created equal.

feature
ccr connections | v OLUME 1, N O .1 | 2007 2 1

VHL was the sixth gene discovered with links

to human cancer, but the first associated

specifically with kidney cancer.

finally narrowed their search to one area of

chromosome 3. Later, the team pinpointed

within that region a mutant gene, called VHL,

which normally functions as a tumor suppressor, a molecular brake on cell division. 

VHL was the sixth gene discovered

with links to human cancer, but the first

associated specifically with kidney cancer.

When VHL is mutated, it cannot do its normal job of holding cellular reproduction in

check, including in the cells that line the

tubules within the kidney (from which carcinomas arise). This finding allowed the CCR

researchers, and many others working

around the world, to work out the biochemical

details of how the VHL gene encodes a 

protein that forms a complex that keeps normal cells from dividing. 

The finding also held clinical benefit.

Drug developers later targeted the VHL

pathway and came up with agents such as

sunitinib maleate (Sutent®; Pfizer) that

appear to work in keeping tumor growth at

bay. Linehan's own laboratory recently

launched a Phase II clinical trial of an antibiotic derivative called 17-AAG (pioneered by

Leonard Neckers, Ph.D., Senior Investigator

in the UOB). It is hoped that this type of

therapy will advance the treatment of kidney

tumors in patients with VHL and, in the

future, help others such as Jeanne McCoy

and Alice Coday (see “Patients: Part of the

Team”) who, thanks to early detection and

treatment, are currently cancer-free, despite

having the associated VHL mutation. 

Unfortunately, the CCR team soon

learned that the faulty VHL genes, while

clearly the cause of von Hippel-Lindau and

most cases of CCRCC, are not the instigators

of all types of kidney cancer. 

The researchers needed to broaden

their focus. 

More Cancers, More Genes

Individuals with hereditary papillary renal

cell carcinoma (HPRCC) are plagued with

multiple tumors in both kidneys. Papillary

kidney cancer represents 5 percent to 10 percent of all cases of renal carcinoma but,

more importantly, can run in families. Thus,

the Linehan team again conducted a thorough genetic analysis, this time in families

affected by HPRCC. 

In 1997, after seven years of research

with Zbar and Urologic Oncology staff scientist Laura Schmidt, Ph.D., the culprit

emerged: the c-Met oncogene. This gene

does the opposite of VHL—it triggers cells

to divide. 

The discovery prompted a thorough

biochemical search for the molecules that 

c-Met and its protein product interact with in

order to accomplish its pro-cell division

function. Today, investigators are now

engaged in “a very intense effort” to develop

agents that block the oncogene, said

Linehan. Clinicians and scientists are

searching for an agent like imatinib mesylate

(Gleevec®)—a Novartis drug first developed

as a treatment for one form of leukemia and

later soft tissue cancer—characterized by

W. Marston Linehan, M.D., Chief of

CCR’s Urologic Oncology Branch, has

spent 25 years crafting better

approaches to treating kidney cancers.

feature

(Photo: R. Baer)
2 2 ccr connections | v OLUME 1, N O .1 | 2007

London showed that HLRCC is caused by

mutations in an enzyme called fumarate

hydratase, which normally acts in a fundamental metabolic pathway called the Krebs

cycle. Although Tomlinson’s group knew that

the enzyme could function as a tumor suppressor, they did not know how.

Linehan, working with senior investigator Maria Merino, M.D., of CCR’s

Laboratory of Pathology, showed that the

tumors taken from patients with HLRCC produce a very high level of a protein called

hypoxia inducible factor (HIF). The protein

normally senses low oxygen in tissues and,

in response, spurs new blood vessel growth,

an increase in glucose transport, and the

secretion of growth factors. Linehan surmised that, in tumors, excess HIF might promutation in the gene c-Kit—that can target

the c-Met gene pathway. An agent like this

should have therapeutic benefit for 

individuals with papillary kidney cancer 

as well as HPRCC. 

One More Time

Individuals with Birt-Hogg-Dubé syndrome

(BHD) have tumors in many tissues, including

benign skin bumps arising from the hair 

follicles. While that manifestation might seem

relatively trivial, 35 percent of these individuals also develop kidney cancer. And since BHD

runs in families, it provided an opportunity for

researchers at CCR to apply their strategy of

gene discovery yet a third time. 

In 2002, after seven years of scrutiny,

Linehan, Zbar, Schmidt, and colleagues 

discovered what they called the BHD gene. 

It makes a protein that the team dubbed 

folliculin, a reference back to the benign hair

follicle tumors.

The gene was novel, with no known

function. Linehan’s team set out to discover

that function, hoping it would lead to more

clues and ultimately therapies for BHD syndrome and the cancers linked to it. Using a

mix of state-of-the-art genomic technologies

and traditional biochemistry, the CCR team

has unraveled the folliculin pathway and,

with that knowledge, identified potential

drugs (see “The BHD Mystery Solved”). 

Collaboration

And still the kidney cancer story continues.

The fourth chapter, and probably not the

last, involves collaboration, a trademark of

the environment at CCR. 

Hereditary leiomyomatosis and renal

cell cancer (HLRCC) is a hamartoma 

syndrome, a condition in which affected

individuals readily develop skin bumps

called myomas. In women, these can also

appear in the uterus as fibroids. About 20

percent of HLRCC patients develop a very

aggressive type of kidney cancer. 

In 2002, Ian P. Tomlinson, Ph.D., and

colleagues at Cancer Research UK in

mote growth and sustenance, making the

molecule or its activity a good target for an

anti-cancer drug. 

Still, Linehan did not have an answer

to the question: what does a mutation in a

Krebs cycle enzyme have to do with an

upsurge in HIF? In a late-night conversation

in the hallway outside his office, Linehan

turned to Neckers. With the help of a chemistry fellow in his lab, Neckers offered the

idea that excess fumarate might compete

with the co-enzyme of another molecule,

prolyl hydroxylase, which is critical for binding and regulating HIF. This was an “ah-ha”

moment for Linehan, because his team had

already implicated the VHL/HIF pathway in

CCRCC. Since one of VHL’s functions is to

Possible placement of FNIP1 in the AMPK and mTOR growth signal transduction

pathways. Proteins indicated in yellow are those that are known to be defective

in hamartoma syndromes. The dotted lines indicate functional interactions that

are not yet clarified. FNIP1 (blue) is regulated by AMPK through phosphorylation

(P). FNIP1 is believed to facilitate folliculin (FLCN) phosphorylation by mTOR and

AMPK signaling. The target(s) of FLCN remains unknown.

feature

(Graphic: Feinstein Kean Healthcare)

(continued on page 24)
ccr connections | v OLUME 1, N O .1 | 2007 2 3

Masaya Baba, M.D., Ph.D.

Donald Bottaro, Ph.D.

Sunil Sudarshan, M.D. 

Although Linehan’s research team in the Urologic Oncology Branch is diverse, they share

two common motivations: patients and a desire for performing in-depth basic research. At

CCR, while people with kidney cancer seek help at the NIH Clinical Center, researchers are

cloning, mapping, and probing DNA two floors below. This close juxtaposition of clinical and

basic research is rare and exactly the reason that lab members have traveled to work here

from around the world. 

Donald P. Bottaro, Ph.D., Senior Scientist 

Before joining the Linehan lab, cell biologist Don Bottaro’s world fit on a microscopic slide.

He spent two fruitful decades at NCI’s Laboratory of Cellular and Molecular Biology, studying how molecules such as hepatic growth factor and a gene called MET signaled to each

other in cells. Then, in 1999, he felt compelled to expand his borders.

“I wanted to use what we do in basic science to help patients with cancer,” Bottaro said.

Thus, he left NCI for a two-year stint at a biotech company called Entremed, dedicated

to discovering anti-cancer drugs. Bottaro then returned to join Linehan’s multitalented, clinical and research-focused team. For three years, Bottaro attended surgeries and grand

rounds each week, in addition to working long hours in the lab.

His heroic efforts to bridge “the very big gap” between basic research and clinical treatment is paying off. He has used the tumors from the patients seen upstairs to decipher how

the VHL gene might cause the renegade invasiveness of cancer cells. 

Masaya Baba, M.D., Ph.D., Postdoctoral Fellow 

On his first day as a urologic surgeon in Japan, Masaya Baba developed a passion for kidney

cancer. He examined a mother of three who had the disease, and who died within five years

of diagnosis.

“That motivated me,” Baba said. “I saw that many patients survive through surgery. But

I thought that more research was necessary.”

Thus, after establishing a clinical practice and later studying von Hippel-Lindau syndrome during graduate school in Japan, Baba wanted to push the frontier of cancer treatment

still further. He wanted to work with a group that had molecular biology and genetic technology expertise, as well as access to many patients with rare, inherited forms of kidney cancers. 

Enter the Linehan team, which Baba joined in 2003. Already he has uncovered the

molecular underpinnings of folliculin. 

Sunil Sudarshan, M.D., Clinical Fellow

Synergy drew Sunil Sudarshan to the Linehan lab in 2005. From the first day he studied biochemistry as an undergraduate to his residency in urology at the Medical University of South

Carolina in Charleston, Sudarshan wanted to work both with patients and with their genes.

Sudarshan walked through the doors of the Linehan lab just as the researchers, in 

collaboration with Len Neckers, had made a breakthrough connection between the rare

hereditary leiomyomatosis and renal cell cancer (HLRCC) and fumarate hydratase, which normally functions in the Krebs cycle. 

Immediately, Sudarshan jumped on board. He now applies this molecular knowledge directly

in patients with HLRCC, seeing them in the clinic as he studies their DNA in the laboratory.

“That is what CCR is set up for,” Sudarshan said. “It is rare that a researcher gets to do

both clinical and basic research on essentially the same thing.”

A Team with a Patient Focus

feature

(Photo: R. Baer) (Photo: R. Baer) (Photo: R. Baer)
2 4 ccr connections | v OLUME 1, N O .1 | 2007

“After working on the complexities of 

biochemical mechanisms, it really brings 

us back to earth to see these patients.”

degrade HIF after oxygen concentrations

reach adequate levels, the idea provided a

possible connection between the two seemingly disparate forms of cancer through one

biochemical pathway. 

The next step was to prove the connection, which Linehan and Neckers both

did. The researchers published the connection between fumarate hydratase and VHL in

the August, 2005, issue of Cancer Cell. With

the assistance of urologic surgeon Sunil

Sudarshan, M.D., (see “A Team with a Patient

Focus”) these investigators are working to

turn these findings into a targeted therapeutic approach for patients with HLRCC-associated kidney cancer. For example, Linehan

is planning a trial to evaluate whether or not

targeting HIF will have an effect on HLRCC

as well. A drug called Avastin® (bevacizumab), which can inhibit new blood vessel

growth, might reverse some of the damage

caused by excess HIF. 

The CCR researchers are in a perfect

position to investigate the promise of

Avastin and other therapies on patients

because of the close association of lab

Individuals with Birt-Hogg-Dubé syndrome

(BHD) have a mysterious condition, characterized by tumors in follicle cells, as well as

those of the kidney, in some cases. To unravel the mystery, W. Marston Linehan, M.D.,

Laura Schmidt, Ph.D., and colleagues

employed cutting-edge genetic mapping and

linkage studies, thereby discovering the 

previously unknown gene folliculin. 

But in order to find out how that genetic

defect can lead to cancer, the CCR team had

to map folliculin’s molecular interactions.

The investigators used a technique called coimmunoprecipitation, in which one protein

linked to a bead or antibody is used to fish

out another from a mix of cellular contents.

With that, the CCR team pulled out folliculin’s

partner, a protein that functions in an energy/

nutrition sensing pathway in the cell. 

What Does Energy Regulation

Have to Do with Follicle Tumors?

It turns out that folliculin-interacting protein-1,

(FNIP1), as the CCR team named it, binds to

and clinic in CCR—the laboratories and

clinic are housed two floors apart in the

NIH Clinical Center. Researchers join clinicians on the Urologic Oncology Branch’s

grand rounds, while clinicians work as fellows in the labs. It is a unique collaborative environment destined to advance the

innovative basic research that translates

to better therapies.

“After working on the complexities of

biochemical mechanisms, it really brings

us to back to earth to see these patients,”

Linehan said. “We never lose that focus.”

folliculin and so puts the brakes on cell division. Thus, this protein pair functions in a

tumor suppressing pathway that appears to

be controlled by the loss or gain of a phosphate group. And that group associates with

an enzyme called 5’-AMP-activated protein

kinase (AMP-K, a key energy sensing molecule within the cell). 

Because the discovery of the folliculinFNIP1-AMP-K relationship is so new—it was

just published in 2006—Linehan, Schmidt,

and colleagues can only speculate on how

problems with an energy sensing pathway

might be linked to renegade cell division. It

could be that an energy deficit or stress triggers AMP-K, which works through another

pathway involving a protein called mTOR.

The kinase, when activated, appears to add

a phosphate group to both FNIP1 and folliculin and so could potentially trigger a braking action within cells. This system likely

evolved as a mechanism to keep cells from

reproducing in times of energy scarcity. 

Cells should release this brake when

energy is plentiful, for example letting 

follicle cells divide and hair grow. But

individuals with BHD make faulty 

folliculin proteins and so may lack this

particular braking system. Thus, the follicle cells divide regardless of whether

energy levels are high or low, fueling the

benign skin bumps. These same mechanisms may allow the kidney cells in BHD

patients to grow, although with more

malignant consequences.

While further delving into how that

putative pathway might work, Linehan's

team has already begun searching for clinical agents that block this pathway.

Promising leads involve other drugs known

to target the mTOR pathway. Linehan says

investigators are studying this lead “very

aggressively,” but cautions that the studies

are preliminary.

The BHD Mystery Solved? 

feature
ccr connections | v OLUME 1, N O .1 | 2007 2 5

Patients like Jeanne McCoy (above

with son Ford, daughter Mary Ellison,

husband Ellison, and son Brooks) and

Alice Coday (below, with her dog

Clancy) are also Linehan’s partners in

kidney cancer research. 

It ran in the family. Jeanne McCoy’s grandmother and mother both suffered from von

Hippel-Lindau syndrome (VHL), which manifests as a combination of one or more of nearly 600 types of tumors in multiple organs. 

For McCoy’s grandmother, the tumors

appeared first on her retina (she went blind at

the age of 30) and also on her brain stem.

Eventually the cancer invaded her kidneys.

Meanwhile McCoy’s mother, who was told at a

young age that she did not have the same

diagnosis, was shocked to learn that she had

already progressed to late-stage kidney cancer. The double diagnosis—combined with

her family history—led McCoy to search the

Internet, learn of the then recently-identified

VHL gene, and seek out the NIH and Linehan. 

Because of the late stage of McCoy’s

mother’s cancer, she was quickly accepted

into the clinical program at the NIH. There,

she tested positive for the VHL mutation.

Several months later, McCoy sent in her own

blood sample and records to the NIH—just in

case. The results confirmed McCoy’s suspicions: she too, carried the VHL mutation, as

did her grandmother. 

But McCoy had no symptoms of kidney

cancer. In fact, at age 34, she had just given

birth only a year previously to the youngest of

her three children. Except for faint back pain,

something all new mothers experience,

McCoy felt fine.

But she also knew that the VHL mutation foretold her fate. And she already had a

benign tumor on the endolymphatic sac of

her inner ear—a common symptom of VHL

syndrome. So McCoy consulted her local

oncologist, who advised her to undergo an

ultrasound and CT-scan in a hospital near her

Greenville, South Carolina, home. Within

hours, she learned that both her kidneys were

riddled with cysts and tumors that, if untreated, could eventually kill her. 

Panicked, she called the NIH. Within two

weeks, she was headed for Bethesda for more

testing and consultation. There, she embarked

upon an odyssey of surgeries, first to remove

the tumor in her ear and then those in her kidneys. It was during the second of her kidney

surgeries, just before Christmas 2003, that

McCoy first met Linehan, who came to see her

in the surgical intensive care unit at the NIH.

“He sat down and talked to me and my

husband,” she recalled. “And suddenly, he put 

a real personal face on the research; that it

wasn't these scientists lost in a lab; that this

was about people, and this was about early

diagnosis and detection, and this was about

finding a cure.”

In that interaction, and all of the subsequent ones over the next four years, McCoy

moved from what she calls “survival mode”

toward a more altruistic focus. She is part of

“something larger,” research that might help

others today, as well as in the future.

The same epiphany occurred for Alice

Coday. The 52-year-old watched as physicians

diagnosed her father, brother, and sister with

VHL. All three had tumors on their brain stems.

Coday did not have that kind of tumor, convincing her she had been spared the mutation. 

But she had been diagnosed instead

with Ménière’s disease, characterized by

tumors on the endolymphatic duct of the

inner ear (just like McCoy). She suffered

severe vertigo and, in 1988, lost hearing in her

right ear. But she experienced nothing of the

brain or kidney tumors that eventually

plagued her family members.

Not until Coday had a happenstance

conversation with a member of the Von

Hippel-Lindau Family Alliance did she suspect a possible mistake in her diagnosis. She

contacted the NIH and traveled from her

home in Seattle for testing. Only then did she

learn that she not only carried the VHL mutation but also had developed tumors in both of

her kidneys and cysts in her pancreas. 

In 1997, surgeons from CCR removed

part of her left kidney and a year later, the

right. She has been traveling to the NIH at

least twice a year ever since.

She knows that if she had had the surgeries

locally, she would have lost both of her 

kidneys entirely and probably would have

needed dialysis. She knows that she could

have died if the tumors had remained undetected. But she does not come to the NIH

today for either of these reasons. Coday is

cancer-free thanks to the discovery of the VHL

Patients: Part of the Team

gene and the efforts of the Linehan group and

others to foster early detection. She now comes

to the NIH because she sees her larger purpose.

“When you go to a traditional doctor, you

think of a doctor-patient relationship,” she

said. “The NIH is something more. You feel

like you are participating. Like you are part of

a team, making history.” (Photo: E. Rawlins) (Photo: A. Davison)

feature
2 6 ccr connections | v OLUME 1, N O .1 | 2007

Therefore, my first goal at CCR was to 

discover a way to predict patient response to

5-FU-based therapy and hopefully spare many

patients the side effects of a treatment that

would otherwise offer no benefit. I developed

the first monoclonal antibodies to the enzyme

human thymidylate synthase (TS), and a number of immunological and tissue-based assays

for quantifying the enzyme. With my colleagues, Carmen Allegra, M.D., and Bruce

Chabner, M.D., I was able to show, in the laboratory, that levels of TS could predict drug

response: low levels of the enzyme forecast a

good drug response, while high levels suggested a poor response. We went on to show that

our TS findings translated to actual patients

with metastatic colorectal cancer, whose 

disease was spreading outside the bowel. 

When we used the same assay in

patients with earlier stage colorectal cancer

(stage II and III non-metastatic colorectal cancer), however, we found something surprising.

The TS levels of early-stage patients failed to

predict response, but could predict whether a

patient’s tumor would behave more benignly

or aggressively after treatment. High TS levels

correlated with a shorter time to relapse and

shorter survival, and low levels a longer time

for both parameters.

While heartening, this finding also posed

a significant problem. We had learned that

simply because an individual with a given

diagnosis had a poor prognosis, he or she

would not necessarily have the best response

to a particular chemotherapeutic agent.

Therefore, simply administering the most

aggressive treatments to the patients with the

worst potential outcomes leaves them open to

the disturbing possibility of excessive—and

unnecessary—pain and suffering. We would

do better to match prognosis, therapy, and

response, delivering only those treatments

that are likely to provide benefit. 

This dilemma remains one of the major

challenges for modern oncology today. With

the introduction of high-throughput technologies, we are now just beginning to meet this

challenge, thanks to the growing arsenal of

genomic tools with the potential to refine

both diagnosis and the prescription of care.

Lessons from CCR

The word “cancer” essentially means that

important molecules in tumor cells have

become abnormal, due either to mutated

genes inherited at birth or alterations caused

later in life because of environmental or

lifestyle factors. At the same time that I was

pondering questions of tumor behavior and

response at CCR, the Human Genome Project

(HGP) was fast uncovering genes that might

be relevant to cancer. Completed in 2003, the

HGP gave a more sophisticated answer to a

long standing question in oncology: Why do

all patients with the same diagnosis not

respond to a specific treatment in exactly the

same way? The HGP offered multiple genetic

reasons for this disparity, and also underlined

the naïveté of our classification schemes for

cancer (naming and treating tumors based on

the organ in which they first appear). For

example, a single tumor in the colon can be

linked to a large number of mutations in a

host of different genes. Further, these mutations

occur in combinations that may differ between

neighboring cells, even those within that

same tumor. Thus, colon cancer is not really

cancer of the colon; rather, it is a combination

and accumulation of genetic mistakes that

happen to occur within colonic epithelial cells.

COMMENTARY

I understood that in order to accurately

predict prognosis with certainty, we needed to

examine both a tumor’s genome and anatomic

location. In the same vein, individual responses to chemotherapy agents also vary between

patients, even those with the same diagnosis,

due to the unique nature of each individual’s

genetic make-up, apart from that of their

tumor. In other words, an individual’s normal

genes can also help forecast drug response. 

Moving Forward—and Overseas

I carried this thinking back to Belfast in 1997,

at a time when researchers had just invented

gene expression microarrays. Using this tool,

we could measure gene expression in colorectal tumors and compare it to healthy tissue.

Instead of one gene, such as TS, we now had

hundreds, perhaps thousands, of genes that

together formed a genetic “signature” that

might herald prognosis or response. 

In Ireland, we and other investigators

went on to use microarrays and other genomic

technologies to search for genetic signatures

that marked good and poor prognosis in colorectal cancer. Thus far, we have successfully

The year I joined CCR—1987—more than 160,000 patients in the U.S. were diagnosed with colorectal cancer.

Oncologists had only one drug to treat the disease, 5-fluorouracil (5-FU). And while that drug did show some 

effectiveness, particularly in cancer that was localized to the bowel, still nearly 60,000 patients either would not

respond or would eventually develop resistance to the drug. Within five years of diagnosis, 60 to 65 percent would die. 

I found these statistics unacceptable.

We would do 

better to match

prognosis, therapy,

and response,

delivering only

those treatments

that are likely to

provide benefit.

A CCR in Belfast
ccr connections | v OLUME 1, N O .1 | 2007 2 7

identified numerous genes involved in cell

replication, tumor suppression, and the

expression of specific molecules that mark a

tumor as cancerous. We also developed the

first disease-specific, transcriptome-based

arrays, tools that can measure gene expression

in tissues fixed in formalin and embedded in

paraffin (earlier technologies could not work

with tissues preserved in this way, though the

lion’s share of pathology samples archived

around the globe are saved in this format). We

are now working with U.S. and European clinical cooperative groups to develop clinical classifiers of disease prognosis and chemotherapeutic response in patients with colorectal

cancer based on this unique technology. 

Prognosis Versus Response:

A Current Debate

But this same genomic evidence also has its

limitations—namely, that the same signatures that tell us whether a tumor will behave

aggressively or benignly do not necessarily

tell us whether it will respond to chemotherapy. For instance, 40 percent of stage II and III 

colorectal cancer patients will suffer a

relapse within five years. Of that group, only

a third will derive any benefit from

chemotherapy. As with the TS assays, molecularly determining whether a patient’s tumor

is more benign or aggressive does not necessarily translate to whether or not that tumor

will respond to chemotherapy. 

Therefore, genomic technology, for all its

value, brings us back to the same debate: 

who will benefit? For a given diagnosis and

therapeutic standard, do we treat everyone

the same and expose those who would not

benefit to undue side effects, or do we treat 

no one and risk the chance that those who

might benefit would die eventually for lack

of treatment? 

While physicians continue to discuss

and debate the best course of clinical treatment for such patient groups, our future

research directions are clear. We must use

emerging technologies to measure and predict

drug responses as well as disease outcomes.

Toward that end, we at the Centre for Cancer

Research and Cell Biology at Queen’s

University, Belfast, are now working toward

identifying exactly those kinds of predictive

markers. For example, we have already identified

numerous genes (e.g., spermine/spermidine

acetyl transferase, annexin II, thymosin-beta-10,

chaperonin-10, MAT-8) in the laboratory whose

expression in colorectal cancer cells is altered

by 5-FU treatment and which may serve as

biomarkers for drug resistance. 

The work is indeed challenging. Today, in

colorectal cancer, we have six chemotherapeutic agents at our disposal instead of one,

which can be used in various combinations

and doses. Therefore, we have many, many

variables to study. 

To investigate them with any meaningful

statistical power, we need ever larger population sets in order to accrue ever larger numbers of tumor samples. To draw useful conclusions from the reams of data produced by

genomic studies, we need to analyze the data

using complex bioinformatic techniques. As

such, I am grateful to my collaborators at NCI

and U.S. cooperative groups supported by

NCI, who have given us access to their collections of tumor biopsies. Collaborations like

these are also helping us access the significant computing power needed to analyze our

biological results. These partnerships would

not have been possible had I not spent nine

years at CCR making contacts and garnering

scientific collaborations. 

A New Infrastructure 

The good news is that our Centre for Cancer

Research and Cell Biology in Belfast now has

the facilities and resources to meet these

challenges. Last year, we opened a new $120

million clinical center—modeled on the U.S.

CCR—and further plan to unveil a $50 million research center in June of this year. My

experience and training in the intramural

program at CCR in Bethesda taught me the

importance of clinicians becoming scientists

and working hand in hand with basic

researchers to devise clinical experiments

that are meaningful to patient treatment and

the understanding of disease. 

The legacy of CCR is greater than the education of this medical oncologist/molecular

pharmacologist. It provides an environment

where one can be mentored and further develop

one’s medical, scientific, and analytical skills

to make fundamental discoveries that ultimately will benefit patients across the globe. I

have embraced the opportunity afforded me

and tried to establish the same culture and

environment here in Belfast. By working

together to solve the challenge of cancer, I

believe we can make important strides in our

understanding of cancer and in advancing 

cancer treatment for the benefit of patients.

The organization and structure of Johnston’s Centre for Cancer Research and Cell

Biology at Queen’s University in Belfast, Northern Ireland, is modeled on CCR.

(Image: Bowell, Mitchell & Johnston architects)

Patrick Johnston M.D., Ph.D.

Department of Oncology 

Centre for Cancer Research and 

Cell Biology, Queen’s University

Belfast, Northern Ireland

COMMENTARY(Photo: Centre for Cancer Research and Cell Biology)
2 8 ccr connections | v OLUME 1, N O .1 | 2007

does a physician deal with severe cosmetic disfigurement in a teen, who is trying to

develop a healthy self-image? How does a

pediatrician relieve the pain of a six-yearold child who has a tumor compressing

her spinal cord?

Ultimately, we scale what we do know

to the level of the children. We are honest,

telling them that we currently do not have

any medicines that will make the tumors go

away, but if we can keep the tumors from

growing while the children grow, then they

will have fewer problems. Reaching that

understanding with a patient is my goal

and my colleagues’ as well. We are working

to learn more about the natural history of

this disorder so that we can better test

potential drugs that might reverse tumor

growth, or at least halt it.

A Tumor Oddity

NF1 is a daunting disease to study, largely

because of its unpredictable nature and multiple manifestations involving essentially

every organ system. PN tumors follow the

paths of nerves. They grow slowly, ten times

slower than typical tumors of the breast or

lung. Although that may be good news for

patients (their life expectancy is only 15 years

less than normal), slow-growing tumors

mean years, even decades, of waiting just 

to observe tumor development—or the 

progression of NF1’s natural history. Thus,

The genetic culprit behind neurofibromatosis type 1 (NF1) is a defect in a gene aptly

named neurofibromin 1 (NF1). The product

of this gene normally suppresses tumor

growth (see “The Culprit: the NF1 Gene”).

About 25 percent of those afflicted develop

tumors in the cells that make up nerve

fibers. These tumors—called “plexiform

neurofibromas” (PN)—are usually benign

and slow-growing. Nonetheless, they can

wreak great havoc. 

NF1-associated PN tumors cause

severe facial and body disfigurement, pain,

and neurological impairment. In addition,

individuals with NF1 develop coffee-colored

“café-au-lait” spots all over their skin and

distinctive freckles on their armpits and

CCR Team Tackles

Neurofibromatosis

When Brigitte Widemann, M.D., and her colleagues Frank Balis, M.D., Elizabeth Fox, M.D., Eva Dombi, M.D., 

and research nurse Andy Gillespie in the Pharmacology and Experimental Therapeutics Section of CCR’s Pediatric

Oncology Branch treat their patients, they deal with more than their disease or the genetic mutations that cause it. 

The researchers study neurofibromatosis type 1 (NF1), a disorder that occurs in 1 out of every 3,500 individuals. 

Figure 1:

Medical

Numerics’

MEDx program

helps doctors

take accurate

measurements

of irregularly

shaped and

slow growing

NF1 tumors.

IN THE CLINIC (Graphic: B. Widemann, CCR)

groins. Some develop tumors on their optic

nerves. Others sprout tiny nodules on their

irises (the colored portion of the eye). The

most serious complication—accounting 

for roughly 5 percent of the total—is the 

progression of PN toward aggressive malignancy (see “Turning Cancerous”). 

There is no effective therapy except

for surgery—which is feasible in only a subset of patients. 

Perhaps the greatest challenge we

face is the young age of our patients: their

median age is eight years. How does a 

doctor talk to a child about a disorder for

which there is no cure, no working treatment, and a paucity of knowledge about

tumor development and progression? How
ccr connections | v OLUME 1, N O .1 | 2007 2 9

time. While this method works for fast

growing, solid cancers, with a round or oval

shape, it is not sensitive enough to pick 

up changes in an irregularly-shaped, 

slow-growing tumor like PN. We needed

something better.

Virtual Measurement

Looking for a way to measure the ungainly

tumors of NF1, we made use of an image

analysis resource available to researchers at

the NCI through a small company called

Sensor Systems (now Medical Numerics, in

(left to right) Brigitte Widemann, M.D.,

nurse Andy Gillespie, and Elizabeth Fox,

M.D., work as a team to help children

with NF1.

Germantown, Md.). In particular, we worked

with a colleague there named Jeffrey

Solomon, a physicist with a strong interest

in applying physics and engineering to medicine. Solomon had developed software for

“multimodality image processing,” a

process for combining the best of different

forms of imaging, including MRI scans and

positron emission technology (PET) scans,

which can help determine the size and

shape of a tumor as it grows over time. 

Rather than relying on diameter or

length estimation, Solomon’s program,

developed on a platform called MEDx,

makes use of contrast and brightness. PN

tissues tend to be brighter than their

healthy neighbors on specific types of MRI

scans. The MEDx program searches for high

“intensity gradients,” quick drop-offs in

brightness where the border of a tumor

meets healthy tissue. The program then

decides what is tumor and what is not, adds

up all tissue deemed “tumor,” and compares

it to the sum of that designated as “healthy.”

In this way, Solomon’s program segments

tumor from tissue and comes up with a

Perhaps the 

greatest challenge

we face is the

median age of our

patients: eight

years old.

testing a potential therapy means we have to

wait even longer before we can see any evidence of its effects. 

There are additional hurdles as well.

Because these tumors snake the length of

the nerves, they take on strange shapes, like

stretched-out, wadded-up chewing gum,

rather than the perfect spheres or ellipses

that characterize many other solid tumors.

They can elongate from spinal cord to upper

leg, for example. Therefore, they are often

impossible to remove surgically. 

NF1 tumors can also grow very large.

Patients less than three years of age can

appear in our clinic with masses in their legs

that account for up to 20 percent of their

body weight, and there are no drugs to date

that can reverse the course of growth. In fact,

until recently, we did not even have an accurate way to measure the growth of these

tumors in order to track their development

and progression. Oncologists who study

other kinds of solid tumors can track their

growth by measuring the change in the

length of the longest segment or the diameter of the fattest portion of the tumor over

(Photo: R. Baer)
3 0 ccr connections | v OLUME 1, N O .1 | 2007

number and a corresponding picture of the

tumor ringed by an outline (Figure 1). The

area of tumor is calculated for each MRI slice

containing tumor, and then summed to 

calculate a final PN volume. While this

method is labor intensive, it is reliable and

reproducible, and it can detect volume

changes as small as 10 percent, much smaller changes than what could be detected with

standard solid tumor measurements.

Launching Clinical Trials

Having this powerful new imaging capability

allowed us to launch our NF1 clinical 

trials program. In 2001, we began recruiting

patients into a trial for an experimental drug

called tipifarnib (ZarnestraTM). Previously

studied in patients with acute myeloid

leukemia (AML) and other types of cancer,

the drug blocks a molecular switch called

Ras, which functions in a biochemical 

pathway that controls cell reproduction. Ras

normally activates neurofibromin (see “The

Culprit: The NF1 Gene”), making the drug a

potentially good candidate for NF1 patients. 

Enrollment in the trial requires

demonstrating that the tumors are growing

by about 20 percent a year, which allows us

to track whether the drug is capable of

slowing or stopping PN growth. This tracking is now possible with the improved

imaging and analysis capabilities provided

by our collaboration with Solomon and

Medical Numerics.

Over the course of the last six years,

the length of this first trial, we have learned

that the younger the child, the faster the

tumors tend to grow. We also learned that

while PN tumor growth rates may differ

among patients, they are fairly constant

within patients, not erratic as was previously thought. This realization was important,

and it raised the urgency for early detection

and treatment intervention. 

To understand the progression 

of dermal neurofibromas, the

Widemann team takes 3D pictures

of a patient’s bumps (top) and 

digitally measures their volume

(above), a procedure termed 

“volume photography.”

Plexiform neurofibromas have yet another

cousin. Called NF1 dermal neurofibromas,

these benign tumors appear as skin bumps that

can cover the entire body. While not fatal, these

tumors are horribly disfiguring. Imagine bumps

the size of peas all over one’s face. They begin to

develop just before adolescence, adding insult

to injury, as youngsters grapple with normal

self-esteem issues amid an outburst of what

appears to be super-intense acne. 

And, as with other NF disorders,

researchers know very little about the natural

history of the disease, except that hormonal

changes, such as those of puberty, might exacerbate the illness. 

Enter a technique called “volume photography,” being applied by researchers at CCR. A

camera takes a three-dimensional picture of a

patient’s skin. Researchers like pediatrician Eva

Dombi, M.D., then use a computer program to

measure and tabulate the volume of each and

every bump. In this way, investigators can measure and clock the progression of the disease.

What do they do to help the young patient

besides collect data on the size of the bumps?

At the same time, Brigitte Widemann,

Beyond Skin Bumps

At the same time, this trial has made

inroads with its unique design. Initially, we

randomly divided 59 patients (the goal is 60,

so enrollment is still open) at the start of the

study into two groups, drug or placebo. After

documenting PN tumor growth, the groups

were switched. In addition to giving us 

critical information on the effects and effectiveness of tipifarnib, this study also gave us

the opportunity to take a first systematic

look at PN’s time to progression and tumor

behavior; we had no knowledge about either

characteristic before this trial. 

We now know from the first treatment

phase that that the median time it takes for

PN tumors to progress is 20 months. But

more data will come. We have not seen any

magic response to any drug, but we now

have a good assessment of tumor growth

and behavior that will be extremely beneficial for future work.

In addition to the tipifarnib trial, we(Graphics: B. Widemann, CCR)

M.D.’s team has also partnered up with medical geneticist Douglas Stewart, M.D., at the

National Human Genome Research Institute.

He is searching for more genetic culprits in

the illness. Widemann and Stewart have won

an NIH-sponsored bench-to-bedside award

for their proposal to combine laboratory

research on NF1 dermal neurofibromas with

clinical treatment. 

At the bench, Stewart is analyzing biopsies

and blood samples from patients and their family members. Using DNA microarrays—tools

that can measure the expression of hundreds of

genes simultaneously—he is hunting for genetic differences between the two NF1 conditions

that might flag individuals who will progress to

more serious forms of the illness. The telltale

genes could then be combined into a “signature,” which would go a long way toward helping

researchers such as Widemann predict which

individuals they should monitor most closely.

And the genetic fingerprints might highlight

promising targets for new NF1 drugs.

“We have so many resources at the NIH,”

says Widemann. “If we can collaborate, we can

make the most of every clinical trial.”

IN THE CLINIC
ccr connections | v OLUME 1, N O .1 | 2007 3 1

While the tumors that mark plexiform neurofibromatosis (PN) are benign and slow-growing,

they can evolve into something more alarming.

About 5 percent of patients with PN develop

malignant peripheral nerve sheath tumors

(MPNSTs), which, unlike their benign PN counterparts, are fast-growing, aggressive, and deadly. 

While MPNSTs can arise in people without

defects in the NF1 gene, such tumors are very

rare (0.001 percent of the general population).

On the other hand, individuals with NF1 mutations develop the deadly tumors at a lifetime

rate of 8 percent to 13 percent. In addition,

those with the mutations may not respond as well to aggressive chemotherapy and,

therefore, do not survive as long as those without the mutations. 

To make matters worse, the cancerous tumors are extremely tough to diagnose. They

start as a tiny nub buried within an enormous and ungainly PN tumor. Thus, if a surgeon

samples the “wrong” section of a PN tumor when taking a biopsy or image, he or she will

miss the tumor-within-a-tumor entirely. And the cancer can spread so aggressively that if

misdiagnosed, it will grow too quickly for even intense chemotherapy to stop its progression.

But the CCR team is working hard to change that outcome. They are testing a 

monitoring method in which they administer a radiolabeled compound called 18F fluorodeoxyglucose (FDG) to patients. Active cells in the body require glucose for energy.

And so the most active cells, those in a fast-growing tumor, for example, metabolize the 

glucose the quickest. The radiolabel tag then lights up on a positron emission tomography

(FDG-PET) scan. This method can now detect benign, but relatively rapidly growing

tumors in PN patients. CCR researchers are now testing whether FDG-PET can pick out

cancerous MPNSTs.

In addition, the CCR team is collaborating with the Sarcoma Alliance for Research

through Collaboration (SARC) in Ann Arbor, Mich., to lead a pilot therapeutic study for

MPNST patients. The study will test a combination of three chemotherapy agents (doxorubicin, ifosfamide, etoposide) that together are standard therapy for other cancers

called soft tissue sarcomas—rare tumors that arise in connective tissues (e.g., muscle,

fat, nerves, blood vessels, bone, cartilage). MPNSTs comprise about 10 percent of all

soft tissue sarcomas, making SARC a logical partner for collaboration.

Upon entry to the new trial, patients will have baseline MRI and FDG-PET scans

followed by four cycles of chemotherapy, as well as any needed surgery or radiation to

relieve pain or decrease tumor size. Widemann and her team will then watch and wait.

Widemann says her team would equate success with a 40 percent rate of patient

response (as evidenced by substantial tumor shrinkage). If they reach that number, her

team will have a “platform study” with which to guide future trials. This designation

means that in the future, clinicians can use the standard chemotherapy (as the platform) and add in more targeted agents, such as imatinib mesylate (Gleevec®, Novartis),

a targeted treatment used to combat soft tissue sarcomas in the gastrointestinal tract.

A malignant MPNST tumor

forms within benign PN

growths. 

Turning Cancerous have five other trials ongoing as well,

including a Phase II trial of an experimentaldrug called pirfenidone (made by

InterMune) in partnership with Roger

Packer, M.D., from Children’s National

Medical Center in Washington, D.C., and

Dusica Babovic-Vuksanovic, M.D., from the

Mayo Clinic in Rochester, Minn. (Figure 2).

All of these trials have multiple participating sites in order to ensure that enough participants enroll to complete the trials in a

timely fashion. To help coordinate these

myriad efforts, the Department of Defense

has taken a lead role in formulating an infrastructure for NF1 clinical trials, including

support of an NF1 consortium that includes

CCR as a key site. For all of these trials, my

CCR colleague, Eva Dombi, has coordinated

and performed tumor volume analyses,

ensuring that the measurements are consistent across trials and that large data sets are

accumulated from each study—critical

information for understanding the natural

history of PN in NF1 as well as defining the

benefits of new agents. 

Although drugs such as tipifarnib and

pirfenidone were developed to treat other

diseases, including multiple myeloma and

pulmonary fibrosis, they influence biochemical targets that relate to NF1, making them

good potential candidates for PN tumors.

Finally, we are also collaborating in three

additional clinical trials of patients with

other diseases in which the NF1 gene also

plays a role (see “Turning Cancerous” and

“Beyond Skin Bumps”).

The Special Case of Children

As we design trial protocols, we never

lose sight of the special considerations of

our patients. Children, diagnosed with NF1

as young as 18 months, are still developing

physically and emotionally. Thus, we have to

be very careful about the toxicity of potential treatments, so as to not impact the children’s normal growth. 

For example, one of the new drugs 

we will soon be evaluating in PN patients,

sorafenib (Nexavar®, Onyx Pharmaceuticals)

blocks the growth of new blood vessels,

those that could potentially feed a growing

tumor. But the drug may potentially stunt

(Photo: B. Widemann, CCR)

IN THE CLINIC
NF1 clinical trials

n/a NHGRI / NCI Dermal neurofibromas

Basic biology and

natural history

Chemotherapy MPNST II SARC

PN

PN

PN

PN

Tumor

NCI/

NF Consortium.

Pittsburgh

NCI

NCI

Coordinating site

I

(opening soon) Sorafenib

PEG-Intron® I, II

Pirfenidone I, II

Tipifarnib I, II

Trial focus Phase

Although Frederich von Recklinghausen

first described neurofibromatosis 1 (NF1) in

1882, it was not until a century later that

National Human Genome Research

Institute director Francis S. Collins, M.D.,

Ph.D., (then at the University of Michigan)

and the University of Utah’s Ray White,

Ph.D., simultaneously but separately

cloned the actual gene involved in the illness. The gene encodes a protein called

neurofibromin that suppresses tumors. 

Neurofibromin is expressed in most

cells of the body, but those of the peripheral and central nervous system seem to produce the most. It normally works within a

pathway involving a protein called Ras, a

signaling molecule that controls a cell’s

reproduction. When mutated, NF1 genes

cause misregulation in Ras signaling,

potentially one cause of the tumors in NF1.

Therefore, clinicians are now testing drugs

in NF1 patients, compounds that act upon

Ras-related targets, such as a molecule

called mTOR. 

Meanwhile, cancer researchers are also

working hard to determine whether or not

Ras regulation is the primary and/or only

function of neurofibromin. If other molecules

are involved, those, too, could become eventual drug targets for novel NF1 therapies.

Figure 2. Widemann’s team—and their collaborators—are conducting a host of

clinical trials on different aspects of NF1. 

skeletal formation. Thus, we had to build into

our trial protocol regular monitoring 

of the so-called “growth plate,” the space

where bone cells lay down new material to

lengthen a child’s growing bones. In addition, consent, compliance, and managing

expectations are issues for preteens and

teenagers, who have lived years with this 

disorder without hope of a cure. 

Because half of the cases involve a

gene being passed down from parent to

child, parents are often afflicted themselves. The disorder has become a lifestyle

in these families, and this fact has implications, including deep feelings of guilt on

the parents’ parts. For example, a parent

with a milder form of NF1 might choose to

bear children. On average, half of the 

couple’s children will get the faulty gene. If

a child inherits that mutation and ends up

with a more severe form of the disease, the

parents may feel intensely guilty. Thus, our

team includes well-trained research nurses,

social workers, psychologists, and psychotherapists who can help parents deal

with these and other emotions tied to their

experience and their child’s. Those same

counselors help children and rebellious

teens to follow their regimens—taking

pills, writing symptoms in a diary, and 

coming in for regular MRI scans. 

Meanwhile, our clinic itself is focused

on being “kid-friendly.” Children walk into 

a space of bright colors and crayoned 

pictures, typical of pediatric wards, and play

together while waiting for their appointments. Two guinea pigs, named Chocolate

and Buttercup, scurry about, ready for 

anyone to pet. 

The CCR program caters to families of

any socioeconomic background. Those who

want to join in a trial need only pay the

transportation costs for their first visit to the

clinic. Subsequent visits are paid for if they

are enrolled in a trial, as are stays at the

nearby Children’s Inn. It is a home away from

home for many, and a place to meet others

with a similar disease. Indeed, many families

who connect here start timing their visits to

meet up with one another. Frequently, the

first time a person with NF1 meets someone

else with the same disorder is when they

come to our clinic, giving them a new feeling

that they are not alone and helping them

deal with the complications of NF1. This

kind of mutual support can do wonders, and

it continues to give us hope that we will

soon find effective new ways to stop this 

terrible disease. 

(Graphic: B. Widemann, CCR)

The Culprit:

The NF1 Gene

Illustration showing the multiple 

functions of NF1. Recent studies have

demonstrated that NF1 is involved in

several critical cellular pathways by

acting directly on RAS, protein kinase

C (PKC) and cyclic AMP (cAMP). By

modulating these intracellular messengers, NF1 can affect several processes

related to cellular growth and division.

Recently, it has also been suggested

that NF1 can interact with actin, affecting cellular structure and motility.

(Graphic: Feinstein Kean Healthcare)

IN THE CLINIC

3 2 ccr connections | v OLUME 1, N O .1 | 2007
Web Sites with More Information about CCR

Center for Cancer Research

http://ccr.cancer.gov

Office of the Director

http://ccr.cancer.gov/about/default.asp

Office of the Clinical Director

http://ccr.cancer.gov/trials/clinical_director.asp

Office of Communications

http://ccr.cancer.gov/news/ooc.asp

Office of Science and Technology Partnerships

http://ccr.cancer.gov/research/ostp

Office of Training and Education

http://ccr.nci.nih.gov/careers/office_training_education.asp

Patient Information on Cancer and Clinical Trials

Open NCI Clinical Trials

http://www.cancer.gov/clinicaltrials

How to Refer a Patient

http://bethesdatrials.cancer.gov/professionals/refer.asp

NCI Cancer Information Service

http://cis.nci.nih.gov

1-800-4-CANCER (1-800-422-6237)

Understanding Cancer Series

http://www.cancer.gov/cancertopics/understandingcancer

Clinical Studies Support Center (CSSC)

http://ccr.cancer.gov/trials/cssc/staff/services.asp

Additional Links

National Cancer Institute (NCI)

http://www.cancer.gov

Working at the NCI

http://www.cancer.gov/aboutnci/working

National Institutes of Health (NIH)

http://www.nih.gov
NIH publication No. 07-6211

June 2007