bluuebunny/crossref_metadata_2025 huggingface dataset:
Prevention of N-Methyl-N-Nitrosourea–Induced Breast Cancer by α-Fetoprotein (AFP)–Derived Peptide, a Peptide Derived from the Active Site of AFP
Authors: Parikh Rahul R. , Gildener-Leapman Neil , Narendran Amithi , Lin Hung-Yun , Lemanski Nicole , Bennett James A. , Jacobson Herbert I. , Andersen Thomas T.
Published: March 2006

Purpose: α-Fetoprotein (AFP) is a protein of pregnancy associated with a decrease in lifetime risk of breast cancer in parous women. A synthetic, cyclic nonapeptide has been developed that mimics the antioncogenic active site of AFP. To test the hypothesis that the AFP-derived peptide (AFPep) can prevent breast cancer, the N-methyl-N-nitrosourea–induced breast cancer model was used in rats.

Experimental Design: AFPep was given daily by injection beginning 10 days after N-methyl-N-nitrosourea treatment and continued for 23 days (a time designed to mimic pregnancy) or for other times to assess efficacy as a function of drug duration. Tumor incidence, multiplicity, and latency were noted as end points. At necropsy, pathology analysis of tumors and major organs were obtained.

Results: AFPep prevented cancer in a dose-dependent fashion. Significantly longer mean tumor-free days (P < 0.02), lower tumor incidence (P = 0.004), and lower tumor multiplicity were observed for AFPep-treated groups. No evidence of host toxicity as measured by body weight, cage activity, fur texture, and organ weights (liver, uterus, heart, kidney, and spleen) were found in animals treated with AFPep. Mechanistic studies using transplantable human breast cancer xenografts showed that the peptide interfered with estrogen-dependent breast cancer growth inhibited the phosphorylation of the estrogen receptor and activated phosphorylation of p53.

Conclusions: AFPep is a well-tolerated, mechanistically novel, chemopreventive agent in models of breast cancer and warrants further development for the prevention and treatment of this disease in humans.
Handicapping the Race to Develop Inhibitors of the Phosphoinositide 3-Kinase/Akt/Mammalian Target of Rapamycin Pathway
Authors: Granville Courtney A. , Memmott Regan M. , Gills Joell J. , Dennis Phillip A.
Published: March 2006

The phosphoinositide 3-kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) pathway controls many cellular processes that are important for the formation and progression of cancer, including apoptosis, transcription, translation, metabolism, angiogenesis, and cell cycle progression. Genetic alterations and biochemical activation of the pathway are frequent events in preneoplastic lesions and advanced cancers and often portend a poor prognosis. Thus, inhibition of the PI3K/Akt/mTOR pathway is an attractive concept for cancer prevention and/or therapy. Inhibitors of individual components, such as PI3K, PDK-1, Akt, and mTOR, are being developed at a rapid pace and have promise for improving the care of cancer patients. Here, we review the published data on inhibitors of the pathway and discuss relevant issues, such as the complex regulation of the pathway, the design of clinical trials, and the likelihood of finding a therapeutic index when targeting such a critical signaling pathway.
The Distribution of the Anticancer Drug Doxorubicin in Relation to Blood Vessels in Solid Tumors
Authors: Primeau Andrew J. , Rendon Augusto , Hedley David , Lilge Lothar , Tannock Ian F.
Published: March 2006

Purpose: Anticancer drugs gain access to solid tumors via the circulatory system and must penetrate the tissue to kill cancer cells. Here, we study the distribution of doxorubicin in relation to blood vessels and regions of hypoxia in solid tumors of mice.

Experimental Design: The distribution of doxorubicin was quantified by immunofluorescence in relation to blood vessels (recognized by CD31) of murine 16C and EMT6 tumors and human prostate cancer PC-3 xenografts. Hypoxic regions were identified by injection of EF5.

Results: The concentration of doxorubicin decreases exponentially with distance from tumor blood vessels, decreasing to half its perivascular concentration at a distance of about 40 to 50 μm, The mean distance from blood vessels to regions of hypoxia is 90 to 140 μm in these tumors. Many viable tumor cells are not exposed to detectable concentrations of drug following a single injection.

Conclusions: Limited distribution of doxorubicin in solid tumors is an important and neglected cause of clinical resistance that is amenable to modification. The technique described here can be adapted to studying the distribution of other drugs within solid tumors and the effect of strategies to modify their distribution.
Stress Hormone–Mediated Invasion of Ovarian Cancer Cells
Authors: Sood Anil K. , Bhatty Robert , Kamat Aparna A. , Landen Charles N. , Han Liz , Thaker Premal H. , Li Yang , Gershenson David M. , Lutgendorf Susan , Cole Steven W.
Published: March 2006

Purpose: There is growing evidence that stress and other behavioral factors may affect cancer progression and patient survival. The underlying mechanisms for this association are poorly understood. The purpose of this study is to determine the effects of stress-associated hormones norepinephrine, epinephrine, and cortisol on the invasive potential of ovarian cancer cells.

Experimental Design: The ovarian cancer cells EG, SKOV3, and 222 were exposed to increasing levels of either norepinephrine, epinephrine, or cortisol, and the in vitro invasive potential was determined using the membrane invasion culture system. Additionally, the effects of these stress hormones on matrix metalloproteinase-2 (MMP-2) and MMP-9 were determined by ELISA. The effects of the β-adrenergic agonist isoproterenol on in vivo tumor growth were determined using nude mice.

Results: Stress levels of norepinephrine increased the in vitro invasiveness of ovarian cancer cells by 89% to 198%. Epinephrine also induced significant increases in invasion in all three cell lines ranging from 64% to 76%. Cortisol did not significantly affect invasiveness of the EG and 222 cell lines but increased invasion in the SKOV3 cell line (P = 0.01). We have previously shown that ovarian cancer cells express β-adrenergic receptors. The β-adrenergic antagonist propanolol (1 μmol/L) completely blocked the norepinephrine-induced increase in invasiveness. Norepinephrine also increased tumor cell expression of MMP-2 (P = 0.02 for both SKOV3 and EG cells) and MMP-9 (P = 0.01 and 0.04, respectively), and pharmacologic blockade of MMPs abrogated the effects of norepinephrine on tumor cell invasive potential. Isoproterenol treatment resulted in a significant increase in tumor volume and infiltration in the SKOV3ip1 in vivo model, which was blocked by propranolol.

Conclusions: These findings provide direct experimental evidence that stress hormones can enhance the invasive potential of ovarian cancer cells. These effects are most likely mediated by stimulation of MMPs.
Identification of Insulin-Like Growth Factor Binding Protein-3 as a Farnesyl Transferase Inhibitor SCH66336-Induced Negative Regulator of Angiogenesis in Head and Neck Squamous Cell Carcinoma
Authors: Oh Seung-Hyun , Kim Woo-Young , Kim Jai-Hyun , Younes Maher N. , El-Naggar Adel K. , Myers Jeffrey N. , Kies Merril , Cohen Pinchas , Khuri Fadlo , Hong Waun K. , Lee Ho-Young
Published: March 2006

The farnesyl transferase inhibitor (FTI) SCH66336 has been shown to have antitumor activities in head and neck squamous cell carcinoma (HNSCC) in vitro and in vivo. However, its mechanism of action has not been well defined. Here, we report that the insulin-like growth factor (IGF) binding protein (IGFBP)-3 mediates antitumor activities of SCH66336 in HNSCC by inhibiting angiogenesis. SCH66336 significantly suppressed HNSCC tumor growth and angiogenesis via mechanisms that are independent of H-Ras and RhoB. By inducing IGFBP-3 secretion from HNSCC cells, this compound suppresses angiogenic activities of endothelial cells, including vessel formation in chorioallantoic membranes of chick, endothelial cell sprouting from chick aorta, and capillary tube formation of human umbilical vascular endothelial cells (HUVEC). Knockdown of IGFBP-3 expression in HNSCC cells by RNA interference or depletion of IGFBP-3 in HUVECs by neutralizing antibody effectively blocked the effects of IGFBP-3 secreted from SCH66336-treated HNSCC cells on HUVECs. These findings suggest that IGFBP-3 could be a primary target for antitumor activities of FTIs and that IGFBP-3 is an effective therapeutic approach against angiogenesis in HNSCC.
Expression of targeting protein for xklp2 associated with both malignant transformation of respiratory epithelium and progression of squamous cell lung cancer.
Authors: Ma Ying , Lin Dongmei , Sun Wenyue , Xiao Ting , Yuan Jinsong , Han Naijun , Guo Suping , Feng Xiaoli , Su Kai , Mao Yousheng , Cheng Shujun , Gao Yanning
Published: March 2006

PURPOSE: Expression of targeting protein for Xklp2 (TPX2), a microtubule-associated protein, is tightly cell cycle regulated. Abnormally expressed TPX2 has been reported in various malignancies, but less is known in lung cancer. The present study appraised the significance of TPX2 aberrant expression for tumorigenesis and progression of human squamous cell carcinoma (SCC) in lung. EXPERIMENTAL DESIGN AND RESULTS: The expressive status of TPX2 was firstly examined with lung cancer (L, PAa, and PG) and immortalized bronchial epithelial (C45, M-BE, Tr, and Y-BE) cell lines, and TPX2 expression was detected at both RNA and protein levels by reverse transcription-PCR and Western blotting, respectively. Immunofluorescence staining on M-BE cells showed that the subcellular localization of TPX2 protein is in nucleus at interphase and mitotic spindle at metaphase. Immunohistochemical analyses were subsequently done on the precancerous lesions derived from 114 patients and the tumor tissues of 432 patients with SCC in lung. Extremely low levels of TPX2 protein were found in the normal bronchial epithelia and alveoli, whereas gradually increased TPX2 protein levels were observed in the squamous metaplasia, dysplasia, carcinoma in situ, and invasive tumor tissues. Statistical analysis showed that the TPX2 immunohistochemistry labeling index was correlated with the differentiation grade, stage, and lymphous metastasis of SCC in lung and that TPX2 overexpression is significantly associated with decreased 5-year survival rate of the patients. CONCLUSIONS: Aberrant expression of TPX2 may play important role(s) in both malignant transformation of respiratory epithelium and progression of squamous cell lung cancer and could serve as a prognostic predictor for the disease.
Erythropoietin Biology in Cancer
Authors: Hardee Matthew E. , Arcasoy Murat O. , Blackwell Kimberly L. , Kirkpatrick John P. , Dewhirst Mark W.
Published: March 2006

Erythropoietin (Epo) has long been known to be the principal hematopoietic growth factor that regulates cellular proliferation and differentiation along the erythroid lineage. Recent studies have shown that Epo is a pleiotropic cytokine that is proangiogenic and exerts broad tissue-protective effects in diverse nonhematopoietic organs. Recombinant Epo (rEpo) has been widely used in the clinic to prevent or treat malignancy-associated anemia. A series of clinical trials have documented the efficacy of rEpo in reducing RBC transfusion requirements and improving quality of life in cancer patients, and a recent meta-analysis suggested a positive effect on survival. However, two randomized trials reported negative outcomes with rEpo, as patients in the rEpo arm fared worse than their placebo-treated counterparts with respect to progression-free survival. The expression of Epo receptor (EpoR) in cancer cells has raised the possibility that exogenous rEpo may exert direct effects on tumor cells associated with the potential for stimulation of proliferation, inhibition of apoptosis, or modulation of sensitivity to chemoradiation therapy. The presence of an autocrine-paracrine Epo-EpoR system in tumors and potential effects of Epo on tumor microenvironment and angiogenesis are consistent with a complex biology for Epo-EpoR signaling in cancer that requires further research. This review describes Epo and EpoR biology, focusing on the pleiotropic effects of Epo on nonhematopoietic tissues as well as the expression and function of EpoR in cancer cells.
Tipifarnib and Bortezomib Are Synergistic and Overcome Cell Adhesion–Mediated Drug Resistance in Multiple Myeloma and Acute Myeloid Leukemia
Authors: Yanamandra Niranjan , Colaco Nandita M. , Parquet Nancy A. , Buzzeo Robert W. , Boulware David , Wright Gabriela , Perez Lia E. , Dalton William S. , Beaupre Darrin M.
Published: March 2006

It has been established in preclinical models of multiple myeloma and acute myeloid leukemia (AML) that the bone marrow microenvironment provides protection from chemotherapy- and death receptor–mediated apoptosis. This form of resistance, termed de novo drug resistance, occurs independent of chronic exposure to cancer-related therapies and likely promotes the development of multidrug resistance. Consequently, it is of major interest to identify compounds or drug combinations that can overcome environment-mediated resistance. In this study, we investigated the activity of tipifarnib (Zarnestra, formerly R115777) combined with bortezomib (Velcade, formerly PS-341) in microenvironment models of multiple myeloma and AML. The combination proved to be synergistic in multiple myeloma and AML cell lines treated in suspension culture. Even in tumor cells relatively resistant to tipifarnib, combined activity was maintained. Tipifarnib and bortezomib were also effective when multiple myeloma and AML cells were adhered to fibronectin, providing evidence that the combination overcomes cell adhesion–mediated drug resistance (CAM-DR). Of importance, activation of the endoplasmic reticulum stress response was enhanced and correlated with apoptosis and reversal of CAM-DR. Multiple myeloma and AML cells cocultured with bone marrow stromal cells also remained sensitive, although stromal-adhered tumor cells were partially protected (relative to cells in suspension or fibronectin adhered). Evaluation of the combination using a transwell apparatus revealed that stromal cells produce a protective soluble factor. Investigations are under way to identify the cytokines and/or growth factors involved. In summary, our study provides the preclinical rationale for trials testing the tipifarnib and bortezomib combination in patients with multiple myeloma and AML.
Systemic anti-hepatocyte growth factor monoclonal antibody therapy induces the regression of intracranial glioma xenografts.
Authors: Kim K Jin , Wang Lihong , Su Yi-Chi , Gillespie G Yancey , Salhotra Amandeep , Lal Bachchu , Laterra John
Published: March 2006

PURPOSE: Hepatocyte growth factor (HGF) and its receptor Met are involved in the initiation, progression, and metastasis of numerous systemic and central nervous system tumors. Thus, an anti-HGF monoclonal antibody (mAb) capable of blocking the HGF-Met interaction could have broad applicability in cancer therapy. EXPERIMENTAL DESIGN: An anti-HGF mAb L2G7 that blocks binding of HGF to Met was generated by hybridoma technology, and its ability to inhibit the various biological activities of HGF was measured by in vitro assays. The ability of L2G7 to inhibit the growth of tumors was determined by establishing s.c. and intracranial xenografts of human U87 and U118 glioma cell lines in nude mice, and treatment with 100 microg of L2G7 or control given i.p. twice per week. RESULTS: MAb L2G7 strongly inhibited all biological activities of HGF measured in vitro, including cell proliferation, cell scattering, and endothelial tubule formation. Treatment with L2G7 completely inhibited the growth of established s.c. xenografts in nude mice. Moreover, systemic administration of L2G7 from day 5 induced the regression of intracranial U87 xenografts and dramatically prolonged the survival of tumor-bearing mice from a median of 39 to >90 days. L2G7 treatment of large intracranial tumors (average tumor size, 26.7 mm(3)) from day 18 induced substantial tumor regression (control group, 134.3 mm(3); L2G7 treated group, 11.7 mm(3)) by day 29 and again prolonged animal survival. CONCLUSIONS: These findings show that blocking the HGF-Met interaction with systemically given anti-HGF mAb can have profound antitumor effects even within the central nervous system, a site previously believed to be resistant to systemic antibody-based therapeutics.
The relationship of insulin-like growth factor-II, insulin-like growth factor binding protein-3, and estrogen receptor-alpha expression to disease progression in epithelial ovarian cancer.
Authors: Lu Lingeng , Katsaros Dionyssios , Wiley Andrew , Rigault de la Longrais Irene A , Risch Harvey A , Puopolo Manuela , Yu Herbert
Published: March 2006

PURPOSE: The insulin-like growth factor (IGF) system plays important roles in cancer; blocking IGF signaling has been shown to have therapeutic effects on tumor growth. Many studies have focused on the effect of IGF-I, but few have addressed IGF-II. To assess the role of IGF-II in cancer, we analyzed IGF-II expression in ovarian cancer and examined its association with disease characteristics and prognosis. EXPERIMENTAL DESIGN: Included in the study were 215 patients with primary epithelial ovarian cancer. Fresh tumor specimens were collected during surgery, and the patients were followed for a median of 31 months. Total RNA was extracted from the tumor and analyzed for IGF-II, IGF binding protein 3 (IGFBP-3), and estrogen receptor-alpha expressions using quantitative reverse transcription PCR. Survival analysis was done to examine the associations of IGF-II with disease progression. RESULTS: IGF-II expression was found to be higher in tumors with poor prognosis; this included tumors with advanced stage, poor differentiation, serous histology, and large residual lesions. Patients with high IGF-II had elevated risk for disease progression and death, although the significance became less evident when the analysis was adjusted for clinical and pathologic variables. IGFBP-3 expression was higher in less aggressive tumors, but was not associated with disease progression. The expression of estrogen receptor-alpha had no effect on survival. CONCLUSION: This study found evidence that IGF-II expression is associated with disease progression, suggesting that IGF-II and IGF signaling are potential targets for ovarian cancer treatment. The study also indicates that IGF-II and IGFBP-3 have limited value in prognosis because of their strong associations with disease stage and tumor grade.
Dual Therapy of Ovarian Cancer Using Measles Viruses Expressing Carcinoembryonic Antigen and Sodium Iodide Symporter
Authors: Hasegawa Kosei , Pham Linh , O'Connor Michael K. , Federspiel Mark J. , Russell Stephen J. , Peng Kah-Whye
Published: March 2006

Purpose: MV-CEA is an oncolytic measles virus currently being tested in patients with ovarian cancer and whose propagation can be monitored by measuring blood carcinoembryonic antigen (CEA) levels. MV-NIS is an oncolytic measles virus coding for the thyroidal sodium iodide symporter (NIS) whose propagation can be mapped by serial radioiodine imaging. Expression of both CEA and NIS genes from a single virus would combine sensitive, quantitative expression monitoring (CEA) with radioisotopic expression mapping (NIS). Because of the unfavorable replication kinetics of measles viruses expressing both CEA and NIS, we explored the feasibility of combining MV-CEA with MV-NIS for comprehensive virotherapy monitoring in ovarian cancer.

Experimental Design and Results: Mice implanted with i.p. SKOV3ip.1 ovarian cancer xenografts received MV-CEA alone, MV-NIS alone, or a combination of MV-CEA plus MV-NIS. Viral gene expression was monitored by measuring blood CEA levels, and the location of virus-infected cells was monitored by gamma camera imaging. Surprisingly, mice receiving the combination of MV-CEA plus MV-NIS showed greatly superior responses to therapy, but this was associated with 10-fold lower plasma levels of CEA compared with mice treated with MV-CEA alone. In vitro studies showed superior replication kinetics of MV-NIS relative to MV-CEA. The gamma camera scans were considerably less sensitive than the plasma CEA marker for monitoring virus infection.

Conclusions: Dual therapy with MV-CEA and MV-NIS is superior to treatment with either virus alone, and it allows noninvasive monitoring of virotherapy via soluble marker peptide and gamma camera imaging. This has important implications for the clinical development of oncolytic measles viruses.
Neosquamous Epithelium Does Not Typically Arise from Barrett's Epithelium
Authors: Paulson Thomas G. , Xu Lianjun , Sanchez Carissa , Blount Patricia L. , Ayub Kamran , Odze Robert D. , Reid Brian J.
Published: March 2006

Purpose: Neosquamous epithelium (NSE) can arise within Barrett's esophagus as a consequence of medical or surgical acid reduction therapy, as well as after endoscopic ablation. Morphologic studies have suggested that NSE can develop from adjacent squamous epithelium, submucosal gland ducts, or multipotent progenitor cell(s) that can give rise to either squamous or Barrett's epithelium, depending on the luminal environment. The cells responsible for Barrett's epithelium self-renewal are frequently mutated during neoplastic progression. If NSE arises from the same cells that self-renew the Barrett's epithelium, the two tissues should be clonally related and share genetic alterations; if NSE does not originate in the self-renewing Barrett's, NSE and Barrett's esophagus should be genetically independent.

Experimental Design: We isolated islands of NSE and the surrounding Barrett's epithelium from 20 patients by microdissection and evaluated each tissue for genetic alterations in exon 2 of CDKN2A or exons 5 to 9 of the TP53 gene. Nine patients had p16 mutations and 11 had TP53 mutations within the Barrett's epithelium.

Results: In 1 of 20 patients, a focus of NSE had a 146 bp deletion in p16 identical to that found in surrounding Barrett's epithelium. The NSE in the remaining 19 patients was wild-type for p16 or TP53.

Conclusion: Our mutational data support the hypothesis that, in most circumstances, NSE originates in cells different from those responsible for self-renewal of Barrett's epithelium. However, in one case, NSE and Barrett's epithelium seem to have arisen from a progenitor cell that was capable of differentiating into either intestinal metaplasia or NSE.
AdCD40LGene Therapy Counteracts T Regulatory Cells and Cures Aggressive Tumors in an Orthotopic Bladder Cancer Model
Authors: Loskog Angelica S.I. , Fransson Moa E. , Totterman Thomas T.H.
Published: March 2006

Purpose: The aim of this study was to develop an immunostimulating gene therapy for the treatment of orthotopic bladder carcinoma by transferring the gene for CD40L into the tumor site. CD40L stimulation of dendritic cells induces interleukin-12 expression that drives Th1 type of immune responses with activation of cytotoxic T cells.

Experimental Design: The gene for murine CD40L was transferred into bladders of tumor-bearing mice using an adenoviral vector construct. To facilitate viral uptake, the bladders were pretreated with Clorpactin. Survival of mice as well as transgene expression and immunologic effect, such as resistance to tumor challenge and presence of T regulatory cells, were monitored.

Results: On viral vector instillation, CD40L expression could be detected by reverse transcription-PCR. As a sign of transgene function, interleukin-12 (IL-12) expression was significantly increased. AdCD40L gene therapy cured 60% of mice with preestablished tumors. The cured mice were completely resistant to subcutaneous challenge with MB49 tumor cells, whereas the growth of a syngeneic irrelevant tumor was unaltered. Furthermore, the mRNA expression level of the T regulatory cell transcription factor Foxp3 was evaluated both in tumor biopsies and lymph nodes. There were no differences within the tumors of the different treatment groups. However, Foxp3 mRNA levels were down-regulated in the lymph nodes of AdCD40L-treated mice. Correspondingly, T cells from AdCD40L-treated mice were not able to inhibit proliferation of naive T cells as opposed to T cells from control-treated, tumor-bearing mice.

Conclusions: AdCD40L gene therapy evokes Th1 cytokine responses and counteracts T regulatory cell development and/or function.
Clinical Course of Patients with Non–Small Cell Lung Cancer and Epidermal Growth Factor Receptor Exon 19 and Exon 21 Mutations Treated with Gefitinib or Erlotinib
Authors: Riely Gregory J. , Pao William , Pham DuyKhanh , Li Allan R. , Rizvi Naiyer , Venkatraman Ennapadam S. , Zakowski Maureen F. , Kris Mark G. , Ladanyi Marc , Miller Vincent A.
Published: March 2006

Purpose: In patients with non–small cell lung cancer (NSCLC), mutations in the epidermal growth factor receptor (EGFR) tyrosine kinase domain have been associated with sensitivity to erlotinib and gefitinib. We undertook this study to explore the relationship between EGFR mutation type and clinical variables, including treatment with gefitinib and erlotinib.

Experimental Design: In patients with NSCLC, EGFR exon 19 deletion mutations and EGFR L858R point mutations were analyzed by nonsequencing PCR-based methods from paraffin blocks of tissue obtained before treatment. The results were correlated with clinical information (sex, pathologic subtype, race/ethnicity, treatment, and overall survival).

Results: The two most common EGFR mutations were identified in 24% (70 of 291; 95% confidence interval, 26%-38%) of tumors from patients with NSCLC. EGFR mutation was associated with Asian ethnicity (P = 0.0023) and being a “never smoker” (P = 0.0001). Among patients with EGFR mutations, 39% (27 of 70) had EGFR L858R, whereas 61% (43 of 70) had an EGFR exon 19 deletion. After treatment with erlotinib (n = 12) or gefitinib (n = 22), patients with EGFR mutations had a median overall survival of 20 months. After treatment with erlotinib or gefitinib, patients with EGFR exon 19 deletions had significantly longer median survival than patients with EGFR L858R (34 versus 8 months; log-rank P = 0.01).

Conclusions: EGFR mutations in exons 19 or 21 are correlated with clinical factors predictive of response to gefitinib and erlotinib. Those with EGFR exon 19 deletion mutations had a longer median survival than patients with EGFR L858R point mutation. These observations warrant confirmation in a prospective study and exploration of the biological mechanisms of the differences between the two major EGFR mutations.
Microphthalmia transcription factor as a molecular marker for circulating tumor cell detection in blood of melanoma patients.
Authors: Koyanagi Kazuo , O'Day Steven J , Gonzalez Rene , Lewis Karl , Robinson William A , Amatruda Thomas T , Kuo Christine , Wang He-Jing , Milford Robert , Morton Donald L , Hoon Dave S B
Published: March 2006

PURPOSE: Microphthalmia transcription factor (Mitf), which is important in melanocyte development and melanoma growth, was assessed using real-time quantitative reverse transcription-PCR assay to investigate its expression as a marker for circulating melanoma cells in blood and determine the correlation with disease stage and survival in melanoma patients. EXPERIMENTAL DESIGN: In optimization studies for Mitf, we tested 15 melanoma cell lines, 41 peripheral blood lymphocytes from healthy volunteers, and 21 metastatic melanoma tissues. Blood specimens were procured from 90 patients with stage I (n = 20), stage II (n = 20), stage III (n = 28), and stage IV (n = 22) melanoma. Blood specimens were also obtained at four bleed intervals from 58 patients enrolled in a prospective multicenter trial of biochemotherapy before and after surgical treatment of American Joint Committee on Cancer stage III melanoma. RESULTS: Under the optimized conditions, Mitf was negative in healthy peripheral blood lymphocytes and positive in all melanoma cell lines and 18 (86%) melanoma tissues. In the 90 patients, the rate of Mitf detection was higher with increasing American Joint Committee on Cancer stage (P < 0.0001). In the 58 patients treated with biochemotherapy and surgery, Mitf detection decreased with treatment (P = 0.019). Mitf detection after treatment was associated with a significantly lower relapse-free (P < 0.0001) and overall (P = 0.001) survival and was a significant independent prognostic factor for relapse-free (risk ratio, 5.63; P = 0.0004) and overall (risk ratio, 5.36; P = 0.005) survival. CONCLUSIONS: Mitf detection in blood can indicate subclinical metastatic disease and predict treatment outcome in melanoma patients.
Anti-CD3 × Anti-Epidermal Growth Factor Receptor (EGFR) Bispecific Antibody Redirects T-Cell Cytolytic Activity to EGFR-Positive Cancers In vitro and in an Animal Model
Authors: Reusch Ursula , Sundaram Magesh , Davol Pamela A. , Olson Sarah D. , Davis James B. , Demel Kurt , Nissim Julie , Rathore Ritesh , Liu Paul Y. , Lum Lawrence G.
Published: March 2006

Purpose: Targeting epidermal growth factor receptor (EGFR) overexpressed by many epithelial-derived cancer cells with anti-EGFR monoclonal antibodies (mAb) inhibits their growth. A limited number of clinical responses in patients treated with the anti-EGFR mAb, (cetuximab), may reflect variability in EGFR type or signaling in neoplastic cells. This study combines EGFR-targeting with the non-MHC–restricted cytotoxicity of anti-CD3 activated T cells (ATC) to enhance receptor-directed cytotoxicity.

Experimental Design: ATC from normal and patient donors were expanded ex vivo. Specific cytolytic activity of ATC armed with anti-CD3 × anti-EGFR (EGFRBi) against EGFR-expressing cancer cells derived from lung, pancreas, colon, prostate, brain, skin, or EGFR-negative breast cancer cells was evaluated in 51Cr release assays. In vivo studies comparing tumor growth delay induced by EGFRBi-armed ATCs or cetuximab were done in severe combined immunodeficient/Beige mice (SCID-Beige) bearing COLO 356/FG pancreatic and LS174T colorectal tumors.

Results: At effector/target ratios from 3.125 to 50, both EGFRBi-armed normal and patient ATC were significantly more cytotoxic, by 23% to 79%, against EGFR-positive cells over ATC, cetuximab, anti-CD3 alone, or ATC armed with irrelevant BiAb directed at CD20. EGFRBi-armed ATC also secreted significantly higher levels of some TH1/TH2 cytokines compared with ATC alone. In mice, i.v. infusions of EGFRBi-armed ATC (0.001 mg equivalent/infusion) were equally effective as cetuximab (1 mg/infusion) alone for significantly delaying growth of established COLO 356/FG but not LS174T tumors compared with mice that received ATC alone or vehicle (P < 0.001).

Conclusions: Combining EGFR antibody targeting with T cell–mediated cytotoxicity may overcome some limitations associated with EGFR-targeting when using cetuximab alone.
Profiling markers of prognosis in colorectal cancer.
Authors: Lyall Matthew S , Dundas Sinclair R , Curran Stephanie , Murray Graeme I
Published: March 2006

PURPOSE: Colorectal cancer is one of the most common forms of cancer in developed nations and the incidence of this disease is increasing. There is a need to further stratify prognostically distinct groups of colorectal cancer, and the purpose of this study was to identify prognostically significant immunohistochemical marker profiles in colorectal cancer. EXPERIMENTAL DESIGN: In this study, a range (n = 23) of markers [pRb, p16, p21, p27, p53, proliferating cell nuclear antigen, cyclin D1, bcl-2, epidermal growth factor receptor, C-erb-B2, topoisomerase-I, liver fatty acid-binding protein, matrix metalloproteinases (MMP) 1-3, 7, 9, and 13, MT1-MMP, MT2-MMP, and tissue inhibitors of MMP 1-3] of putative prognostic significance have been investigated by immunohistochemistry on formalin-fixed, wax-embedded sections in a series (n = 90) of stage III (Dukes C) colorectal cancers. An immunohistochemical score based on the intensity of immunoreactivity and, where relevant, the proportion of immunoreactive cells was established for each marker. RESULTS: Unsupervised two-dimensional hierarchical cluster analysis identified three distinct cluster groups (designated groups 1-3) with different marker profiles. There were significant survival differences between groups 1 and 2 (log rank = 11.48; P = 0.0007) and between groups 1 and 3 (log rank = 8.32; P = 0.0039). Multivariate analysis showed that the complete marker profile was independently the most significant prognostic factor (hazard ratio, 2.27; 95% confidence interval, 1.15-4.48; P = 0.004). CONCLUSIONS: This study has identified an immunohistochemical marker profile of colorectal cancer and showed that it is an independent indicator of prognosis in this type of cancer.
Eradication of Leukemia Stem Cells as a New Goal of Therapy in Leukemia
Authors: Ravandi Farhad , Estrov Zeev
Published: March 2006

Leukemias have traditionally been classified and treated on the basis of phenotypic characteristics, such as morphology and cell-surface markers, and, more recently, cytogenetic aberrations. These classification systems are flawed because they do not take into account cellular function. The leukemia cell population is functionally heterogeneous: it consists of leukemia stem cells (LSC) and mature leukemia cells that differentiate abnormally to varying extents. Like normal hematopoietic stem cells, LSCs are quiescent and have self-renewal and clonogenic capacity. Because they are quiescent, LSCs do not respond to cell cycle–specific cytotoxic agents used to treat leukemia and so contribute to treatment failure. These cells may undergo mutations and epigenetic changes, further leading to drug resistance and relapse. Recent data suggest that mature leukemia cells may acquire LSC characteristics, thereby evading chemotherapeutic treatment and sustaining the disease. Ongoing research is likely to reveal the molecular mechanisms responsible for LSC characteristics and lead to novel strategies for eradicating leukemia.
Antitumor Efficacy of a Combination of CMC-544 (Inotuzumab Ozogamicin), a CD22-Targeted Cytotoxic Immunoconjugate of Calicheamicin, and Rituximab against Non-Hodgkin's B-Cell Lymphoma
Authors: DiJoseph John F. , Dougher Maureen M. , Kalyandrug Lyka B. , Armellino Douglas C. , Boghaert Erwin R. , Hamann Philip R. , Moran Justin K. , Damle Nitin K.
Published: March 2006

Purpose: CMC-544 is a CD22-targeted cytotoxic immunoconjugate, currently being evaluated in B-cell non-Hodgkin's lymphoma (B-NHL) patients. Rituximab is a CD20-targeted antibody commonly used in B-NHL therapy. Here, we describe antitumor efficacy of a combination of CMC-544 and rituximab against B-cell lymphoma (BCL) in preclinical models.

Experimental Design: BCLs were cultured in vitro with CMC-544, rituximab, or their combination. BCLs were injected either s.c. or i.v. to establish localized s.c. BCL in nude mice or disseminated BCL in severe combined immunodeficient mice, respectively. I.p. treatment with CMC-544 or rituximab was initiated at various times either alone or in combination and its effect on s.c. BCL growth or survival of mice with disseminated BCL was monitored.

Results: In vitro growth-inhibitory activity of CMC-544 combined with rituximab was additive. Rituximab but not CMC-544 exhibited effector functions, such as antibody-dependent cellular cytotoxicity and complement-dependent cytotoxicity. Rituximab was less effective in inhibiting growth of established BCL xenografts than developing xenografts. In contrast, CMC-544 was equally effective against both developing and established BCL xenografts. Although CMC-544 and rituximab individually caused partial inhibition of the growth of BCL xenografts at suboptimal doses examined, their combination suppressed xenograft growth by >90%. In a disseminated BCL model, 60% of CMC-544-treated mice and 20% of rituximab-treated mice survived for 125 days. In contrast, 90% of mice treated with the combination of CMC-544 and rituximab survived for longer than 125 days.

Conclusion: The demonstration of superior antitumor activity of a combination of CMC-544 and rituximab described here provides the preclinical basis for its clinical evaluation as a treatment option for B-NHL.
Combination of p53 Cancer Vaccine with Chemotherapy in Patients with Extensive Stage Small Cell Lung Cancer
Authors: Antonia Scott J. , Mirza Noweeda , Fricke Ingo , Chiappori Alberto , Thompson Patricia , Williams Nicholas , Bepler Gerold , Simon George , Janssen William , Lee Ji-Hyun , Menander Kerstin , Chada Sunil , Gabrilovich Dmitry I.
Published: March 2006

Purpose: The initial goal of this study was to test the immunologic and clinical effects of a new cancer vaccine consisting of dendritic cells (DC) transduced with the full-length wild-type p53 gene delivered via an adenoviral vector in patients with extensive stage small cell lung cancer.

Experimental Design: Twenty-nine patients with extensive stage small cell lung cancer were vaccinated repeatedly at 2-week intervals. Most of the patients received three immunizations. p53-specific responses were evaluated, and phenotype and function of T cells, DCs, and immature myeloid cells were analyzed and correlated with antigen-specific immune responses. Objective clinical response to vaccination as well as subsequent chemotherapy was evaluated.

Results: p53-specific T cell responses to vaccination were observed in 57.1% of patients. Immunologic responses to vaccination were positively associated with a moderate increase in the titer of antiadenovirus antibodies, and negatively with an accumulation of immature myeloid cells. One patient showed a clinical response to vaccination whereas most of the patients had disease progression. However, we observed a high rate of objective clinical responses to chemotherapy (61.9%) that immediately followed vaccination. Clinical response to subsequent chemotherapy was closely associated with induction of immunologic response to vaccination.

Conclusions: This study provides clinical support for an emerging paradigm in cancer immunotherapy, wherein optimal use of vaccination might be more effective, not as a separate modality, but in direct combination with chemotherapy.
Prognostic Relevance of AGR2 Expression in Breast Cancer
Authors: Fritzsche Florian Rudolf , Dahl Edgar , Pahl Stefan , Burkhardt Mick , Luo Jun , Mayordomo Empar , Gansukh Tserenchunt , Dankof Anja , Knuechel Ruth , Denkert Carsten , Winzer Klaus-Jürgen , Dietel Manfred , Kristiansen Glen
Published: March 2006

Purpose: We aimed to evaluate the expression of the human anterior gradient-2 (AGR2) in breast cancer on RNA and protein level and to correlate it with clinicopathologic data, including patient survival.

Experimental Design: AGR2 mRNA expression was assessed by reverse transcription-PCR in 25 breast cancer samples and normal tissues. A polyclonal rabbit AGR antiserum was used for immunohistochemistry on 155 clinicopathologically characterized cases. Statistical analyses were applied to test for prognostic and diagnostic associations.

Results: Immunohistochemical detection of AGR2 was statistically significantly associated with positive estrogen receptor status and lower tumor grade. AGR2-positive tumors showed significantly longer overall survival times in univariate analyses. For the subgroup of nodal-negative tumors, an independent prognostic value of AGR2 was found.

Conclusions: The expression of AGR2 in breast cancer is strongly associated with markers of tumor differentiation (estrogen receptor positivity, lower tumor grade). A prognostic effect of AGR2 for overall survival could be shown, which became independently significant for the group of nodal-negative tumors.
2-Methoxyestradiol Inhibits Prostate Tumor Development in Transgenic Adenocarcinoma of Mouse Prostate: Role of Tumor Necrosis Factor-α–Stimulated Gene 6
Authors: Garcia Gretchen E. , Wisniewski Hans-Georg , Lucia M. Scott , Arevalo Nicole , Slaga Thomas J. , Kraft Susan L. , Strange Robert , Kumar Addanki P.
Published: March 2006

Purpose: 2-Methoxyestradiol, an estrogenic metabolite, is in clinical trials for the treatment of hormone-refractory prostate cancer. However, neither the chemopreventive role nor the mechanism of 2-methoxyestradiol–induced biological activities is fully understood.

Experimental Design: Eight- and 24-week-old transgenic adenocarcinoma of mouse prostate (TRAMP) mice were fed a diet containing 50 mg 2-methoxyestradiol/kg body weight for 16 and 8 weeks, respectively. Chemopreventive efficacy was evaluated by magnetic resonance imaging, determining the prostate-seminal vesicle complex volume and histologic analysis of prostate tumor or tissue. Tumor invasion assays were used to show the role of tumor necrosis factor-α–stimulated gene (TSG-6), a 2-methoxyestradiol–up-regulated gene identified by DNA array analysis. Expression of TSG-6 was analyzed in a human tissue array containing different grades of prostate tumors.

Results: Dietary administration of 2-methoxyestradiol prevented the development of preneoplastic lesions independent of progression stage. TSG-6 was low or undetectable in prostate cancer cells (LNCaP, PC-3, and DU145) and TRAMP tumors but up-regulated in response to 2-methoxyestradiol. Immunohistochemistry of the human prostate tumor array showed a decrease in TSG-6–positive cells with increasing grade relative to normal prostate (P = 0.0001). Although overexpression of TSG-6 inhibited invasion of androgen-independent cells (P = 0.007), antisense TSG-6 reversed this effect.

Conclusions: To the best of our knowledge, this is the first report showing the potential of 2-methoxyestradiol as a chemopreventive agent. We have also identified TSG-6 as a potential marker that could be used for early diagnosis and prognosis of cancerous or precancerous lesions.
A Randomized Phase II Trial of the Matrix Metalloproteinase Inhibitor BMS-275291 in Hormone-Refractory Prostate Cancer Patients with Bone Metastases
Authors: Lara Primo N. , Stadler Walter M. , Longmate Jeff , Quinn David I. , Wexler Jason , Van Loan Marta , Twardowski Przemyslaw , Gumerlock Paul H. , Vogelzang Nicholas J. , Vokes Everett E. , Lenz Heinz Josef , Doroshow James H. , Gandara David R.
Published: March 2006

Background: BMS-275291 is a selective matrix metalloproteinase inhibitor (MMPI) that does not inhibit sheddases implicated in the dose-limiting arthritis of older MMPIs. We conducted a randomized phase II trial of two doses of BMS-275291 (1,200 versus 2,400 mg) in hormone-refractory prostate cancer (HRPC) patients with bone metastases to probe for a dose-response relationship and to assess differential toxicities. Serial serum and urine specimens were collected to assess for markers of bone metabolism.

Methods: The primary end point was 4-month progression-free survival (PFS). Eligibility criteria included documentation of androgen-independent disease (including anti-androgen withdrawal), skeletal metastasis, adequate end-organ function and performance status, and no more than one prior chemotherapy regimen. Patients were randomized to 1,200 mg orally once daily (arm A) or 1,200 mg orally twice daily (arm B). Response was assessed every 56 days.

Results: Eighty patients were enrolled: 39 in arm A and 41 in arm B. There were no responders by prostate-specific antigen or measurable disease to treatment. Stable disease was noted at 8 weeks in 39% of patients in arm A and in 17% of patients in arm B. Progression of disease at 8 weeks was seen in 61% of patients in arm A versus 83% of patients in arm B. Median survival time was 21.6 months (95% confidence interval, 17.5; not reached), whereas median PFS time was 1.8 months (95% confidence interval 1.74; 2) for all patients. Patients in arm A had a median survival time that was not reached, whereas patients on arm B has a median survival time of 21 months (P = 0.2). PFS at 4 months favored arm A: 22% versus 10% (log-rank, P = 0.008). Grade 3 toxicities occurred in 5 (13%) patients in arm A and in 9 (22%) patients in arm B. Grade 4 toxicities were uncommon (only 4% of patients): one each of thrombosis, fatigue, and motor neuropathy was seen in the arm B. Bone marker studies showed that baseline serum levels of N-telopeptide, osteocalcin, procollagen I NH2-terminal propeptide, and PICP had prognostic significance for PFS and/or overall survival.

Conclusions: Regardless of dose schedule, BMS-275291 was well tolerated in HRPC patients and had no dose-limiting arthritis. Toxicities differed modestly according to the dose schedule employed. As overall survival and PFS favored the once daily schedule, this dose schedule is recommended for future studies. Baseline markers of bone metabolism may have prognostic value in HRPC patients with bone metastases.
Human Kallikrein 8 Protein Is a Favorable Prognostic Marker in Ovarian Cancer
Authors: Borgoño Carla A. , Kishi Tadaaki , Scorilas Andreas , Harbeck Nadia , Dorn Julia , Schmalfeldt Barbara , Schmitt Manfred , Diamandis Eleftherios P.
Published: March 2006

Human kallikrein 8 (hK8/neuropsin/ovasin; encoded by KLK8) is a steroid hormone–regulated secreted serine protease differentially expressed in ovarian carcinoma. KLK8 mRNA levels are associated with a favorable patient prognosis and hK8 protein levels are elevated in the sera of 62% ovarian cancer patients, suggesting that KLK8/hK8 is a prospective biomarker. Given the above, the aim of the present study was to determine if tissue hK8 bears any prognostic significance in ovarian cancer. Using a newly developed ELISA, hK8 was quantified in 136 ovarian tumor extracts and correlated with clinicopathologic variables and outcome [progression-free survival (PFS); overall survival (OS)] over a median follow-up period of 42 months. hK8 levels in ovarian tumor cytosols ranged from 0 to 478 ng/mg total protein, with a median of 30 ng/mg. An optimal cutoff value of 25.8 ng/mg total protein (74th percentile) was selected based on the ability of hK8 values to predict the PFS of the study population and to categorize tumors as hK8 positive or negative. Women with hK8-positive tumors most often had lower-grade tumors (G1), no residual tumor after surgery, and optimal debulking success (P < 0.05). Univariate and multivariate analyses revealed that patients with hK8-positive tumors had a significantly longer PFS and OS than hK8-negative patients (P < 0.05). Kaplan-Meier survival curves further confirmed a reduced risk of relapse and death in women with hK8-positive tumors (P = 0.001 and P = 0.014, respectively). These results indicate that hK8 is an independent marker of favorable prognosis in ovarian cancer.
Adjuvant Endocrine Therapy for Postmenopausal Women with Early Breast Cancer
Authors: Ingle James N.
Published: March 2006

Results from multiple clinical trials involving aromatase inhibitors have added to the knowledge base relating to endocrine therapy of postmenopausal women with hormone receptor–positive early breast cancer. In the extended adjuvant setting, data from the Austrian Breast and Colorectal Cancer Study Group 6a trial showed an advantage for anastrozole following 5 years of tamoxifen treatment, consistent with the more robust MA.17 trial that examined letrozole versus placebo following 5 years of tamoxifen treatment. The combined analysis of the Austrian Breast and Colorectal Cancer Study Group 8 trial and the German Arimidex Nolvadex 95 trial, plus the Italian Tamoxifen Anastrozole trial, have shown the advantage of switching to anastrozole over continuing the tamoxifen to complete the full 5 years of adjuvant therapy. These trials support the previously reported larger and double-blind Intergroup Exemestane Study. The Arimidex, Tamoxifen, Alone or in Combination trial now has data out to 68 months of median follow-up showing the maintenance of a significant advantage of anastrozole over tamoxifen for disease-free survival. In this initial treatment setting, the Breast International Group 1-98 trial recently showed a significant advantage for letrozole over tamoxifen. The current debate is centered on whether the optimal strategy is to give an aromatase inhibitor initially or after several years of tamoxifen treatment. Multiple important questions remain, including the predictive value of molecular markers such as progesterone receptor, the optimal duration of aromatase inhibitor therapy, the long-term adverse effects, and the relative efficacy and toxicity of the different aromatase inhibitors.