bluuebunny/crossref_metadata_2025 huggingface dataset:
The Novel Combination of Chlorpromazine and Pentamidine Exerts Synergistic Antiproliferative Effects through Dual Mitotic Action
Authors: Lee Margaret S. , Johansen Lisa , Zhang Yanzhen , Wilson Amy , Keegan Mitchell , Avery William , Elliott Peter , Borisy Alexis A. , Keith Curtis T.
Published: December 2007

Combination therapy has proven successful in treating a wide variety of aggressive human cancers. Historically, combination treatments have been discovered through serendipity or lengthy trials using known anticancer agents with similar indications. We have used combination high-throughput screening to discover the unexpected synergistic combination of an antiparasitic agent, pentamidine, and a phenothiazine antipsychotic, chlorpromazine. This combination, CRx-026, inhibits the growth of tumor cell lines in vivo more effectively than either pentamidine or chlorpromazine alone. Here, we report that CRx-026 exerts its antiproliferative effect through synergistic dual mitotic action. Chlorpromazine is a potent and specific inhibitor of the mitotic kinesin KSP/Eg5 and inhibits tumor cell proliferation through mitotic arrest and accumulation of monopolar spindles. Pentamidine treatment results in chromosomal segregation defects and delayed progression through mitosis, consistent with inhibition of the phosphatase of regenerating liver family of phosphatases. We also show that CRx-026 synergizes in vitro and in vivo with the microtubule-binding agents paclitaxel and vinorelbine. These data support a model where dual action of pentamidine and chlorpromazine in mitosis results in synergistic antitumor effects and show the importance of systematic screening for combinations of targeted agents. [Cancer Res 2007;67(23):11359–67]
Adaptor Protein LAPF Recruits Phosphorylated p53 to Lysosomes and Triggers Lysosomal Destabilization in Apoptosis
Authors: Li Nan , Zheng Yuanyuan , Chen Wei , Wang Chunmei , Liu Xingguang , He Weigang , Xu Hongmei , Cao Xuetao
Published: December 2007

Evidence suggests a functional association between the tumor suppressor p53 and apoptosis-involved organelle lysosome; however, the detailed mechanisms remain poorly understood. We recently reported that a lysosome-targeting protein, LAPF (lysosome-associated and apoptosis-inducing protein containing PH and FYVE domains), could initiate apoptosis of L929 cells through a lysosomal-mitochondrial pathway. In this study, we show that LAPF specifically interacted with phosphorylated p53 (Ser15/18) both in vitro and in vivo, which could be enhanced by apoptotic stimuli, such as tumor necrosis factor α (TNF-α) and ionizing irradiation. The PH domain of LAPF and the transactivation domain of p53 mediated the interaction between both molecules. Phosphorylated p53 (Ser15/18) could translocate to lysosomes before lysosomal membrane permeabilization (LMP) in LAPF-initiated and TNF-induced apoptosis. Silencing of LAPF expression abrogated lysosomal translocation of phosphorylated p53 (Ser15/18), whereas silencing of p53 expression had no effect on lysosomal translocation of LAPF. Similar to that of LAPF silencing, silencing of endogenous p53 expression in L929 cells could significantly impair TNF-α–induced LMP and apoptosis. However, reexpression of wild-type p53, p53S15D (substitution of Ser15 to Asp that mimics a phosphorylated state), and p53R175H (a transcription-deficient mutant) in p53-knockdown L929 cells could rescue the decrease in TNF-induced apoptosis. The data suggest that phosphorylated p53 (Ser15/18) might translocate to lysosome via forming complexes with adaptor protein LAPF and subsequently result in LMP and apoptosis, which might be in a transcription-independent manner. [Cancer Res 2007;67(23):11176–85]
Polo-like Kinase 1 Is Involved in Invasion through Extracellular Matrix
Authors: Rizki Aylin , Mott Joni D. , Bissell Mina J.
Published: December 2007

Polo-like kinase 1 (PLK1) has important functions in maintaining genome stability via its role in mitosis. Because PLK1 is up-regulated in many invasive carcinomas, we asked whether it may also play a role in acquisition of invasiveness, a crucial step in transition to malignancy. In a model of metaplastic basal-like breast carcinoma progression, we found that PLK1 expression is necessary but not sufficient to induce invasiveness through laminin-rich extracellular matrix. PLK1 mediates invasion via vimentin and β1 integrin, both of which are necessary. We observed that PLK1 phosphorylates vimentin on Ser82, which in turn regulates cell surface levels of β1 integrin. We found PLK1 to be also highly expressed in preinvasive in situ carcinomas of the breast. These results support a role for the involvement of PLK1 in the invasion process and point to this pathway as a potential therapeutic target for preinvasive and invasive breast carcinoma treatment. [Cancer Res 2007;67(23):11106–10]
Identification of Genes Required for Protection from Doxorubicin by a Genome-Wide Screen in Saccharomyces cerevisiae
Authors: Xia Ling , Jaafar Lahcen , Cashikar Anil , Flores-Rozas Hernan
Published: December 2007

Anthracyclines are chemotherapeutic agents commonly used to treat a broad range of malignancies. Although effective, these drugs present serious complications, most notably cardiotoxicity. To determine the mechanisms that mediate cytoprotection from doxorubicin, we have screened the collection of Saccharomyces cerevisiae haploid gene deletion mutants. We have identified 71 deletion strains that display varying degrees of hypersensitivity to doxorubicin at a concentration that does not significantly reduce the viability of wild-type cells. Complementation of the doxorubicin-sensitive phenotype of the deletion strains with the wild-type genes proves that the sensitivity of the strain to doxorubicin is due to the gene deletion. The genes that mediate cytoprotection from doxorubicin belong to multiple pathways including DNA repair, RNA metabolism, chromatin remodeling, amino acid metabolism, and heat shock response. In addition, proteins with mitochondrial, osmosensing, vacuolar, and ribosomal functions are also required for protection from doxorubicin. We tested the sensitivity of the deletion strains to other cytotoxic agents, which resulted in different drug-specific sensitive groups. Most of the identified genes have mammalian homologues that participate in conserved pathways. Our data may prove useful to develop strategies aimed at sensitizing tumor cells to doxorubicin as well as protecting cardiac cells from its cytotoxic effects. [Cancer Res 2007;67(23):11411–8]
Identification of Novel Modifier Loci of ApcMin Affecting Mammary Tumor Development
Authors: Wang Hua , Teske Douglas , Tess Alyssa , Kohlhepp Rebecca , Choi YounJeong , Kendziorski Christina , Moser Amy Rapaich
Published: December 2007

Genetic background affects the susceptibility to mammary tumor development in ApcMin/+ mice. Here we report the identification of four novel modifier loci that influence different aspects of mammary tumor development in ApcMin/+ mice. Analysis of tumor development in a backcross of (FVBB6 ApcMin/+) × B6 ApcMin/+ mice has identified a modifier on chromosome 9 that significantly affects tumor multiplicity, and a modifier on chromosome 4 that significantly affects tumor latency and affects tumor number with suggestive significance. This modifier was also identified in a backcross involving 129X1/SvJ and B6 ApcMin/+ mice. A modifier on chromosome 18 specifically affects tumor latency but not tumor number. Kaplan-Meier analysis suggests there is at least an additive interaction affecting tumor latency between the loci on chromosomes 4 and 18. We also identified a modifier locus on chromosome 6 that interacts with the loci on chromosome 4 and chromosome 9 to affect tumor number. These results suggest that multiple genetic loci control different aspects of mammary tumor development. None of these modifiers is associated with intestinal tumor susceptibility, which indicates that these modifiers act on tumor development in a tissue-specific manner. [Cancer Res 2007;67(23):11226–33]
The Guardian's Little Helper: MicroRNAs in the p53 Tumor Suppressor Network
Authors: He Xingyue , He Lin , Hannon Gregory J.
Published: December 2007

Several microRNAs (miRNAs) have been implicated in tumor development based on both changes in their expression patterns and gene structural alterations in human tumors. However, we are only now beginning to see how miRNAs interact with classic oncogene and tumor suppressor mechanisms. Several recent studies have implicated the miR-34 family of miRNAs in the p53 tumor suppressor network. The expression of miR-34a, miR-34b, and miR-34c is robustly induced by DNA damage and oncogenic stress in a p53-dependent manner. When overexpressed, miR-34 leads to apoptosis or cellular senescence, whereas reduction of miR-34 function attenuates p53-mediated cell death. These findings, together with the fact that miR-34 is down-regulated in several types of human cancer, show that miRNAs can affect tumorigenesis by working within the confines of well-known tumor suppressor pathways. [Cancer Res 2007;67(23):11099–101]
CD83 Gene Polymorphisms Increase Susceptibility to Human Invasive Cervical Cancer
Authors: Zhang Zhengyan , Borecki Ingrid , Nguyen Loan , Ma Duanduan , Smith Kimberly , Huettner Phyllis C. , Mutch David G. , Herzog Thomas J. , Gibb Randall K. , Powell Matthew A. , Grigsby Perry W. , Massad L. Stewart , Hernandez Enrique , Judson Patricia L. , Swisher Elizabeth M. , Crowder Sara , Li Jianduan , Gerhard Daniela S. , Rader Janet S.
Published: December 2007

We previously mapped a nonrandom frequent loss of heterozygosity (LOH) region in cervical cancers to 1 Mb of 6p23. Here, we describe the identification of a novel cervical cancer susceptibility gene, CD83. The gene was identified by several complementary approaches, including a family-based association study, comparison of transcript expression in normal and cancerous tissue, and genomic sequencing of candidate. CD83 encodes an inducible glycoprotein in the immunoglobulin superfamily and is a marker for mature dendritic cells. The association study that includes 377 family trios showed that five single nucleotide polymorphisms (SNP) within 8 kb of its 3′-end showed significant allelic association that was strengthened in a subgroup of women with invasive cancers infected by high-risk human papillomavirus type 16 and 18 (rs9296925, P = 0.0193; rs853360, P = 0.0035; rs9230, P = 0.0011; rs9370729, P = 0.0012; rs750749, P = 0.0133). Investigation of CD83 uncovered three alternative transcripts in cervical tissue and cell lines, with variant 3 (lacking exons 3 and 4) being more frequent in cervical cancer than in normal cervical epithelium (P = 0.0181). Genomic sequencing on 36 paired normal and cervical tumors revealed several somatic mutations and novel SNPs in the promoter, exons, and introns of CD83. LOH was confirmed in >90% of cervical cancer specimens. Immunofluorescence colocalized CD83 protein to the Golgi apparatus and cell membrane of cervical cancer cell lines. None of seven nearby genes was differentially expressed in cervical cancer. The importance of CD83 in epithelial versus dendritic cells needs to be determined, as does its role in promoting cervical cancer. [Cancer Res 2007;67(23):11202–8]
Cells Deficient in the FANC/BRCA Pathway Are Hypersensitive to Plasma Levels of Formaldehyde
Authors: Ridpath John R. , Nakamura Ayumi , Tano Keizo , Luke April M. , Sonoda Eiichiro , Arakawa Hiroshi , Buerstedde Jean-Marie , Gillespie David A.F. , Sale Julian E. , Yamazoe Mitsuyoshi , Bishop Douglas K. , Takata Minoru , Takeda Shunichi , Watanabe Masami , Swenberg James A. , Nakamura Jun
Published: December 2007

Formaldehyde is an aliphatic monoaldehyde and is a highly reactive environmental human carcinogen. Whereas humans are continuously exposed to exogenous formaldehyde, this reactive aldehyde is a naturally occurring biological compound that is present in human plasma at concentrations ranging from 13 to 97 μmol/L. It has been well documented that DNA-protein crosslinks (DPC) likely play an important role with regard to the genotoxicity and carcinogenicity of formaldehyde. However, little is known about which DNA damage response pathways are essential for cells to counteract formaldehyde. In the present study, we first assessed the DNA damage response to plasma levels of formaldehyde using chicken DT40 cells with targeted mutations in various DNA repair genes. Here, we show that the hypersensitivity to formaldehyde is detected in DT40 mutants deficient in the BRCA/FANC pathway, homologous recombination, or translesion DNA synthesis. In addition, FANCD2-deficient DT40 cells are hypersensitive to acetaldehyde, but not to acrolein, crotonaldehyde, glyoxal, and methylglyoxal. Human cells deficient in FANCC and FANCG are also hypersensitive to plasma levels of formaldehyde. These results indicate that the BRCA/FANC pathway is essential to counteract DPCs caused by aliphatic monoaldehydes. Based on the results obtained in the present study, we are currently proposing that endogenous formaldehyde might have an effect on highly proliferating cells, such as bone marrow cells, as well as an etiology of cancer in Fanconi anemia patients. [Cancer Res 2007;67(23):11117–22]
Inhibition of the Intrinsic Apoptosis Pathway Downstream of Caspase-9 Activation Causes Chemotherapy Resistance in Diffuse Large B-Cell Lymphoma
Authors: Cillessen Saskia A.G.M. , Hess Corine J. , Hooijberg Erik , Castricum Kitty C.M. , Kortman Pim , Denkers Fedor , Vos Wim , van de Wiel Mark A. , Schuurhuis Gerrit J. , Ossenkoppele Gert J. , Meijer Chris J.L.M. , Oudejans Joost J.
Published: December 2007

Purpose: Inhibition of the apoptosis cascade is an important cause of therapy resistance in diffuse large B-cell lymphomas (DLBCL). In this study, we investigated possible mechanisms and expression levels of apoptosis-related genes in the apoptosis pathway that may be responsible for differences in chemotherapy sensitivity between DLBCL patients.

Experimental Design: Twenty-eight DLBCL patient samples were investigated for their expression levels of apoptosis-related genes using reverse transcription-multiplex ligation-dependent probe amplification analysis. Functional analysis of the intrinsic, caspase-9–mediated pathway was done using fluorescence-activated cell sorting analysis, Western blot analysis, and immunohistochemistry.

Results: Two DLBCL groups were identified: one with low expression levels of both proapoptotic and antiapoptotic genes and one group with high expression levels of these genes. DLBCL with high expression levels of proapoptotic and antiapoptotic genes frequently seemed to be refractory to clinical chemotherapy. Functional analysis in these latter DLBCL samples and DLBCL cell lines with comparable expression profiles revealed high levels of spontaneous caspase-9 activity without induction of apoptosis, indicating disruption of the apoptosis pathway downstream of caspase-9 activation. This disruption of the apoptosis pathway could be restored using a small-molecule XIAP antagonist.

Conclusions: We conclude that the intrinsic, caspase-9–mediated apoptosis pathway is constitutively activated in part of chemotherapy-refractory DLBCL with concomitant downstream inhibition of the convergence apoptosis pathway and that inhibition of XIAP might be an alternative therapy for chemotherapy-refractory DLBCL.
The Bcl-2/Bcl-XL Family Inhibitor ABT-737 Sensitizes Ovarian Cancer Cells to Carboplatin
Authors: Witham James , Valenti Melanie R. , De-Haven-Brandon Alexis K. , Vidot Susanne , Eccles Suzanne A. , Kaye Stan B. , Richardson Alan
Published: December 2007

Purpose: The effective treatment of ovarian cancer is hampered by the development of drug resistance, which may be mediated by members of the Bcl-2 family of apoptosis regulators. ABT-737 is a recently described inhibitor of members of this family. We investigated whether this compound could sensitize ovarian cancer cells to chemotherapeutic agents.

Experimental Design: The sensitivity of ovarian cancer cell lines to ABT-737 in combination with either carboplatin or paclitaxel was tested either in vitro by assessing cell growth/survival and apoptosis or in xenograft studies.

Results: As a single agent, ABT-737 inhibited the growth of eight ovarian cancer cell lines, although with relatively poor potency. However, ABT-737, but not a less active enantiomer, increased the sensitivity of several cell lines to carboplatin. The increased sensitivity to carboplatin was accompanied by a decrease in time at which apoptosis was observed when assessed according to the number of attached cells, PARP cleavage, and nucleosome formation. ABT-737 was more effective at sensitizing IGROV-1 cells when ABT-737 was administered after carboplatin. In addition, ABT-737 significantly enhanced the activity of carboplatin in one of three primary cultures derived directly from ascitic tumor cells in patients recently treated with chemotherapy. Small interfering RNA directed to Bcl-XL also increased the sensitivity of ovarian cancer cell lines to carboplatin. ABT-737 was also able to augment the inhibition of IGROV-1 tumor xenograft growth beyond that obtained with carboplatin alone.

Conclusions: These data suggest that ABT-737, in combination with carboplatin, may find utility in the treatment of patients with ovarian cancer.
Telomere DNA Content Predicts Breast Cancer–Free Survival Interval
Authors: Heaphy Christopher M. , Baumgartner Kathy B. , Bisoffi Marco , Baumgartner Richard N. , Griffith Jeffrey K.
Published: December 2007

Background: Telomeres are nucleoprotein complexes that protect chromosome ends from degradation and recombination. Critically shortened telomeres generate genomic instability. It has been postulated that the extent of telomere DNA loss is related to the degree of genomic instability within a tumor and therefore may presage clinical outcome. The objective of this investigation was to evaluate the hypothesis that telomere DNA content (TC) in breast tumor tissues predicts breast cancer–free survival interval.

Materials and Methods: Slot blot titration assay was used to quantitate TC in 530 archival breast tumor tissues in a population-based cohort. The relationships between TC, 12 risk factors for breast cancer adverse events (i.e., death due to breast cancer, breast cancer recurrence, or development of a new primary breast tumor), and breast cancer–free survival interval were evaluated by Fisher's exact test, log-rank analysis, and univariate and multivariate Cox proportional hazards models.

Results: TC was independent of each of the 12 risk factors. Ethnicity, tumor-node-metastasis stage, estrogen receptor, progesterone receptor, and p53 status, chemotherapy sequence, adjuvant therapy, and TC each conferred significant relative hazards. The best overall multivariate Cox proportional hazards model included TC, p53 status, tumor-node-metastasis stage, and estrogen receptor status as independent predictors of breast cancer–free survival interval (P < 0.00005). Low TC (≤200% of standard), relative to the high-TC group (>200% of standard), conferred an adjusted relative hazard of 2.88 (95% confidence interval, 1.16-7.15; P = 0.022) for breast cancer–related adverse events.

Conclusions: TC in breast cancer tissue is an independent predictor in this group of breast cancer–free survival interval.
Reversal of the Estrogen Receptor–Negative Phenotype in Breast Cancer and Restoration of Antiestrogen Response
Authors: Bayliss Jill , Hilger Amy , Vishnu Prakash , Diehl Kathleen , El-Ashry Dorraya
Published: December 2007

Purpose: In breast cancer, the presence of estrogen receptor α (ER) denotes a better prognosis and response to antiestrogen therapy. Lack of ERα correlates with overexpression of epidermal growth factor receptor or c-erbB-2. We have shown that hyperactivation of mitogen-activated protein kinase (MAPK) directly represses ERα expression in a reversible manner. In this study, we determine if inhibition of MAPK in established ERα− breast cancer cell lines and tumors results in reexpression of ERα, and further, if reexpression of ERα in these ERα− tumors and cell lines could restore antiestrogen responses.

Experimental Design: Established ERα− breast cancer cell lines, ERα− breast tumors, and tumor cell cultures obtained from ERα− tumors were used in this study. Inhibition of hyperactive MAPK was accomplished via the MAPK/ERK kinase 1/2 inhibitor U0126 or via upstream inhibition with Iressa or Herceptin. Western blotting or reverse transcription-PCR for ERα was used to assess the reexpression of ERα in cells treated with U0126. Growth assays with WST-1 were done to assess restoration of antiestrogen sensitivity in these cells.

Results: Inhibition of MAPK activity in ERα− breast cancer cell lines results in reexpression of ERα; upstream inhibition via targeting epidermal growth factor receptor or c-erbB-2 is equally effective. Importantly, this reexpressed ERα can now mediate an antiestrogen response in a subset of these ERα− breast cancer cell lines. Treatment of ERα− tumor specimens with MAPK inhibitors results in restoration of ERα mRNA, and similarly in epithelial cultures from ERα− tumors, MAPK inhibition restores both ERα protein and antiestrogen response.

Conclusions: These data show both the possibility of restoring ERα expression and antiestrogen responses in ERα− breast cancer and suggest that there exist ERα− breast cancer patients who would benefit from a combined MAPK inhibition/hormonal therapy.
Alteration of Cellular and Humoral Immunity by Mutant p53 Protein and Processed Mutant Peptide in Head and Neck Cancer
Authors: Couch Marion E. , Ferris Robert L. , Brennan Joseph A. , Koch Wayne M. , Jaffee Elizabeth M. , Leibowitz Michael S. , Nepom Gerald T. , Erlich Henry A. , Sidransky David
Published: December 2007

Purpose: To determine if serologic recognition of p53 mutations at the protein level depends upon the ability of mutant p53 to express new peptide epitopes that bind to human leukocyte antigen (HLA) class II molecules, we used anti-p53 antibody production as a marker for HLA class II–restricted T-cell involvement in head and neck cancer.

Experimental Design: An anti-p53 antibody response was correlated with specific p53 mutations and the patients' HLA class II alleles and haplotypes. HLA binding studies and in vitro stimulation (IVS) of peripheral blood mononuclear cells were done using a mutant versus wild-type HLA-DQ7-binding p53 peptide.

Results: Certain HLA-DQ and HLA-DR alleles were frequently present in p53 seropositive patients who produced serum anti-p53 antibodies. Selected mutated p53 peptides fit published allele-specific HLA class II binding motifs for the HLA-DQ7 or HLA-DR1 molecules. Moreover, a mutant p53 peptide bound with a 10-fold greater affinity than the wild-type p53 peptide to HLA-DQ7 molecules. IVS of CD4+ T cells from seven healthy HLA-DQ7+ donors using this mutant p53 peptide (p53220C) was associated with a partial T helper type 2 phenotype compared with IVS using the wild-type p53210-223 peptide.

Conclusions: Our results support the hypothesis that mutated p53 neoantigens can bind to specific HLA class II molecules, leading to a break in tolerance. This may lead to skewing of the CD4+ T lymphocyte response toward a tumor-permissive T helper type 2 profile in head and neck cancer patients, as manifested by seropositivity for p53.
CD8+ Foxp3+ Regulatory T Cells Mediate Immunosuppression in Prostate Cancer
Authors: Kiniwa Yukiko , Miyahara Yoshihiro , Wang Helen Y. , Peng Weiyi , Peng Guangyong , Wheeler Thomas M. , Thompson Timothy C. , Old Lloyd J. , Wang Rong-Fu
Published: December 2007

Purpose: Although elevated proportions of CD4+CD25+ regulatory T (Treg) cells have been shown in several types of cancers, very little is known about the existence and function of CD8+ Treg cells in prostate cancer. In this study, we investigated prostate tumor–derived CD8+ Treg cells and their function.

Experimental Design: Tumor-infiltrating lymphocytes (TIL) from fresh tumor specimens of patients with prostate cancer were generated and subjected to phenotypic and suppressive function analyses. In particular, we investigated the role and function CD8+ Treg cells in prostate cancer.

Results: We show that high percentages of CD4+CD25+ T cells are probably present in the majority (70%) of prostate TILs. Remarkably, both CD4+ and CD8+ T-cell subpopulations possessed potent suppressive activity. T-cell cloning and fluorescence-activated cell sorting analyses showed the presence of CD8+CD25+ Treg cell clones that expressed FoxP3 and suppressed naïve T-cell proliferation, in addition to the previously known CD4+CD25+ Treg cells. These CD8+ Treg cells suppressed naïve T-cell proliferation mainly through a cell contact–dependent mechanism. Importantly, the suppressive function of CD8+ Treg cells could be reversed by human Toll-like receptor 8 (TLR8) signaling.

Conclusion: Our study shows that like CD4+CD25+ Treg cells, CD8+ Foxp3+ Treg cells present in prostate tumor–derived TILs suppress immune responses and that their suppressive function can be regulated by TLR8 ligands, raising the possibility that the manipulation of Treg cell function by TLR8 ligands could improve the efficacy of immunotherapy for prostate cancer patients.
Phase I Study of Temozolomide and Irinotecan for Recurrent Malignant Gliomas in Patients Receiving Enzyme-Inducing Antiepileptic Drugs: A North American Brain Tumor Consortium Study
Authors: Loghin Monica E. , Prados Michael D. , Wen Patrick , Junck Larry , Lieberman Frank , Fine Howard , Fink Karen L. , Metha Minesh , Kuhn John , Lamborn Kathleen , Chang Susan M. , Cloughesy Timothy , DeAngelis Lisa M. , Robins Ian H. , Aldape Kenneth D. , Yung W.K. Alfred
Published: December 2007

Purpose: To determine the maximum tolerated dose of irinotecan when administrated with temozolomide every 28 days, in patients with recurrent malignant glioma who were also receiving CYP450 enzyme-inducing antiepileptic drugs (EIAED), and to characterize the pharmacokinetics of irinotecan and its metabolites. The study was also intended to assess whether temozolomide affects the conversion of irinotecan to SN-38.

Design: Patients with recurrent malignant glioma received a fixed dose of temozolomide (150 mg/m2) daily for 5 days from days 1 to 5 every 28 days, and an i.v. infusion of irinotecan on days 1 and 15 of each cycle. The starting dose of irinotecan was 350 mg/m2, which was escalated to 550 mg/m2 in 50-mg/m2 increments. The plasma pharmacokinetics of irinotecan and its active metabolite, SN-38, were determined during the infusion of irinotecan on cycle 1, day 1.

Results: Thirty-three patients were enrolled into the study and treated. Thirty-one patients were evaluable for both tumor response and toxicity and two patients were evaluable for toxicity only. Common toxicities included neutropenia and thrombocytopenia, nausea, vomiting, and diarrhea. Dose-limiting toxicities were grade 3 diarrhea and nausea/vomiting. The maximum tolerated dose for irinotecan was determined to be 500 mg/m2.

Conclusions: The recommended phase II dose of irinotecan in combination with temozolomide for patients receiving EIAEDs is 500 mg/m2, administrated every 15 days on a 28-day schedule. This study also confirmed that concomitant administration of EIAEDs increases irinotecan clearance and influences SN-38 disposition. No pharmacokinetic interaction was observed between temozolomide and irinotecan.
Glucocorticoids in the Treatment of Children with Acute Lymphoblastic Leukemia and Hodgkin's Disease: A Pilot Study on the Adverse Psychological Reactions and Possible Associations with Neurobiological, Endocrine, and Genetic Markers
Authors: Felder-Puig Rosemarie , Scherzer Christiane , Baumgartner Michaela , Ortner Magdalena , Aschenbrenner Claudia , Bieglmayer Christian , Voigtländer Till , Panzer-Grümayer E. Renate , Tissing Wim J.E. , Koper Jan W. , Steinberger Karl , Nasel Christian , Gadner Helmut , Topf Reinhard , Dworzak Michael
Published: December 2007

Purpose: We did a controlled study to assess adverse psychological reactions (APR) associated with high-dose glucocorticoid therapy and tried to detect somatic correlates for the observed reactions.

Patients and Methods: Our study included 37 patients with acute lymphoblastic leukemia (ALL) and 11 patients with Morbus Hodgkin (MH) disease, who were treated with high-dose glucocorticoid therapy, and 26 control patients with other types of malignancies. APRs were assessed with a standardized measure via parent-report. Patients with ALL and MH were further analyzed for signs of neuronal cell death in the cerebrospinal fluid, polymorphisms of the glucocorticoid receptor gene, as well as cortisol, adrenocorticorticotropic hormone, and dehydroepiandrosterone sulfate blood levels.

Results: Fifty-four percent of ALL, 36% of MH, and 23% of control patients developed APR in the first few weeks of therapy. Approximately 3.5 months later, the majority of patients with ALL showed no APR, similar to control patients. Patients demonstrating a higher, nonsuppressible secretion of cortisol and/or adrenocorticorticotropic hormone during glucocorticoid therapy were found to be more likely to develop APR. No sign of neuronal cell destruction and no correlation of APR with specific glucocorticoid receptor polymorphisms were found.

Conclusion: Our results suggest that the development of APR due to glucocorticoid therapy is measurable and correlates with hormonal reaction patterns.
Selective Inhibition of Fatty Acid Synthase for Lung Cancer Treatment
Authors: Orita Hajime , Coulter Jonathan , Lemmon Colleen , Tully Ellen , Vadlamudi Aravinda , Medghalchi Susan M. , Kuhajda Francis P. , Gabrielson Edward
Published: December 2007

Purpose: Fatty acid synthase (FAS) is overexpressed in many human cancers and is considered to be a promising target for therapy. However, in vitro use of previous generations of FAS inhibitors has been limited by severe, but reversible, anorexia in treated animals, which is thought to be related to a parallel stimulation of fatty acid oxidation by these agents. This study investigated pharmacologic inhibition of FAS using C93, a rationally designed molecule that inhibits FAS activity without affecting fatty acid oxidation in preclinical models of lung cancer.

Experimental Design: Activity of C93 on FAS and fatty acid oxidation was evaluated in cultured non–small cell lung cancer (NSCLC) cells. Antineoplastic activity of the compound, given orally or by i.p. injection, was evaluated in s.c. and orthotopic NSCLC xenografts.

Results: Our experiments confirm that C93 effectively inhibits FAS without stimulating fatty acid oxidation in lung cancer cells. More importantly, C93 significantly inhibits the growth of both s.c. and orthotopic xenograft tumors from human NSCLC cell lines without causing anorexia and weight loss in the treated animals.

Conclusions: We conclude that inhibition of FAS can be achieved without parallel stimulation of fatty acid oxidation and that inhibition of tumor growth in vivo can be achieved without anorexia and weight loss. Thus, this therapeutic strategy holds promise for clinical treatment of cancers, including non–small cell lung cancer, the leading cause of cancer mortality in the United States and Europe.
Negative Effect of DNA Hypermethylation on the Outcome of Intensive Chemotherapy in Older Patients with High-Risk Myelodysplastic Syndromes and Acute Myeloid Leukemia following Myelodysplastic Syndrome
Authors: Grövdal Michael , Khan Rasheed , Aggerholm Anni , Antunovic Petar , Astermark Jan , Bernell Per , Engström Lena-Maria , Kjeldsen Lars , Linder Olle , Nilsson Lars , Olsson Anna , Wallvik Jonas , Tangen Jon Magnus , Öberg Gunnar , Jacobsen Sten Eirik , Hokland Peter , Porwit Anna , Hellström-Lindberg Eva
Published: December 2007

Purpose: Promoter hypermethylation of, for example, tumor-suppressor genes, is considered to be an important step in cancerogenesis and a negative risk factor for survival in patients with myelodysplastic syndromes (MDS); however, its role for response to therapy has not been determined. This study was designed to assess the effect of methylation status on the outcome of conventional induction chemotherapy.

Experimental Design: Sixty patients with high-risk MDS or acute myeloid leukemia following MDS were treated with standard doses of daunorubicin and 1-β-d-arabinofuranosylcytosine. Standard prognostic variables and methylation status of the P15ink4b (P15), E-cadherin (CDH), and hypermethylated in cancer 1 (HIC) genes were analyzed before treatment.

Results: Forty percent of the patients achieved complete remission (CR). CR rate was lower in patients with high WBC counts (P = 0.03) and high CD34 expression on bone marrow cells (P = 0.02). Whereas P15 status alone was not significantly associated with CR rate (P = 0.25), no patient with hypermethylation of all three genes achieved CR (P = 0.03). Moreover, patients with CDH methylation showed a significantly lower CR rate (P = 0.008), and CDH methylation retained its prognostic value also in the multivariate analysis. Hypermethylation was associated with increased CD34 expression, but not with other known predictive factors for response, such as cytogenetic profile.

Conclusions: We show for the first time a significant effect of methylation status on the outcome of conventional chemotherapy in high-risk MDS and acute myelogenous leukemia following MDS. Provided confirmed in an independent study, our results should be used as a basis for therapeutic decision-making in this patient group.
Stem Cell Marker Nestin and c-Jun NH2-Terminal Kinases in Tumor and Peritumor Areas of Glioblastoma Multiforme: Possible Prognostic Implications
Authors: Mangiola Annunziato , Lama Gina , Giannitelli Cecilia , De Bonis Pasquale , Anile Carmelo , Lauriola Libero , La Torre Giuseppe , Sabatino Giovanni , Maira Giulio , Jhanwar-Uniyal Meena , Sica Gigliola
Published: December 2007

Purpose: It has been hypothesized that brain tumors are derived from stem cell or transiently dividing precursor transformation. Furthermore, c-Jun NH2-terminal kinases (JNKs) have been involved in gliomagenesis. This study analyzes stem cell marker nestin and JNK expression in glioblastoma multiforme (GBM) and peritumor tissue and assesses their possible prognostic implications.

Experimental Design: Nestin and both total JNK (tJNK) and phosphorylated JNK (pJNK) expression was investigated by immunohistochemistry in 20 GBMs. Samples were derived from tumors (first area), from tissues at a distance <1 cm (second area), and between 1 and 3.5 cm (third area) from the macroscopic tumor border. The relationships between patients' age, Karnofsky performance status, gender, protein expression, and survival were analyzed.

Results: Nestin cytoplasmic immunoreactivity was observed in the majority of cells in tumor but infrequently in peritumor areas. tJNK, observed in the nucleus and cytoplasm, was widely expressed in the three areas; pJNK, mostly located in the nuclei, was found in a variable percentage of cells in the tumor and peritumor tissue. Nestin and JNK expression in peritumor areas was independent of the presence of neoplastic cells. Univariate analysis indicated that survival was longer (19 versus 12 months; P = 0.01) for patients whose pJNK/nestin and (pJNK/tJNK)/nestin ratios in the second area were ≥2.619 and ≥0.026, respectively. The same variables showed an independent prognostic value in multivariate analysis.

Conclusions: Nestin and JNK expression indicates that peritumor tissue, independently of the presence of neoplastic cells, may present signs of transformation. Moreover, pJNK/nestin and (pJNK/tJNK)/nestin ratios in that tissue seem to have some prognostic implications in GBM patients.
Interleukin-21 Signaling: Functions in Cancer and Autoimmunity
Authors: Davis Ian D. , Skak Kresten , Smyth Mark J. , Kristjansen Paul E.G. , Miller Dennis M. , Sivakumar Pallavur V.
Published: December 2007

Interleukin-21 (IL-21) is a cytokine with structural and sequence homology to IL-2 and IL-15, yet possesses several biological properties distinct from these cytokines. IL-21 is produced mainly by activated CD4+ T cells and natural killer T cells and mediates its activity by binding to the IL-21 receptor (IL-21R), consisting of an IL-21–specific α chain (IL-21Rα; JAK/STAT) that heterodimerizes with the common γ chain (CD132). Intracellular signaling occurs through the Janus-activated kinase/signal transducer and activator of transcription pathways. Physiologic expression of IL-21R is restricted to lymphoid tissues and peripheral blood mononuclear cells; however, other tissues such as epithelium, synovium, or transformed cells can acquire expression of both components of IL-21R heterodimer. IL-21 has complex activities on a wide variety of cell types, leading to enhancement of adaptive T-cell immunity, antibody production, activation of natural killer cell subtypes, and opposition to suppressive effects mediated by regulatory T cells. Functionally, these activities promote immune responses and point to a physiologic role of IL-21 in autoimmunity and immune enhancement. Therapeutic manipulation of IL-21 activity may allow improved immunotherapy for cancer as well as insights into autoimmune disease. Recently conducted phase 1 trials in metastatic melanoma and renal cell carcinoma have shown that recombinant IL-21 has a favorable safety profile and support its continued investigation as a potential anticancer drug.
Pilot Study of Neoadjuvant Treatment with Erlotinib in Nonmetastatic Head and Neck Squamous Cell Carcinoma
Authors: Thomas Fabienne , Rochaix Philippe , Benlyazid Adil , Sarini Jérôme , Rives Michel , Lefebvre Jean Louis , Allal Ben C. , Courbon Frédéric , Chatelut Etienne , Delord Jean-Pierre
Published: December 2007

Purpose: To determine the safety and efficacy of erlotinib given as neoadjuvant treatment in patients with head and neck squamous cell carcinoma (HNSCC). Further objectives were to identify markers of response to erlotinib and to assess the pharmacodynamic effects of erlotinib in tumor cells.

Experimental Design: Patients with locally advanced nonmetastatic HNSCC were treated with erlotinib 150 mg daily pending surgical management. Tumor samples were collected before and after erlotinib treatment and were analyzed using immunohistochemistry. Epidermal growth factor receptor copy number was determined in tumors using CISH analysis.

Results: Between November 2003 and December 2005, 35 patients were included in the study. Neoadjuvant treatment with erlotinib in HNSCC patients was well tolerated and did not necessitate modification to routine surgical procedures. Among 31 evaluable patients, erlotinib was given for a median of 20 days. At the time of surgery, tumor shrinkage was observed in nine patients (29%). Immunohistochemistry analyses were done for 31 patients and showed a decrease in phosphorylated tyrosine residues and phosphorylated erk immunostaining after erlotinib treatment. In a retrospective analysis, baseline p21waf expression in the basal-like cell layer was statistically positively correlated with clinical response to treatment. Epidermal growth factor receptor copy number did not correlate with response to erlotinib.

Conclusion: Neoadjuvant treatment of HNSCC with erlotinib was well tolerated. Baseline p21waf expression was associated with response to erlotinib and so might be useful as a tool to select patients for erlotinib therapy in this setting.
Novel Markers of Subclinical Disease for Ewing Family Tumors from Gene Expression Profiling
Authors: Cheung Irene Y. , Feng Yi , Danis Karen , Shukla Neerav , Meyers Paul , Ladanyi Marc , Cheung Nai-Kong V.
Published: December 2007

Purpose: Targeting subclinical disease in the bone marrow is particularly relevant in metastatic Ewing family tumors (EFT) where cure is difficult. Genome-wide expression arrays can uncover novel genes differentially expressed in tumors over normal marrow/blood, which may have potentials as markers of subclinical disease.

Experimental Design: Gene expression array data were obtained on 28 EFT tumors using the Affymetrix U133 gene chip and compared with 10 normal blood samples. Ten genes with high tumor to blood ratios were identified. Quantitative reverse transcription-PCR was done to study (a) the dynamic range of detection of rare tumor cells, (b) the gene expression in normal blood/marrow samples, (c) the gene expression among EFT tumors, and (d) the detection and prognostic impact of marker positivity in histology-negative diagnostic marrows of EFT patients.

Results: Five of 10 genes (i.e., six-transmembrane epithelial antigen of the prostate 1 [STEAP1], cyclin D1 [CCND1], NKX2-2 transcription factor [NKX2-2], plakophilin 1 [PKP1], and transmembrane protein 47 [TMEM47]) were chosen for further analyses based on their steep linear dynamic range in detecting tumor cells seeded in normal mononuclear cells and on their homogeneous expression among EFT tumors. Prognostic effect was evaluated in 35 histology-negative diagnostic marrows. Marker negativity of STEAP1, CCND1, or NKX2-2, as well as three markers in combination, was strongly correlated with patient survival as well as survival without new metastases.

Conclusions: This gene expression array-based approach identified novel markers that may be informative at diagnosis for risk group assessment. Their clinical utility needs to be tested in large patient cohorts.
Gain of 1q Is a Potential Univariate Negative Prognostic Marker for Survival in Medulloblastoma
Authors: Lo Ken C. , Ma Changxing , Bundy Brian N. , Pomeroy Scott L. , Eberhart Charles G. , Cowell John K.
Published: December 2007

Purpose: Tumor risk stratification during diagnosis is paramount for children with medulloblastomas, primarily because very young patients (<3 years) suffer cognitive deficits from radio- and chemotherapy sequelae. Thus, distinguishing tumors that are biologically more aggressive is essential for medulloblastoma management to maximize the delay in radiation treatment without adversely affecting survival outcome. In this context, current strategies for risk assessment, which are based on clinical parameters, remain unsatisfactory.

Experimental Design: Array-based comparative genomic hybridization (aCGH) was used to identify chromosomal copy number abnormalities in a cohort of 49 medulloblastoma tumors. Based on the karyotypes generated from aCGH analysis, each tumor was scored for copy number abnormalities, and the log-rank test was used to evaluate whether any cytogenetic events were associated with survival.

Results: A single copy gain of 1q was shown to be a negative prognostic marker for survival in medulloblastomas with high statistical significance (P < 0.0001, log-rank test).

Conclusion: A gain of 1q provides a potential means of predicting overall survival in medulloblastoma.
Prognostic Role of HuR in Hereditary Breast Cancer
Authors: Heinonen Mira , Fagerholm Rainer , Aaltonen Kirsimari , Kilpivaara Outi , Aittomäki Kristiina , Blomqvist Carl , Heikkilä Päivi , Haglund Caj , Nevanlinna Heli , Ristimäki Ari
Published: December 2007

Purpose: HuR is an mRNA-binding protein that enhances the stability of certain transcripts and can regulate their translation. Elevated cytoplasmic expression of HuR protein has been linked to carcinogenesis and is associated with reduced survival in breast, ovarian, and gastric adenocarcinomas.

Experimental Design: Here, we have explored the relevance of HuR in familial breast cancer. Tumor samples were collected from patients with identified BRCA1 (n = 51) or BRCA2 (n = 47) mutations or familial non-BRCA1/2 cases (n = 525), and analyzed by immunohistochemistry.

Results: Among familial non-BRCA1/2 breast cancer patients, cytoplasmic HuR protein expression was present in 39.4% of the cases and was associated with estrogen receptor negativity, progesterone receptor negativity, p53 positivity, high tumor grade, and ductal type of the tumor. In multivariate analysis, cytoplasmic HuR expression was an independent marker of reduced survival in the non-BRCA1/2 group along with tumor size >2 cm, lymph node metastasis, and high histologic grade. In patients with BRCA1 or BRCA2 mutations, cytoplasmic HuR expression was more frequent (62.7% for BRCA1 and 61.7% for BRCA2) than in the non-BRCA1/2 group, but in BRCA-mutated subgroups cytoplasmic HuR expression did not associate with survival.

Conclusions: Our results show that HuR is an important prognostic factor in familial breast cancer patients and may contribute to carcinogenesis in this disease.
Notch-1 Mutations Are Secondary Events in Some Patients with T-Cell Acute Lymphoblastic Leukemia
Authors: Mansour Marc R. , Duke Veronique , Foroni Letizia , Patel Bella , Allen Christopher G. , Ancliff Phil J. , Gale Rosemary E. , Linch David C.
Published: December 2007

Purpose: Activating Notch-1 mutations are frequent in T-cell acute lymphoblastic leukemia (T-ALL), occurring in >50% of patients. In murine models of T-ALL, Notch-1 activation can both directly initiate leukemia and cooperate secondarily to other primary events. Whether acquisition of Notch-1 mutations is an early initiating event or a secondary event in the pathogenesis of human T-ALL is unclear.

Experimental Design: We used denaturing high-performance liquid chromatography, sequencing, and fragment analysis to analyze Notch-1 mutational status and mutant level in 62 patients at presentation as well as 16 matched presentation-relapse samples.

Results: We detected Notch-1 mutations in 47 patients (76%). Seven of these were low-level mutations (quantified at ≤10%), despite high blast counts, suggesting that they were acquired as a secondary event in a subclone. Of 16 matched presentation-relapse samples studied, 7 were wild-type at both presentation and relapse. Five of nine mutant-positive patients at presentation relapsed with the same mutation(s) at the same high level. Four patients had evidence of a change in mutant at relapse. One lost a PEST mutation and became wild-type. Two others lost mutations at relapse but acquired different mutations, despite unchanged T-cell receptor rearrangements, suggesting that the latter event predated the acquisition of the Notch-1 mutation. One relapsed with a secondary T-cell leukemia and different Notch mutation.

Conclusions: These results suggest that Notch-1 mutations can sometimes be acquired as secondary events in leukemogenesis and must be used cautiously as solitary minimal residual disease markers.
Sequential Influences of Leukemia-Specific and Genetic Factors on P-Glycoprotein Expression in Blasts from 817 Patients Entered into the National Cancer Research Network Acute Myeloid Leukemia 14 and 15 Trials
Authors: Seedhouse Claire H. , Grundy Martin , White Paul , Li Yun , Fisher Janet , Yakunina Darya , Moorman Anthony V. , Hoy Terence , Russell Nigel , Burnett Alan , Pallis Monica
Published: December 2007

Purpose: P-glycoprotein (Pgp) is a major prognostic factor for chemotherapy failure in acute myeloid leukemia (AML). This study compared the influence of genetic and leukemia-specific factors on Pgp.

Experimental Design: Eight hundred and seventeen samples were studied prospectively for Pgp protein expression and function and G1199A, G2677T, and C3435T polymorphisms in the encoding gene ABCB1.

Results: Age, low WBC count, high bcl-2, secondary AML and myelodysplastic syndrome, and adverse cytogenetics all correlated strongly with high Pgp (MRK16) protein expression. However, ABCB1 3435TT homozygosity was negatively correlated with Pgp. Pgp protein is only expressed in 41% of samples such that the negative effect of the polymorphism was not seen at baseline Pgp levels but was marked in the upper 41% of samples (MRK16 Δmean fluorescence intensity of 75th centile sample = 9 units for TT variant samples and 26 units for CC/CT; P = 0.003). However, no association was found between genetic factors and Pgp function using rhodamine 123 accumulation.

Conclusions: The genetic polymorphism 3435TT (which results in unstable mRNA) has a significant effect on Pgp expression, but this is only seen in ∼40% of cases in which mRNA and protein are detectable. Moreover, leukemia-specific factors, such as low WBC count and poor risk cytogenetics, have a much greater effect than genetic polymorphisms on Pgp expression in AML blasts.