bluuebunny/crossref_metadata_2025 huggingface dataset:
Epithelial-Mesenchymal Transition Events during Human Embryonic Stem Cell Differentiation
Authors: Eastham Angela M. , Spencer Helen , Soncin Francesca , Ritson Sarah , Merry Catherine L.R. , Stern Peter L. , Ward Christopher M.
Published: December 2007

Epithelial-mesenchymal transition (EMT) occurs during embryonic development and may also be associated with the metastatic spread of epithelial tumors. During EMT, E-cadherin is down-regulated and this correlates with increased motility and invasion of cells. We show that differentiation of human embryonic stem (ES) cells in monolayer culture is associated with an E- to N-cadherin switch, increased vimentin expression, up-regulation of E-cadherin repressor molecules (Snail and Slug proteins), and increased gelatinase (matrix metalloproteinases; MMP-2 and MMP-9) activity and cellular motility, all characteristic EMT events. The 5T4 oncofetal antigen, previously shown to be associated with early human ES cell differentiation, is also part of this process. Abrogation of E-cadherin–mediated cell-cell contact in undifferentiated ES cells using neutralizing antibody (nAb) SHE78.7 resulted in increased cellular motility, altered actin cytoskeleton arrangement and a mesenchymal phenotype together with presentation of the 5T4 antigen at the cell surface. nAb-treated ES cells remained in an undifferentiated state, as assessed by OCT-4 protein expression, and did not express EMT-associated transcripts. Removal of nAb from ES cells resulted in the restoration of cell-cell contact, absence of cell surface 5T4, decreased mesenchymal cellular morphology and motility, and enabled the differentiation of the cells to the three germ layers upon their removal from the fibroblast feeder layer. We conclude that E-cadherin functions in human ES cells to stabilize the cortical actin cyoskeletal arrangement and this prevents cell surface localization of the 5T4 antigen. Furthermore, human ES cells represent a useful model system with which to study EMT events relevant to embryonic development and tumor cell metastasis. [Cancer Res 2007;67(23):11254–62]
Differential Regulation of Elafin in Normal and Tumor-Derived Mammary Epithelial Cells Is Mediated by CCAAT/Enhancer Binding Protein β
Authors: Yokota Tomoya , Bui Tuyen , Liu Yanna , Yi Min , Hunt Kelly K. , Keyomarsi Khandan
Published: December 2007

CCAAT/enhancer binding protein β (C/EBPβ) is a transcription factor implicated in the control of development, differentiation, and proliferation of mammary epithelial cells. However, it remains unclear how C/EBPβ is involved in tumor suppression through its interaction with specific downstream genes in breast cancer. Tumor cells overexpress serine proteases, which play crucial roles in tumor invasion and metastasis. Elafin is an endogenous serine protease inhibitor and is transcriptionally down-regulated in most tumor cell lines. In this study, we show that C/EBPβ is differentially expressed in normal versus tumor cell lines and normal adjacent versus tumor tissues obtained from breast cancer patients. We identified elafin as a downstream effector of C/EBPβ and show that elafin is also differentially regulated between normal and tumor cells. The mechanism by which C/EBPβ regulates elafin expression is through its direct interaction with the elafin promoter. There are three C/EBPβ binding sites involved in the elafin promoter activity, and the overexpression of C/EBPβ transactivates the elafin gene through these sites in tumor cells. RNA interference studies in normal cells further evidenced the requirement of the C/EBPβ for the elafin expression and negative feedback loop between C/EBPβ and elafin. We suggest that elafin is a novel substrate of C/EBPβ, and alterations in C/EBPβ isoforms result in their differential binding to the elafin promoter, leading to the altered expression of the elafin between normal and tumor cells. [Cancer Res 2007;67(23):11272–83]
Aurora-A Kinase Regulates Breast Cancer–Associated Gene 1 Inhibition of Centrosome-Dependent Microtubule Nucleation
Authors: Sankaran Satish , Crone Donna E. , Palazzo Robert E. , Parvin Jeffrey D.
Published: December 2007

Breast cancer–associated gene 1 (BRCA1) regulates the duplication and the function of centrosomes in breast cells. We have previously shown that BRCA1 ubiquitin ligase activity directly inhibits centrosome-dependent microtubule nucleation. However, there is a paradox because centrosome microtubule nucleation potential is highest during mitosis, a phase when BRCA1 is most abundant at the centrosome. In this study, we resolve this conundrum by testing whether centrosomes from cells in M phase are regulated differently by BRCA1 when compared with other phases of the cell cycle. We observed that BRCA1-dependent inhibition of centrosome microtubule nucleation was high in S phase but was significantly lower during M phase. The cell cycle–specific effects of BRCA1 on centrosome-dependent microtubule nucleation were detected in living cells and in cell-free experiments using centrosomes purified from cells at specific stages of the cell cycle. We show that Aurora-A kinase modulates the BRCA1 inhibition of centrosome function by decreasing the E3 ubiquitin ligase activity of BRCA1. In addition, dephosphorylation of BRCA1 by protein phosphatase 1α enhances the E3 ubiquitin ligase activity of BRCA1. These observations reveal that the inhibition of centrosome microtubule nucleation potential by the BRCA1 E3 ubiquitin ligase is controlled by Aurora-A kinase and protein phosphatase 1α–mediated phosphoregulation through the different phases of the cell cycle. [Cancer Res 2007;67(23):11186–94]
Differing Phenotypes between Intraepithelial and Stromal Lymphocytes in Early-Stage Tongue Cancer
Authors: Katou Fuminori , Ohtani Haruo , Watanabe Yoshiko , Nakayama Takashi , Yoshie Osamu , Hashimoto Kenji
Published: December 2007

The significance of tumor-infiltrating lymphocytes (TIL) has attracted much attention in relation to the prognosis of patients. We herein examined the activation status of the TILs in relation to the tumor microenvironment. By using frozen sections of human early-stage tongue cancers (n = 22), the TILs in the cancer nests and those in the cancer stroma were compared for the expression of PD-1, NKG2A, NKG2D, CD69, and Ki-67. The lymphocytes in oral lichen planus, an active immune response-mediated mucosal disease, were also analyzed for comparison purposes. All of the cancer specimens were abundantly infiltrated by CD8+ T cells and CD56+ natural killer (NK) cells in the stroma, as well as in the tumor nest. The tumor nest–infiltrating (intraepithelial) CD8+ T cells frequently expressed PD-1, an inhibitory receptor, in sharp contrast to those in the stroma or in the lichen planus. Conversely, the intraepithelial CD8+ T cells only infrequently expressed NKG2D, an activating receptor, in contrast to those in the stroma or in the lichen planus. No intraepithelial CD8+ T cells expressed Ki-67, a proliferation-associated marker, whereas those in the stroma frequently expressed it. Furthermore, the intraepithelial NK cells expressed NKG2A, an inhibitory receptor, more frequently than those in the stroma or the lichen planus. Collectively, the intraepithelial CD8+ T cells and NK cells are phenotypically inactivated, whereas stromal counterparts are phenotypically just as active as those in the lichen planus. These results suggest the first-step occurrence of an immune evasion mechanism in the tumor nest of oral squamous cell carcinoma. [Cancer Res 2007;67(23):11195–201]
Genetic Alterations in the Tyrosine Kinase Transcriptome of Human Cancer Cell Lines
Authors: Ruhe Jens E. , Streit Sylvia , Hart Stefan , Wong Chee-Hong , Specht Katja , Knyazev Pjotr , Knyazeva Tatjana , Tay Liang Seah , Loo Hooi Linn , Foo Priscilla , Wong Winnie , Pok Sharon , Lim Shu Jing , Ong Huimin , Luo Ming , Ho Han Kiat , Peng Kaitian , Lee Tze Chuen , Bezler Martin , Mann Christian , Gaertner Silvia , Hoefler Heinz , Iacobelli Stefano , Peter Stephan , Tay Alice , Brenner Sydney , Venkatesh Byrappa , Ullrich Axel
Published: December 2007

Protein tyrosine kinases (PTKs) play a critical role in the manifestation of cancer cell properties, and respective signaling mechanisms have been studied extensively on immortalized tumor cells. To characterize and analyze commonly used cancer cell lines with regard to variations in the primary structure of all expressed PTKs, we conducted a cDNA-based sequence analysis of the entire tyrosine kinase transcriptome of 254 established tumor cell lines. The profiles of cell line intrinsic PTK transcript alterations and the evaluation of 155 identified polymorphisms and 234 somatic mutations are made available in a database designated “Tykiva” (tyrosine kinome variant). Tissue distribution analysis and/or the localization within defined protein domains indicate functional relevance of several genetic alterations. The cysteine replacement of the highly conserved Y367 residue in fibroblast growth factor receptor 4 or the Q26X nonsense mutation in the tumor-suppressor kinase CSK are examples, and may contribute to cell line–specific signaling characteristics and tumor progression. Moreover, known variants, such as epidermal growth factor receptor G719S, that were shown to mediate anticancer drug sensitivity could be detected in other than the previously reported tumor types. Our data therefore provide extensive system information for the design and interpretation of cell line–based cancer research, and may stimulate further investigations into broader clinical applications of current cancer therapeutics. [Cancer Res 2007;67(23):11368–76]
Choline Kinase Down-regulation Increases the Effect of 5-Fluorouracil in Breast Cancer Cells
Authors: Mori Noriko , Glunde Kristine , Takagi Tomoyo , Raman Venu , Bhujwalla Zaver M.
Published: December 2007

Identifying strategies to increase cancer cell kill while sparing normal tissue is critically important in cancer chemotherapy. Choline kinase (Chk), the enzyme that converts choline to phosphocholine (PC), is elevated in cancer cells and presents a novel target for increasing cell kill. Here, we have examined the effects of transiently down-regulating Chk by small interfering RNA against Chk (siRNA-chk) on PC and total choline-containing compound (tCho) levels and on the viability/proliferation of estrogen receptor–negative and estrogen receptor–positive breast cancer cell lines and a nonmalignant mammary epithelial cell line. We investigated the effects of combination treatment with transient siRNA-chk transfection and the anticancer drug 5-fluorouracil (5-FU) in those cell lines. Microarray analysis of the invasive estrogen receptor–negative MDA-MB-231 cell line was done to characterize molecular changes associated with Chk down-regulation. Chk down-regulation decreased PC and tCho levels in the malignant cell lines, whereas the cell viability/proliferation assays detected a decrease in proliferation in these cells. In contrast, Chk down-regulation had an almost negligible effect on PC and tCho levels as well as cell viability/proliferation in the nonmalignant cell line. A combination of siRNA-chk with 5-FU treatment resulted in a larger reduction of cell viability/proliferation in the breast cancer cell lines; this reduction was evident to a much lesser degree in the nonmalignant cells. Microarray analysis showed that Chk down-regulation affected 33 proliferation-related genes and 9 DNA repair–related genes. Chk down-regulation with siRNA-chk may provide a novel alternative to enhance the effect of anticancer drugs in malignant cells. [Cancer Res 2007;67(23):11284–90]
Down-regulation of Platelet-Derived Growth Factor-D Inhibits Cell Growth and Angiogenesis through Inactivation of Notch-1 and Nuclear Factor-κB Signaling
Authors: Wang Zhiwei , Kong Dejuan , Banerjee Sanjeev , Li Yiwei , Adsay N. Volkan , Abbruzzese James , Sarkar Fazlul H.
Published: December 2007

Platelet-derived growth factor-D (PDGF-D) signaling plays critical roles in the pathogenesis and progression of human malignancies; however, the precise mechanism by which PDGF-D causes tumor cell invasion and angiogenesis remain unclear. Because Notch-1, nuclear factor-κB (NF-κB), vascular endothelial growth factor (VEGF), and matrix metalloproteinases (MMP) are critically involved in the processes of tumor cell invasion and metastasis, we investigated whether PDGF-D down-regulation could be mechanistically associated with the down-regulation of Notch-1, NF-κB, VEGF, and MMP-9, resulting in the inhibition of tumor cell invasion and angiogenesis. Our data showed that down-regulation of PDGF-D leads to the inactivation of Notch-1 and NF-κB DNA-binding activity and, in turn, down regulates the expression of its target genes, such as VEGF and MMP-9. We also found that the down-regulation of PDGF-D by small interfering RNA (siRNA) decreased tumor cell invasion, whereas PDGF-D overexpression by cDNA transfection led to increased cell invasion. Consistent with these results, we also found that the down-regulation of PDGF-D not only decreased MMP-9 mRNA and its protein expression but also inhibited the processing of pro-MMP-9 protein to its active form. Moreover, conditioned medium from PDGF-D siRNA–transfected cells showed reduced levels of VEGF and, in turn, inhibited the tube formation of human umbilical vascular endothelial cells, suggesting that down-regulation of PDGF-D leads to the inhibition of angiogenesis. Taken together, we conclude that the down-regulation of PDGF-D by novel approaches could lead to the down-regulation of Notch-1 and, in turn, inactivate NF-κB and its target genes (i.e., MMP-9 and VEGF), resulting in the inhibition of invasion and angiogenesis. [Cancer Res 2007;67(23):11377–85]
The Cooked Meat Carcinogen 2-Amino-1-Methyl-6-Phenylimidazo[4,5-b]Pyridine Activates the Extracellular Signal–Regulated Kinase Mitogen-Activated Protein Kinase Pathway
Authors: Creton Stuart K. , Zhu Huijun , Gooderham Nigel J.
Published: December 2007

During the cooking of meat, mutagenic and carcinogenic heterocyclic amines are formed, the most abundant of which, 2-amino-1-methyl-6-phenylimidazo[4-5-b]pyridine (PhIP), induces tumors of the prostate, colon, and mammary gland in rats. Humans consuming cooked meat are exposed to PhIP on a daily basis, yet few studies have assessed the effects of PhIP at dietary relevant concentrations. In addition to its genotoxic properties, recent studies have shown that PhIP can activate estrogen receptor–mediated signaling pathways at doses that are similar to those that may be present in the body following consumption of a cooked meat meal. In the present study, we examined whether such doses of PhIP can affect estrogen receptor–independent signal transduction via the mitogen-activated protein kinase (MAPK) extracellular signal–related kinase (ERK) pathway to influence proliferation and migration in the human mammary epithelial cell line MCF10A and the prostate cancer cell line PC-3. At doses shown to have a proliferative effect on MCF10A cells (10−11–10−7 mol/L), PhIP induced a rapid, transient increase in phosphorylation of both MAPK/ERK kinase 1/2 and ERKs. Inhibition of this pathway significantly reduced the PhIP-induced proliferation of MCF10A cells and the migration of PC-3 cells. The data presented here show that levels of PhIP that approximate to human dietary exposure stimulate cellular signaling pathways and result in increased growth and migration, processes linked to the promotion and progression of neoplastic disease. These findings provide strong evidence that PhIP acts as a tumor initiator and promoter and that dietary exposure to this compound could contribute to carcinogenesis in humans. [Cancer Res 2007;67(23):11455–61]
3′-Deoxy-3′-[18F]Fluorothymidine Positron Emission Tomography Is a Sensitive Method for Imaging the Response of BRAF-Dependent Tumors to MEK Inhibition
Authors: Solit David B. , Santos Elmer , Pratilas Christine A. , Lobo Jose , Moroz Maxim , Cai Shangde , Blasberg Ronald , Sebolt-Leopold Judith , Larson Steven , Rosen Neal
Published: December 2007

Activating mutations of BRAF occur in ∼7% of all human tumors and in the majority of melanomas. These tumors are very sensitive to pharmacologic inhibition of mitogen-activated protein kinase/extracellular signal-regulated kinase kinase (MEK), which causes loss of D-cyclin expression, hypophosphorylation of Rb, and G1 arrest. Growth arrest is followed by differentiation or senescence and, in a subset of BRAF mutant tumors, by apoptosis. The former effects result in so-called “stable disease” and, in patients with cancer, can be difficult to distinguish from indolent tumor growth. The profound G1 arrest induced by MEK inhibition in BRAF mutant tumors is associated with a marked decline in thymidine uptake and is therefore potentially detectable in vivo by noninvasive 3′-deoxy-3′-[18F]fluorothymidine ([18F]FLT) positron emission tomography (PET) imaging. In SKMEL-28 tumor xenografts, MEK inhibition completely inhibited tumor growth and induced differentiation with only modest tumor regression. MEK inhibition also resulted in a rapid decline in the [18F]FLT signal in V600E BRAF mutant SKMEL-28 xenografts but not in BRAF wild-type BT-474 xenografts. The data suggest that [18F]FLT PET can effectively image induction of G1 arrest by MEK inhibitors in mutant BRAF tumors and may be a useful noninvasive method for assessing the early biological response to this class of drugs. [Cancer Res 2007;67(23):11463–9]
Plasma Cysteinylglycine Levels and Breast Cancer Risk in Women
Authors: Lin Jennifer , Manson JoAnn E. , Selhub Jacob , Buring Julie E. , Zhang Shumin M.
Published: December 2007

Cysteinylglycine, a prooxidant generated during the catabolism of glutathione, has been suggested to induce oxidative stress and lipid peroxidation, leading to the development of human cancers. Observational data relating cysteinylglycine status to breast cancer risk are lacking. We prospectively evaluated plasma cysteinylglycine levels and invasive breast cancer risk among 812 case-control pairs nested in the Women's Health Study, a completed randomized trial evaluating low-dose aspirin and vitamin E in middle-aged and older women. We additionally evaluated the effect modification by risk factors for oxidative stress, such as vitamin E assignment, alcohol consumption, obesity, and postmenopausal hormone use. Logistic regression controlling for matching factors, as well as other risk factors for breast cancer, was used to estimate relative risks (RR) and 95% confidence intervals (95% CI). All statistical tests were two sided. We observed no overall association between plasma cysteinylglycine and invasive breast cancer risk. However, higher cysteinylglycine levels were marginally associated with an increased risk of breast cancer in the high oxidative stress groups. Women in the highest quintile group of cysteinylglycine relative to the lowest group had multivariate RRs (95% CIs) of 1.64 (1.01–2.66; Ptrend = 0.04) in the vitamin E placebo group, 2.51 (1.01–6.24; Ptrend = 0.07) in the high alcohol intake group (≥9 g/day), and 1.66 (0.97–2.84; Ptrend = 0.03) in the overweight and obese group. Our findings suggest that women who are susceptible to experiencing oxidative stress may be at a greater risk for developing breast cancer. [Cancer Res 2007;67(23):11123–7]
Automated, Quantitative Screening Assay for Antiangiogenic Compounds Using Transgenic Zebrafish
Authors: Tran T. Cameron , Sneed Blossom , Haider Jamil , Blavo Delali , White Audrey , Aiyejorun Temitope , Baranowski Timothy C. , Rubinstein Amy L. , Doan Thanh N. , Dingledine Raymond , Sandberg Eric M.
Published: December 2007

Pathologic angiogenesis has emerged as an important therapeutic target in several major diseases. Zebrafish offer the potential for high-throughput drug discovery in a whole vertebrate system. We developed the first quantitative, automated assay for antiangiogenic compound identification using zebrafish embryos. This assay uses transgenic zebrafish with fluorescent blood vessels to facilitate image analysis. We developed methods for automated drugging and imaging of zebrafish in 384-well plates and developed a custom algorithm to quantify the number of angiogenic blood vessels in zebrafish. The assay was used to screen the LOPAC1280 compound library for antiangiogenic compounds. Two known antiangiogenic compounds, SU4312 and AG1478, were identified as hits. Additionally, one compound with no previously known antiangiogenic activity, indirubin-3′-monoxime (IRO), was identified. We showed that each of the hit compounds had dose-dependent antiangiogenic activity in zebrafish. The IC50 of SU4312, AG1478, and IRO in the zebrafish angiogenesis assay was 1.8, 8.5, and 0.31 μmol/L, respectively. IRO had the highest potency of the hit compounds. Moreover, IRO inhibited human umbilical vein endothelial cell tube formation and proliferation (IC50 of 6.5 and 0.36 μmol/L, respectively). It is therefore the first antiangiogenic compound discovered initially in a zebrafish assay that also has demonstrable activity in human endothelial cell-based angiogenesis assays. [Cancer Res 2007;67(23):11386–92]
Variants on 9p24 and 8q24 Are Associated with Risk of Colorectal Cancer: Results from the Colon Cancer Family Registry
Authors: Poynter Jenny N. , Figueiredo Jane C. , Conti David V. , Kennedy Kathleen , Gallinger Steven , Siegmund Kimberly D. , Casey Graham , Thibodeau Stephen N. , Jenkins Mark A. , Hopper John L. , Byrnes Graham B. , Baron John A. , Goode Ellen L. , Tiirikainen Maarit , Lindor Noralane , Grove John , Newcomb Polly , Jass Jeremy , Young Joanne , Potter John D. , Haile Robert W. , Duggan David J. , Le Marchand Loic ,   for the Colon CFR
Published: December 2007

Recent publications have reported that common variants on 8q24 are associated with both prostate and colorectal cancers (CRC). In addition, one of these studies (the ARCTIC study) initially observed an association with a single nucleotide polymorphism (SNP) on 9p24 that was not confirmed in some of their validation data sets. In the research described here, we conducted a case-unaffected sibling analysis using population- and clinic-based discordant sibships (N = 1,567 sibships) from the Colon Cancer Family Registry (Colon CFR) to investigate the associations between common variants at 9p24 and 8q24 and risk of CRC. We also evaluated whether these associations differed by age, family history, and tumor characteristics, including microsatellite instability and tumor site. Associations were estimated using conditional logistic regression, treating sibship as the matching factor. Analyses were adjusted for age and sex, and stratified by ascertainment source (population versus clinic). We observed an association between a SNP on 9p24 (rs719725) and risk of CRC in the population-based series (AA versus CC: odds ratios, 1.46; 95% confidence interval, 1.06–2.02; AC versus CC: odds ratios, 1.50; 95% confidence interval, 1.14–1.98; P = 0.011 on 2 df). In the population-based series, we also detected statistically significant associations between two SNPs on 8q24, rs10505477 and rs6983267, and risk of CRC (P = 0.005 and P = 0.002, respectively). There was no evidence of statistically significant heterogeneity by age at diagnosis, family history of CRC, microsatellite instability, or tumor site at either locus and no evidence of interaction between SNPs on 8q24 and 9p24. These data suggest that common variants may play important roles in the risk of CRC. [Cancer Res 2007;67(23):11128–32]
Benefit of Complete Response in Multiple Myeloma Limited to High-Risk Subgroup Identified by Gene Expression Profiling
Authors: Haessler Jeffrey , Shaughnessy John D. , Zhan Fenghuang , Crowley John , Epstein Joshua , van Rhee Frits , Anaissie Elias , Pineda-Roman Mauricio , Zangari Maurizio , Hollmig Klaus , Mohiuddin Abid , Alsayed Yazan , Hoering Antje , Tricot Guido , Barlogie Bart
Published: December 2007

Experimental Design: To determine whether the clinical benefit of complete remission (CR) may depend on prognostic subgroups of patients with multiple myeloma.

Patients and Methods: Newly diagnosed patients with myeloma received a tandem autotransplant regimen. Using multivariate regression analyses, we examined the prognostic implications of time-dependent onset of CR on overall survival and event-free survival in the context of standard prognostic factors (SPF) and gene expression profiling–derived data available for 326 patients.

Results: CR benefited patients regardless of risk status when only SPFs were examined. With knowledge of gene array data, a survival (and event-free survival) benefit of CR only pertained to the small high-risk subgroup of 13% of patients (hazard ratio, 0.23; P = 0.001), whereas the majority of patients with low-risk disease had similar survival expectations whether or not CR was achieved (hazard ratio, 0.68; P = 0.128).

Conclusions: Access to gene expression information permitted the recognition of a small very high-risk subgroup of 13% of patients, in whom prolonged survival critically depended on achieving CR. Absence of such benefit in the remainder should lead to a reassessment of clinical trial designs that rely on this end point as a surrogate for long-term prognosis.
GlutathioneS-Transferase T1 and M1: Gene Sequence Variation and Functional Genomics
Authors: Moyer Ann M. , Salavaggione Oreste E. , Hebbring Scott J. , Moon Irene , Hildebrandt Michelle A.T. , Eckloff Bruce W. , Schaid Daniel J. , Wieben Eric D. , Weinshilboum Richard M.
Published: December 2007

Purpose: The glutathione S-transferases (GSTs) catalyze the glutathione conjugation of reactive electrophiles, including carcinogens and many antineoplastic drugs. GSTT1 and GSTM1 are polymorphically deleted, but the full range of genetic variation in these two genes has not yet been explored. We set out to systematically identify common polymorphisms in GSTT1 and GSTM1, followed by functional genomic studies.

Experimental Design: First, multiplex PCR was used to determine GSTT1 and GSTM1 copy number in 400 DNA samples (100 each from 4 ethnic groups). Exons, splice junctions, and 5′-flanking regions (5′-FR) were then resequenced using DNA samples that contained at least one copy of GSTT1 or GSTM1.

Results: Gene deletion frequencies among ethnic groups were from 33.5% to 73.5% for GSTT1 and from 50.5% to 78.0% for GSTM1. GSTT1 deletion data correlated with the results of mRNA microarray expression studies. The 18 single nucleotide polymorphisms (SNP) observed in GSTT1 included three nonsynonymous coding SNPs (cSNPs) and one single-nucleotide deletion, whereas the 51 GSTM1 SNPs included two nonsynonymous cSNPs. Two of the GSTT1 nonsynonymous cSNPs resulted in decreases in levels of immunoreactive protein to 56% and 12% of wild type (WT), whereas those in GSTM1 resulted in modest increases in protein levels. Reporter gene assays showed that one GSTT1 5′-FR haplotype, with a frequency of 32% in African-American subjects, resulted in an increase in transcription in JEG-3 cells to 351% of that for the WT sequence, and one GSTM1 5′-FR haplotype resulted in an increase in transcription in JEG-3 cells to 129% of WT.

Conclusions: These observations suggest that functionally significant pharmacogenomic variation beyond GSTT1 and GSTM1 gene deletion may contribute to carcinogenesis or individual variation in antineoplastic drug therapy response.
Nutritional Modulation of Antitumor Efficacy and Diarrhea Toxicity Related to Irinotecan Chemotherapy in Rats Bearing the Ward Colon Tumor
Authors: Xue Hongyu , Sawyer Michael B. , Field Catherine J. , Dieleman Levinus A. , Baracos Vickie E.
Published: December 2007

Purpose: To evaluate and compare the influence of dietary elements on cancer progression, chemotherapy efficacy, and toxicity, particularly severe, late-onset diarrhea related to irinotecan (CPT-11) treatment.

Experimental Design: We used laboratory rats fed a standardized basal diet, Ward colon tumor, and CPT-11 therapy for the study of CPT-11–induced diarrhea. Dietary interventions were selected from nutrients already established to modify other forms of colitis and which have been hypothesized to mitigate chemotherapy-induced gastrointestinal injury (glutamine, n-3 fatty acids, prebiotic oligosaccharides). Animals adapted to test diets were treated with CPT-11 at the maximum tolerated dose (125 mg/kg × 3 days) and diarrhea was followed continuously for 1 week.

Results: The inclusion of n-3 fatty acids in the diet (5%, w/w of total fat) suppressed tumor growth and enhanced CPT-11's efficacy; this treatment did not affect the incidence or severity of diarrhea. By contrast, oral glutamine bolus (0.75 g/kg) administered prior to each CPT-11 treatment reduced the incidence of severe diarrhea (34.1 ± 4.7% versus 53.8 ± 4.2%, P < 0.005) and decreased the area under the curve of diarrhea score (16.5 ± 1.0 versus 18.8 ± 0.5, P < 0.05). Identical results were obtained with i.v. bolus glutamine administration. Glutamine treatment did not alter CPT-11's antitumor efficacy. The addition of prebiotic oligosaccharides to the diet (8%, w/w of diet) did not mitigate the severity of diarrhea, and it raised the activity of β-glucuronidase in cecal contents, a key bacterial enzyme mediating CPT-11–related intestinal toxicity.

Conclusion: Our experiments suggest that glutamine and n-3 fatty acids might be potentially useful adjuncts to CPT-11 treatment.
BCR-ABL Messenger RNA Levels Continue to Decline in Patients with Chronic Phase Chronic Myeloid Leukemia Treated with Imatinib for More Than 5 Years and Approximately Half of All First-Line Treated Patients Have Stable Undetectable BCR-ABL Using Strict Sensitivity Criteria
Authors: Branford Susan , Seymour John F. , Grigg Andrew , Arthur Chris , Rudzki Zbigniew , Lynch Kevin , Hughes Timothy
Published: December 2007

Purpose: In the first years of imatinib treatment, BCR-ABL remained detectable in all but a small minority of patients with chronic myeloid leukemia. We determined whether BCR-ABL continues to decline with longer imatinib exposure and the incidence and consequence of undetectable BCR-ABL.

Experimental Design: BCR-ABL levels were measured in a subset of 53 imatinib-treated IRIS trial patients for up to 7 years (29 first-line, 24 second-line). Levels were deemed undetectable using strict PCR sensitivity criteria.

Results: By 18 months, the majority achieved a 3-log reduction [major molecular response (MMR)]. BCR-ABL continued to decline but at a slower rate (median time to 4-log reduction and undetectable BCR-ABL of 45 and 66 months for first-line). The probability of undetectable BCR-ABL increased considerably from 36 to 81 months of first-line imatinib {7% [95% confidence interval (95% CI), 0-17%] versus 52% (95% CI, 32-72%)}. Undetectable BCR-ABL was achieved in 18 of 53 patients and none of these 18 lost MMR after a median follow-up of 33 months. Conversely, MMR was lost in 6 of 22 (27%) patients with sustained detectable BCR-ABL and was associated with BCR-ABL mutations in 3 of 6. Loss of MMR was recently defined as suboptimal imatinib response. There was no difference in the probability of achieving molecular responses between first- and second-line patients but first-line had a significantly higher probability of maintaining MMR [P = 0.03; 96% (95% CI, 88-100%) versus 71% (95% CI, 48-93%)].

Conclusions: With prolonged therapy, BCR-ABL continued to decline in most patients and undetectable BCR-ABL was no longer a rare event. Loss of MMR was only observed in patients with sustained detectable BCR-ABL.
Expression of Indoleamine 2,3-Dioxygenase in Tumor Endothelial Cells Correlates with Long-term Survival of Patients with Renal Cell Carcinoma
Authors: Riesenberg Rainer , Weiler Christoph , Spring Oliver , Eder Martin , Buchner Alexander , Popp Tanja , Castro Mirna , Kammerer Robert , Takikawa Osamu , Hatz Rudolf A. , Stief Christian G. , Hofstetter Alfons , Zimmermann Wolfgang
Published: December 2007

Purpose: The inflammatory enzyme indoleamine 2,3-dioxygenase (IDO) participates in immune tolerance and tumor immune escape processes by degradation of the essential amino acid tryptophan and formation of toxic catabolites. Here, we analyzed the role of IDO in tumor growth and disease progression in patients with clear cell renal cell carcinoma (RCC).

Experimental Design: Expression of IDO mRNA was analyzed by quantitative reverse transcription-PCR in 55 primary and 52 metastatic RCC, along with 32 normal kidneys. Western blot and immunohistochemistry analyses were used to semiquantitatively determine IDO proteins in a subset of tumor samples, in RCC cell lines, and microvessel endothelial cells. IDO expression was correlated with expression of the proliferation marker Ki67 in tumor cells and survival of patients with tumor.

Results: More than 75% of the clear cell RCC in comparison to normal kidney contained elevated levels of IDO mRNA, which correlated with their IDO protein content. Low IDO mRNA levels in primary tumors represented an unfavorable independent prognostic factor (hazard ratio, 3.8; P = 0.016). Unexpectedly, immunohistochemical analyses revealed that IDO is nearly exclusively expressed in endothelial cells of newly formed blood vessels and is virtually absent from tumor cells, although RCC cells could principally synthesize IDO as shown by in vitro stimulation with IFN-γ. A highly significant inverse correlation between the density of IDO-positive microvessels and the content of proliferating Ki67-positive tumor cells in primary and metastatic clear cell RCC was found (P = 0.004).

Conclusions: IDO in endothelial cells might limit the influx of tryptophan from the blood to the tumor or generate tumor-toxic metabolites, thus restricting tumor growth and contributing to survival.
Low-Dose 12-O-Tetradecanoylphorbol-13-Acetate Enhances Tumor Necrosis Factor–Related Apoptosis-Inducing Ligand–Induced Apoptosis in Prostate Cancer Cells
Authors: Zhang Xiaoping , Li Wenhua , Olumi Aria F.
Published: December 2007

Purpose: Previously, we have shown that c-Fos/activator protein-1 (AP-1) promotes tumor necrosis factor (TNF)–related apoptosis-inducing ligand (TRAIL)–induced apoptosis by repressing the antiapoptotic molecule c-FLIP(L). In this study, we investigated whether synthetic induction of c-Fos/AP-1 by 12-O-tetradecanoylphorbol-13-acetate (TPA) converts the phenotype of TRAIL-resistant prostate cancer cells to a TRAIL-sensitive phenotype in vitro and in vivo.

Experimental Design: Low-dose TPA was used to determine whether LNCaP prostate cancer cells could be converted to a TRAIL-sensitive phenotype in in vitro and in vivo studies. We also assessed whether TPA enhancement of TRAIL-induced apoptosis varies between androgen-sensitive and androgen-insensitive prostate cancer cells and evaluated the role of TRAIL receptors, DR4 and DR5, in TPA-enhanced TRAIL-induced apoptosis.

Results: We show that the combination of TRAIL with low-dose TPA has no effect on nonmalignant prostate epithelial cells; however, TPA up-regulates most AP-1 proteins and AP-1 activity, reduces c-FLIP(L), and potentiates TRAIL-induced apoptosis. We show that the combination of TPA + TRAIL is effective in promoting apoptosis in both hormone-sensitive LNCaP and hormone-insensitive LNCaP-C4-2 prostate cancer cells. Although TPA enhances the TRAIL-receptor 1 (DR4) level, sensitization of prostate cancer cells seems to be more dependent on TRAIL-receptor 2 (DR5) than TRAIL-receptor 1 levels. In vivo xenograft experiments suggest that TPA elevates the expression of c-Fos and reduces c-FLIP(L). Combination of TPA with TRAIL-receptor 2 agonist antibody, lexatumumab, effectively increases apoptosis and reduces LNCaP xenograft tumor burden.

Conclusions: TPA, when combined with the proapoptotic agent TRAIL, is effective in changing the phenotype of some TRAIL-resistant prostate cancer cells to a TRAIL-sensitive phenotype.
High-risk Human Papillomavirus E7 Oncoprotein Detection in Cervical Squamous Cell Carcinoma
Authors: Ressler Sigrun , Scheiden René , Dreier Kerstin , Laich Andreas , Müller-Holzner Elisabeth , Pircher Haymo , Morandell Dieter , Stein Ines , Viertler Hans-Peter , Santer Frédéric R. , Widschwendter Andreas , Even Jos , Jansen-Dürr Pidder , Capesius Catherine , Zwerschke Werner
Published: December 2007

Purpose: Persistent infections by high-risk human papillomavirus (HPV) types are the main etiologic factor for cervical cancer. The objective of this study was to evaluate whether high-risk E7 oncoprotein is adequate as a marker for the detection of cervical cancer.

Experimental Design: HPV typing was done in biopsies from 58 cervical carcinoma and 22 normal cervical squamous epithelia. The HPV-16 E7, HPV-18 E7, and HPV-45 E7 oncoprotein levels were monitored by immunohistochemistry and compared with those of p16INK4a and Ki67.

Results: Fifty-five (94.8%) tumors were high-risk HPV-DNA–positive (46 HPV-16, 2 HPV-16 and HPV-18, 4 HPV-18, 1 HPV-33, and 2 HPV-45). HPV-DNA could not be detected in three tumors (5.2%). High HPV E7 oncoprotein levels were shown in 57 cervical cancers (98.3%), without correlation between expression levels and tumor stages.

Conclusion: This is the first study which systematically analyzes the levels of the major HPV oncoproteins in cervical carcinomas demonstrating that the high-risk HPV E7 proteins are regularly expressed in these cancers. This suggests that high-risk E7 oncoproteins are necessary for cervical cancers and apparently essential as tumor marker.
NOXA and PUMA Expression Add to Clinical Markers in Predicting Biochemical Recurrence of Prostate Cancer Patients in a Survival Tree Model
Authors: Diallo Jean-Simon , Aldejmah Abdulhadi , Mouhim Abdelali Filali , Péant Benjamin , Fahmy Mona Alam , Koumakpayi Ismaël Hervé , Sircar Kanishka , Bégin Louis R. , Mes-Masson Anne-Marie , Saad Fred
Published: December 2007

Purpose: To assess the expression of proapoptotic NOXA and PUMA in prostate tissues and delineate their association with prostate cancer (PCa) recurrence.

Experimental Design: Normal, prostatic intraepithelial neoplasia (PIN), hormone-sensitive (HS) PCa, and hormone-refractory (HR) PCa tissues were used to build tissue microarrays encompassing a total of 135 patients. Two observers assessed the intensity of NOXA and PUMA immunohistochemical staining using a composite color scale. One hundred and eighty recursive partitioning and regression tree (RPART) models were generated to predict biochemical recurrence (BCR) within HS cancer patients using NOXA, PUMA, and clinical parameters. Models were then ranked according to the integrated Brier score (IBS).

Results: Increasing NOXA expression was associated with PCa progression, reaching the highest levels in HR PCa. Increased NOXA expression was observed in 68% of HS cancer patients and was predictive of BCR (LR = 8.64; P = 0.003). In contrast, PUMA expression was highest in HS cancer, and although 70% of HS cancer patients exhibited increased PUMA expression, PUMA alone could not predict the onset of BCR. Interestingly, the top-ranking RPART model generated [IBS = 0.107; 95% confidence interval (95% CI), 0.065-0.128] included surgical margin status and NOXA and PUMA expression, although recurrent prognostic classification schemes obtained in the top 10 models favored a survival tree model containing margin status, NOXA expression, and preoperative prostate-specific antigen (PSA) (IBS = 0.114; 95% CI, 0.069-0.142).

Conclusion: We conclude that NOXA and PUMA expression may be linked to PCa progression and propose further validation of a survival tree model including surgical margin status, NOXA expression, and preoperative PSA for predicting BCR.
A Multiparametric Panel for Ovarian Cancer Diagnosis, Prognosis, and Response to Chemotherapy
Authors: Zheng Yingye , Katsaros Dionyssios , Shan Shannon J.C. , de la Longrais Irene Rigault , Porpiglia Mauro , Scorilas Andreas , Kim Nam W. , Wolfert Robert L. , Simon Iris , Li Lin , Feng Ziding , Diamandis Eleftherios P.
Published: December 2007

Purpose: Our goal was to examine a panel of 11 biochemical variables, measured in cytosolic extracts of ovarian tissues (normal, benign, and malignant) by quantitative ELISAs for their ability to diagnose, prognose, and predict response to chemotherapy of ovarian cancer patients.

Experimental Design: Eleven proteins were measured (9 kallikreins, B7-H4, and CA125) in cytosolic extracts of 259 ovarian tumor tissues, 50 tissues from benign conditions, 35 normal tissues, and 44 tissues from nonovarian tumors that metastasized to the ovary. Odds ratios and hazard ratios and their 95% confidence interval were calculated. Time-dependent receiver operating characteristic curves for censored survival data were used to evaluate the performance of the biomarkers. Resampling was used to validate the performance.

Results: Most biomarkers effectively separated cancer from noncancer groups. A composite marker provided an area under the curve of 0.97 (95% confidence interval, 0.95-0.99) for discriminating normal and cancer groups. Univariately, hK5 and hK6 were positively associated with progression. After adjusting for clinical variables in multivariate analysis, both hK10 and hK11 significantly predicted time to progression. Increasing levels of hK13 were associated with chemotherapy response, and the predictive power of hK13 to chemotherapy response was improved by a panel of five biomarkers.

Conclusions: The evidence shows that a group of kallikreins and multiparametric combinations with other biomarkers and clinical variables can significantly assist with ovarian cancer classification, prognosis, and response to platinum-based chemotherapy. In particular, we developed a multiparametric strategy for predicting ovarian cancer response to chemotherapy, comprising several biomarkers and clinical features.
E2F1 Overexpression Correlates with Thymidylate Synthase and Survivin Gene Expressions and Tumor Proliferation in Non–Small-Cell Lung Cancer
Authors: Huang Cheng-long , Liu Dage , Nakano Jun , Yokomise Hiroyasu , Ueno Masaki , Kadota Kyuichi , Wada Hiromi
Published: December 2007

Purpose: We investigated the clinical significance of E2F1 gene expression in relation to its target genes, thymidylate synthase (TS) and Survivin, in case of non–small-cell lung cancer (NSCLC).

Experimental Design: One hundred twenty-seven cases of resected NSCLC were analyzed. Quantitative reverse transcription-PCR was done to evaluate the gene expression of E2F1, TS, and Survivin. Immunohistochemistry was done to investigate the protein expression of E2F1, TS, and Survivin. The Ki-67 proliferation index and the apoptotic index using the terminal deoxyribonucleotidyl transferase–mediated dUTP nick-end labeling method were also evaluated.

Results: E2F1 gene expression significantly correlated with the Ki-67 proliferation index (r = 0.487; P < 0.0001), although no correlation was observed between E2F1 gene expression and the apoptotic index. With regard to E2F1 target genes, E2F1 gene expression significantly correlated with TS gene expression (r = 0.709; P < 0.0001) and Survivin gene expression (r = 0.403; P < 0.0001). The overall survival rate was significantly lower in patients with high-E2F1 tumors than in those with low-E2F1 tumors (P = 0.0027), especially among patients with stage II to III NSCLCs (P = 0.0188). A Cox regression analysis showed that the E2F1 status was a significant prognostic factor for NSCLC patients (hazard ratio, 2.052; P = 0.0261).

Conclusions: The present study revealed that E2F1 gene expression correlates with TS and Survivin gene expressions and tumor proliferation. During the progression of NSCLC, E2F1 overexpression could produce more aggressive tumors with a high proliferation rate and chemoresistance.
A Phase I Trial of Lenalidomide in Patients with Recurrent Primary Central Nervous System Tumors
Authors: Fine Howard A. , Kim Lyndon , Albert Paul S. , Duic J. Paul , Ma Hilary , Zhang Wei , Tohnya Tanyifor , Figg William D. , Royce Cheryl
Published: December 2007

Purpose: Inhibition of angiogenesis represents a promising new therapeutic strategy for treating primary malignant brain tumors. Lenalidomide, a potent analogue of the antiangiogenic agent thalidomide, has shown significant activity in several hematologic malignancies, and therefore we chose to explore its tolerability and activity in patients with primary central nervous system tumors.

Experimental Design: A phase I interpatient dose escalation trial of lenalidomide in patients with recurrent primary central nervous system tumors was conducted.

Results: Thirty-six patients were accrued to the study, of which 28 were evaluable for toxicity, the primary end point of the trial. We show that lenalidomide can be given safely up to doses of 20 mg/m2, with the only toxicity being a probable increased risk of thromboembolic disease. Pharmacokinetic studies reveal good bioavailability, linear kinetics, and no effects of enzyme-inducing antiepileptic drugs on the metabolism of lenalidomide. No objective radiographic responses were seen in any of the treated patients. In the group of 24 patients with recurrent glioblastoma, the median time to tumor progression was <2 months and only 12.5% of patients were progression-free at 6 months.

Conclusion: Lenalidomide is well tolerated in patients with recurrent glioma in doses up to 20 mg/m2. Treatment may be associated with an increased risk of thromboembolic disease. Preliminary data suggest that single agent activity may be limited in patients with recurrent glioblastoma at the doses evaluated although larger studies will be needed to confirm these observations.
CD8+ T Cells Induce Complete Regression of Advanced Ovarian Cancers by an Interleukin (IL)-2/IL-15–Dependent Mechanism
Authors: Yang Taimei , Wall Erika M. , Milne Katy , Theiss Patty , Watson Peter , Nelson Brad H.
Published: December 2007

Purpose: In vitro studies suggest that ovarian cancer evades immune rejection by fostering an immunosuppressive environment within the peritoneum; however, the functional responses of ovarian cancer–specific T cells have not been directly investigated in vivo. Therefore, we developed a new murine model to enable tracking of tumor-specific CD8+ T-cell responses to advanced ovarian tumors.

Experimental Design: The ovarian tumor cell line ID8 was transfected to stably express an epitope-tagged version of HER-2/neu (designated NeuOT-I/OT-II). After i.p. injection into C57BL/6 mice, ID8 cells expressing NeuOT-I/OT-II gave rise to disseminated serous adenocarcinomas with extensive ascites. CD8+ T cells expressing a transgenic T-cell receptor specific for the OT-I epitope of NeuOT-I/OT-II were adoptively transferred into tumor-bearing mice, and functional responses were monitored. Cytokine signaling requirements were evaluated by comparing the responses of wild-type donor T cells with those with genetic deletion of the interleukin (IL)-2/IL-15 receptor β subunit (CD122) or the IL-2 receptor α subunit (CD25).

Results: On adoptive transfer into tumor-bearing hosts, wild-type OT-I T cells underwent a striking proliferative response, reaching peak densities of ∼40% and ∼90% of CD8+ T cells in peripheral blood and ascites, respectively. OT-I cells infiltrated and destroyed tumor tissue, and ascites completely resolved within 10 days. By contrast, CD122−/− OT-I cells and CD25−/− OT-I cells proliferated in blood but failed to accumulate in ascites or tumor tissue or induce tumor regression.

Conclusions: Contrary to expectation, advanced ovarian cancers can support extraordinary CD8+ T-cell proliferation and antitumor activity through an IL-2/IL-15–dependent mechanism.
Prepositional Phrase Attachment without Oracles
Authors: Atterer Michaela , Schütze Hinrich
Published: December 2007

Work on prepositional phrase (PP) attachment resolution generally assumes that there is an oracle that provides the two hypothesized structures that we want to choose between. The information that there are two possible attachment sites and the information about the lexical heads of those phrases is usually extracted from gold-standard parse trees. We show that the performance of reattachment methods is higher with such an oracle than without. Because oracles are not available in NLP applications, this indicates that the current evaluation methodology for PP attachment does not produce realistic performance numbers. We argue that PP attachment should not be evaluated in isolation, but instead as an integral component of a parsing system, without using information from the gold-standard oracle.