bluuebunny/crossref_metadata_2025_split huggingface dataset:
Clinical Relevance of Dominant-Negative p73 Isoforms for Responsiveness to Chemotherapy and Survival in Ovarian Cancer: Evidence for a Crucial p53-p73 Cross-talk In vivo
Authors: Concin Nicole , Hofstetter Gerda , Berger Astrid , Gehmacher Adriana , Reimer Daniel , Watrowski Rafal , Tong Dan , Schuster Eva , Hefler Lukas , Heim Kurt , Mueller-Holzner Elisabeth , Marth Christian , Moll Ute M. , Zeimet Alain G. , Zeillinger Robert 
Published: March 2006

Abstract
Purpose: We aimed to determine the clinical role of the p53 family members p53 and p73 in the responsiveness to platinum-based chemotherapy and survival in ovarian cancer, considering their cross-talk and the p53 polymorphism at codon 72.
Experimental Design: A detailed analysis of p53 and p73 in a series of 122 ovarian cancers was done. We used a functional yeast-based assay to determine the p53 mutational status. Red yeast colonies, indicating mutant p53, were subsequently sequenced to determine the specific p53 alteration. p53 mutations were divided into two groups according to their previous characterization in the literature: those that efficiently inhibit transcriptionally active TAp73 function and those that do not. A p53 polymorphism at codon 72 was determined in corresponding normal tissue or blood of ovarian cancer patients. Isoform-specific p73 expression analysis using real-time reverse transcription-PCR has previously been done in the majority of ovarian cancers included in this study. In a retrospective chart review, responsiveness to chemotherapy was assessed, and survival data with long follow-up times were collected.
Results: Eighty of 122 (65.6%) of ovarian cancers harbored p53 mutations. p53 mutational status was an important determinant of responsiveness to platinum-based chemotherapy in all patients with a residual tumor of &lt;2 cm in diameter after initial surgery (wild-type versus mutant, P = 0.029). In addition, p53 mutational status was a strong prognosticator for recurrence-free and overall survival (P &lt; 0.0001 and P = 0.003, respectively) in univariate analyses. High expression levels of dominant-negative p73 isoforms (ΔNp73 and ΔN′p73) significantly correlated with chemotherapeutic failure (P = 0.048) and with worse recurrence-free and overall survival in patients with p53 mutant cancers (P = 0.048 and P = 0.005, respectively). Eight p53 mutations, present in 19 cases, were found that efficiently inhibit TAp73 (i.e., 175H, 220C, 245S, 245D, 248W, 248Q, 266E, and 273H). Patients with p53 mutations that efficiently inhibit TAp73 function had a significantly shorter overall survival than patients with p53 mutations of unknown effect on TAp73 (P = 0.044). The p53 polymorphism at codon 72 had no influence on responsiveness to chemotherapy or survival.
Conclusion: We provide the first clinical evidence that dominant-negative p73 isoforms contribute to drug resistance in vivo, underscoring the importance of a p53-p73 cross-talk. NH2-terminally truncated p73 isoforms were of significant clinical effect by providing an additional unfavorable factor for response to platinum-based chemotherapy and survival in p53 mutant ovarian cancers.
Increased Expression of Mitotic Checkpoint Genes in Breast Cancer Cells with Chromosomal Instability
Authors: Yuan Bibo , Xu Yi , Woo Ju-Hyung , Wang Yunyue , Bae Young Kyung , Yoon Dae-Sung , Wersto Robert P. , Tully Ellen , Wilsbach Kathleen , Gabrielson Edward 
Published: March 2006

Abstract
Purpose: Most breast cancers have chromosomal instability that seems related to defective mitotic spindle checkpoints. Because the molecular basis of this defect is unknown, we evaluated breast cancer cell lines and tissues for possible defects involving the major mitotic checkpoint genes responsible for maintaining chromosomal stability.
Experimental Design: We analyzed sequences and expression levels (RNA and protein) of eight major spindle checkpoint genes (MAD1L1, MAD2L1, MAD2L2, BUB1, BUB1B, BUB3, CDC20, and TTK) in a panel of 12 breast cancer cell lines, most with established genetic instability and defective spindle damage checkpoint response. mRNA levels of these genes were also measured in primary tumor samples, and immunohistochemical staining was used to evaluate BUB1B protein levels in a panel of 270 additional cases of breast cancer.
Results: No functionally significant sequence variations were found for any of the eight genes in the breast cancer cell lines with chromosomal instability. More surprisingly, the mRNA and protein levels for these checkpoint genes are significantly higher in the genetically unstable breast cancer cell lines and in high-grade primary breast cancer tissues than in the stable (and checkpoint proficient) MCF-10A and normal mammary epithelial cells, or in normal breast tissues. In fact, overexpression of the BUB1B protein is a marker that recognizes nearly 80% of breast cancers in paraffin-embedded tissues.
Conclusions: Defective mitotic spindle checkpoints in breast cancer are most likely not caused by low expression or mutations of these eight checkpoint genes. High levels of these particular transcripts could represent a cellular compensation for defects in other molecular components of the mitotic spindle damage checkpoint, and increased expression of these genes might be markers of breast cancers with chromosomal instability.
Effect of Exemestane on Tamoxifen Pharmacokinetics in Postmenopausal Women Treated for Breast Cancer
Authors: Hutson Paul R. , Love Richard R. , Havighurst Thomas C. , Rogers Eric , Cleary James F. 
Published: March 2006

Abstract
Purpose: Rodent models of human breast cancer suggest that the combination of the steroidal aromatase inhibitor exemestane with tamoxifen may have additive activity. Clinical trials combining tamoxifen with letrozole or anastrazole have shown minor pharmacokinetic drug interactions. We did an open-label crossover clinical trial of the effect of exemestane on tamoxifen pharmacokinetics.
Design: Thirty-two postmenopausal women who were clinically disease-free following primary treatments for breast cancer receiving tamoxifen for at least 3 months were studied. Blood was collected for pharmacokinetic analysis after at least 4 months of receiving 20 mg tamoxifen daily. Subjects then began 8 weeks of oral exemestane (25 mg daily), followed by another set of blood samples.
Results: There were no serious toxicities noted when the two drugs were combined. There was no significant effect of exemestane on the area under the plasma concentration versus time curve (AUC) of tamoxifen at steady state before [3.04 mg h/L; 90% confidence interval (90% CI), 2.71-3.44] and during exemestane treatment (3.05 mg h/L; 90% CI, 2.72-3.41). There were no significant changes in the formation of primary tamoxifen metabolites. Oral clearance of exemestane averaged 602 L/h based on an average plasma exemestane AUC of 41.5 μg h/L (90% CI, 36.7-62.6). Plasma concentrations of estradiol, estrone, and estrone sulfate decreased when exemestane was begun; estradiol concentrations consistently decreased below the limit of quantitation.
Conclusions: There is no pharmacokinetic interaction between tamoxifen and exemestane. No modification in the standard regimen of either drug seems to be indicated if they are used in combination. The combination of the two drugs was well tolerated during the 8-week evaluation period.
Response of Some Head and Neck Cancers to Epidermal Growth Factor Receptor Tyrosine Kinase Inhibitors May Be Linked to Mutation ofERBB2rather thanEGFR
Authors: Cohen Ezra E.W. , Lingen Mark W. , Martin Leslie E. , Harris Patricia L. , Brannigan Brian W. , Haserlat Sara M. , Okimoto Ross A. , Sgroi Dennis C. , Dahiya Sonika , Muir Beth , Clark John R. , Rocco James W. , Vokes Everett E. , Haber Daniel A. , Bell Daphne W. 
Published: March 2006

AbstractPurpose: Small-molecule tyrosine kinase inhibitors (TKI) of the epidermal growth factor receptor (EGFR) have shown modest yet reproducible response rates in patients with squamous cell carcinoma of the head and neck (SCCHN). Somatic mutations in EGFR have recently been shown to be predictive of a clinical response in patients with non–small cell lung cancer (NSCLC) treated with these inhibitors. The objective of this study was to determine if such mutations, or recently reported mutations in ERBB2, also underlie EGFR-TKI responsiveness in SCCHN patients.Experimental Design: We sequenced the kinase domain of EGFR and exon 20 of ERBB2 in tumor specimens from eight responsive patients. In addition, mutational analysis was done on tumor specimens from nine gefitinib nonresponders and 65 unselected cases of SCCHN.Results: None of eight TKI-responsive specimens had mutations within the kinase domain of EGFR. EGFR amplification was also not associated with drug responsiveness. However, a single responsive case had a somatic missense mutation within exon 20 of ERBB2.Conclusion: Our data indicate that unlike NSCLC, EGFR kinase mutations are rare in unselected cases of SCCHN within the United States and are not linked to gefitinib or erlotinib responses in SCCHN. Alternative mechanisms, including ERBB2 mutations, may underlie responsiveness in this tumor type.
Phase I Study of the Taxane BMS-188797 in Combination with Carboplatin Administered Every 3 Weeks in Patients with Solid Malignancies
Authors: Fishman Mayer N. , Garrett Christopher R. , Simon George R. , Chiappori Alberto A. , Lush Richard M. , Dinwoodie William R. , Mahany J. Joseph , Dellaportas Anne M. , Cantor Alan , Gollerki Ashwin , Cohen Marvin B. , Sullivan Daniel M. 
Published: March 2006

Abstract
Rationale: BMS-188797 is one of several novel taxanes in ongoing clinical development. It has superior activity in experimental tumor models when compared with paclitaxel. BMS-188797 has a single C-4 modification, a 4-desacetyl-4-methylcarbonate, compared with paclitaxel.
Methods: We did a phase I study, in which a fixed dose of carboplatin was combined with a dose escalation schedule of BMS-188797, both administered once every 3 weeks, in patients with advanced solid malignancies.
Results: Thirty patients were treated, 11 at the proposed recommended phase II dose. The dose-limiting toxicity was myelosuppression. There was a linear relationship between administered dose of BMS-188797 and the measured area under the curve (AUC). There was significant interpatient variability of BMS-188797 AUC at the maximum tolerated dose. Two radiographic partial responses were observed: one patient with duodenal adenocarcinoma and one patient with esophageal adenocarcinoma (time on study, 19 and 30 weeks, respectively).
Conclusion: The recommended phase II dose for BMS-188797 and carboplatin administered on a once-every-3 week schedule is carboplatin AUC = 5 mg min/mL and BMS-188797 at a dose of 135 mg/m2.
PC Cell–Derived Growth Factor Confers Resistance to Dexamethasone and Promotes Tumorigenesis in Human Multiple Myeloma
Authors: Wang Wengang , Hayashi Jun , Serrero Ginette 
Published: March 2006

Abstract
Purpose: We have shown previously that the 88 kDa glycoprotein PC cell–derived growth factor (PCDGF/GP88) is expressed and acts as an autocrine growth factor in human multiple myeloma cells. The present study investigates whether PCDGF/GP88 expression in multiple myeloma cells leads to the development of resistance to dexamethasone, a conventional drug for multiple myeloma patients.
Experimental Design: PCDGF functions and signaling pathways in dexamethasone-induced apoptosis were studied using a representative dexamethasone-sensitive multiple myeloma cell line ARP-1. The effect of PCDGF/GP88 was further confirmed in PCDGF/GP88–overexpressed ARP-1 cells.
Results: Dexamethasone inhibits cell growth and induces apoptosis in a time- and dose-dependent fashion. Exogenous addition of PCDGF/GP88 to the ARP-1 cells prevented dexamethasone-induced apoptosis as examined by flow cytometry analysis and poly(ADP-ribose)polymerase cleavage assay. Signaling studies showed that mitogen-activated protein kinase, phosphatidylinositol 3-kinase, and nuclear factor-κB were involved in the antiapoptotic effect of PCDGF/GP88. Overexpression of PCDGF/GP88 in ARP-1 cells rendered the cells refractory to dexamethasone-mediated apoptosis, enhanced their ability to form colonies in soft agar, and to form tumors in vivo without any change in glucocorticoid receptor expression and function.
Conclusion: These data suggest that expression of PCDGF/GP88 confers resistance to dexamethasone and increase tumorigenesis of multiple myeloma cells in mouse xenografts. Our data here also raises the possibility of PCDGF/GP88 as a potential therapeutic target for dexamethasone-resistant multiple myeloma.
Detection ofEGFRGene Mutation in Lung Cancer by Mutant-Enriched Polymerase Chain Reaction Assay
Authors: Asano Hiroaki , Toyooka Shinichi , Tokumo Masaki , Ichimura Kouichi , Aoe Keisuke , Ito Sachio , Tsukuda Kazunori , Ouchida Mamoru , Aoe Motoi , Katayama Hideki , Hiraki Akio , Sugi Kazuro , Kiura Katsuyuki , Date Hiroshi , Shimizu Nobuyoshi 
Published: March 2006

AbstractPurpose: Mutations in the epidermal growth factor receptor (EGFR) gene have been reported to be present in non–small cell lung cancer (NSCLC) and related to the responsiveness of tumors to EGFR tyrosine kinase inhibitors, suggesting its usefulness as a biomarker. Because clinical samples contain tumor and normal cells or genes, a highly sensitive assay for detecting mutation is critical for clinical applications.Experimental Design: The mutant-enriched PCR is a rapid and sensitive assay with selective restriction enzyme digestion. We developed the mutant-enriched PCR assay targeting exons 19 and 21 of EGFR and applied the developed assay to detect mutations in 108 cases of surgically resected specimens of NSCLCs, 18 samples of computed tomography (CT)–guided needle lung biopsies, and 20 samples of pleural fluid. In addition, results were then compared with those from direct sequencing and a nonenriched PCR assay.Results: The mutant-enriched PCR that was proved to enrich one mutant of 2 × 103 normal genes detected mutations in 37 cases of 108 resected tumors, seven samples of CT-guided lung biopsies, and seven samples of pleural fluid. Among mutant cases, four resected tumors, two CT-guided lung biopsies, and two pleural fluid were identified as additional mutant cases by the mutant-enriched PCR, which were considered normal based on nonenriched assays.Conclusions: Our results indicate that EGFR mutations are readily detectable by mutant-enriched PCR in various clinical samples. Thus, mutant-enriched PCR may provide a valuable method of potentially detecting a small fraction of mutant genes in heterogeneous specimens, indicating its possible use in clinical application for NSCLC.
Increased Nuclear Localization of Transcription Factor Y-Box Binding Protein 1 Accompanied by Up-Regulation of P-glycoprotein in Breast Cancer Pretreated with Paclitaxel
Authors: Fujita Tomoyuki , Ito Ken-ichi , Izumi Hiroto , Kimura Morihiko , Sano Muneaki , Nakagomi Hiroshi , Maeno Kazuma , Hama Yoshihisa , Shingu Kiyoshi , Tsuchiya Shin-ichi , Kohno Kimitoshi , Fujimori Minoru 
Published: March 2006

Abstract
Purpose: The Y-box binding protein 1 (YB-1) regulates expression of P-glycoprotein encoded by the MDR1 gene. There have been no previous studies regarding the involvement of YB-1 in the development of resistance to paclitaxel. The present study was done to examine how paclitaxel affects the localization and expression of YB-1 in breast cancer.
Experimental Design: We evaluated the expression and localization of YB-1 and P-glycoprotein in breast cancer tissues obtained from 27 patients before and after treatment with paclitaxel. The effect of paclitaxel on localization of cellular YB-1 was examined by using GFP-YB-1. Interaction of YB-1 with the Y-box motif of the MDR1 promoters was studied by electrophoretic mobility shift assay. The effects of paclitaxel on MDR1 promoter activity were examined by luciferase assay.
Results: Of 27 breast cancer tissues treated with paclitaxel, nine (33%) showed translocation of YB-1 from the cytoplasm to the nucleus together with increased expression of P-glycoprotein during the course of treatment. Twelve breast cancer tissues (44%) showed neither translocation of YB-1 nor increased expression of P-glycoprotein. Nuclear translocation of YB-1 was correlated significantly with increased expression of P-glycoprotein (P = 0.0037). Confocal analysis indicated that paclitaxel induced nuclear translocation of green fluorescent fused YB-1 in MCF7 cells. Furthermore, binding of YB-1 to the Y-box of MDR1 promoter was increased in response to treatment with paclitaxel. In addition, MDR1 promoter activity was significantly up-regulated by paclitaxel in MCF7 cells (P &lt; 0.001).
Conclusions: The results of the present study suggested that YB-1 may be involved in the development of resistance to paclitaxel in breast cancer.
Differential Features of Colorectal Cancers Fulfilling Amsterdam Criteria without Involvement of the Mutator Pathway
Authors: Llor Xavier , Pons Elisenda , Xicola Rosa M. , Castells Antoni , Alenda Cristina , Piñol Virgínia , Andreu Montserrat , Castellví-Bel Sergi , Payá Artemio , Jover Rodrigo , Bessa Xavier , Girós Anna , Roca Anna , Gassull Miquel A. ,   for the Gastrointestinal Oncology Group of the Spanish Gastroenterological Association
Published: March 2006

Abstract
Purpose: Hereditary nonpolyposis colorectal cancer (HNPCC) is the commonest form of inherited colorectal cancer. Whereas it has been known that mismatch repair gene mutations are the underlying cause of HNPCC, an undetermined number of patients do not have these alterations. The main objectives of this study were to assess the relevance of clinically defined HNPCC patients without characteristic mutator pathway alterations and to identify their specific features.
Experimental Design: This was a prospective, population-based, cohort that included 1,309 newly diagnosed colorectal cancer patients. Demographic, clinical, pathologic data and tumor DNA from probands as well as a detailed family history were collected. Microsatellite analysis and MLH1, MSH2, and MSH6 immunohistochemistry were done. Germ line MLH1 and MSH2 mutational analysis was done in all patients with evidence of MMR alterations.
Results: Twenty-five patients (1.9%) fulfilled Amsterdam criteria of HNPCC but 15 (60%) of them did not have microsatellite instability and showed normal expression of MMR proteins. These patients presented mostly left-sided tumors without lymphocytic infiltrate; they were older, had fewer family members affected with colorectal or endometrial cancers, and more often fulfilled Amsterdam II criteria than HNPCC patients with microsatellite instability. Like unstable HNPCC patients, this group without mutator pathway alterations had a significant percentage of synchronous and metachronous adenomatous polyps and cancers.
Conclusions: We define an important group of HNPCC families with specific features, no evidence of mismatch repair deficiency, and an autosomal dominant trait with a lesser penetrance than HNPCC with deficiency.
The Up-Regulation of Y-Box Binding Proteins (DNA Binding Protein A and Y-Box Binding Protein-1) as Prognostic Markers of Hepatocellular Carcinoma
Authors: Yasen Mahmut , Kajino Kazunori , Kano Sayaka , Tobita Hiroshi , Yamamoto Junji , Uchiumi Takeshi , Kon Shigeyuki , Maeda Masahiro , Obulhasim Gulanbar , Arii Shigeki , Hino Okio 
Published: March 2006

Abstract
Purpose: The development of hepatocellular carcinoma is associated with the chronic inflammation of the liver caused by various factors such as hepatitis B or C virus infection. Previously, we reported DNA binding protein A (dbpA) as a candidate molecule that can accelerate inflammation-induced hepatocarcinogenesis. DbpA belongs to the Y-box binding protein family, and Y-box binding protein-1 (YB-1), the prototype member of this family, is reported to be a prognostic marker of malignant diseases other than hepatocellular carcinoma. The purpose of this study is to examine the significance of the expression of dbpA or of the T-to-G transversion in the dbpA promoter region, which enhances the promoter activity in vitro, for the progression of hepatocellular carcinoma.
Experimental Design: We studied the expression of dbpA (as well as of YB-1) in 82 formalin-fixed hepatocellular carcinoma tissues by immunohistochemistry and determined the sequence of the dbpA promoter region in 42 frozen hepatocellular carcinoma tissues. We examined the relationship between these findings and the clinicopathologic factors of hepatocellular carcinoma patients.
Results: DbpA expression was associated with the advanced stages of hepatocellular carcinoma, and the cases with the nuclear dbpA expression had a poor prognosis. DbpA contributed more significantly to this association than YB-1. Furthermore, the T-to-G transversion in the dbpA promoter region was related to the nuclear localization of dbpA.
Conclusion: DbpA was a more significant prognostic marker of hepatocellular carcinoma than YB-1. The T-to-G transversion in the dbpA promoter region was suggested to be a predisposing factor for the progression of hepatocellular carcinoma.
Microsatellite Instability and Colorectal Cancer Prognosis
Authors: Benatti Piero , Gafà Roberta , Barana Daniela , Marino Massimiliano , Scarselli Alessandra , Pedroni Monica , Maestri Iva , Guerzoni Laura , Roncucci Luca , Menigatti Mirco , Roncari Barbara , Maffei Stefania , Rossi Giuseppina , Ponti Giovanni , Santini Alessandra , Losi Lorena , Di Gregorio Carmela , Oliani Cristina , Ponz de Leon Maurizio , Lanza Giovanni 
Published: March 2006

Abstract
Purpose: Many studies have evaluated the role of high levels of microsatellite instability (MSI) as a prognostic marker and predictor of the response to chemotherapy in colorectal cancer (CRC); however, the results are not conclusive. The aim of this study was to analyze the prognostic significance of high levels of MSI (MSI-H) in CRC patients in relation to fluorouracil-based chemotherapy.
Experimental Design: In three different institutions, 1,263 patients with CRC were tested for the presence of MSI, and CRC-specific survival was then analyzed in relation to MSI status, chemotherapy, and other clinical and pathologic variables.
Results: Two hundred and fifty-six tumors were MSI-H (20.3%): these were more frequently at a less advanced stage, right-sided, poorly differentiated, with mucinous phenotype, and expansive growth pattern than microsatellite stable carcinomas. Univariate and multivariate analyses of 5-year–specific survival revealed stage, tumor location, grade of differentiation, MSI, gender, and age as significant prognostic factors. The prognostic advantage of MSI tumors was particularly evident in stages II and III in which chemotherapy did not significantly affect the survival of MSI-H patients. Finally, we analyzed survival in MSI-H patients in relation to the presence of mismatch repair gene mutations. MSI-H patients with hereditary non–polyposis colorectal cancer showed a better prognosis as compared with sporadic MSI-H; however, in multivariate analysis, this difference disappeared.
Conclusions: The type of genomic instability could influence the prognosis of CRC, in particular in stages II and III. Fluorouracil-based chemotherapy does not seem to improve survival among MSI-H patients. The survival benefit for patients with hereditary non–polyposis colorectal cancer is mainly determined by younger age and less advanced stage as compared with sporadic MSI-H counterpart.