bluuebunny/crossref_metadata_2025 huggingface dataset:
Carbonic Anhydrase II Is a Tumor Vessel Endothelium–Associated Antigen Targeted by Dendritic Cell Therapy
Authors: Yoshiura Kenta , Nakaoka Takashi , Nishishita Toshihide , Sato Katsuaki , Yamamoto Akifumi , Shimada Shinji , Saida Toshiaki , Kawakami Yutaka , Takahashi Tsuneo A. , Fukuda Hiroyuki , Imajoh-Ohmi Shinobu , Oyaizu Naoki , Yamashita Naohide
Published: March 2006

Tumor-associated antigens are promising candidates as target molecules for immunotherapy and a wide variety of tumor-associated antigens have been discovered through the presence of serum antibodies in cancer patients. We previously conducted dendritic cell therapy on 10 malignant melanoma patients and shrinkage or disappearance of metastatic tumors with massive necrosis occurred in two patients. In this study, we found a 29-kDa protein against which antibody was elicited by dendritic cell therapy in one of the two patients. Matrix-assisted laser desorption ionization-time of flight/mass spectrometry analysis of the protein isolated by two-dimensional electrophoresis combined with Western blots revealed that the 29-kDa protein was carbonic anhydrase II (CA-II). Immunohistochemistry of the tumors and normal tissues showed that CA-II was expressed in the tumor vessel but not in normal vessel endothelium. CA-II expression in tumor endothelium was observed as well in other cancers including esophageal, renal, and lung cancers. In an in vitro angiogenesis model, CA-II expression of normal human vein endothelial cells was significantly up-regulated when cells were cultured in the acidic and hypoxic conditions indicative of a tumor environment. These findings suggest that CA-II is a tumor vessel endothelium–associated antigen in melanoma and other cancers, and elicitation of serum anti–CA-II antibody by dendritic cell therapy may be associated with good clinical outcome including tumor reduction.
Heat-Induced Up-Regulation of NAD(P)H:Quinone Oxidoreductase Potentiates Anticancer Effects of β-Lapachone
Authors: Park Heon Joo , Choi Eun Kyung , Choi Jihyung , Ahn Ki-Jung , Kim Eun Jung , Ji In-Mi , Kook Yeon Hee , Ahn Seung-Do , Williams Brent , Griffin Robert , Boothman David A. , Lee Chung K. , Song Chang W.
Published: March 2006

Purpose: The purpose of the present study was to evaluate the efficacy of mild hyperthermia to potentiate the anticancer effects of β-lapachone (3,4-dihydro-2,2-dimethyl-2H-naphthol[1,2-b]pyran-5,6-dione) by up-regulating NAD(P)H:quinone oxidoreductase (NQO1) in cancer cells.

Experimental Design: Effects of β-lapachone alone or in combination with mild heating on the clonogenic survival of FSaII fibrosarcoma cells of C3H mice and A549 human lung tumor cells in vitro was determined. Effects of heating on the NQO1 level in the cancer cells in vitro were assessed using Western blot analysis for NQO1 expression, biochemical determination of NQO1 activity, and immunofluorescence microscopy for NQO1 expression. Growth of FSaII tumors in the hind legs of C3H mice was determined after treating the host mice with i.p. injection of 45 mg/kg β-lapachone followed by heating the tumors at 42°C for 1 hour every other day for four times.

Results: Incubation of FSaII tumor cells and A549 tumor cells with β-lapachone at 37°C reduced clonogenic survival of the cells in dose-dependent and incubation time–dependent manner. NQO1 level in the cancer cells in vitro increased within 1 hour after heating at 42°C for 1 hour and remained elevated for >72 hours. The clonogenic cell death caused by β-lapachone increased in parallel with the increase in NQO1 levels in heated cells. Heating FSaII tumors in the legs of C3H mice enhanced the effect of i.p.-injected β-lapachone in suppressing tumor growth.

Conclusion: We observed for the first time that mild heat shock up-regulates NQO1 in tumor cells. The heat-induced up-regulation of NQO1 enhanced the anticancer effects of β-lapachone in vitro and in vivo.
Histone Deacetylase Inhibitor FK228 Activates Tumor Suppressor Prdx1 with Apoptosis Induction in Esophageal Cancer Cells
Authors: Hoshino Isamu , Matsubara Hisahiro , Hanari Naoyuki , Mori Mikito , Nishimori Takanori , Yoneyama Yasuo , Akutsu Yasunori , Sakata Haruhito , Matsushita Kazuyuki , Seki Naohiko , Ochiai Takenori
Published: March 2006

Purpose: The histone deacetylase inhibitor FK228 shows strong activity as a potent antitumor drug but its precise mechanism is still obscure. The purpose of this study is to reveal the effect of FK228 on gene expression in the cell and to determine the mechanism of the antitumor activity of FK228 for further clinical applications.

Experimental Design and Results: Microarray analysis was applied to verify the gene expression profiles of 4,608 genes after FK228 treatment using human esophageal squamous cell cancer cell lines T.Tn and TE2. Among them, peroxiredoxin 1 (Prdx1), a member of the peroxiredoxin family of antioxidant enzymes having cell growth suppression activity, as well as p21WAF1, were significantly activated by FK288. In addition, FK228 strongly inhibited the cell growth of T.Tn and TE2 by the induction of apoptosis. Further, chromatin immunoprecipitation analysis revealed that FK228 induced the accumulation of acetylated histones H3 and H4 in Prdx1 promoter, including the Sp1-binding site. In mouse xenograft models of T.Tn and TE2 cells, FK228 injection resulted in significant tumor regression as well as activated Prdx1 expression in tumor tissues. Prdx1 suppression by RNA interference hindered the antitumor effect of FK228.

Conclusion: Our results indicate that the antitumor effect of FK228 in esophageal cancer cells is shown at least in part through Prdx1 activation by modulating acetylation of histones in the promoter, resulting in tumor growth inhibition with apoptosis induction.
Expression of HER2 and the Coamplified Genes GRB7 and MLN64 in Human Breast Cancer: Quantitative Real-time Reverse Transcription-PCR as a Diagnostic Alternative to Immunohistochemistry and Fluorescence In situ Hybridization
Authors: Vinatzer Ursula , Dampier Brigitta , Streubel Berthold , Pacher Margit , Seewald Michael J. , Stratowa Christian , Kaserer Klaus , Schreiber Martin
Published: March 2006

Purpose: Accurate testing of HER2 is centrally important for breast cancer therapy and prognosis. Immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH) are current standard testing methods. As a potential alternative for assessment of HER2, we explored quantitative real-time reverse transcription-PCR (RT-PCR), a fast and inexpensive method yielding quantitative results insensitive to interobserver variability and amenable to standardized scoring.

Experimental Design: We assessed HER2 status at the DNA, mRNA, and protein levels with FISH, quantitative RT-PCR, and IHC in 136 tumor samples from 85 breast cancer patients. Expression of GRB7, MLN64, and p21, genes coregulated with HER2, was also quantified with quantitative RT-PCR and correlated with the overall survival (OS) and disease-free survival (DFS) individually and in combination with HER2.

Results: Twenty-nine percent and 19% of the patients scored HER2 positive with IHC and quantitative RT-PCR, respectively. In 18 of 19 cases, HER2 statuses in tumors and lymph node metastases were identical. HER2 status significantly correlated with DFS when determined by IHC (P < 0.01), quantitative RT-PCR (P < 0.003), but not with FISH (P = 0.09). The combination of HER2 with MLN64, but not with GRB7 or p21, enhanced the prognostic power for the DFS (P < 0.00005) and OS (P < 0.0008).

Conclusions: Quantitative RT-PCR seems to be clinically as useful in the assessment of HER2 status as IHC and FISH, yielding comparable correlations of HER2 status with the OS and DFS. Thus, quantitative RT-PCR analysis of HER2 or HER2 plus MLN64 is a promising complement or alternative to current methods for HER2 testing, particularly in laboratories lacking FISH or IHC technology.
The Relationship between Global Methylation Level, Loss of Heterozygosity, and Microsatellite Instability in Sporadic Colorectal Cancer
Authors: Matsuzaki Koji , Deng Guoren , Tanaka Hirofumi , Kakar Sanjay , Miura Soichiro , Kim Young S.
Published: March 2006

Purpose: The relationship between global hypomethylation, chromosomal instability (CIN), and microsatellite instability (MSI) remains unclear in colorectal cancer. The aim of this study was to investigate the relationship between global methylation status, loss of heterozygosity (LOH), and MSI in sporadic colorectal cancer.

Experimental Design: We determined global methylation levels in 80 sporadic colorectal cancers, 51 adjacent normal tissues, and 20 normal tissues using the long interspersed nucleotide elements–combined bisulfite restriction analysis method. We also analyzed 80 colorectal cancers for MSI status and LOH at chromosomes 5q21, 8p12-22, 17p13, and 18q21.

Results: We identified 14 cases of MSI (17.5%) and 58 cases of LOH (72.5%). LOH was observed more frequently in microsatellite stable (MSS) cancers than in MSI cancers at all loci. Colorectal cancers showed significantly lower global methylation levels than did normal tissues (41.0 ± 9.7% versus 54.3 ± 6.5%; P < 0.001). MSS cancers showed significantly lower global methylation levels when compared with MSI cancers (39.5 ± 9.4% versus 48.2 ± 8.2%; P = 0.003). Tumors with global hypomethylation (with ≤40% of methylation levels) had a significantly increased number of chromosomal loci with LOH than did tumors without global hypomethylation (1.9 versus 0.9; P < 0.001); 11 tumors (13.9%) lacked both MSI and LOH. This subgroup had significantly higher global methylation levels (46.8 ± 8.7%) than did MSS cancers with LOH (38.0 ± 9.0%; P = 0.006).

Conclusions: These data showed a significant association between global hypomethylation and chromosomal instability in sporadic colorectal cancer. This suggests that global hypomethylation plays an important role in inducing genomic instability in colorectal carcinogenesis.
MHC Class I–Related Chain A Conjugated to Antitumor Antibodies Can Sensitize Tumor Cells to Specific Lysis by Natural Killer Cells
Authors: Germain Claire , Larbouret Christel , Cesson Valérie , Donda Alena , Held Werner , Mach Jean-Pierre , Pèlegrin André , Robert Bruno
Published: March 2006

Purpose: As a first step for the development of a new cancer immunotherapy strategy, we evaluated whether antibody-mediated coating by MHC class I–related chain A (MICA) could sensitize tumor cells to lysis by natural killer (NK) cells.

Experimental Design: Recombinant MICA (rMICA) was chemically conjugated to Fab′ fragments from monoclonal antibodies specific for tumor-associated antigens, such as carcinoembryonic antigen, HER2, or CD20.

Results: Flow cytometry analysis showed an efficient coating of MICA-negative human cancer cell lines with the Fab-rMICA conjugates. This was strictly dependent on the expression of the appropriate tumor-associated antigens in the target cells. Importantly, preincubation of the tumor cells with the appropriate Fab-rMICA conjugate resulted in NK cell–mediated tumor cell lysis. Antibody blocking of the NKG2D receptor in NK cells prevented conjugate-mediated tumor cell lysis.

Conclusions: These results open the way to the development of immunotherapy strategies based on antibody-mediated targeting of MICA.
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

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 <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 < 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

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

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

Purpose: 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

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

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

Purpose: 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

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 < 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

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

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

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.
Roscovitine Modulates DNA Repair and Senescence: Implications for Combination Chemotherapy
Authors: Crescenzi Elvira , Palumbo Giuseppe , Brady Hugh J.M.
Published: March 2006

Purpose: Treatment of tumor cells by chemotherapy activates a series of responses ranging from apoptosis to premature senescence and repair. Survival responses are characterized by inhibition of cyclin-dependent kinases. Because inhibition of cyclin-dependent kinases represents a distinctive feature of DNA damage–induced prosurvival responses, we investigated the possibility that the cyclin-dependent kinase inhibitor roscovitine modulates drug-induced responses in human adenocarcinoma cells, favoring cell survival.

Experimental Design: Sublethal concentrations of doxorubicin were used to induce premature senescence in human adenocarcinoma cells. The effect of the cyclin-dependent kinase inhibitor roscovitine on the doxorubicin-dependent cell cycle checkpoint activation and DNA repair pathways was evaluated.

Results: Roscovitine reinforces doxorubicin-dependent G1 checkpoint in A549 and HEC1B cells leading to decreased frequency of double-strand breaks and to the preferential induction of senescence and enhanced clonogenic survival. However, in other tumor cell lines, such as HCT116 and H1299, combined treatment with doxorubicin and roscovitine increases the frequency of double-strand breaks and dramatically sensitizes to doxorubicin. This unexpected effect of roscovitine depends on a novel ability to inhibit DNA double-strand break repair processes and requires inactivation of the pRb pathway.

Conclusions: Roscovitine, by hindering DNA repair processes, has the potential to inhibit recovery of mildly damaged tumor cells after doxorubicin treatment and to increase the susceptibility of tumor cells to chemotherapy. However, in some tumor cells, the cell cycle inhibitory function of roscovitine prevails over the DNA repair inhibitory activity, favoring premature senescence and clonogenic growth. These data indicate a novel mechanism underlying combined chemotherapy, which may have wide application in treatment of carcinomas.
Androgen Mediation of Thrombocytosis in Epithelial Ovarian Cancer Biology
Authors: Li Andrew John , Young Karlan Beth
Published: March 2006

Purpose: Preoperative thrombocytosis (platelet count > 400 × 109/L) at initial exploration for epithelial ovarian carcinoma is associated with decreased surgical cytoreducibility and poor survival. Platelets express androgen receptor (AR), which contains a polymorphic CAG trinucleotide repeat sequence of which the length inversely correlates with AR transactivation function. We hypothesized that androgen-mediated thrombocytosis promotes aggressive ovarian cancer biology.

Experimental Design: Sixty-three patients with epithelial ovarian carcinoma underwent genotype analysis of the CAG repeat polymorphism in AR. Medical records were reviewed to assess preoperative thrombocytosis, surgical findings, and survival. Data were examined using the Fisher's exact, logistic regression, and Kaplan-Meier analyses.

Results: AR CAG repeat lengths ranged from 8 to 27, with a median of 23. Fifteen of 63 patients (23.8%) showed preoperative thrombocytosis. Short AR allelotype (≤ 20 CAG repeats) was associated with a higher incidence of thrombocytosis (P = 0.04). The combination of short AR allelotype and thrombocytosis was the only significant factor that predicted inability to achieve optimal surgical cytoreduction (P = 0.02). Women with short AR allelotype and thrombocytosis showed statistically decreased progression-free survival (13 versus 37 months, P = 0.01) and overall survival (37 versus 65 months, P = 0.02) when compared with women with long AR allelotype and normal platelet counts. On multivariate analyses, suboptimal cytoreduction was the only significant factor predictive of disease-specific overall survival (P = 0.0002) but the combination of short AR allelotype and thrombocytosis approached statistical significance (P = 0.08).

Conclusions: Androgen modulation of thrombocytosis may promote aggressive epithelial ovarian cancer biology.
CG0070, a Conditionally Replicating Granulocyte Macrophage Colony-Stimulating Factor–Armed Oncolytic Adenovirus for the Treatment of Bladder Cancer
Authors: Ramesh Nagarajan , Ge Ying , Ennist David L. , Zhu Mingzhu , Mina Mervat , Ganesh Shanthi , Reddy P. Seshidhar , Yu De-Chao
Published: March 2006

Purpose: The purpose of this study was to examine the tumor specificity, cytotoxicity, and granulocyte macrophage colony-stimulating factor expression of CG0070, a conditionally replicating oncolytic adenovirus, in human bladder transitional cell carcinoma (TCC) cell lines and determine its antitumor efficacy in bladder TCC tumor models.

Experimental Design: Virus yield and cytotoxicity assays were used to determine tumor specificity and virus replication-mediated cytotoxicity of CG0070 in a panel of human bladder TCC cell lines and primary cells in vitro. Two s.c. and one orthotopic bladder TCC xenograft tumor models were used to assess antitumor activity of CG0070.

Results: In a matched isogenic pair of cell lines with differing retinoblastoma (Rb) pathway status, CG0070 showed selective E1a and granulocyte macrophage colony-stimulating factor (GM-CSF) expression in Rb pathway–defective cells. CG0070 replicated in Rb-defective bladder TCC cell lines as efficiently as wild-type adenovirus but produced 100-fold less virus in normal human cells. CG0070 was up to 1,000-fold more cytotoxic in Rb pathway–defective bladder TCC cells in comparison with normal human cells. Antitumor activity of CG0070 was shown in two bladder TCC s.c. xenograft tumor models following intratumoral injections and intravesical treatment in an orthotopic xenograft tumor model when compared with PBS treatment.

Conclusions: In vitro and in vivo studies showed the selective replication, cytotoxicity, GM-CSF production, and antitumor efficacy of CG0070 in several bladder TCC models, suggesting a potential utility of this oncolytic agent for the treatment of bladder cancer. Further studies are warranted to show the role of human GM-CSF in the antitumor efficacy of CG0070.
Synergistic Interaction between Histone Deacetylase and Topoisomerase II Inhibitors Is Mediated through Topoisomerase IIβ
Authors: Marchion Douglas C. , Bicaku Elona , Turner Joel G. , Daud Adil I. , Sullivan Daniel M. , Munster Pamela N.
Published: March 2006

Background: DNA topoisomerase II inhibitors and poisons are among the most efficacious drugs for the treatment of cancer. Sensitivity of cancer cells to the cytotoxic effects of topoisomerase II targeting agents is thought to depend on the expression of the topoisomerase IIα isoform, and drug resistance is often associated with loss or mutation of topoisomerase IIα. Histone deacetylase inhibitors (HDACi) are a novel class of compounds that potentiate the antitumor effects of topoisomerase II–targeting agents.

Methods: The interaction between HDACi and topoisomerase II–targeting agents in cancer cells was evaluated as a function of topoisomerase IIα and topoisomerase IIβ expression. Topoisomerase II isoforms were selectively depleted using small interfering RNA and antisense. Drug-induced formation of cleavable complexes involving topoisomerase IIα and topoisomerase IIβ was evaluated by trapped-in-agarose DNA immunostaining and band depletion assays in the presence and absence of HDACi.

Results: Preexposure to HDACi increased the cytotoxicity of topoisomerase II poisons. This was associated with a down-regulation of topoisomerase IIα expression but had no effects on topoisomerase IIβ. In the setting of HDACi-induced chromatin decondensation and topoisomerase IIα depletion, topoisomerase II poison cytotoxicity was mediated through topoisomerase IIβ cleavable complex formation. The HDACi-induced sensitization was also observed in cells with target-specific resistance to topoisomerase II poisons.

Conclusions: The recruitment of topoisomerase IIβ as a target may overcome primary or emergent drug resistance to topoisomerase II–targeting agents and hence may broaden the applicability of this important class of anticancer agents.
Lymphangiogenesis Correlates with Lymph Node Metastasis, Prognosis, and Angiogenic Phenotype in Human Non–Small Cell Lung Cancer
Authors: Renyi-Vamos Ferenc , Tovari Jozsef , Fillinger Janos , Timar Jozsef , Paku Sandor , Kenessey Istvan , Ostoros Gyula , Agocs Laszlo , Soltesz Ibolya , Dome Balazs
Published: March 2006

Purpose: Recent experimental studies have revealed that lymphangiogenesis plays an important role in cancer progression, but its clinical significance in the case of non-small cell lung cancer (NSCLC) remains unclear. Our aim was to assess the lymphangiogenesis of human NSCLC, and to correlate this with angiogenic phenotype (angiogenic versus nonangiogenic growth pattern) and clinical behavior.

Experimental Design: One hundred and three patients with NSCLC and complete follow-up information were included. Tumor samples were immunostained for vascular endothelial growth factor-C (VEGF-C), the lymphatic endothelial markers, LYVE-1 and D2-40/Podoplanin, and the panvascular marker, CD31. Lymphatic vessel density (LVD) and perimeters were evaluated within the tumor and peritumorally.

Results: LVDs at the tumor periphery were significantly higher in lymph node metastatic tumors (P < 0.005) and high LVDs correlated with poor overall survival (P < 0.001). However, this tendency proved to be significant only in the angiogenic tumor group (P < 0.001). Although 68% of the patients with nonangiogenic tumors had lymph node metastasis (P = 0.0048 versus angiogenic tumors), in the patient group with nonangiogenic NSCLCs, there was no information from the LVDs in any investigated tumor area (P > 0.05). In contrast to angiogenic tumors, which had actively sprouting lymphatics in all of the investigated tumor areas, nonangiogenic tumors showed no Ki67 staining intratumorally.

Conclusions: Our results reveal tumor lymphangiogenesis as a novel prognostic indicator for the risk of lymph node metastasis in NSCLC. Moreover, it also provides the first evidence that nonangiogenic NSCLCs mainly co-opt host tissue lymphatics during their growth, in contrast to most of the angiogenic tumors, which expand with concomitant lymphangiogenesis.
Phosphatidylinositol 3-Kinase Inhibition by LY294002 Radiosensitizes Human Cervical Cancer Cell Lines
Authors: Lee Christopher M. , Fuhrman Christa B. , Planelles Vicente , Peltier Morgan R. , Gaffney David K. , Soisson Andrew P. , Dodson Mark K. , Tolley H. Dennis , Green Christopher L. , Zempolich Karen A.
Published: March 2006

Purpose: The phosphatidylinositol 3-kinase (PI3K) catalytic subunit is amplified in cervical cancers, implicating PI3K in cervical carcinogenesis. We evaluated the radiosensitizing effect of PI3K inhibition by LY294002 on clonogenic survival, growth characteristics, and gene expression in cervical cancer cell lines (HeLa and CaSki).

Experimental Design: Cervical cancer cells were treated separately and concurrently with the PI3K inhibitor LY294002 (10 μmol/L) and radiation (2 Gy) with serial analysis of cell count, apoptosis, and flow cytometry. PI3K inhibition was assessed by protein analysis of phosphorylated Akt. Clonogenic assays were done with varying doses of radiation and LY294002 and varied time points of administration of LY294002 proximate to the radiation dose. Surviving fractions and dose modification factors (DMF) were calculated. Each experiment was done in triplicate and analyzed using ANOVA regression analysis and Dunnett's t Test. Microarray gene expression analysis was done on the HeLa cell line.

Results: PI3K inhibition with LY294002 alone did not decrease cell survival. However, treatment with LY294002 significantly radiosensitized HeLa and CaSki cell lines with DMFs (1 log cell kill) of 1.95 and 1.37, respectively. Compared with post-irradiation, pretreatment produced more radiosensitization (P < 0.0001). DMFs were 2.2, 2.0, 2.0, and 1.2 for LY294002 added at 6, 2, and 0.5 hours before irradiation and 6 hours after irradiation, respectively. LY294002 pretreatment in irradiated HeLa cells led to altered gene expression.

Conclusions: Although LY294002 alone did not produce cytotoxic effects, PI3K inhibition with LY294002 produced significant radiosensitization, showed significant time-dependent effects, increased apoptosis, and altered gene expression. These findings support future investigation of PI3K inhibitors in combination with radiation therapy for carcinoma of the cervix.