Publications by authors named "Noriyuki Omura"

The methylation status of a promoter influences gene expression and aberrant methylation during tumor development has important functional consequences for pancreatic and other cancers. Using methylated CpG island amplification and promoter microarrays, we identified ANK1 as hypomethylated in pancreatic cancers. Expression analysis determined ANK1 as commonly overexpressed in pancreatic cancers relative to normal pancreas.

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A 50-year-old female patient underwent distal gastrectomy and intraperitoneal CDDP administration for advanced gastric cancer accompanied by severe peritoneal dissemination. She valued her quality of life and chose an oral anticancer drug, S-1, as a postoperative chemotherapy agent. S-1 was administered at a dose of 100mg/body/day for 4 weeks, followed by a 2- week rest.

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To identify potentially important genes dysregulated in pancreatic cancer, we analyzed genome-wide transcriptional analysis of pancreatic cancers and normal pancreatic duct samples and identified the transcriptional coactivator, EYA2 (Drosophila Eyes Absent Homologue-2) as silenced in the majority of pancreatic cancers. We investigated the role of epigenetic mechanisms of EYA2 gene silencing in pancreatic cancers, performed in vitro and in vivo proliferation and migration assays to assess the effect of EYA2 silencing on tumor cell growth and metastasis formation, and expression analysis to identify genes transcriptionally regulated by EYA2. We found loss of tumoral Eya2 expression in 63% of pancreatic cancers (120/189 cases).

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We report a rare case in which hemothorax occurred in addition to hemoperitoneum due to spontaneous rupture of hepatocellular carcinoma (HCC) originating from the caudate lobe of the liver. The case pertains to a 56-year-old female who was transported to our hospital for impaired consciousness due to hemorrhagic shock. Computed tomography (CT) demonstrated ruptured HCC originating from the caudate lobe and accompanying hemoperitoneum and right hemothorax.

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Purpose: Cancer associated stromal fibroblasts (CAFs) undergo transcriptional and phenotypic changes that contribute to tumor progression, but the mechanisms responsible for these changes are not well understood. Aberrant DNA methylation is an important cause of transcriptional alterations in cancer cells but it is not known how important DNA methylation alterations are to CAF behavior.

Experimental Design: We used Affymetrix exon arrays to compare genes induced by the DNA methylation inhibitor 5-aza-dC in cultured pancreatic cancer associated fibroblasts, pancreatic control fibroblasts and pancreatic cancer cell lines.

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Pancreatic ductal adenocarcinoma (PDAC) is a lethal malignancy, with most patients facing an adverse clinical outcome. Aberrant Notch pathway activation has been implicated in the initiation and progression of PDAC, specifically the aggressive phenotype of the disease. We used a panel of human PDAC cell lines as well as patient-derived PDAC xenografts to determine whether pharmacologic targeting of Notch pathway could inhibit PDAC growth and potentiate gemcitabine sensitivity.

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Purpose: Characterizing the earliest chromosomal alterations of pancreatic precursor neoplasms from individuals with a familial aggregation of pancreatic cancer may provide clues as to the loci of pancreatic cancer susceptibility genes.

Experimental Design: We used Illumina 370/660K SNP arrays to conduct genome-wide copy number analysis in 60 benign neoplasms [58 mostly low-grade pancreatic intraepithelial neoplasias (PanIN) and intraductal papillary mucinous neoplasms (IPMN) and two pancreatic neuroendocrine tumors (PNET)] and matched normal tissues from 16 individuals with a family history of pancreatic cancer. PanINs and IPMNs were analyzed for KRAS codon 12/13 mutations.

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Purpose: It is still technically difficult to collect high purity cancer cells from tumor tissues, which contain noncancerous cells. We hypothesized that xenograft models of NOG mice expressing enhanced green fluorescent protein (eGFP), referred to as NOG-EGFP mice, may be useful for obtaining such high purity cancer cells for detailed molecular and cellular analyses.

Methods: Pancreato-biliary cancer cell lines were implanted subcutaneously to compare the tumorigenicity between NOG-EGFP mice and nonobese diabetic/severe combined immunodeficiency (NOD/SCID) mice.

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Purpose: Intraductal papillary mucinous neoplasms (IPMN) are precursors to infiltrating pancreatic ductal adenocarcinomas. Widespread epigenetic alterations are characteristic of many cancers, yet few studies have systematically analyzed epigenetic alterations of neoplastic precursors. Our goal was to conduct genome-wide CpG island methylation profiling to identify aberrantly methylated loci in IPMNs.

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Purpose: The goal of this study was to comprehensively identify CpG island methylation alterations between pancreatic cancers and normal pancreata and their associated gene expression alterations.

Experimental Design: We employed methylated CpG island amplification followed by CpG island microarray, a method previously validated for its accuracy and reproducibility, to analyze the methylation profile of 27,800 CpG islands covering 21 MB of the human genome in nine pairs of pancreatic cancer versus normal pancreatic epithelial tissues and in three matched pairs of pancreatic cancer versus lymphoid tissues from the same individual.

Results: This analysis identified 1,658 known loci that were commonly differentially methylated in pancreatic cancer compared with normal pancreas.

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Aberrant DNA methylation and microRNA expression play important roles in the pathogenesis of pancreatic cancer. While interrogating differentially methylated CpG islands in pancreatic cancer, we identified two members of miR-200 family, miR-200a and miR-200b, that were hypomethylated and overexpressed in pancreatic cancer. We also identified prevalent hypermethylation and silencing of one of their downstream targets, SIP1 (ZFHX1B, ZEB2), whose protein product suppresses E-cadherin expression and contributes to epithelial mesenchymal transition.

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Genes that are differentially expressed in pancreatic cancers and under epigenetic regulation are of considerable biological and therapeutic interest. We used global gene expression profiling and epigenetic treatment of pancreatic cell lines including pancreatic cancer cell lines, pancreatic cancer-associated fibroblasts, and cell lines derived from nonneoplastic pancreata. We examined expression and epigenetic alterations of cyclooxygenase-1 (COX-1) and COX-2 in pancreatic cancers and normal pancreas and performed proliferation, knockdown, and coculture experiments to understand the role of stromal sources of prostaglandins for pancreatic cancers.

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DNA methyltransferase I (DNMT1) is the major methyltransferase responsible for methylating DNA and is overexpressed in many cancers. DNMT1 is also a therapeutic target for chemotherapy and chemoprevention. We hypothesized that loss of DNMT1 copy number could result in reduced DNMT1 levels and greater sensitivity to DNMT1 inhibitors.

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Purpose: Accumulating evidence suggests that cancer-associated stromal fibroblasts (CAF) contribute to tumor growth by actively communicating with cancer cells. Our aim is to identify signaling pathways involved in tumor-stromal cell interactions in human pancreatic cancer.

Experimental Design: We established primary fibroblast cultures from human pancreatic adenocarcinomas and nonneoplastic pancreas tissues.

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Approximately 35-60% of patients with colorectal cancers will develop liver lesions during their life span. Previously colorectal liver metastases have traditionally been categorized as incurable systemic disease. However, the introduction of new chemotherapeutic regimens(e.

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Background/purpose: The Frey procedure, the coring out of the pancreatic head and longitudinal pancreaticojejunostomy, is a safe, easy, and reliable method to solve most of the problems associated with chronic pancreatitis. During long-term follow up, unexpected relapse in the pancreatic tail was encountered. The pattern of failure and the rationale for a new procedure to treat or prevent such relapse were investigated.

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Markers of early pancreatic cancer and its precursors are needed to improve the uniformly poor prognosis of this disease. Fatty acid synthase (FAS) catalyzes the synthesis of long-chain fatty acids and is overexpressed in most human solid tumors. We therefore evaluated serum FAS as a marker of pancreatic adenocarcinoma.

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Aberrant expression of microRNAs (miRNAs) has emerged as an important hallmark of cancer. However, the putative mechanisms regulating miRNAs per se are only partially known. It is well established that many tumor suppressor genes in human cancers are silenced by chromatin alterations, including promoter methylation and histone deacetylation.

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It has been reported that germline mutations in the palladin gene (PALLD) cause the familial aggregation of pancreatic cancer, but the evidence is weak and controversial. We sequenced the coding regions of PALLD in 48 individuals with familial pancreatic cancer. We did not find any deleterious mutations and find no evidence to implicate mutations in PALLD as a cause of familial pancreatic cancer.

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Pancreatic cancer remains a major therapeutic challenge. In 2008, there will be approximately 37,680 new cases and 34,290 deaths attributable to pancreatic cancer in the United States (U.S.

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Background: Little is known about the genetic and epigenetic changes that contribute to familial pancreatic cancers. The aim of this study was to compare the prevalence of common genetic and epigenetic alterations in sporadic and familial pancreatic ductal adenocarcinomas.

Methods: DNA was isolated from the microdissected cancers of 39 patients with familial and 36 patients with sporadic pancreatic adenocarcinoma.

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Ductal adenocarcinoma of the pancreas is the fourth leading cause of cancer death and is usually diagnosed late. Intraductal papillary mucinous neoplasms are an increasingly recognized precursor to invasive ductal adenocarcinoma of the pancreas. Identifying the alterations in DNA methylation that arise during intraductal papillary mucinous neoplasm development may facilitate the development of markers that could be used to differentiate intraductal papillary mucinous neoplasms from non-neoplastic pancreatic cystic lesions.

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Unlabelled: Many genes undergo aberrant methylation in human cancers, and microarray platforms enable more comprehensive profiling of aberrant DNA methylation patterns.

Results: 1,010 of 87,922 probes on the 88 K promoter array (606 genes) had a higher signal (log(2) > 2) in the pancreatic cancer line, Panc-1 compared to the non-neoplastic pancreatic duct line, HPDE. Using this cut-off, bisulfite sequencing and/or MSP confirmed differential methylation of all 27 genes (66 probes) predicted to be methylated by the MCA array.

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Background: Recent studies have reported widespread copy number alterations and p53 mutations arising in cancer associated stromal cells. The aim of this study was to determine if pancreatic cancer associated fibroblasts display similar genetic alterations.

Design: Cancer-associated fibroblast cultures were established from 7 primary pancreatic adenocarcinomas.

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We have developed a novel gene therapy that targets genetic alterations in pancreatic cancer using oncolytic replication-selective adenoviruses in tumor cells. E1B-55kDa-deleted adenovirus (AxE1AdB) can selectively replicate in TP53-deficient human cancer cells but not cells with functional TP53. Consecutive injection with AxE1AdB markedly inhibited the growth of human pancreatic tumors in severe combined immunodeficiency disease mice.

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