Abstract 1897: Application of a novel DNA methylation analysis method (MSE) for mucin expression in pancreatic juices for diagnosis of pancreatic neoplasms

Abstract

Abstract Mucins play crucial roles in diagnostic and prognostic prediction and in carcinogenesis and tumor invasion. In our clinicopathological investigation for mucin expression in human pancreatic ductal adenocarcinomas (PDACs) and intraductal papillary mucinous neoplasms (IPMNs), we had reported that MUC1 (pan-epithelial membrane mucin) or MUC4 (tracheobronchial mambrane mucin) expression is related with the aggressive behavior and a poor outcome of the patients, whereas MUC2 (intestinal secretory mucin) expression tends to be related with the indolent behavior and a favorable outcome of the patients. We investigated the mechanism of mucin genes expression from the DNA methylation standpoint in human cancer cell lines using the mapping of methylated cytosines by the quantitative MassARRAY analysis, followed by the confirmation with MSP analysis and a novel DNA methylation analysis method ‘methylation specific electrophoresis (MSE, international patent open: WO 2011/132798)’, and compared the results with expression levels of mucin core protein and mRNA in the cancer cells. The results obtained showed that MUC1, MUC2 and MUC4 expression is regulated by DNA methylation at their proximal 5′ flanking regions in the cancer cells. The MSE method greatly decreases the amount of input DNA, although conventional analytical methods for DNA methylation require a large amount of DNA and have low sensitivity. The lower detection limit for distinguishing different methylation status is under 0.1% and the detectable minimum amount of DNA is 20 pg, which can be obtained from only a few cells. We applied the MSE method to human pancreatic juices from 45 patients with various pancreatic lesions. The analyses for DNA methylation status of MUC1, MUC2 and MUC4 combined with image data were useful for differential diagnosis of various human pancreatic neoplasms. The examination of 45 samples of human pancreatic juices by the MSE method combined with the image examination showed the following specificity and sensitivity by quadratic discrimination analysis: PDAC, 87% and 80%; gastric-type IPMN (safe type), 88% and 77%; intestinal-type IPMN (dangerous type), 100% and 88%; respectively. The MSE analysis of human pancreatic juices may give us very useful informations for the selection of the treatment methods for pancreatic neoplasms. Citation Format: Suguru Yonezawa, Seiya Yokoyama, Michiyo Higashi. Application of a novel DNA methylation analysis method (MSE) for mucin expression in pancreatic juices for diagnosis of pancreatic neoplasms. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 1897. doi:10.1158/1538-7445.AM2014-1897