Abstract 730: High sensitive detecting procedure of circulating repetitive RNA as novel early marker of pancreatic cancer

Abstract

Abstract Pancreatic ductal adenocarcinoma (Pdac) is one of the most intractable malignancies due to difficulties in early detection. Although promising biomarkers are increasingly reported, such methods are not yet easy to apply clinically, mainly due to their low reproducibility or technical difficulties. In this study, we developed a convenient and sensitive method for quantifying aberrantly expressed satellite repeat RNAs in sera, which can be used to efficiently detect patients with Pdac. It is difficult to correctly quantitate repeat arrays because its repetitive nature makes it difficult to establish appropriate primers that amplify a single product using simple PCR procedures. Here, we introduce a Tandem Repeat Amplification by nuclease Protection (TRAP) method combined with droplet digital PCR (ddPCR) to detect human satellite II (HSATII) RNAs, which are specifically expressed in human Pdacs at greater levels than normal tissues. HSATII RNA core sequence levels in sera were significantly higher in Pdac patients compared with non-cancer patients (median copy number: 14.75 and 3.17 per µl in the training set and 17.35 and 2.9 in the validation set, respectively). In addition, patients with intraductal papillary mucinous neoplasm (IPMN), a precancerous lesion of Pdac, could also be efficiently detected. This method can be routinely applied to screen patients with Pdac and high-risk patients, facilitating the development of preventive medicine for this disease. Citation Format: Takahiro Kishikawa, Motoyuki Otsuka, Kazuhiko Koike. High sensitive detecting procedure of circulating repetitive RNA as novel early marker of pancreatic cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 730. doi:10.1158/1538-7445.AM2017-730