title: Quantitation of circulating satellite RNAs in pancreatic cancer patients.
abstract: Pancreatic ductal adenocarcinoma (Pdac) is a malignancy with a poor prognosis 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. 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 but are difficult to measure due to their repetitive sequences and irregularities. HSATII RNA core sequence levels in sera were significantly higher in Pdac patients compared with noncancer 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.
authors.affiliation: Department of Gastroenterology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.
authors.forename: Takahiro
authors.initials: T
authors.lastname: Kishikawa
authors.affiliation: Department of Gastroenterology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.|Precursory Research for Embryonic Science and Technology (PRESTO), Japan Science and Technology Agency (JST), Kawaguchi, Saitama, Japan.
authors.forename: Motoyuki
authors.initials: M
authors.lastname: Otsuka
authors.affiliation: Department of Gastroenterology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Yoshikawa
authors.affiliation: Department of Gastroenterology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.
authors.forename: Motoko
authors.initials: M
authors.lastname: Ohno
authors.affiliation: Department of Gastroenterology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.
authors.forename: Keisuke
authors.initials: K
authors.lastname: Yamamoto
authors.affiliation: Department of Gastroenterology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.
authors.forename: Natsuyo
authors.initials: N
authors.lastname: Yamamoto
authors.affiliation: Precursory Research for Embryonic Science and Technology (PRESTO), Japan Science and Technology Agency (JST), Kawaguchi, Saitama, Japan.|Division of Hematological Malignancy, The Institute of Medical Sciences, Tokai University, Isehara, Kanagawa, Japan.
authors.forename: Ai
authors.initials: A
authors.lastname: Kotani
authors.affiliation: Department of Gastroenterology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Koike
mesh_terms: D021441:Carcinoma, Pancreatic Ductal / Q000097:blood*; D002460:Cell Line; D006801:Humans; D010190:Pancreatic Neoplasms / Q000097:blood*; D019244:RNA, Satellite / Q000097:blood*; D015203:Reproducibility of Results
chemical_list: D019244:RNA, Satellite