EMca: serous, endometrioid, normal (miRNA)

To determine the expression profiles of microRNAs (miRNAs) and to examine specific miRNA expression in endometrial serous adenocarcinoma in comparison with normal endometrial tissue and endometrial endometrioid adenocarcinoma.　Twenty-one serous adenocarcinoma tissues, 20 endometrioid adenocarcinoma tissues, and 7 normal endometrial tissues were enrolled.　miRNA expression profiles were examined using miRNA microarray. After obtaining informed consent, 21 serous adenocarcinoma tissues, 20 endometrioid adenocarcinoma tissues, and 7 normal endometrial tissue　were retrieved from the surgical pathology files at Tohoku University Hospital (Sendai, Japan). The research protocol was approved by the Ethics Committee at Tohoku University Graduate School of Medicine (Sendai, Japan). All specimens were obtained from surgery that was performed between January 2001 and December 2006 at Tohoku University Hospital (Sendai, Japan). We also obtained nonpathologic endometrial tissues as normal controls from hysterectomy specimens performed due to non-endometrial carcinomas. No patient had received preoperative irradiation or chemotherapy. The lesions were classified according to the Histological Typing of Female Genital Tract Tumors by the WHO and staged according to the International Federation of Gynecology and Obstetrics system. Only those patients whose endometrial carcinomas were comprised of pure adenocarcinoma and did not have any other histological components were enrolled. These specimens were processed in 10% formalin, fixed for 24-48 hours, paraffin embedded, and thin-sectioned (3 μm). All of these archival specimens were embedded immediately in OCT compound (Sakura Finetechnical, Tokyo, Japan) and stored at -80℃ for further use. Only sections containing a minimum of 90% carcinoma by examination with hematoxylin-eosin staining were used for total RNA preparation. Total RNA, including miRNA, was extracted using a QIAzol Lysis reagent (Qiagen, Valencia, CA, USA) and a miRNeasy Mini Kit (Qiagen) according to the manufacturer’s instructions.