Low expression of miR-449 in gynecologic clear cell carcinoma.

Clinical detection of ovarian clear cell carcinomas is important because of the poor prognosis. To identify microRNA profiles specific for clear cell carcinomas, microRNA expression profiles were compared between clear cell carcinomas and serous carcinomas of the ovary using microRNA microarray. In parallel, clear cell carcinomas were compared with germ cell tumors of the ovary. Six microRNAs differentially expressed between ovarian clear cell and serous carcinomas distinguished uterine clear cell carcinomas from endometrioid carcinomas. MiR-449 was underexpressed in both ovarian and uterine clear cell carcinomas. When germ cell tumors were compared with clear cell carcinomas of the ovary, miR-302d was the most significantly overexpressed microRNA in germ cell tumors. Thus, here we describe microRNA profiles characteristic for clear cell carcinomas of the ovary and uterus.