The expression of the miRNA-200 family in endometrial endometrioid carcinoma.

Recent reports suggest that targeting the unique miRNAs highly expressed in several cancers may be a promising approach in the development of new cancer therapeutic tools. The purpose of this study was to evaluate the roles of miRNAs as therapeutic targets in human endometrial endometrioid carcinomas (EECs). We evaluated the differential expressions of miRNAs in EECs and normal endometrial tissues using microarrays and cluster analysis. After validation of differentially expressed miRNAs in another set of EECs and normal endometrial tissues, we performed the in vitro experiment using endometrial cancer cells with anti-miRNA (anti-miR) to evaluate the roles of miRNAs that are highly expressed in EECs for cell proliferation and chemosensitivity. A miRNA microarray showed that the miR-200 family, including hsa-miR-141, hsa-miR-200a, hsa-miR-200b, hsa-miR-200c, and hsa-miR-429, was up-regulated in EECs as compared with that in normal endometrial tissues. When we treated endometrial cancer cells with specific anti-miRs, including anti-miR-141, -200a, -200b, -200c, or -429, we found that anti-miR-200a, -200b, -200c, and -429 significantly inhibited the growth of HEC-1A cells and anti-miR-141, -200c, and -429 significantly inhibited the growth of Ishikawa cells. Moreover, transfection with anti-miR-429 enhanced the cytotoxic effect of cisplatin in HEC-1A cells. These results indicate that the miR-200 family is highly expressed in EECs compared with that of normal endometrial tissues and could play an important role in cancer growth. Specifically, anti-miR-429 could enhance the cytotoxic activity with cisplatin in EECs. Therefore, the miR-200 family may offer new candidate targets to be exploited in therapeutic strategies for patients with these carcinomas.