Interactions between microRNA-200 family and Sestrin proteins in endometrial cancer cell lines and their significance to anoikis

In the present study, we intend to determine whether Sestrin proteins 1, 2, and 3 (SESN1-3) are targets of microRNA-200 family (miR-200) in endometrial cancer (EC) Ishikawa, AN3CA, KLE, and RL 95-2 cell lines and to investigate how these potential interactions influence anoikis resistance of EC cell lines. The luciferase reporter assay, qRT-PCR, and western blotting assays were used to verify whether SESN1-3 are direct targets of miR-200. Moreover, the anoikis assay and transient transfections of miR-200 mimics or inhibitors into EC cell lines were performed to evaluate the modulatory role of miR-200 and SESN proteins on anoikis resistance. We demonstrated that SESN2 protein is a direct target of mir-141 in KLE and RL-95-2 EC cell lines and the functional interaction of miR-141 and SESN2 protein has a downstream effect on anoikis resistance and SESN2 expression level in Ishikawa and AN3CA cell lines. Moreover, we have shown that SESN3 protein is a direct target of miR-200b, miR-200c, and miR-429 in Ishikawa, AN3CA, and KLE cell lines. Our results show that manipulation of miR-200b, miR-200c, and miR-429 expression patterns also has an influence on anoikis resistance in EC cell lines. In conclusion, we identified new interactions between miR-200 and the oxidative stress response SESN proteins that affect anoikis resistance in human EC cells.