Evidence for miR-17-92 and miR-134 gene cluster regulation of ovarian cancer drug resistance.

OBJECTIVE: Ovarian cancer treatments are often impeded by drug resistance. It has been proposed that microRNA (miRNA) expression patterns may play a role in drug resistance among ovarian cancers. The present study investigated the relationship between resistance to the cancer drug paclitaxel and miRNA expression. MATERIALS AND METHODS: We compared the expression patterns of miRNA genes in paclitaxel-sensitive (SKOV3) and paclitaxel-resistant (SKOV3-TR30) cell lines. RESULTS: Expression of the miR-134 gene cluster was found to be significantly lower in the paclitaxel-resistant cell line than in the paclitaxel-sensitive cell line, while the expression of the miR-17-92 gene cluster was significantly higher in the paclitaxel-resistant cells. An analysis of miRNA target gene protein expression revealed that several targets of miR-17-92 were significantly altered between the two cell types. CONCLUSIONS: The higher expression of miR17-92 and lower expression of mi-134 and the associated alterations of target gene expression may be associated with the drug-resistant nature of some ovarian cancers.