MicroRNA-185 (miR-185) is down-regulated in various tumor types. However, the cytological mechanism for inhibiting and restraining tumor growth of non-small-cell carcinoma (NSCLC) remains to be elucidated. In this study, it was revealed that miR-185 is significantly down-regulated in both NSCLC tumor tissues and cell lines, and over-expression of miR-185 inhibited cell growth, migration and invasion. To investigate the cellular machinery involved in miR-185's regulation of tumor growth, it was found that miR-185 directly targets SRY-Box 13 (SOX13). In addition, miR-185 regulated cell proliferation, migration, invasion and increased chemo-sensitivity in H1975 cells by inhibiting SOX13. MiR-185 also inhibited tumor growth and suppressed SOX13 in nude mouse xenograft tumors. To investigate the clinical relevance of these consequences, 24 pairs of NSCLC tissues and adjacent normal tissues were collected to determine expression of miR-185 and SOX13. It was demonstrated that miR-185 levels are significantly and inversely correlated with SOX13 levels in these NSCLC tissues, suggesting that these findings have implications for translational application with respect to NSCLC diagnostics and therapy.
Keywords: NSCLC; SOX13; chemo-resistance; miR-185.