MiR-125b targets BCL3 and suppresses ovarian cancer proliferation.

Micro-RNAs (miRNAs) important for post-transcriptional gene expression as negative regulators are endogenous 21- to 23-nucleotide noncoding RNAs. Many miRNAs are expressed in ovarian cancer (OC). In this study, we reported that miR-125b was underexpressed in human OC specimens. Ectopic expression of miR-125b in OC cells induced cell cycle arrest and led to reduction in proliferation and clonal formation. This inhibitory effect on OC cell growth was mediated by miR-125b inhibition of the translation of an mRNA encoding a proto-oncogene, BCL3. Furthermore, expression of miR-125b suppressed the tumor formation generated by injecting OC cells in nude mice. Our results suggest that aberrantly expressed miR-125b may contribute to OC development.