MicroRNA-214 is Aberrantly Expressed in Cervical Cancers and Inhibits the Growth of HeLa Cells

MicroRNAs are a group of endogenously expressed, single-stranded, 18-24 nt RNAs that regulate diverse cellular pathways. Although documented evidence indicates that some microRNAs can function as oncogenes or tumor-suppressors, the role of miR-214 in regulating human cervical cancer cells remains unexplored. We determined the expression level of miR-214 and found it is downregulated in cervical cancer compared with normal tissue. Overexpression of miR-214 in HeLa cells, a human cervical cancer cell line, significantly inhibited cell proliferation according to the MTT and colony forming assays. HeLa cells that stably overexpress miR-214 downregulate the expression of MEK3 and JNK1 at both mRNA and protein levels. Further investigation revealed that miR-214 regulates the expression of MEK3 and JNK1 by targeting the 3'UTRs of these genes. Collectively, these results suggest that miR-214 negatively regulates HeLa cell proliferation by targeting the noncoding regions of MEK3 and JNK1 mRNAs.