SummaryMicroRNAs are a group of endogenously expressed, singlestranded, 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 0 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.

No abstract

RNA interference (RNAi) has been shown to be an effective method for inhibiting the expression of a given gene in human cells by targeting with short duplex RNA (short-interfering RNA or siRNA). However, more and more studies suggest that non-specific effects can be induced by siRNAs, such as off-target inhibition, activation of interferon response, and saturation of cellular silencing machinery. It has been known that more than 90% of human tumors exhibit telomerase activity. Consequently, telomerase is believed to be a broad-spectrum molecular marker of malignancies. In the present study we attempt to develop a tumor-specific RNAi system using the human telomerase reverse transcriptase promoter. This system may provide a basis for RNAi therapy.