MicroR-19a/b Regulate Cervical Carcinoma Cell Proliferation And Invasion By Targeting CUL5

[Background and Aims] MicroRNAs(miRNAs) are a class of single-stranded non-coding regulatory small molecule RNA. They represents an important new class of regulatory biomolecules that play fundamental global roles in human biology, including development, differentiation, apoptosis, metabolism, viral infection and tumor genesis, suggesting that it very likely to play a key role in the occurrence and development of the cervical cancer. Uterine cervical cancer is one of the most common cancers in women worldwide and there is a strong need for a non-invasive, fast and dfficient method to diagnose the disease. The processes of migration and invasion in cervical cancer are cascade of linked sequential steps involving multiple regulated genes. Study demonstrates that microRNA-19a (miR-19a) and microRNA-19a (miR-19b) are highly expressed in human cervical carcinoma tissue samples. The objective of this paper is to find the molecular mechanisms of miR-19a and miR-19b in initiation and progression of cervical carcinoma.[Methods] First, we examined miR-19a and miR-19b expression in human cervical carcinomas and matched normal tissues by real-time RT-PCR assay. Using the WST-1, colony formation and cell growth curve assays to detect the effect of miR-19a and miR-19b on the growth capacity of cervical carcinomas cell lines. We integrated the bioinformatics-based predictions and the resulting candidate functions and selected the CUL5gene that had the highest recurrence rate as a potential target gene of miR-19a/b, and the reliability of the direct target miRNA miR-19a、miR-19b of CUL5was confirmed by fluorescent reporter experiment. The mRNA and protein levels of target gene were tested by Real-time PCR and Western blot. Finally, the function of CUL5was rescued or knocked down in cervical carcinomas cell lines and the changes of cell phenotypes were detected with WST-1assay, cell growth curve assays, colony formation assay and transwell assays.[Result] Upregulation of miR-19a and miR-19b induced the malignant phenotype of HeLa and C33A cells, whereas knockdown of miR-19a and miR-19b reversed this phenotype via induction of CUL5expression. In addition, knockdonwn of miR-19a and miR-19b notably inhibited cell growth and invasion. The seed sequence of miR-19a and miR-19b complimentary to the3’UTR of CUL5, and introducing a CUL5cDNA without the3’UTR into HeLa cells abrogated the miR-19a and miR-19b-induced malignant phenotype. CUL5-3’UTR luciferase reporter assay confirmed CUL5as a direct target of miR-19a and miR-19b. [Conclusion] These results demonstrate that miR-19a and miR-19b regulate cell growth and invasion of HeLa cells, possibly via direct modulation of CUL5expression. Our study suggests that inhibition of miR-19a and miR-19b might be potential value of development new therapeutic approach for human cervical carcinoma.