Exploration of tumor-suppressive microRNAs silenced by DNA hypermethylation in cervical cancer

Background: Multiple studies proved that miRNAs have a causal role in tumorigenesis. Some miRNAs are regulated by epigenetic alterations in their promoter regions and can be activated by chromatin-modifying drugs. Methods: We treated cervical cancer cells with 5-aza-2'-deoxycytidine and get a microarray analysis. Dysregulation of miRNAs was measured by qPCR in cervical cell lines and methylation status of them in cervical cancer tissue were performed with MeDIP-qPCR assay. Results: We found hypermethylation of miR-432, miR-1286, miR-641, miR-1290, miR-1287 and miR-95 may have some relationship with HPV infection in cervical cell lines. In primary tumors of cervix with paired normal tissue, expression levels of miRNAs were inversely correlated with their DNA methylation status in the cervical cancer cell lines treated with 5-AZA. Conclusions: Our results indicate that miRNAs might play a role in the pathogenesis of human cervical cancer with HPV and identify altered miRNA methylation as a possible epigenetic mechanism involved in their aberrant expression.