MicroRNA miR-886-5p inhibits apoptosis by down-regulating Bax expression in human cervical carcinoma cells

Objective. MicroRNA (miRNA) plays an essential role in the progression of a variety of cancers, but its role in cervical cancer progression is not well defined. We aimed to test whether special miRNAs and their target mRNAs contribute to cervical cancer progression. Methods. The expression profiles of 1145 microRNAs in cervical squamous cell carcinomas (CSCC) and adjacent non-tumor tissues were investigated using an Illumina microRNA microarray platform. Differentially expressed miRNAs were validated by RT-PCR. Downstream target validation was performed for miR-886-5p. Results. We found that the expression levels of seven miRNAs differed significantly between CSCC tissues and adjacent non-tumor tissues. Forced expression of one miRNA, miR-886-5p, over-expressed in CSCC tissues lowered expression of the pro-apoptotic protein Bax, reduced apoptosis and promoted cell proliferation in H8, an HPV16-immortalized human cervical squamous epithelial cell line. Knockdown of miR-886-5p increased Bax protein and apoptotic cell death in cells of the cervical squamous carcinoma cell line, SiHa. Conclusion. MicroRNA miR-886-5p inhibits apoptosis of cervical cancer cells by down-regulating the production of Bax. (C) 2010 Elsevier Inc. All rights reserved.