Up-regulated microRNA-155 expression is associated with poor prognosis in cervical cancer patients

MicroRNAs (miRNAs) play important roles in tumor development and progression. The purposes of the study was to investigate the role of miR-155 in cervical cancer.

Quantitative real-time RT-PCR (qRT-PCR) was performed to examine miR-155 expression in cervical cancer tissues and adjacent non-cancerous tissues. The association with overall survival of patients was analyzed by Kaplan-Meier survival analysis. Small interfering RNA (siRNA) was used to suppress miR-155 expression in cervical cancer cells. In vitro assays were performed to further explore the biological functions of miR-155 in cervical cancer.

We found that miR-155 expression was markedly up-regulated in cervical cancer tissues and correlated with FIGO stage, lymph nodes metastasis, vascular invasion and HPV. Patients with high miR-155 expression level had poorer overall survival than those with low miR-155 expression. Furthermore, multivariate Cox regression analysis suggested that increased miR-155 was an independent prognostic indicator for cervical cancer (P=0.007; HR=2.320; 95%CI: 1.259-4.276). Moreover, knockdown of miR-155 was demonstrated to inhibit cell proliferation, migration, and invasion in vitro.

Our study presents that miR-155 is a novel molecule involved in cervical cancer progression, which provide a potential prognostic biomarker and therapeutic target.