MicroRNA-492 overexpression involves in cell proliferation, migration, and radiotherapy response of cervical squamous cell carcinomas

Abstract

MicroRNAs (miRNAs) are small non-coding RNA that target protein-coding mRNAs at the post-transcriptional level. The aim of this study was to define the role of miR-492 in cervical squamous cell carcinomas. After microRNA profiling and comparison, we firstly detected miR-492 expression in 104 tumor tissues biopsies derived from advanced staged (FIGO IIB-IIIB) cervical squamous cell carcinoma patients before receiving concomitant chemoradiotherapy and found miR-492 expression was significantly higher in the specimens that were sensitive to concomitant chemoradiotherapy, as compared with insensitive cancer specimens (P < 0.05). Moreover, higher expression of miR-492 was associated with pelvic lymph node metastasis (LNM) (P < 0.05). Further studies illustrated ectopic miR-492 overexpression in SiHa cells promoted cell proliferation, migration, and enhanced the sensitivity of cervical cancer cells to irradiation by promoting apoptosis. In addition, we identified TIMP2 as a direct miR-492 target, which has been shown to be critical in modulating cancer cell migration and invasion. We also confirmed that miR-492 expression levels in positive pelvic LNM were much higher than negative LNM and miR-492 played a vital role in pelvic lymph node metastasis via regulating miR-492/TIMP2/MMP10 axis. In particular, miR-492 was correlated with prognosis in the subgroup of patients with negative pelvic LNM (P < 0.05) and had a promising value in predicting treatment response in the subgroup of patients with positive pelvic LNM (an AUC of 85%, 75.00% specificity, and 95.24% sensitivity). Taken together, the results suggested that miR-492 may serve as a potential biomarker for cervical cancer treatment and prognosis.

Keywords: TIMP2; cervical cancer; metastasis; miR-492; pelvic lymph node; radiosensitivity.