MicroRNA-195-5p suppresses metastasis by targeting VEGFA in nasopharyngeal carcinoma

Abstract

Background MicroRNA (miRNA) plays an important role in nasopharyngeal carcinoma (NPC). We aimed to identify a microRNA that can help us understand the molecular mechanism and develop target therapy for NPC. Methods: MiRNA expression levels in 18 specimens of nasopharyngeal carcinoma were firstly analysed using quantitative real-time PCR (qRT-PCR). Then we further detected vascular endothelial growth factor A (VEGFA) protein with immunohistochemistry in 108 paraffin-embedded samples from the First Affiliated Hospital of Guangzhou Medical University (Guangzhou, China). The cell line Hone1, 5-8F, CNE1 and CNE2 were employed in transwell invasion assay, western blot, RT-PCR and dual luciferase assay. Results: We found miR-195-5p had a lower expression level in high metastasis potential NPC, compared with low metastasis potential NPC (p < 0.05). In in-vitro experiment, the over expressed miR-195-5p resulted in significant decrease in migration and invasion of NPC cells. In contrast, the down-regulation of miR-195-5p increased their migration and invasion. By using dual luciferase assay, we found a binding site between miR-195-5p and 3’-UTR of VEGFA. Through direct binding, miR-195-5p can suppress VEGFA in NPC cell. The results of immunohistochemistry showed that patients with high expression of VEGFA had a poor distance-metastasis free survival (p < 0.05). Conclusions: It was concluded that the expression level of miR-195-5p in patients with NPC was associated with metastasis by targeting VEGFA, which suggests that miR-195-5p is a potential biomarker of prognosis and molecular therapeutic target in NPC.