miR-137 Regulates Proliferation, Migration, Invasion and EMT of Nasopharyngeal Carcinoma Cells by Targeting TWIST1

Abstract

To investigate the effects of miR-137 on biological cell function of nasopharyngeal carcinoma (NPC) cells. Totally, 31 pairs of NPC tissues and para-cancer tissues were collected. Meanwhile, human immortalized nasopharyngeal epithelial cell lines (NP69) and human NPC cell lines (6-10B) were cultured. The abilities of cell proliferation, invasion and migration were detected by CCK-8 and Transwell assay, respectively. The relative protein and mRNA expression level was detected by Western blot and quantitative real-time polymerase chain reaction (qRT-PCR) analysis. In quantitative real-time polymerase chain reaction (qRT-PCR) experiment, miR-137 was found widely low-expressed in clinical samples and cell lines of nasopharyngeal carcinoma (NPC). On-line target gene prediction software was applied to screen potential downstream target of miR-137 in NPC. Then, Twist Family BHLH Transcription Factor 1 (TWIST1) was verified by luciferase reporter assay and Western blot experiments as a target for negative regulation of miR-137 in NPC cells. We up-regulated the expression of miR-137 and/or TWIST1 in 6-10Bin vitro, and then examined the effects of cell function after by CCK8, Transwell, scratch-wound and Western blot experiments. The results showed that decreased expression of TWIST1 resulting from up-regulation of miR-137 in 6-10B cells could inhibit the biological functions of cells including proliferation, invasion, migration and process of epithelial-mesenchymal transition (EMT). Our research discovered the suppressor function of miR-137 on NPC cells by targeting TWIST1, suggesting that miR-137 could be used as a potential therapeutic target for NPC.