MALAT1通过VHL/β-catenin通路影响口腔鳞状细胞癌生长侵袭的实验研究

摘要

目的:探讨肺腺癌转移相关转录因子1(metastasis-associated lung adenocarcinoma transcript 1,MALAT1)对口腔鳞状细胞癌(oral squamous cell carcinoma,OSCC)生长侵袭的影响及其作用机制.方法:使用小干扰RNA(small interfering RNA,siRNA)敲低MALAT1在人OSCC细胞系SCC25、UM1中的表达;CCK-8法、流式细胞术检测敲低MALAT1表达后OSCC增殖能力、细胞周期及细胞凋亡的变化;细胞迁移实验及Transwell实验检测细胞运动及侵袭能力的变化;蛋白质印迹法检测细胞周期及凋亡相关蛋白、上皮间质转化(epithelial-mesenchymal transition,EMT)及侵袭相关蛋白、VHL及β-catenin等蛋白表达变化.结果:敲低OSCC中MALAT1表达后,细胞增殖能力显著下降,细胞周期出现G1/S期阻滞,周期相关蛋白cyclin D1表达减少,P21表达增多;细胞凋亡增多,凋亡相关蛋白cleaved caspase-3、Bax表达增多;且EMT相关蛋白N-cadherin、vimentin表达减少,E-cadherin表达增多,侵袭相关蛋白MMP-2、MMP-9蛋白表达减少,细胞迁移、侵袭能力下降;同时发现敲低MALAT1表达后VHL蛋白表达增多,β-catenin蛋白表达减少.结论:MALAT1是OSCC生长侵袭的重要调节因素,可能通过VHL/β-catenin通路发挥调控作用.%Objective:To investigate the effect and mechanism of metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) in modulating the growth and invasion of oral squamous cell carcinoma (OSCC). Methods:MALAT1 siRNA was transfected into SCC25 and UM1 human OSCC cell lines. Cell counting kit-8 assay and flow cytometry were used to test the proliferation, cell cycle, and apop-tosis of the cells after infection by the MALAT1 siRNA. Cell invasive and migration ability were evaluated by Transwell assay and cell mi-gration assay, respectively. The expression levels of the proteins VHL andβ-catenin, which regulate the cell cycle, apoptosis, epithelial-mesenchymal transition, invasion, and migration, were examined by Western blot assay. Results:After down regulation of the MALAT1 expression in the cells, the proliferation was inhibited, and G1/S arrest was triggered. The expression of cyclin D1 was down regulated and that of P21 was up regulated. Cell apoptosis increased, and the expression levels of Bax and cleaved caspase-3 were up regulated. Migration and invasion were attenuated. The expression levels of N-cadherin, vimentin, and MMP-2/9 were down regulated, and the expression of E-cadherin was up regulated in the cells after the knockdown of MALAT1. These findings show significant differences be-tween the transfected cells and negative-control cells. We found that VHL expression was up regulated and that ofβ-catenin was down regulated. Conclusion:MALAT1 is an important factor for the growth and invasion of OSCC. MALAT1 possibly modulates these process-es through the VHL/β-catenin signal pathway.