MiR-188-5p Inhibits The Growth,Invasion And Metastasis Of Hepatocellular Carcinoma By Targeting HDAC9

【Objective】To investigate the role of miR-188-5p in inhibiting the proliferation,invasion and migration of hepatoma cells by targeting HDAC9,and explore the related molecular mechanism.【Methods】RT-qPCR was used to detect the expression level of miR-188-5p in human hepatocyte L-02 and 6 kinds of human hepatoma cell lines including BEL-7402,HCC-LM3,MHCC97 H,SK-Hep-1,Hep G2 and HuH-7.The cell line with the lowest expression level was selected to construct the miR-188-5p-overexpressing cell line by the lentiviral stable transfection technique.Then we setted up 3 experimental groups in following experiments: positive transfection group(miR-188-5p overexpression group),negative transfection group(transfection without overexpression of miR-188-5p),blank control group(had not been transfected group).Firstly,cell biological behaviors of the three groups of cells were detected and compared: proliferation was detected by CCK8 proliferation assay,invasion was detected by Transwell invasion assay,and migration was detected by scratch detection.Moreover,the difference of HDAC9 protein expression in 3groups of cells wsa detected by Western blot.Finally,dual luciferase assay was used to analyze the correlation between HDAC9 and miR-188-5p.【Results】The expression level of miR-188-5p was significantly lower in the 6 kinds of hepatoma cell lines than that in the hepatocyte L-02,while HuH-7 cell line just has 5%level of L-02(P<0.001),showing the most significant decrease.After constructing a miR-188-5p-overexpressing HuH-7 cell line by stably transfecting with lentivirus successfully,we performed a series of cell function experiments which exhibited that,the ability of cell proliferation,invasion and migration of the positive transfection group were significantly inhibited(all P<0.01)compared with the negative transfection group and the blank control group respectively.The HDAC9 protein expression was also significantly decreased(P<0.001).Furthermore,the result of dual luciferase assays demonstrated that HDAC9 is a target gene downstream of miR-188-5p.【Conclusion】Mi R-188-5p is down-regulated in hepatoma cell.Up-regulating of miR-188-5p expression level could inhibit the growth,invasion and metastasis of hepatoma cells by targeting HDAC9,which also could reduce the protein levels of HDAC9.