Study on the mechanism of tRNA-ValAAC-5 in promoting the proliferation and migration of hepatocellular carcinoma cells

Objective:To demonstrate the role and mechanism of tRNA-ValAAC-5 expression in hepatocellular carcinoma(HCC)cells.Methods:The expression levels of tRNA-ValAAC-5 in HCC(Hep3B,HuH7,SNU398,Hep3G2)and human hepatocellular carcinoma(THLE2,THLE3)were detected by real-time PCR.HEP3B and Hep3G2 cells were respectively transfected with tRNA-ValAAC-5-inhibitor and tRNA-ValAAC-5-NC as the inhibitor group and the NC group.Then the ability of cell proliferation was detected by CCK-8 assay and the ability of invasion and metastasis was detected by Transwell assay.The protein expression levels of p21,Matrix metalloproteinase 2(MMP2)and Matrix metalloproteinase 9(MMP9)were determined by Western blot.Results:The relative expression of tRNA-ValAAC-5 in Hep3B,HuH7,SNU398 and Hep3G2 cells were significantly higher than THLE2 and THLE3 cells,the differences were statistically significant(P<0.05).After tRNA-ValAAC-5-inhibitor transfection,the expression of tRNA-ValAAC-5 in Hep3B and Hep3G2 cells were reduced than tRNA-ValAAC-NC group.Both of the differences were statistically significant(t=36.52,27.45,P<0.001),which indicated the transfection was successful.The proliferative ability of Hep3B and Hep3G2 cells transfected with tRNA-ValAAC-5-inhibitor after 24,48,72,96 h were inhibited effectively compared with tRNA-ValAAC-5-NC group.All of the differences were statistically significant in Hep3B(t=5.25,8.23,7.33,14.16,P<0.001)and Hep3G2(t=4.25,5.11,9.39,7.59,P<0.001)cells.The number of invasion and metastasis of Hep3B and Hep3G2 cells were reduced in tRNA-ValAAC-5-inhibitor group compared with tRNA-ValAAC-5-NC group,there was significant difference(t=14.01,21.85,P<0.001).The protein expression levels of P21 were lower,MMP2 and MMP9 were higher in tRNA-ValAAC-5-inhibitor group compared with tRNA-ValAAC-5-NC group,the differences were statistically significant in Hep3B(t=8.96,12.80,4.652,P<0.001)cells and Hep3G2(t=15.17,22.36,12.61,P<0.001)cells.Conclusion:tRNA-ValAAC-5 can effectively promote the proliferation,invasion and metastasis of HCC,and its possible mechanism is related to regulating the expression of p21,MMP2 and MMP9.