The Research Of SET8 Gene Silencing Inhibit The Growth Of Hepatocellular Carcinoma

Objective: The lysine methyltransferase SET8,which is mainly involved in gene transcription,DNA synthesis and repair,heterochromatin formation,genome stability,cell cycle process and other aspects of regulation.As such,it is predicted that SET8 might be involved in the development and progression of multiple tumors.Our previous study suggested that the lysine methyltransferase SET8,whose expression was regulated by miR-502 through the binding site in the 3'UTR of SET8,implicated in the prognosis of hepatocellular carcinoma.Subsequent studies have shown that siRNA-mediated silencing of the SET8 gene could significantly inhibit cell proliferation,invasion and migration abilities for human hepatocellular carcinoma of SMMC-7721 cells in vitro.This study is to investigate the effect of small interference siRNAmediated silencing of the SET8 gene on growth of human hepatocellular carcinoma SMMC-7721 cells in vivo.Methods:1 Designed and transcriptive synthesized a fluorescein-labeled siRNAs targeting the SET8 gene in vitro,which were transfected into SMMC-7721 cells by LipofectamineTM2000.2 SET8-siRNA and control-siRNA stably transfected SMMC-7721 monoclonal cells was selected by puromycin.3 Western Blotting techniques were used to verification the inhibitory effect of siRNA on the expressions of SET8 protein.4 The animal experiments were used to observe the effect of SET8 gene silencing on hepatocellular carcinoma.The SET8-siRNA stably transfected and control-siRNA stably transfected SMMC-7721 cells were subcutaneously inoculated into the subcutaneous of the mice.The tumor size and growth rate of nude mice were observed every week,and the tumor volume was calculated.The green fluorescent images for the xenograft was measured using the NightOwl Bioimager(Berthold Technologies,Bad Wildbad,Germany)once a week.5 SPSS 21.0 statistical software was used for statistical analysis,t test and One-way ANOVA were used to compare differences between groups,with P <0.05 was considered statistically significant.Results:1 The cells transfected with SET8-siRNA and control-si RNA were successfully constructed.The transfection efficiency was 100% under fluorescence microscope scan.2 Compared with control-siRNA group and blank-control group,the expression of SET8 protein in SET8-siRNA group was significantly reduced(P<0.05),and the inhibition rate was about 49% compared with controlsiRNA group.3 Compared with control-siRNA group and blank-control group,the growth of xenografts in SET8-siRNA group was significantly inhibited on the7 th,14th and 21 st day after implantation(the 7th day,P<0.05;the 14 th day,P<0.05;the 21 st day,P<0.05).Conclusion:SiRNA-mediated silencing of the SET8 gene could inhibit the growth of hepatocellular carcinoma in vivo.