ABSTRACT
[Objective]To investigate the effect of KIF23 gene expression on the proliferation,migration and invasion of human hepatocellular carcinoma HepG2 cells in vitro,and to explore the possible mechanism.[Methods]The KIF23 siRNA was transfected into HepG2 cells by lipofectamine 3000.The expression of KIF23 mRNA and protein in HepG2 cells was de-tected by qRT-PCR and Western blot.The effect of silencing KIF23 on the proliferation of HepG2 cells was studied by CCK-8 assay and plate clone formation assay.The tumor cell abilities of migration and invasion after transfection were measured by scratch assay and Transwell assay.The expression of protein kinase B(PKB/Akt)and phosphorylated Akt(p-Akt)protein in HepG2 cells transfected with KIF23-siRNA2 was detected by Western blot.[Results]KIF23-siRNA could effectively si-lence the expression of KIF23 mRNA and protein in HepG2 cells(P<0.01).The results of CCK-8 assay,plate clone forma-tion assay,scratch assay and Transwell assay demonstrated that the cell proliferation,migration and invasion ability of the KIF23-siRNA2 interference group were significantly inhibited,compared to the negative control group and the blank control group(P<0.05).The expression level of total Akt protein in HepG2 cells was not changed,but the expression level of phos-phorylated Akt protein was down-regulated(P<0.05).[Conclusions]KIF23 may promote the proliferation,migration and in-vasion of human hepatocellular carcinoma cells by activating Akt signal transduction pathway.KIF23 is expected to be a new target for gene therapy of hepatocellular carcinoma.
ABSTRACT
<p><b>OBJECTIVE</b>To investigate the effects of farnesoid X receptor (FXR) on lipid metabolism in human hepatic L02 cells.</p><p><b>METHODS</b>A steatosis model and an intervention model were established by treating human hepatocyte line L02 cells with sodium oleate or sodium oleate and sodium chenodeoxycholate (a natural agonist of FXR) respectively. Non-treated L02 cells served as controls. At three time points of 24, 48 and 72 hours, the accumulation of lipid droplets in the hepatocytes was observed by optical microscopy after oil red O staining, and the the expression of FXR and SREBP-1c receptors was detected by RT-PCR and Western blot.</p><p><b>RESULTS</b>Compared with the controls, expressions of FXR mRNA and protein were down-regulated gradually in the steatosis model at 24, 48 and 72 hours, FXR mRNA/beta-actin mRNA was 0.186+/-0.02, 0.182+/-0.028 and 0.181+/-0.022, FXR protein/beta-tubulin protein was 0.105+/-0.016, 0.103+/-0.012 and 0.103+/-0.018, F from 0.01 to 0.14; 24 h vs 48 h, 48 vs72 h: P more than 0.05. The expressions of SREBP-1c mRNA and protein were increased gradually. At 24, 48 and 72 hours, SREBP-1c mRNA/beta-actin mRNA was 0.495+/-0.062, 0.579+/-0.064 and 0.612+/-0.067, SREBP-1c protein/beta-tubulin protein was 0.394+/-0.044, 0.488+/-0.066 and 0.543+/-0.064, F from 0.80 to 4.66, 24 h vs 48 h, 48 vs 72 h: P less than 0.05. In the intervention model, expressions of FXR mRNA and protein were increased markedly compared with the steatosis model. At 24, 48 and 72 hours, FXR mRNA/beta-actin mRNA was 0.253+/-0.041, 0.298+/-0.042 and 0.334+/-0.051, and FXR protein/beta-tubulin protein was 0.221+/-0.022, 0.313+/-0.041 and 0.341+/-0.046, F from 6.41 to 50.93, intervention models vs steatosis models at the same time points: P less than 0.05-0.01. Expressions of SREBP-1 c mRNA and protein were significantly reduced. At 24, 48 and 72 hours, SREBP-1c mRNA/beta-actin mRNA was 0.296+/-0.038, 0.328+/-0.037 and 0.341+/-0.055, and FXR protein /beta-tubulin protein was 0.295+/-0.038, 0.334+/-0.047 and 0.355+/-0.054, F from 8.84 to 48.46; intervention models vs steatosis models at the same time point: P less than 0.01. Both in the steatosis model and the intervention model, content of TG and lipids accumulations were much more than those in the controls. Compared with the intervention model, levels of TG and lipids accumulation were markedly increased in the steatosis model at 24, 48, 72 hours. At 24, 48 and 72 hours, TG/cellular total protein in microg/mg was 173.0+/-20.5, 253.4+/-36.1 and 361.2+/-50.7 in the steatosis model, while in the intervention model the data was 84.1+/-17.2, 113.0+/-14.5 and 127.2+/-20.1, F from 38.70 to 268.13, intervention models vs steatosis models at the same time point: P less than 0.01.</p><p><b>CONCLUSION</b>Expression of FXR is closely associated with lipid homeostasis in hepatocytes. Up-regulation of the expression of FXR may improve lipidosis in L02 cells. Its possible mechanism involves reduction of SREBP-1c expression and lipogenesis in hepatocytes.</p>