PI3K/AKT信号转导通路在肝癌细胞生长和黏附中的作用

Role of PI3K/Akt pathway in the growth and adherence of human hepatocelluar carcinoma cells

目的:探讨PI3K/AKT(磷脂酰肌醇-3-激酶/蛋白激酶B)信号转导通路在人肝癌细胞株SMMC-7221生长和黏附中的作用机制.方法:应用LY294002作用于SMMC-7221细胞,并设对照组和实验组(LY294002:5、10、20、40μmol/L),MTT法检测LY294002作用24、48、72、96h后,对SMMC-7221细胞增殖的影响;采用肿瘤细胞-基质黏附实验检测对照组和干预组SMMC-7221黏附能力的变化;流式细胞仪检测肝癌细胞黏附分子CD44s表达情况;细胞免疫化学S-P法检测SMMC-7221细胞血管内皮生长因子(vascular endothelial growth factor,VEGF)和CD44V6蛋白表达.结果:LY294002对SMMC-7221细胞的增殖有抑制作用,呈剂量和时间依赖性;5、10mol/L的LY294002作用于肝癌细胞后与对照组相比CD44s,VEGF,CD44V6蛋白表达下降(CD44s:42.84%±6.35%,20.21%±4.5%vs89.23%±3.91%,P<0.01;VEGF:103.11±18.60,68.99±15.99vs137.84±22.50,P<0.01;CD44V6:47.33±6.15,33.09±5.23vs61.36±7.39,P<0.01);5、10μmol/L的LY294002干预后与对照组相比SMMC-7221黏附能力下降(0.498±0.024,0.407±0.029vs0.616±0.080,P<0.01).结论:阻断PI3K/AKT信号传导通路,肝癌细胞生长受到抑制、黏附能力下降.LY294002抑制肝癌细胞黏附力的作用机制与通过降低CD44V6、CD44s和VEGF水平有关.

AIM： To investigate the role of phosphoinositide 3-kinase （PI3K）-protein kinase B （Akt） pathway in the growth, adherence and invasion of human hepatoma carcinoma cell line SMMC-7221 and its mechanism. METHODS： MTT reduction assay was used to evaluate the inhibition of SMMC-7221 cells treated with LY294002 （5, 10, 20, 40 μmol/L） for 24, 48, 72, 96 h. The tumor adhesion ability was detected by cell-matrix adhesion experiment. Flow cytometry （FCM） was used to detect CD44s expression. Immunocytochemistry was used to detect the expression of vascular endothelial growth factor （VEGF） and CD44V6 in SMMC-7221 cells. RESULTS： LY294002 at concentrations of 5, 10, 20 and 40 μmol/L inhibited the proliferation of SMMC-7221 cells in a time- and dose-dependent manner. LY294002 at 5 and 10 μmol/L induced down-regulation of VEGF, CD44V6 and CD44s protein expression as compared with the control group （VEGF： 103.11 ± 18.60, 68.99± 15.99 vs 137.84 ± 22.50, P 〈 0.01; CD44V6：47.33 ± 6.15, 33.09 ± 5.23 vs 61.36 ± 7.39, P 〈 0.01; CD44s： 42.84% ± 6.35%, 20.21% ± 4.5% vs 89.23% ± 3.91%, P 〈 0.01）; meanwhile, LY294002 at 5 and 10 μmol/L reduced the adhesion ability of SMMC-7221 cells in comparison with the control group （0.498 ± 0.024, 0.407 ± 0.029 vs 0.616 ± 0.080, P 〈 0.01）. CONCLUSION： PI3K/AKT pathway plays an important role in the growth, adherence and invasion of SMMC-7221 cells, and its catastaltic may be used in the management of hepatocellular carcinoma.