阻断胰岛素样生长因子Ⅰ型受体对肝癌细胞生长的影响

IGF-Ⅰ receptor blockage inhibits the growth of human hepatocellular carcinoma cells

目的 了解胰岛素样生长因子Ⅰ型受体（IGF-IR）在人肝癌细胞株HepG2及正常人肝细胞株Chang Liver的表达和定位；观察胰岛素样生长因子Ⅰ型受体单克隆抗体（αIR3）对HepG2细胞生长的生物学作用。方法 免疫组织化学法检测HepG2及Chang Liver细胞的IGF-ⅠR表达；四甲基偶氮唑蓝（MTT）法检测αIR3对HepG2细胞增殖的影响；流式细胞术分析αIR3对HepG2细胞细胞周期及凋亡的影响；透射电镜观察αIR3作用于HepG2细胞后的形态学变化。结果 与ChangLiver细胞相比，HepG2细胞膜高表达IGF-ⅠR；αIR3（0．1μg／ml）作用于HepG2细胞48h，其相对生长指数（GI）为103．41％，与对照组相比差异有统计学意义（F=19．936，P〈0．01），αIR3（0．2～4．0μg／ml）作用于HepG2细胞24h～96h，其GI分别为97．63％～70．51％，且呈时间-剂量依赖关系，与对照组相比差异有统计学意义（F=3．902～34．95，P〈0．05或P〈0．01）；αIR3（0．5～2．0μg／ml）能增加G0／G1期HepG2细胞比值、减少S期HepG2细胞比值（F=1099．055、450．056，P〈0．01），但对G2／M期HepG2细胞比值无明显影响，同时使细胞凋亡率也增高（F=3465．914，P〈0．01）；透射电镜观察到细胞凋亡现象。结论 肝癌细胞的恶性表型与IGF-ⅠR的过度表达有关；在一定浓度范围，胰岛素样生长因子Ⅰ型受体单克隆抗体αIR3可以通过阻断IGF-IR抑制HepG2的增殖、诱导其凋亡。

Objective To study the expression level and localization of IGF- I receptor （ IGF- Ⅰ R） in hepatocellular carcinoma cell lines HepG2 and normal hepatic cell lines Chang Liver, and to observe the effect of anti-IGF- Ⅰ R monoclonal antibody （αIR3） on the growth of HepG2 cells. Methods The expression of IGF- Ⅰ R in HepG2 cells and Chang Liver cells was detected by immunohistochemistry method. The influence of αIR3 on proliferation and apoptosis were examined by 3-（4,5-dimethylthiazol-2-yl）-2, 5-diphenyhetrazolium bromide （MTT） assay and electron microscopy, respectively. Flow cytometry（FCM） was used to measure cell cycle and apoptosis. Results Located in cell membrane of the two cell lines, the expression level of IGF- Ⅰ R was higher in HepG2 cells. The cell growth index （GI） of HepG2 cells treated for48 h in vitro by 0. 1 μg/ml αIR3 was 103.41% , significantly higher than that of control group（F = 19. 936,P 〈0. 01 ）. Treated with αIR3 from 24 h to 96 h at final concentration ranging from 0. 2 μg/ml to 4. 0 μg/ml, the GI of HepG2 cells decreased from 97.63% to 70. 51% in a dose- and time-dependent manner, lower than that of control group （ F = 3. 902 - 34. 95, P 〈 0. 05 or P 〈 0. 01 ）. At final concentration from 0. 5 μg/ml to 2. 0 μg/ml, treatment with αIR3 increased the proportion of G0/G1 phase cells and decreased that of S phase cells significantly （ F = 1099.055.450.056, P 〈 0.01 ）, but there was no significant change in the proportion of G2/M phase cells. Observed under electron microscope the rate of apoptosis was obviously increased （ F = 3465. 914,P 〈 0. 01 ）. Conclusions The malignant cell phenotype of human heptatocarcinorma cell is related to overexpression of IGF-Ⅰ R; The blockage of IGF- Ⅰ R with αIR3 inhibits HepG2 cell proliferation and induces cell apoptosis.