人肝癌原发性耐药细胞亚系的建立及耐药机制的初步探讨

目的从人肝癌细胞系HeFG2中筛选出原发性耐药株,建立相应的细胞亚系并探讨其耐药机制.方法采用阿霉素(adriamycin,ADM)大剂量冲击法筛选原发性耐药细胞株,倒置显微镜下观察其形态学变化,细胞计数法绘制生长曲线,MTT法检测药物敏感性,流式细胞术分析细胞周期和检测耐药蛋白的表达.结果随冲击次数的增加,筛选出细胞的耐药指数(resistance index, RI)逐渐升高,筛选3次后对ADM的RI可达30.5;其形态学特点、生长特性及细胞周期分布与亲本细胞有明显差异,同时发现耐药蛋白P-gp、MRPt LRP表达增强.结论肝癌细胞系HepG2是个非均质的群体,其中存在着原发性耐药细胞株.

Establishment of intrinsic drug resistant human hepatocellular carcinoma cell sublines and investigation of drug resistance mechanism

Objective To establish intrinsic drug resistant strains from human hepatocellular carcinoma cell line HepG2, and to investigate the drug resistance mechanism. Methods Pulse exposures of parental HepG2 cells to high concentration of adriamy cin(ADM) were performed to select intrinsic resistant strains. Drug sensitivity was evaluated by MTT assay. Cell cycle distributions and multidurg-resistant-associated markers were determined by flow cytometry. Results The resistance indexes (RI) of the survival cells to several chemotherapy agents were gradually improved due to ADM exposure. After the third exposure, the RI to ADM reached a high level of 30. 5. The morphology, growth character and cell cycle distribution of resistant cells are remarkably different from that of the parental cells. Meanwhile the expression of multidurg-resistant-associated markers such as P glycoprotein(P-gp), multidrug-resistant-associated protein(MRP) and lung-resistant-associated protein(LRP) were enhanced. Conclusion Hepatocellular carcinoma cell line HepG2 is a heterogenous population wherein intrinsic drug resistant strains exist.