携带mda-7基因的复制缺陷性腺病毒联合阿霉素致肝癌细胞HepG2凋亡机制的研究

Mechanism of apoptosis of HCC HepG2 cells induced with replication-defective virus carrying mda-7 in combination with ardriamycin

目的 探讨黑色素瘤分化相关基因-7/白介素-24（MDA-7/IL-24）基因联合阿霉素杀伤肝癌细胞HepG2,并逆转HepG2多药耐药的机制.方法 以人肝癌细胞系HepG2为实验对象,使用MTT法和流式细胞仪比较Ad.mda-7联合阿霉素处理组与阿霉素组、Ad.mda-7组对肝癌细胞HepG2的作用差异.阐明MDA-7/IL-24对多药耐药的逆转作用的机制.实时定量PCR检测MDR-1、STAT-3、BCL-2、BAXmRNA的变化.Western blot检测gp-170、stat3、P-stat-3、PKB、bcl-2、hax蛋白的表达的变化.结果 低浓度的Ad.mda-7联合正常肝细胞半抑制浓度浓度的阿霉素（1.5 mg/L）使得细胞抑制率从阿霉素组的17.46%上升到79.5%,生长抑制逆转4.55倍（P＜0.05）.联合化疗组MDR-1mRNA相对表达量从16.49±0.11下降至5.48±0.05.STAT-3 mRNA相对表达量从13.17±0.08上升至21.57±0.11.BCL-2及BAX表达与其他实验组相比较差异均有显著统计学意义（P＜0.05）.联合实验组P-170蛋白的表达量较其他组明显降低,PKB蛋白表达量明显降低,磷酸化stat-3蛋白的表达量增加.结论 Ad.mda-7具有逆转肝癌细胞HepG2多药耐药的作用.其在下调MDR-1mRNA表达的同时,通过抑制PKB蛋白和活化STAT-3信号通路的表达降低促进肝癌细胞凋亡.

Objective To explore the mechanism of melanoma differentiation associated gene-7（mda-7） in combination with adriamycin（ADM） killing the HCC HepG2 cells and reversing their multidrug resistance （MDR）. Methods The experiment was conducted in three groups including the combined group, ADM group and mda-7 group. MTT assay and FCM were used to determine the differences among the 3 groups and clarify the reversing effect of combined treatment on multidrug resistance of the tumor cells. Expression levels of MDR-1, STAT-3, BCL-2, BAXmRNA were determined with real-time PCR. Western blotting was performed to observe the changes of proteins gp-l70, stat3,P-stat3, PKB, bcl-2,bax in all 3 groups. Result After transfection with 100VP/cell Ad. mda-7,the growth suppression rate of HepG2 treated by ADM （1.5 mg/L） rose from 17.46% to 79. 5%.According to the changes, killed HepG2 cells were increased by a factor of 4.55. times. MDR-1 mRNA was decreased from （16.49 ± 0. 11） to （5.48±0.05） and STAT-3 mRNA increased from （13.17±0. 08） to （21. 57±0. 11）（P〈0.05）. Western blotting also showed that P-170 and PKB was decreased and the phosphorylation-stat-3 increased after the combined treatment. Conclusion Ad.mda-7 can reverse the multidrug resistance HepG2 cells. It inhibits the expression of MDR-1 mRNA,then arrests PKB protein and the signaling pathway of active stat-3 to induce apoptosis of HCC cells.