【摘要】 目的:探讨二苯并呋喃-2-基喹啉-8-磺酸盐(dibenzofuran-2-ylquinoline-8-sulfo-nate,DFQS)以靶向拓扑异构酶Ⅰ(topoisomerase I,TopoⅠ)的方式诱导人肝癌细胞HepG-2凋亡。方法:采用p BR322 DNA质粒超螺旋松弛实验确认DFQS是一种新型的TopoⅠ抑制剂; CCK-8法检测DFQS对HepG-2细胞生存率影响; Hoechst 33258和AO/EB荧光染色法以及流式细胞术探究细胞凋亡变化情况; Western Blot法检测DFQS对HepG-2细胞caspase-3和TopoⅠ蛋白表达影响;利用分子对接阐明DFQS与TopoⅠ相互作用方式。结果:DFQS可抑制TopoⅠ对DNA的催化解旋作用,可显著降低HepG-2细胞存活率,抑制效应呈时间浓度依赖性; DFQS致HepG-2胞核凝集固缩,呈典型凋亡形态学、凋亡率明显提升、caspase-3表达显著增加、TopoⅠ的表达下降;分子模拟结果表明DFQS可结合到TopoⅠ活性区域。结论:DFQS可靶向抑制TopoⅠ活性诱导HepG-2细胞凋亡,发挥其抗癌效应。更多还原

【Abstract】 Objective: To study the effect of dibenzofuran-2-ylquinoline-8-sulfonate( DFQS) on inducing apoptosis of human hepatocellular carcinoma Hep G-2 in a manner of targeting topoisomerase I( TopoⅠ) . Methods:DFQS was confirmed as a novel Topo Ⅰ inhibitor using pBR322 DNA plasmid supercoiled relaxation assay. The effect of DFQS on survival rate of HepG-2 cells was analyzed by CCK-8 method. Hoechst 33258,AO/EB fluorescencestaining and flow cytometry were used to detect the change of apoptosis. Western Blot was used to detect the effect of DFQS on the expressions of caspase-3 and Topo I in HepG-2 cells. The interaction between DFQS and Topo I was elucidated using molecular docking method. Results: DFQS inhibited the catalytic unwinding effect of Topo I on DNA and significantly reduced the survival rate of Hep G-2 cells. This inhibitory effect was time-concentrationdependent. DFQS induced HepG-2 nucleus agglutination and pyknosis,showing typical apoptotic morphology. The apoptotic rate and the caspase-3 expression significantly increased,while the expression of Topo I decreased. The results of molecular simulation indicated that DFQS binded to the active region of Topo I. Conclusion: DFQS can induce the apoptosis of HepG-2 cells by inhibiting the activity of Topo I thus exert its anticancer effect.更多还原