Cytotoxicity and reversal of multidrug resistance by tryptanthrin-derived indoloquinazolines
作者:Sung-tsai Yu、Ji-wang Chern、Tzer-ming Chen、Yi-fan Chiu、Hui-ting Chen、Yen-hui Chen
DOI:10.1038/aps.2009.198
日期:2010.2
To evaluate the effects and elucidate the mechanisms of a series of indoloquinazolines as novel anticancer agents. Condensation of the substituted isatoic anhydride with the substituted isatin was performed to prepare compounds 1â4, followed by adding malononitrile to prepare compounds 5â7. Cytotoxicity was measured by MTT assays. Apoptosis induction was evaluated using DNA fragmentation, cell cycle assay, caspase 3/7 activity and Western blot. Compounds 3, 4, and 5 display cytotoxicity against MCF-7, HeLa, SKOV3, and A498 cancer cells. DNA ladders appear in cells treated with compounds 3, 4, and 5. Within those, compound 4 exhibits the greatest activity in regards to sub-G1 accumulations in the cell cycle and the activation of caspase-3/7. Furthermore, Fas and Fas ligand levels are elevated by compound 4, implying that the apoptosis is in part mediated through the signals. On the other hand, compounds 1 and 7 display chemosensitizing activity since cytotoxicity of doxorubicine and etoposide is enhanced in combination with compound 1 and 7, respectively, in MCF-7/adr (doxorubicin-resistant) and MCF-7/vp (etoposide-resistant). The cytotoxicity of indoloquinazolines is structure-dependent rather than cell type-dependent due to the similar degree of cytotoxicity induced by the individual compounds in all four cell lines. Further modification of the tryptanthrin skeleton is important to develop novel anticancer agents bearing either cytotoxicity against MCF-7 cells or drug resistance reversal in MCF-7/adr and MCF-7/vp.
评估一系列吲哚喹唑啉类化合物作为新型抗癌剂的效果并阐明其作用机制。将取代的异酸酐与取代的靛红进行缩合,制备出化合物 1â4 ,然后加入丙二腈,制备出化合物 5â7 。细胞毒性通过 MTT 试验测定。凋亡诱导采用 DNA 断裂、细胞周期测定、caspase 3/7 活性和 Western 印迹法进行评估。化合物 3、4 和 5 对 MCF-7、HeLa、SKOV3 和 A498 癌细胞具有细胞毒性。经化合物 3、4 和 5 处理的细胞出现 DNA 梯状。其中,化合物 4 在细胞周期的亚 G1 累积和 caspase-3/7 激活方面表现出最大的活性。此外,化合物 4 还提高了 Fas 和 Fas 配体的水平,这意味着细胞凋亡部分是通过信号介导的。另一方面,化合物 1 和 7 显示出化疗增敏活性,因为在 MCF-7/adr(对多柔比星耐药)和 MCF-7/vp(对依托泊苷耐药)中,多柔比星和依托泊苷的细胞毒性分别与化合物 1 和 7 结合使用时会增强。吲哚喹唑啉类化合物的细胞毒性是结构依赖性的,而不是细胞类型依赖性的,这是因为单个化合物在所有四种细胞系中诱导的细胞毒性程度相似。要开发出对 MCF-7 细胞具有细胞毒性或可逆转 MCF-7/adr 和 MCF-7/vp 耐药性的新型抗癌剂,进一步修饰胰黄素骨架非常重要。