目的观察姜黄素前体化合物诱导膀胱癌细胞凋亡的生物学效应,并探讨其可能的机制。方法,N-马来酰-L-缬氨酸酯姜黄素、N-马来酰-甘氨酸酯姜黄素分别作用于人膀胱癌EJ细胞、肾小管上皮HKC细胞6~24h后,采用台盼蓝活细胞拒染法检测细胞生长活性,透射电镜观察细胞超微结构改变,DNA片段化原位荧光标记技术、流式细胞术检测细胞凋亡及比率。结果10μmol·L^-1~40μmol·L^-1的,N-马来酰-L-缬氨酸酯姜黄素、N-马来酰-甘氨酸酯姜黄素作用6~24h后,EJ细胞生长抑制率分别为6.11%~66.23%(P〈0.05)、8.96%~68.21%(P〈0.05),呈浓度、时间依赖性;部分癌细胞出现凋亡形态学改变,DNA直方图上可见“亚G1峰”,12h细胞凋亡率分别为10.13%~23.36%(P〈0.05)、12.42%~28.56%(P〈0.05)。两种前体化合物对HKC细胞生长的抑制作用较同浓度姜黄素降低(P〈0.05)。结论姜黄素前体化合物能在体外有效诱导膀胱癌EJ细胞凋亡,降低对正常二倍体细胞生长的抑制作用,为深入研制肿瘤靶向性化疗药物提供了新的途径。
Aim To study the apoptosis-inducing effects of curcumin prodrug on bladder cancer cells and its mechanism. Methods Human bladder cancer EJ cell line and renal tubular epithelial (HKC) cells were cultured and incubated with N-maleoyl-L-valine-curcumin (NVC) or N-maleoyl-glycine-curcumin (NGC) for 6 -24 h. Cell viability was detected by trypan blue staining assay. Cellular uhrastructure changes were observed by electronic microscopy. Cell apoptosis and its rates were detected by in situ DNA fragmentation fluorescent assay and flow cytometry. Results After treatment with 10 -40 μmol · L^-1 NVC and NGC for 6 - 24 h, the growth inhibition of EJ cells were 6. 11% - 66.23% (P〈0.05), 8.96% -68.21%(P〈0.05),respectively, in dose- and time-dependent manners. Partial cancer cells presented morphological characters of apoptosis, with sub-G1 peaks on DNA histograms. When treated for 12 h, cell apoptosis rates were 10.13% - 23.36% (P 〈 0.05) and 12.42% 28.56% ( P 〈 0. 05) respectively. Compared with curcumin of same concentrations, these two prodrugs resulted in decreased inhibition effects on the growth of HKC cells (P 〈0.05). Conclusion The prodrugs of curcumin could induce apoptosis of bladder cancer EJ cells, and reduce the side effects on normal diploid cells. This provided a novel strategy for further exploration of tumor-targeted chemotherapeutic drugs.