三氧化二砷联合氟尿嘧啶抗人结肠癌Lovo细胞作用及其机制的研究

目的: 探讨三氧化二砷(As2O3)与氟尿嘧啶(5 FU)联合应用对人结肠腺癌细胞株Lovo的影响及其作用机制。方法:经不同浓度的As2O3 和(或)5- FU处理Lovo细胞后,采用MTT法测定细胞的增殖抑制效应;AO/EB荧光染色、DNA电泳、电镜和流式细胞术观察细胞凋亡和形态学及细胞周期变化;免疫组织化学法观察凋亡相关基因表达的变化。结果:与As2O3 或5 -FU单药作用相比,As2O3 与5- FU联合应用可显著增强人结肠癌细胞增殖抑制作用和诱导结肠癌细胞凋亡作用,联合用药后细胞周期分布发生改变,S期和G2/M期细胞比例下降,G0/G1 期细胞比例上升,癌细胞bcl- 2基因表达明显下降, bax和Fas基因表达显著增强。结论:As2O3与5 -FU联合应用具有显著协同抗大肠癌作用,其机制可能与增强诱导大肠癌细胞凋亡、细胞周期特异性药物与细胞周期调控剂联合增效以及调控凋亡相关基因的表达有关。

Anti-tumor effect and its mechanism of arsenic trioxide combined with fluorouracil on human coloncarcinoma cell line Lovo

OBJECTIVE:To study the anti-tumor effect of arsenic trioxide(As_2O_3) combined with fluorouracil(5-FU) on the human coloncarcinoma cell line Lovo,and explore its mechanism.METHODS: In vitro ,human coloncarcinoma cell line Lovo was treated by As_2O_3 and 5-FU in various concentrations respectively alone or in combination,and then the cell growth was assayed by MTT method,apoptosis,morphological and periodic return changes were observed by acridine orange(AO)/ethidiumbromide(EB) fluorescent staining, DNA gel electrophoresis,electron microscopy detection and flow cytometry,and the expression of apoptosis-related genes were analyzed by immunohistochemical staining method. RESULTS: Compared with As_2O_3 or 5-FU individual drug groups, As_2O_3 combined with 5-FU obviously increased the inhibitatory rate and apoptosis rate of the human coloncarcinoma cell line Lovo.The cell cycle distribution was altered and the ratio of S phase and G_2/M phase cell decreased and the portion of G_0/G_1 phase cell increased following the treatment with As_2O_3 combined with 5-FU, with bcl-2 gene expression down-regulated,and bax and Fas gene expression up-regulated. CONCLUSION: Arsenic trioxide combined with 5-FU may obviously increase the anti-coloncarcinoma effect,and maybe its mechanism is increasing apoptosis-inducing effect which is regulated by several genes and enhancing anti-tumor effect of cell cycle specific agent combined with cell cycle regulatory agent.