TPL与5-FU联合作用对人结肠癌HT-29细胞增殖与凋亡的影响

Combined Effect and Anti-tumor Mechanism of Triptolide and 5-Fluorouracil on HT-29 Cells in Vitro

目的:研究雷公藤内酯醇(TPL)与5-氟尿嘧啶(5-FU)联合应用对人结肠癌HT-29细胞增殖、凋亡的影响。方法:常规培养HT-29细胞,MTT比色法检测不同浓度TPL与5-FU单独或联合应用对HT-29细胞的增殖抑制率,透射电镜在亚细胞结构形态上证实凋亡细胞,流式细胞学定量分析凋亡细胞比例,免疫细胞化学分析突变型P53、bcl-2蛋白表达的变化。结果:①TPL与5-FU单独应用均能抑制HT-29细胞的增殖,且在一定范围内存在浓度依赖性。两药联合作用最高增殖抑制率最高达到(94.92±2.76)%,48 h凋亡率达(41.71±1.38)%。②TPL与5-FU在低剂量联合应用时对HT-29细胞增殖抑制作用有协同效应(CI<1),其机制可能为促进细胞凋亡。③与对照组比较,TPL与5-FU单独应用及联合应用后HT-29细胞突变型P53蛋白表达率均有显著降低,而bcl-2蛋白表达没有明显变化。结论:TPL与5-FU在小剂量联合应用时为协同效应,可能通过下调突变型P53蛋白诱导凋亡从而抑制细胞生长。本结果对于结肠癌的治疗具有一定的临床意义。

Objective： To study the effects of triptolide （TPL） and 5-fluorouracil （5-FU） on proliferation and apoptosis of human colon carcinoma cell line HT-29 in vitro. Methods： HT-29 cells were cultured with RPMI1640 medium in regular condition. The inhibition effects were evaluated by MTT assay. The subcellular morphology was observed by transmission electron microscope. Cell apoptosis was detected by flow cytometry. The changes of bcl-2 and p53 in protein level were quantified by immunocytochemistry. Results： （1） TPL and 5-FU either combined or alone inhibited significantly the proliferation of HT-29 cells and induced obvious apoptosis. Growth inhibition rate arrived at （94.92±2.76） %,and apoptic rate at 48 h reached （41.71±1.38）%. （2） The interaction of the two drugs was synergistic （CI〈1） at lower concentrations. The mechanism may partly attribute to cell apoptosis. （3） TPL and 5-FU affected p53 protein expression but did not affect expression of bcl-2 protein. Conclusion： The interaction of TPL and 5-FU was synergistic at lower concentrations. The apoptosis may be dependent on the p53 and independent on bcl-2 passway. The result may play an important role in the treatment of colon cancer.