熊果酸诱导结肠癌HT-29细胞凋亡与凋亡相关基因的关系

Relationship between apoptosis in HT-29 cell induced by ursolic acid and expression of caspase-9,bcl-2 and bax

目的:体外实验探讨熊果酸诱导结肠癌HT-29细胞凋亡的可能性,揭示该凋亡发生与其相关基因之间的关系。方法:采用四甲基偶氮唑蓝比色、TUNEL法、流式细胞术检测熊果酸对结肠癌HT-29细胞的增殖抑制与杀伤作用;应用免疫组织化学SP法检测凋亡相关基因caspase-9、bcl-2、bax的表达。结果:熊果酸在体外对HT-29细胞有中度增殖抑制效应,在熊果酸作用下,HT-29细胞出现显著的细胞凋亡征象,TUNEL法显示细胞固缩,核染色质聚集或断裂,形成凋亡小体。流式细胞术检测在G 1期之前出现sub-G1峰,凋亡率最高为11.63%,熊果酸的作用具有浓度和时间依赖性。在HT-29细胞凋亡过程中,凋亡相关基因caspase-9、bax的表达增强,bcl-2的表达减弱。结论:熊果酸在体外对结肠癌HT-29细胞有诱导凋亡作用,而caspase-9和bax的表达增强,bcl-2的表达减弱可能是其作用机制之一。

Objective To study the antitumor effect of ursolic acid and its mechanism. Methods The human colorectal carcinoma HT-29 cells were treated with ursolic acid. The proliferation inhibitory was examined by MTT method. Morphological study, TUNEL method and flow cytometry were used to detect apoptosis. Immunohistochemical method was used to detect the expression of apoptosis related gene caspase-9, bcl-2 and bax. Results Ursolic acid inhibited the proliferation of HT-29 cell. HT-29 cell treated with ursolic acid was induced to apoptosis. The morphology of HT-29 changed as nuclear chromosomal condensation and segmentation. Sub-G1 peak was found with flow cytometry. The expression of caspase-9 and bax gene was enhanced. The expression of bcl-2 gene was weak. Conclusion Apoptosis of HT-29 cell is the key mechanism to ursolic acid＇s killing action in the treatment of cancer.