藤黄酸抑制人结肠癌SW480细胞增殖过程中APC蛋白的表达变化

Suppression of APC production during apoptosis of human colorectal cancer cell line SW480 induced by gambogic acid

目的观察藤黄酸对人结肠癌SW480细胞增殖和APC蛋白表达的影响,探讨其可能抗肿瘤的作用机制。方法以不同浓度(0、0.5、1、4μg/ml)的藤黄酸干预体外培养的人结肠癌细胞株SW480,分别于24、36、48h后,应用MTT法检测细胞的增殖活性,流式细胞仪检测细胞周期分布和细胞凋亡率,Western-blot分析APC蛋白的变化。结果 1μg/ml以上浓度的藤黄酸可以显著抑制人结肠癌细胞株SW480细胞增殖,且随浓度增加效果增强,随着时间增加抑制率显著增加(P<0.01)。藤黄酸浓度达到4μg/ml时,G2/M期细胞达到54.74%;藤黄酸浓度为0、0.5、1、4μg/ml时SW480细胞的凋亡率分别为(0.17±0.08)%、(0.85±0.19)%、(7.12±1.21)%、(15.87±1.59)%。用不同浓度的藤黄酸处理SW480细胞株24h,APC蛋白的表达随药物浓度的升高而增加(P<0.01)。结论藤黄酸能够抑制人结肠癌细胞株SW480增殖并诱导其凋亡,干扰SW480细胞周期使其阻断于G2/M期,高表达APC蛋白有可能是藤黄酸抗癌作用的重要机制。

Objective To investigate the effect of gambogic acid on human colorectal cancer cell line SW480. Methods Methyl thiazolyl tetrazolium （MTT） assay was used to test the changes in the proliferation of SW480 cells cultured with different concentrations of gambogic acid for 24, 36 and 48 h in vitro. Cell-cycle kinetics and apoptosis were analyzed by flow cytometry （FCM）. Western-blot was applied to examine the protein expression of APC. Results Gambogic acid with concentration greater than 1 μg/ml could significantly inhibit the proliferation of human colorectal cancer cell line SW480 and the effect was more prominent as time went on （P〈0.01）. The G2/M phase cells reached 54.74% with gambogic acid at concentration of 4 μg/ml. When SW480 cells were treated with gambogic acid at the concentration of 0, 0.5, 1 and 4 μg/ml, the rate of apoptosis of SW480 cell were （0.17±0.08）%, （0.85±0.19）%, （7.12±1.21）%, and （15.87±1.59）%, respectively. After SW480 cells were treated with 0, 0.5, 1 and 4 μg/ml gambogic acid for 24 h respectively, the level of APC protein increased as concentration increased （P〈0.01）. Conclusion Gambogic acid can significantly inhibit the proliferation and induces G2/M arrest in human colon cancer cell line SW480. The effect mechanism is related to the suppression of APC protein production.