藤黄酸诱导膀胱癌细胞凋亡和细胞周期阻滞作用

Gambogic acid induces the apoptosis and arrests the cycle of human bladder cancer cells

目的藤黄酸能抑制包括乳腺癌、肝癌、血液系肿瘤以及乳腺癌在内的多种肿瘤细胞的生长,但是目前对于藤黄酸在泌尿系肿瘤作用的报道尚少。文中旨在研究藤黄酸诱导膀胱癌细胞凋亡和细胞周期阻滞作用可能的机制。方法实验分为4组,藤黄酸1.0μmol/L组、2.0μmol/L组、3.0μmol/L组及阴性对照组(加入等渗盐水)。体外培养人膀胱癌细胞株BIU-87,将不同浓度藤黄酸加入处于对数生长期的人膀胱癌BIU-87细胞共培养,免疫组化法检测瘤组织Caspase-3蛋白的表达,使用流式细胞仪检测分析藤黄酸诱导人膀胱癌细胞的凋亡作用和细胞周期变化。结果藤黄酸1.0μmol/L组、2.0μmol/L组、3.0μmol/L组免疫组化评分分别为(4.28±1.86、5.03±0.78和6.47±1.31),较对照组(2.13±1.27)明显升高,差异均有统计学意义(P<0.05)。流式细胞术结果显示:细胞周期G0/G1期细胞逐渐减少,G2/M期细胞逐渐增多,S期细胞变化不明显。结论藤黄酸可通过增加Caspase-3蛋白的表达来促进膀胱癌细胞凋亡,可阻滞膀胱肿瘤细胞周期,抑制膀胱肿瘤细胞的增殖。

Objective Gambogic acid （GA） can suppress the growth of multiple tumor cells, including gastric carcinoma, hepatoma, hematologic neoplasms and breast carcinoma, but there have been few reports about its effect on urologic neoplasms. This study was to investigate the possible mechanisms of GA inducing bladder cancer cell apoptosis and cell cycle arrest. Methods We cultured human bladder cancer BIU-87 cell lines in vitro and treated the cells in the logarithmic growth phase with isotonic saline solution （ negative control） or GA at the concentrations of 1. O, 2.0, and 3.0μmol/L, respectively. We determined the expression of the Caspase-3 protein in the tumor tissue using the immunohistochemical S-P method and detected GA-induced apoptosis of the bladder cancer cells and cell cycle changes by flow cytometry. Results The expressions of the Caspase-3 protein were 4.28 ± 1.86, 5.03 ±0. 78, and 6.47 ±1.31 in the 1. 0, 2. 0, and 3.0 μmol/L GA groups, respectively, significantly higher than 2.13 ± 1.27 in the negative control （ P 〈 0.05 ）. Flow cytometry showed a gradual decrease of the cells in the G0/G1 phase and a gradual increase in the GJM phase, but no obvious change in the S phase. Conclusion Gambogic acid can promote the apoptosis, arrest the cell cycle, and inhibit the proliferation of bladder cancer cells by increasing the expression of the Caspase-3 protein