曲古霉素A对人胃癌细胞的抑制作用及其机制探讨

背景：组蛋白去乙酰基酶抑制剂（HDACi）是一类新型抗肿瘤药物。曲古霉素A（TSA）是目前研究最为广泛的HDACi之一，已发现其对多种肿瘤细胞具有明显抑制作用，但关于TSA对胃癌作用的研究尚少。目的：观察TSA对人胃癌细胞增殖、凋亡、细胞周期以及相关基因表达的影响，探讨其抑制人胃癌细胞的可能作用机制。方法：以不同浓度TSA（0—1μmol／L）处理人胃癌细胞株AGS和HGC-27。CCK-8实验检测细胞增殖抑制情况，流式细胞术检测细胞凋亡和细胞周期，realtimeRT-PCR和蛋白质印迹法检测细胞凋亡、细胞周期相关基因mRNA和蛋白水平的表达。结果：TSA能剂量依赖性地抑制AGS、HGC-27细胞增殖（P=0．000），对两者的半数致死浓度分别约为0．25μmol／L和0．5μmol／L。TSA能诱导AGS、HGC-27细胞发生G0／G1期和G2／M期阻滞，以G0／G11期阻滞更为明显。TSA对AGS细胞的诱导凋亡作用强于HGC-27细胞（P〈0．05）。TSA尚能上调p21、p53、BaxmRNA和蛋白表达，下调Bel-2、CDK2、cyelinD1mRNA和蛋白表达，作用均呈时间依赖性（P〈0．05）。结论：TSA抑制人胃癌细胞增殖、诱导细胞凋亡的作用可能是通过调节细胞凋亡、细胞周期相关分子、激活多种肿瘤相关信号通路实现的。

Inhibitory Effect of Trichostatin A on Human Gastric Cancer Cells and its Possible Mechanism

Background： Histone deacetylase inhibitors （HDACi） represent a new class of anticancer agents. Trichostatin A （TSA） is a widely investigated HDACi and has been shown to inhibit the growth of various cancer cells, however, few studies have focused on its role in gastric cancer. Aims： To investigate the effect of TSA on proliferation, apoptosis, cell cycle and related genes expressions in human gastric cancer cells, and to determine the possible mechanism underlying the inhibitory effect of TSA on human gastric cancer cells. Methods： Human gastric cancer cell lines AGS and HGC-27 were treated with TSA at different concentrations （0-1 μmol/L）. CCK-8 assay was employed to evaluate the proliferation inhibition effect of TSA on AGS and HGC-27 cells; the apoptosis and cell cycle distribution were analyzed by flow cytometry; and the expressions of apoptosis- and cell cycle-related genes at mRNA and protein level were determined by real time RT-PCR and Western blotting. Results： TSA inhibited cell proliferation of AGS and HGC-27 cells in a dose- dependent manner （P = 0.000）, the median lethal concentration for AGS cells was 0.25 μmol/L and that for HGC-27 cells was 0.5 μmol/L, approximately. TSA also arrested cell cycle progression of AGS and HGC-27 cells at G0/G1 phase and G2/M phase, especially G0/G1 phase. The apoptosis induction effect of TSA was more prominent on AGS cells than on HGC-27 cells （P 〈 0.05 ）. The inhibitory effect of TSA on AGS and HGC-27 cells was accompanied by up-regulation of p21, p53, Bax mRNA and protein expressions, and down-regulation of Bcl-2, CDK2 and cyclin D1 mRNA and protein expressions in a time-dependent manner （ P 〈 0.05 ）. Conclusions ： TSA may inhibit cell proliferation and induce apoptosis of human gastric cancer cells through modulation of apoptosis and cell cycle regulators and activation of tumor-related signal pathways.