目的:研究NS-398(一种选择性环氧合酶-2抑制剂)对结肠癌HT-29细胞的生长抑制作用并探讨其机制. 方法: 通过MTT法检测细胞的增殖情况,通过流式细胞术检测细胞凋亡率和细胞周期,通过RT-PCR检测bcl-2 mRNA和bax mRNA表达,通过共聚焦激光扫描显微镜观察细胞骨架成分F-actin的变化. 结果: NS-398对结肠癌HT-29细胞生长的抑制具有时间和剂量依赖性.流式细胞术结果显示NS-398可剂量依赖地诱导HT-29细胞凋亡,使其停滞于G0/G1期.经不同浓度的NS-398处理72 h后,bcl-2 mRNA 在HT-29细胞的表达降低,bcl-2/bax比值降低.细胞骨架成分F-actin主要分布在HT-29细胞核周围,呈环状结构,NS-398作用后细胞核周围的环状结构消失. 结论: NS-398可显著抑制结肠癌细胞的体外生长并诱导其凋亡,这与下调bcl-2/bax比值以及细胞骨架的破坏有关.%AIM: To evaluate the growth-inhibitory effects of NS-398, a selective cyclooxygenase-2 inhibitor, in human colon cancer HT-29 cells and its possible mechanisms. METHODS: MTT assay was applied to detect the cell proliferation. Flow cytometry was performed to detect apoptosis rate and cell cycle. RT-PCR was used to detect the expression of bcl-2 mRNA and bax mRNA. Alteration of cytoskeleton component F-actin was observed by confocal laser scanning microscope. RESULTS: NS-398 could inhibit growth of HT-29 cells in dose-and time-dependent manners. Flow cytometry revealed that NS-398 could induce apoptosis and cause G0/G1 arrest of HT-29 cells in a dose-dependent manner. After 72 h incubation with NS-398 at different concentrations, the expression level of bcl-2 mRNA was lowered and the ratio of bcl-2 to bax was decreased in HT-29 cells. F-actin was mainly distributed around nuclei forming annular structure in HT-29 cells. After exposure to NS-398, the annular structure around nuclei disappeared and fluorescence intensity of F-actin decreased obviously. CONCLUSION: NS-398 can inhibit the growth effectively and induce apoptosis in HT-29 cells in vitro, which is associated with the down-regulation of bcl-2 to bax ratio and the disruption of cytoskeleton.
展开▼
