尼莫地平对人结肠癌细胞系HCT增殖的影响及机制探讨

目的：研究钙拮抗剂尼莫地平对人结肠癌细胞系HCT生长的影响及探讨其相应的机制。方法：MTT法检测不同剂量尼莫地平对HCT细胞生长的影响。探讨经尼莫地平作用的HCT细胞是否发生凋亡；用流式细胞术检测凋亡细胞亚二倍体峰；DNA凝胶电泳检测HCT细胞DNA的梯度条带；瑞士－姬姆萨染色观察HCT细胞的形态学变化，激光共聚焦扫描显微镜检测在尼莫地平作用下HCT细胞内钙离子的浓度及分布状态的变化。结果：MTT法示尼莫地平可抑制人结肠癌细胞系HCT的生长。流式细胞术检测显示，尼莫地平作用后，HCT细胞亚二倍体峰面积增大，且凋亡细胞数呈剂量依赖性，高剂量尼莫地平组可见典型的DNA的梯度条带；细胞形态呈现细胞的胞膜泡化，胞质浓缩，染色质断裂等变化。Fluo-3荧光标记显示尼莫地平作用于HCT细胞后，细胞内Ca^2 浓度Ca^2 ]i升高，PI荧光标记的细胞核型发生变化。结论：尼莫地平作为钙拮抗剂对结肠癌HCT细胞系的生长有抑制作用；其机制可能是通过细胞凋亡作用的。

Influences of nimodipine on human colonic carcinoma HCT cells proliferation and its mechanism

AIM: To investigate the influences of nimodipine on HCT cells proliferation and explore the mechanism. METHODS: HCT cells were treated with different concentrations of nimodipine, and its proliferation was inspected by MTT assay. The apex areas of sub diploid were measured by Flow Cytometry and the DNA ladder were found by agarose gel electrophoresis. The characteristic changes in morphology were observed under the light microscopy. The cellular distribution and concentration of calcium were studied by using the laser confocus scanning microscopy. RESULTS: The growth of HCT cells was inhibited by different concentrations of nimodipine. Data from Flow Cytometry showed the apex areas of sub diploid enlarge in the drug treating group, suggesting that the number of apoptosis cells increased in dose dependent manner. Gel electrophoresis displayed DNA cleavage pattern typical of apoptosis: DNA ladder in high dose nimodipine treated HCT cells. The light microscopy presented cellular morphological changes: cell membrane blebs, the cytoplasm and nuclear chromatin condensation. The concentration of cytosolic free calcium increased when treated with nimodipine showed by the laser confocus scanning microscopy. CONCLUSION: Nimodipine can cause inhibition of the cell proliferation of HCT cells. The mechanism of inhibition might involve the cell apoptosis.