鬼臼苦素对人结直肠癌HCT-15细胞增殖和周期的影响及其作用机制

目的 探讨鬼臼苦素（PPP）对人结直肠癌细胞系HCT-15细胞增殖和周期的影响及其作用机制。方法 不同浓度PPP处理HCT-15细胞，采用细胞计数试剂盒8（CCK-8）法检测HCT-15细胞的增殖活性；倒置显微镜下观察HCT-15细胞的形态变化；流式细胞术检测HCT-15细胞周期的改变；Western blotting检测增殖细胞核抗原（PCNA）及细胞周期蛋白D1（cyclinD1）的蛋白表达水平。结果 CCK-8法结果显示，PPP能显著抑制HCT-15细胞的增殖活性，并呈剂量-时间依懒性；倒置显微镜下观察发现，细胞失去原有形态回缩为圆形，折光性降低，活细胞数量明显减少；流式细胞术结果显示，G₂/M期细胞比例显著升高，G₀/G₁期和S期细胞比例明显降低；Western blotting结果显示，PCNA、细胞周期蛋白D1的表达水平明显降低。结论 PPP可显著抑制人结直肠癌HCT-15细胞的增殖，其作用机制可能是通过下调PCNA、cyclinD1的表达水平，进而将细胞阻滞于G₂/M期发挥抑制作用。

Effects of picropodophyllin on proliferation and cell cycle of human colorectal cancer HCT-15 cells and its mechanism#br#

Objective To investigate the effect of picropodophyllin(PPP) on proliferation and cell cycle of human colorectal cancer cell line HCT-15 and to clarify the related mechanism.Methods Different concentrations of PPP were used to treat HCT-15 cells, the proliferative activity of HCT-15 cells was detected by cell courting kit-8(CCK-8). Morphological changes of HCT-15 cells were observed under inverted microscope. Flow cytometry was used to detect the changes of HCT-15 cell cycle and Western blotting was used to detect the expression of proliferating cell nuclear antigen (PCNA) and cell cyclinD1. Results The result of CCK-8 assay showed that PPP inhibited the proliferation of HCT-15 cells in a dose-time-dependent manner. Under the inverted microscope, it was found that the HCT-15 cells lost their original shape and became round, the refractive index decreased, and the number of living cells decreased significantly. Flow cytometry showed that the proportion of G₂/M cells increased significantly, and the proportion of G₀/G₁ phase and S phase cells decreased significantly. Western Blot result showed that the expression of PCNA, cyclinD1 protein was significantly decreased.Conclusion PPP significantly inhibited the proliferation of human colorectal cancer HCT-15 cells, suggesting that the mechanism might be to block the cells in G₂/M phase by down-regulating the expression of PCNA, cyclinD1 protein.