桔梗皂苷D抑制前列腺癌细胞生长的体外研究

Platycodin D induces growth arrest and cell cycle arrest in prostate cancer

目的研究来自桔梗的皂苷类单体化合物-桔梗皂苷D(platycodin D,PD)对前列腺癌细胞的杀伤效应及可能的机制。方法培养前列腺癌细胞株:PC3、DU145、LNCa P,四甲基偶唑氮(MTT)法检测PD对肿瘤细胞的存活率的影响;流式细胞仪检测PD阻滞细胞周期的能力;蛋白免疫印迹实验检测PD对周期相关蛋白表达的影响。结果 PD杀伤前列腺癌细胞(PC3,DU145,LNCa P)的IC50值均小于30μM(PC3:11.17μM,DU145:26.13μM,LNCa P:24.6μM),随处理浓度增加,杀伤效应更为明显,呈明显剂量效应关系,其中以PC3细胞最为敏感。PD明显阻滞前列腺癌细胞周期,10μM PD、15μM PD将PC3细胞阻滞在G2/M期;而将DU145和LNCa P细胞阻滞在G0/G1期。PD影响PC3细胞的细胞周期相关蛋白:E2F1,CDK2,CDK4,CDK6,Cyclin D1,Cdc2,Cyclin B1蛋白表达量呈现下降趋势,与PD对细胞周期的阻滞作用相符合。结论 PD能够杀伤前列腺癌细胞,阻滞细胞周期进展,从而抑制肿瘤的发展。

Objective To evaluate the anti-tumor activity and possible mechanism(s) of Platycodin D (PD), a major saponin derived from Platycodin grandilforum, in human prostate cancer cell lines. Methods Human prostate cancer cell lines (PC3, DU145 and LNCaP cells), and the non-malignant human prostate epithelial cell line, RWPE-1, were exposed to various concentrations of PD to evaluate its cytotoxicity in vitro (via the MTT assay). Cell cycle analysis was indicated by PI staining with lfow cytometry. Cell cycle-related proteins levels were assessed by Western blotting. Results PD exerted cytotoxicity against three prostate cancer cell lines, PC3 cells, DU145 cells, and LNCaP cells, with half-maximal inhibitory concentrations (IC50) in the range of 11.17 to 26.13μmol/L. The PC3 cells were the most sensitive to PD. After being treated with PD for 48 hours, the PC3 cells were arrested in the G2/M phase, and the DU145 and LNCaP cells were arrested in the G0/G1 phase. Western blotting analysis indicated that PD exposure decreased the levels of cell cycle-related proteins, including E2F1, CDK2, CDK4, CDK6, CyclinD1, Cdc2, CyclinB1. Conclusions PD exhibits signiifcant inhibitory activities against prostate cancer cells, which provides a basis for future development of human prostate cancer chemotherapy.