吉祥草中甾体皂苷RCE-4对人宫颈癌Caski细胞Ras/Erk和p16/cyclinD1/CDK4通路的影响

目的: 研究吉祥草中甾体皂苷RCE-4影响Ras/Erk和p16/cyclinD1/CDK4信号通路促进Caski细胞凋亡的作用机制。方法: 体外培养人宫颈癌Caski细胞株，用RCE-4作为处理因素，MTT法检测细胞增殖活力；流式细胞术检测细胞周期分布；Real-time PCR检测p16、cyclinD1和CDK4 mRNA表达水平；Western blot检测Ras/Erk信号通路总蛋白和磷酸化蛋白表达水平。 结果: RCE-4呈剂量依赖性抑制Caski细胞增殖，其作用24 h的IC50值为12.33 μmol/L；升高G0/G1期细胞比例，降低S期细胞比例；抑制Ras、p-Raf、p-Mek1/2和p-Erk1/2蛋白表达，降低p-Raf/Raf、p-Mek1/2/Mek1/2和p-Erk1/2/Erk1/2比值，上调p16的mRNA表达，下调cyclinD1和CDK4的mRNA表达。 结论: RCE-4可抑制Caski细胞的增殖，诱导细胞在G0/G1期阻滞，其诱导作用与其抑制Ras/Erk和p16/cyclinD1/CDK4信号通路激活有关。

Effects of steroidal saponin RCE-4 from Reineckia Carnea (Andr.) Kunth on Ras/Erk and p16/cyclinD1/ CDK4 signaling pathways in the human cervix cancer Caski cells

AIM: To investigate the effects of steroidal saponin RCE-4 from Reineckia Carnea (Andr.) Kunth on Ras/Erk and p16/cyclinD1/CDK4 signaling pathways in the human cervix cancer Caski cells, and to explore its possible mechanism. METHODS: The Caski cell line was cultured in vitro, the cell viability and the distribution of cell cycle was detected by MTT and flow cytometry, respectively; the quantitative real-time PCR was used to evaluate the mRNA expressions of p16, cell cycle-related cyclinD1 and CDK4；Western blot was used to determine the total protein and phosphorylated protein of Ras/Erk signaling pathway. RESULTS:RCE-4 could significantly inhibit the growth of Caski cells compared with the control group, the IC50 was 12.33 μmol/L in the 24 h, and it increased the percentage of G0/G1 phase cells, decreased the percentage of S phase cells, inhibited the proteins levels of Ras, p-Raf, p-Mek1/2 and p-Erk1/2, decreased the p-Raf:Raf,p-Mek1/2:Mek1/2 and p-Erk1/2:Erk1/2 ratios, up-regulated the mRNA expression of p16, down-regulated the expressions level of cyclinD1 and CDK4. CONCLUSION: RCE-4 could significantly inhibit the proliferation of Caski cells and induce the cells to block in G0/G1 phase, and the mechanism is related to inhibiting the Ras/Erk and p16/cyclinD1/CDK4 signaling pathways.