齐墩果酸诱导人白血病HL-60细胞凋亡及细胞周期阻滞

目的：探讨齐墩果酸诱导HL-60细胞凋亡作用及其对细胞周期的影响。方法：以HL-60细胞为研究对象，以不同剂量的齐墩果酸处理HL-60细胞12 h、24 h、48 h、72 h后，用MTT法观察HL-60细胞的生长抑制率；琼脂糖凝胶电泳测定DNA梯形条带；流式细胞仪分析HL-60细胞细胞周期的变化；同时用Western blotting 检测凋亡途径最终执行者caspase-3的表达。结果：齐墩果酸对HL-60细胞生长具有明显的抑制作用，其中80 μmol/L齐墩果酸作用48 h对HL-60细胞的抑制率达到50%以上，齐墩果酸诱导细胞凋亡呈明显的时间和剂量依赖性； HL-60经齐墩果酸处理48 h出现典型的DNA梯形条带；以80 μmol/L的齐墩果酸处理HL-60细胞12 h即可以使caspase-3的前体procaspase-3断裂为有活性的caspase-3；流式细胞技术检测结果表明HL-60细胞经齐墩果酸处理后细胞周期阻滞于G₁期，其中48 h和72 h分别达到63.24%和67.90%。结论：齐墩果酸可以诱导HL-60细胞凋亡，并使细胞阻滞于G₁期。

Effects of oleanolic acid on apoptosis and cell cycle of HL-60 cells in vitro

AIM: To study the mechanism of oleanolic acid induced apoptosis and its influence on cell cycle in HL-60 cells in vitro. METHODS: The HL-60 cells were treated with different concentrations of oleanolic acid and then cultured for 12 h, 24 h, 48 h and 72 h, respectively. MTT assay was used to evaluate the inhibitory effect of oleanolic acid on HL-60 cells in vitro. The argarose gel electrophoresis was used to detect the chromatin DNA fragmentation. FACS was used to analyze the cell cycle of HL-60 cells. Western blotting was used to detect the activation of caspase-3 which has been confirmed the last execution of apoptosis pathway. RESULTS: MTT assay showed that oleanolic acid dramatically inhibited the growth of HL-60 cells in vitro, more than 50% HL-60 cells were inhibited when the cells were treated with 80 μmol/L oleanolic acid for 48 h; the apparent DNA ladder was detected after exposure of HL-60 cells to oleanolic acid for 48 h. FACS analysis showed that cell cycle of HL-60 cells was arrested in G₁ phase, the inhibition ratio of HL-60 cells achieved 63.24% and 67.90% after treated with oleanolic acid for 48 h and 72 h correspondingly. Western blotting detected the activation of caspase-3 after exposure of HL-60 cells to 80 μmol/L oleanolic acid for 48 h. CONCLUSION: These results suggest that oleanolic acid induces apoptosis and the cell cycle of HL-60 cells is arrested in G₁ phase.