c-myc在大黄素抑制HL-60细胞增殖及诱导凋亡中的作用

目的研究中药大黄素(emodin)对人髓系白血病细胞株HL-60细胞的影响及探讨c—myc基因在其中的作用。方法应用MTT法绘制细胞生长曲线；细胞集落培养观察大黄素对HL-60细胞增殖的影响；DNA倍体分析、线粒体细胞凋亡检测法、末端缺失原位标记(TUNEL)法及DNA凝胶电泳分析细胞凋亡；RT—PCR及Western blot检测大黄素作用前后c—myc基因mRNA及蛋白表达水平的变化。结果大黄素能明显抑制HL-60细胞增殖，半数抑制浓度(IC50)约为20μmol／L；DNA片段化、亚G1峰(凋亡峰)的检出及线粒体细胞凋亡检测等证实大黄素能有效诱导HL-60细胞凋亡，细胞凋亡率与药物作用浓度呈正相关。大黄素与HL-60细胞作用后c—myc基因mRNA及蛋白的表达水平与作用时间呈负相关。结论大黄素能有效抑制HL-60细胞增殖，诱导其凋亡；c—myc基因可能参与了大黄素抑制HL-60细胞增殖和诱导凋亡的过程。

Effects of emodin on the proliferation inhibition and apoptosis induction in HL-60 cells and the involvement of c-myc gene

OBJECTIVE: To investigate the effects of emodin on apoptosis induction and proliferation inhibition in human apoptosis and on c-myc protein and mRNA expression in human myeloid leukemia cell line HL-60 cells. METHODS: HL-60 cells were exposed to emodin at different dosages. Growth inhibition was detected by MTT assay and colony formation assay, and cell apoptosis by flow cytometry, TUNEL labeling method, DNA fragmentation and MitoCapture apoptosis detection. The expression of c-myc was detected by RT-PCR and Western-blot. RESULTS: Emodin remarkably inhibited the cell proliferation, with an IC(50) value of 20 micromol/L. HL-60 cells apoptosis could be efficiently induced by emodin in a dose dependent manner. The c-myc protein and mRNA expressions on HL-60 cells were decreased after emodin treatment. CONCLUSION: Emodin could efficiently induce growth inhibition and apoptosis in HL-60 cells. c-myc may be involved in this process.