DADS 通过MAPK 和PI3K/Akt 信号通路下调Mcl-1诱导白血病细胞凋亡

摘要

目的:二烯丙基二硫(DADS)为天然植物大蒜中的提取物,能抑制多种肿瘤细胞生长,本文探讨丝裂原激活的蛋白激酶(MAPKs)、3-磷酸肌醇激酶(PI3K/Akt)信号通路和Bcl-2家族成员在DADS诱导的人白血病HL-60细胞凋亡中的作用.方法:利用流式细胞术检测DADS诱导的白血病细胞凋亡,Western blot研究MAPKs和PI3K/Akt信号通路在DADS诱导的人白血病HL-60细胞凋亡中的变化及对Bcl-2家族凋亡相关蛋白表达的影响.结果:DADS呈浓度和时间依赖性地诱导人白血病HL-60细胞凋亡,在此过程中ERK/MAPK和PI3K/Akt信号通路被抑制,而p38MAPK信号通路被激活,ERK/MAPK和PI3K/Akt信号通路通过降低Mcl-1(myeloid cell leukemia-1)和升高Bax的表达诱导人白血病细胞凋亡,而p38MAPK则不是通过调控Mcl-1和Bax的表达诱导人白血病细胞凋亡,进一步利用RNA干扰技术沉默Mcl-1基因可增加DADS对HL-60细胞增殖抑制和诱导凋亡作用.结论:MAPK和PI3K/Akt信号通路通过下调Mcl-1的表达参与了DADS诱导的HL-60细胞凋亡作用.%Objective: To investigate the role of MAPKs, phosphatidylinositol 3-kinase-Akt pathway, and the Bcl-2 family proteins in diallyl disulfide (DADS)-induced apoptosis.Methods: Flow cytometry analysis was used to detect apoptotic cells.Western blot analysis of the expression of phospho-MAPKs ( ERK and p38 ), phospho-AKT, and the Bcl-2 family proteins was used to elucidate the possible mechanisms of DADS-induced apoptosis.Results: DADS induced significant apoptosis, which exhibited a dose-dependent and time-dependent response ( P ＜ 0.05 ).DADS inhibited the ERK/MAPK and the PI3K/AKT pathways, followed by the downregulation of the anti-apoptotic factor Mcl-1 and the upregulation of the pro-apoptotic factor Bax.The P38/MAPK pathways were activated and did not affect the expression of Mcl-1 and Bax.Small interfering RNA-mediated downregulation of Mcl-1 significantly sensitized the leukemia cells to DADS-induced apoptosis.Conclusion: These results clearly demonstrate that the PI3K/AKT and MAPK signaling path-way is involved in the induction of apoptosis by DADS and it is mediated by the downregulation of Mcl-1 in human HL-60 cells.