人白细胞介素1β(IL-1β)在诱导人黑色素瘤A375-S2细胞凋亡过程中的细胞周期阻滞作用和对线粒体Bcl-2家族蛋白的调节

Interleukin-1β promotes apoptosis in human melanoma A375-S2 cells by cell cycle arrest and altering expression of Bcl-2 family proteins

目的研究人白细胞介素1β(interleukin-1β,IL-1β)体外诱导人黑色素瘤A375-S2细胞凋亡的机制。方法通过Hoechst33258荧光染色,观察A375-S2细胞在IL-1β作用下的形态学变化。使用琼脂糖凝胶电泳法检测IL-1β对细胞DNA降解的影响。应用流式细胞分析技术研究IL-1β对A375-S2细胞周期的影响。利用Westernβlot方法检测IL-1β对细胞线粒体内Bcl-2家族蛋白表达的调节作用。结果IL-1β(1nM)能够诱导A375-S2细胞凋亡,72h时细胞体变小,细胞核呈现固缩、断裂,并出现因凋亡引起的DNA梯状条带。IL-1β可将细胞周期阻滞在G0/G1期,并具有时间依赖性。IL-1β诱导细胞凋亡过程中,抗凋亡蛋白Bcl-2和Bcl-xL的表达减少,促凋亡蛋白Bax的表达增加。结论IL-1β通过将细胞周期阻滞在G0/G1期,上调线粒体内Bax/Bcl-2和Bax/Bcl-xL的表达比例诱导A375-S2细胞凋亡。

Objective To investigate the machinery of IL-1β-induced cell apoptosis in human malignant melanoma A375-S2 cells. Methods The morphologic changes of cell were observed by Hoechst 33258 staining. DNA fragmentation was detected by agrose gel electrophoresis. Cell cycle analysis was performed by flowcytometry. The expression of Bcl-2 family proteins was assayed by Western blot analysis. Results Cell nuclear condensation and DNA fragmentation were observed after treatment with 1 nM IL-1β for 72 h. IL-1β arrested A375-S2 cells at G0/G1 phase of the cell cycle in a time dependent manner. In apoptotic progress induced by IL-1β, expression of antiapoptotic Bcl-2 and Bcl-xL were decreased, while proapoptotic Bax expression was slightly increased. Conclusion IL-1β induced apoptosis in A375-S2 cells through G0/G1 arrest and upregulation of the ratio of Bax/Bcl-2 and Bax/Bcl-xL expression.