凋亡信号调节激酶1在紫花牡荆素诱导结肠癌细胞凋亡中的作用

目的:研究紫花牡荆素诱导人结肠癌细胞凋亡作用及其作用机制。方法:体外培养人结肠癌HT-29细胞。碘化丙啶(P)I染色流式细胞术(FCM)和细胞凋亡ELISA试剂盒检测细胞凋亡。荧光探针二氯荧光素(DCFH-DA)标记FCM测定细胞内活性氧的含量。Western blot和小干扰RNA转染用于探索其分子机制。结果:紫花牡荆素以浓度依赖性的方式诱导结肠癌HT-29细胞系细胞凋亡。紫花牡荆素引起活性氧(ROS)的产生,并激活HT-29细胞的凋亡信号调节激酶1(ASK1)。N-乙酰半胱氨酸(NAC)预处理HT-29细胞有效地抑制ASK1活性,减弱紫花牡荆素处理引起的细胞凋亡。ASK1特异小干扰RNA能显著减弱紫花牡荆素诱导HT-29细胞凋亡作用。结论:紫花牡荆素通过刺激活性氧形成活化ASK1诱导结肠癌HT-29细胞凋亡。

Role of apoptosis signal-regulating kinase 1 activation in casticin-induced apoptosis of colon cancer cells

Objective To investigate the apoptotic effects of casticin on human colon cancer HT-29 cells and its molecular mechanism.Methods Human colon cancer HT-29 cells was cultured in vitro.The apoptotic cell death was examined using flow cytometry(FCM) using propidium iodide(PI) staining and the cell apoptosis ELISA detection kit.Intracellular reactive oxygen species(ROS) was measured by FCM using the fluorescent probe 2’,7’-dichlorofluorescein diacetate(DCFH-DA).Multiple molecular techniques,such as Western blot analysis and small interfering RNA(siRNA) transfection were used to explore the molecular mechanisms of this action.Results Casticin significantly induced apoptosis in a concentration-dependent manner in three colon cancer cell line HT-29.Casticin provoked the generation of reactive oxygen species(ROS) and activation of apoptosis signal-regulating kinase 1(ASK1) in HT-29 cells.The pretreatment with N-acetylcysteine(NAC) inhibited activation of ASK1 and protected HT-29 cells from apoptotic death by casticin treatment.Small interfering RNA for ASK1 significantly attenuated induction of apoptotic cell death following casticin treatment in HT-29 cells.Conclusion Casticin significantly induced apoptosis through activation of ASK1 by accumulation of ROS in colon cancer HT-29 cells.