Lee Maria, Song Byoung-Joon, Kwon Yongil
Department of Obstetrics and Gynecology, Seoul National University College of Medicine, Seoul National University Hospital, Seoul, Korea.
Section of Molecular Pharmacology and Toxicology, Laboratory of Membrane Biochemistry and Biophysics, National Institute on Alcohol Abuse and Alcoholism, Bethesda, USA.
J Cancer Prev. 2014 Mar;19(1):39-46. doi: 10.15430/jcp.2014.19.1.39.
The mechanisms of cell or organ damage by chronic alcohol consumption are still poorly understood. The present study aimed to investigate the role of the mitogen-activated protein kinases during ethanol-induced damage to SK-N-SH neuroblastoma cells.
Cells were treated with ethanol and subsequently analyzed for cell morphology, viability, and DNA fragmentation. Immunoblot analysis was performed to assess various proteins levels associated with cell cycle arrest and apoptosis after ethanol exposure.
Ethanol induced time- and dose-dependent cell death in SK-N-SH cells and increased c-Jun N-terminal protein kinase (JNK) activity in a time- and concentration dependent manner. In contrast, p38 kinase activity increased transiently. After treatment with JNK or p38 kinase inhibitors, ethanol-induced cell death significantly reduced. Ethanol-induced cell death was accompanied by increased cytochrome c release and caspase 3 activity observed at 12 h. In contrast, the level of anti-apoptotic Bcl-2 protein did not change. Ethanol also increased the phosphorylation of p53 and p53 activation was followed by an increase in the p21 tumor suppressor protein accompanied by a gradual decrease in phospho-Rb protein.
Our results suggest that ethanol mediates apoptosis of neuroblastoma cells by stimulating p53-related cell cycle arrest mediated through activation of the JNK-related pathway.
长期饮酒导致细胞或器官损伤的机制仍知之甚少。本研究旨在探讨丝裂原活化蛋白激酶在乙醇诱导的SK-N-SH神经母细胞瘤细胞损伤中的作用。
用乙醇处理细胞，随后分析细胞形态、活力和DNA片段化。进行免疫印迹分析以评估乙醇暴露后与细胞周期停滞和凋亡相关的各种蛋白质水平。
乙醇诱导SK-N-SH细胞发生时间和剂量依赖性细胞死亡，并以时间和浓度依赖性方式增加c-Jun氨基末端蛋白激酶（JNK）活性。相比之下，p38激酶活性短暂增加。用JNK或p38激酶抑制剂处理后，乙醇诱导的细胞死亡显著减少。乙醇诱导的细胞死亡伴随着12小时时观察到的细胞色素c释放增加和半胱天冬酶3活性增加。相比之下，抗凋亡Bcl-2蛋白水平没有变化。乙醇还增加了p53的磷酸化，p53激活后，p21肿瘤抑制蛋白增加，同时磷酸化Rb蛋白逐渐减少。
我们的结果表明，乙醇通过激活JNK相关途径刺激p53相关的细胞周期停滞，从而介导神经母细胞瘤细胞的凋亡。
