Department of Physiology, Medical School, Research Institute for Endocrine Sciences, Chonbuk National University, Jeonju 561-180, Republic of Korea.
Int J Oncol. 2014 Jan;44(1):301-8. doi: 10.3892/ijo.2013.2152. Epub 2013 Oct 29.
PX-12 (1-methylpropyl 2-imidazolyl disulfide) is an inhibitor of thioredoxin (Trx-1), which has antitumor effects. However, little is known about the toxicological effect of PX-12 on cancer cells. We investigated the anti-growth effects of PX-12 on A549 lung cancer cells in relation to reactive oxygen species (ROS) and glutathione (GSH) levels. Based on MTT assays, PX-12 inhibited the growth of A549 cells with an IC50 of approximately 20 µM at 72 h. DNA flow cytometric analysis indicated that PX-12 significantly induced the G2/M phase arrest of the cell cycle in A549 cells. This agent also induced apoptotic cell death, as demonstrated by Annexin V-FITC staining cells and the loss of mitochondrial membrane potential MMP (∆ψm). In addition, the administration of Bax siRNA attenuated PX-12-induced A549 cell death. All the tested caspase inhibitors, especially Z-VAD significantly prevented apoptosis induced by PX-12. With respect to ROS and GSH levels, PX-12 increased ROS levels including O2(•)- in A549 cells and induced GSH depletion. N-acetyl cysteine (NAC) markedly reduced ROS levels in PX-12-treated A549 cells. NAC also prevented apoptotic cell death and GSH depletion induced by PX-12. This is the first report to show that PX-12 inhibits the growth of A549 cells via G2/M phase arrest, and Bax-mediated and ROS-dependent apoptosis.
PX-12（1-甲基丙基 2-咪唑二硫）是一种硫氧还蛋白（Trx-1）抑制剂，具有抗肿瘤作用。然而，关于 PX-12 对癌细胞的毒理作用知之甚少。我们研究了 PX-12 对 A549 肺癌细胞的生长抑制作用与活性氧（ROS）和谷胱甘肽（GSH）水平的关系。基于 MTT 测定，PX-12 在 72 小时时以约 20µM 的 IC50 抑制 A549 细胞的生长。DNA 流式细胞术分析表明，PX-12 显著诱导 A549 细胞周期的 G2/M 期阻滞。该药物还诱导凋亡细胞死亡，如 Annexin V-FITC 染色细胞和线粒体膜电位 MMP（∆ψm）的丧失所示。此外，Bax siRNA 的给药减弱了 PX-12 诱导的 A549 细胞死亡。所有测试的半胱氨酸天冬氨酸蛋白酶抑制剂，特别是 Z-VAD，显著预防了 PX-12 诱导的凋亡。关于 ROS 和 GSH 水平，PX-12 增加了包括 O2(•)-在内的 A549 细胞中的 ROS 水平，并诱导 GSH 耗竭。N-乙酰半胱氨酸（NAC）显著降低了 PX-12 处理的 A549 细胞中的 ROS 水平。NAC 还预防了 PX-12 诱导的凋亡细胞死亡和 GSH 耗竭。这是第一个表明 PX-12 通过 G2/M 期阻滞、Bax 介导的和 ROS 依赖性凋亡抑制 A549 细胞生长的报告。
