Disulfiram inhibits TNF-alpha-induced cell death

Disulfiram, a clinically employed alcohol deterrent, was recently discovered to inhibit caspase-3 and DNA fragmentation. Using LLC-PK1 cells and murine liver as models, we examined if the drug inhibited TNF-alpha-induced cell death. Disulfiram produced dose-dependent inhibition of TNF-alpha-induced cell death as well as caspase-3-like activity. Disulfiram retained 80% of its effect when added 4 h after TNF-alpha. Disulfiram protected the cells from cytokine-induced death for at least 6 days. The cells rescued by the drug preserved the ability to proliferate. The cells died spontaneously after exposure to TNF-alpha for just 70 min. Co-administration of 15 microM disulfiram and TNF-alpha for 70 min prior to their removal abolished TNF-alpha-induced killing, and this was associated with restoration of mitochondrial membrane potential and suppression of reactive oxygen species. Treatment of mice with TNF-alpha and D-galactosamine for 5 h markedly increased hepatic DNA fragmentation and caspase-3-like activity. Disulfiram at 0.6 mmol/kg abolished these effects. We conclude that disulfiram is a potent inhibitor of TNF-alpha-induced cell death in vitro. The underlying mechanisms include stabilization of mitochondrial membrane potential, suppression of reactive oxygen species, and inhibition of caspase-3-like activity. We further conclude that disulfiram inhibits DNA fragmentation in vivo in association with the blockade of caspase-3-like activity.     

双硫仑抗癌作用研究进展

双硫仑作为一种治疗慢性酒精中毒的药物在临床中广泛使用。近几十年研究发现它除了戒酒作用还在治疗癌症中具有巨大潜力,针对它在体外和体内模型的研究结论已有部分在临床治疗中得到证实。双硫仑通过其代谢产物抑制乙醛脱氢酶活性导致体内乙醛含量积累,增加细胞毒性从而抑制肿瘤干细胞增殖分化;提高细胞内活性氧的浓度诱导细胞凋亡;抑制蛋白酶体活性,积累大量废弃蛋白质诱导细胞凋亡;通过抑制NF-κB下调来抑制上皮间质转化等。此外双硫仑与抗癌药物联合使用可提升抗癌药物药效。由于具有低毒、低成本且对肿瘤组织有趋向性等特点,双硫仑重新应用于临床作为抗癌药物具有广阔前景。简要回顾了双硫仑最新研究中阐明的双硫仑抗癌作用分子机制,展望了未来双硫仑用作新临床抗癌药物的前景,以期为双硫仑在抗癌药物中的应用研究提供参考。     

Disulfiram is a potent in vitro inhibitor of DNA topoisomerases.

The drug disulfiram is a thiol-reacting drug that is relatively nontoxic when used alone and has been used in the therapy of alcohol abuse for more than 40 years. Several effects of this drug have been reported for DNA synthesis and cell proliferation. In this study, the inhibitory effect of disulfiram on topoisomerase I and II activity was investigated by measuring the relaxation of superhelical plasmid pBR322 DNA. Disulfiram (1-100 microM) inhibited topoisomerase I and II in a concentration-dependent manner (IC(50) congruent with 42 +/- 8 and 30 +/- 9 microM, respectively). Consistent with the assumption that a thiol residue is involved, dithiothreitol (1 mM) markedly prevented the inhibitory effect of disulfiram on the activity of both classes of topoisomerases. These findings might explain certain aspects of disulfiram toxicity and encourage new studies to determine the usefulness of this drug and its analogues as antineoplastic agent.