title: Effects of hydroxyl radical scavenging on cisplatin-induced p53 activation, tubular cell apoptosis and nephrotoxicity.
abstract: Nephrotoxicity is a major side effect of cisplatin, a widely used cancer therapy drug. Recent work has suggested a role of p53 in renal cell injury by cisplatin. However, the mechanism of p53 activation by cisplatin is unclear. This study determined the possible involvement of oxidative stress in p53 activation under the pathological condition using in vitro and in vivo models. In cultured renal proximal tubular cells, cisplatin at 20 microM induced an early p53 phosphorylation followed by protein accumulation. Cisplatin also induced reactive oxygen species (ROS), among which hydroxyl radicals showed a rapid and drastic accumulation. Dimethylthiourea (DMTU) and N-acetyl-cysteine (NAC) attenuated hydroxyl radical accumulation, and importantly, diminished p53 activation during cisplatin treatment. This was accompanied by the suppression of PUMA-alpha, a p53-regulated apoptotic gene. Concomitantly, mitochondrial cytochrome c release and apoptosis were ameliorated. Notably, DMTU and NAC, when added post-cisplatin treatment, were also inhibitory to p53 activation and apoptosis. In C57BL/6 mice, cisplatin at 30 mg/kg induced p53 phosphorylation and protein accumulation, which was also abrogated by DMTU. DMTU also ameliorated tissue damage, tubular cell apoptosis and cisplatin-induced renal failure. Collectively, this study has suggested a role of oxidative stress, particularly hydroxyl radicals, in cisplatin-induced p53 activation, tubular cell apoptosis and nephrotoxicity.
authors.affiliation: Department of Cellular Biology and Anatomy, Medical College of Georgia and Veterans Affairs Medical Center, 1459 Laney Walker Blvd., Augusta, GA 30912, United States.
authors.forename: Man
authors.initials: M
authors.lastname: Jiang
authors.forename: Qingqing
authors.initials: Q
authors.lastname: Wei
authors.forename: Navjotsin
authors.initials: N
authors.lastname: Pabla
authors.forename: Guie
authors.initials: G
authors.lastname: Dong
authors.forename: Cong-Yi
authors.initials: CY
authors.lastname: Wang
authors.forename: Tianxin
authors.initials: T
authors.lastname: Yang
authors.forename: Sylvia B
authors.initials: SB
authors.lastname: Smith
authors.forename: Zheng
authors.initials: Z
authors.lastname: Dong
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects* / Q000502:physiology; D002478:Cells, Cultured; D002945:Cisplatin / Q000494:pharmacology; D016166:Free Radical Scavengers / Q000494:pharmacology*; D016158:Genes, p53 / Q000502:physiology; D017665:Hydroxyl Radical / Q000378:metabolism*; D007668:Kidney / Q000187:drug effects* / Q000473:pathology; D007684:Kidney Tubules / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D051381:Rats; D017382:Reactive Oxygen Species; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism*
chemical_list: D016166:Free Radical Scavengers; D017382:Reactive Oxygen Species; D016159:Tumor Suppressor Protein p53; D017665:Hydroxyl Radical; D002945:Cisplatin