title: Effects of SOD/catalase mimetic platinum nanoparticles on radiation-induced apoptosis in human lymphoma U937 cells.
abstract: Since polyacrylic acid capped platinum nano-particles (nano-Pts) are known to have a unique ability to quench superoxide (O2(-)) and hydrogen peroxide (H2O2), the anti-oxidant activity of nano-Pts against apoptosis induced by x-irradiation in human lymphoma U937 cells was investigated. DNA fragmentation assay, Annexin V-FITC/PI by flow cytometry and Giemsa staining revealed a significant decrease in apoptosis induced by 10 Gy, when cells were pre-treated with nano-Pts in a dose-dependent manner. Pre-treatment with nano-Pts significantly decreased radiation-induced reactive oxygen species (ROS) production, Fas expression and loss of mitochondrial membrane potential as determined by flow-cytometry. Furthermore, western blot analysis also showed that the expression of cleaved caspase-3, Bid and cytosolic cytochrome-c were significantly reduced in nano-Pts pretreated cells. Due to the catalase mimetic activity of nano-Pts, these results indicate that pre-treatment of U937 cells with nano-Pts significantly protect radiation-induced apoptosis by inhibiting intracellular ROS (mainly H2O2), which plays a key role in the induction of apoptosis, because of no practical observation of intracellular O2(-) formation.
authors.affiliation: Department of Radiological Sciences, Graduate School of Medicine and Pharmaceutical Sciences University of Toyama, Toyama, Japan.
authors.forename: Paras
authors.initials: P
authors.lastname: Jawaid
authors.forename: Mati ur
authors.initials: Mu
authors.lastname: Rehman
authors.forename: Yoko
authors.initials: Y
authors.lastname: Yoshihisa
authors.forename: Peng
authors.initials: P
authors.lastname: Li
authors.forename: Qing li
authors.initials: Ql
authors.lastname: Zhao
authors.forename: Mariame Ali
authors.initials: MA
authors.lastname: Hassan
authors.forename: Yusei
authors.initials: Y
authors.lastname: Miyamoto
authors.forename: Tadamichi
authors.initials: T
authors.lastname: Shimizu
authors.forename: Takashi
authors.initials: T
authors.lastname: Kondo
mesh_terms: D000180:Acrylic Resins; D000975:Antioxidants / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects* / Q000528:radiation effects; D002374:Catalase / Q000737:chemistry*; D006801:Humans; D053768:Metal Nanoparticles; D018716:Molecular Mimicry; D010984:Platinum / Q000494:pharmacology*; D017382:Reactive Oxygen Species / Q000378:metabolism; D013482:Superoxide Dismutase / Q000737:chemistry*; D020298:U937 Cells
chemical_list: D000180:Acrylic Resins; D000975:Antioxidants; D017382:Reactive Oxygen Species; D010984:Platinum; C006903:carbopol 940; D002374:Catalase; D013482:Superoxide Dismutase