Oxygen-releasing manganese clay hybrid complex triggers p53-mediated cancer cell death in hypoxia

Abstract

Hypoxia in tumor microenvironment is responsible for resistance to conventional modes of cancer therapeutics. A manganese-clay hybrid compound MHC was shown to generate molecular oxygen in aqueous solution. In this study we have shown that MHC, in hypoxia, causes cancer cell death, through release of molecular oxygen and via p53-dependent apoptosis. MHC treatment of cells results in depletion of mitochondrial membrane potential and inhibition of ROS production, in a cell-specific manner. In hypoxia, the oxygen from MHC releases cells from S-phase arrest thus causing p53-dependent apoptosis. The induction of apoptosis by MHC is higher in p53 Wt/Wt cells when it is compared with p53 Mt/Mt cells. The released oxygen from MHC triggers apoptosis via p53 activation through its enhanced homo-oligomerization, post-translational modifications and nuclear localization. Thus MHC as a cellular oxygen-releasing compound has high potential as a drug for hypoxic tumor regression.