Lysine Specific Demethylase 1 (KDM1A / LSD1) regulates mitochondrial respiration and stabilizes HIF-1A (hypoxia-inducible factor 1A). HIF-1A modulates reactive oxygen species (ROS) levels by increasing cellular glucose uptake, glycolysis, and endogenous antioxidants. The role of KDM1A in cellular ROS response has not previously been described. We determined the role of KDM1A in regulating the ROS response and the utility of KDM1A inhibitors in combination with ROS-inducing cancer therapies. Our results show that KDM1A inhibition sensitized cells to oxidative stress and increased total cellular ROS, which was mitigated by treatment with the antioxidant N-acetyl cysteine. KDM1A inhibition decreased basal mitochondrial respiration and impaired induction of HIF-1A after ROS exposure. Overexpression of HIF-1A salvaged cells from KDM1A inhibition enhanced sensitivity to ROS. Thus we found that increased sensitivity of ROS after KDM1A inhibition was mediated by HIF-1A and depletion of endogenous glutathione. We also show that KDM1A-specific inhibitor bizine synergized with antioxidant-depleting therapies, buthionine sulfoximine, and auranofin in rhabdomyosarcoma cell lines (Rh28 and Rh30). In this study, we describe a novel role for KDM1A in regulating HIF-1A functions under oxidative stress and found that dual targeting of KDM1A and antioxidant systems may serve as an effective combination anticancer strategy.
Keywords: HIF-1A; KDM1A; antioxidants; cancer; reactive oxygen species.