ΔNp63 Inhibits Oxidative Stress-Induced Cell Death, Including Ferroptosis, and Cooperates with the BCL-2 Family to Promote Clonogenic Survival

Abstract

Summary: The BCL-2 family proteins are central regulators of apoptosis. However, cells deficient for BAX and BAK or overexpressing BCL-2 still succumb to oxidative stress upon DNA damage or matrix detachment. Here, we show that ΔNp63α overexpression protects cells from oxidative stress induced by oxidants, DNA damage, anoikis, or ferroptosis-inducing agents. Conversely, ΔNp63α deficiency increases oxidative stress. Mechanistically, ΔNp63α orchestrates redox homeostasis through transcriptional control of glutathione biogenesis, utilization, and regeneration. Analysis of a lung squamous cell carcinoma dataset from The Cancer Genome Atlas (TCGA) reveals that TP63 amplification/overexpression upregulates the glutathione metabolism pathway in primary human tumors. Strikingly, overexpression of ΔNp63α promotes clonogenic survival of p53−/−Bax−/−Bak−/− cells against DNA damage. Furthermore, co-expression of BCL-2 and ΔNp63α confers clonogenic survival against matrix detachment, disrupts the luminal clearance of mammary acini, and promotes cancer metastasis. Our findings highlight the need for a simultaneous blockade of apoptosis and oxidative stress to promote long-term cellular well-being. : Apoptosis-defective cells remain vulnerable to oxidative stress, which limits long-term survival. Wang et al. identify ΔNp63α as a central regulator of redox homeostasis through transcriptional control of a tightly coupled glutathione metabolic circuit. ΔNp63α alleviates oxidative stress and cooperates with the BCL-2 family to promote both long-term cellular well-being and cancer metastasis. Keywords: oxidative stress, ROS, apoptosis, necrosis, programmed necrotic death, TP63, BCL-2, ferroptosis, redox, glutathione metabolism