The HIF-2 transcription factor mediates resistance to ferroptosis in pancreatic cancer

Abstract

Ferroptosis is an iron-dependent form of cell death converging on lipid peroxidation first identified by examining compounds with enhanced lethality to KRAS mutant cells. Despite over 90% of pancreatic ductal adenocarcinoma (PDAC) tumors harboring KRAS mutations, PDAC exhibits relative resistance to ferroptosis compared with other tumor types, and the mechanisms behind this resistance remain unclear. Here, we report that exposure to pancreatic tumor interstitial fluid in synergy with hypoxia induced robust protection against ferroptosis in a manner dependent on the hypoxia-inducible transcription factor 2 (HIF-2). HIF-2 upregulates the expression of both components of the system Xc^- cystine transporter and transsulfuration pathway enzymes CBS and CTH to increase intracellular cysteine levels, enabling anti-ferroptotic glutathione production. HIF-2 also induces the Parkin mitophagy factor and suppresses mitochondrial function and reactive oxygen species (ROS) generation. Altogether, our findings uncover an unforeseen role of the HIF-2 transcription factor as a coordinator of anti-ferroptotic mechanisms in pancreatic cancer.

Keywords: HIF-2 transcription factor; ferroptosis; hypoxia; pancreatic ductal adenocarcinoma.