Abstract
Pancreatic ductal adenocarcinoma is characterized by a three-dimensional (3D) tumor microenvironment devoid of oxygen and nutrients but enriched in extracellular matrix, which acts as a physical and chemical barrier. In 3D, cancer cells reprogram their metabolic pathways in ways that help them survive hostile conditions. However, little is known about the metabolic phenotypes of cancer cells in 3D and the intrinsic cues that modulate them. We found that Cxcl5 deletion restricted pancreatic tumor growth in a 3D spheroid-in-Matrigel culture system without affecting cancer cell growth in 2D culture. Cxcl5 deletion impaired 3D-specific global metabolic reprogramming, resistance to hypoxia-induced cell death, and upregulation of Hif1α and Myc. Overexpression of Hif1α and Myc, however, effectively restored 3D culture-induced metabolic reconfiguration, growth, redox homeostasis, and mitochondrial function in Cxcl5-/- cells, reducing ferroptosis. We also found that pancreatic cancer patients with higher expression of hypoxia and metabolism-related genes whose expression is well-correlated with CXCL5 generally have poorer prognosis. Together, our findings identify an unanticipated role of Cxcl5 in orchestrating the cancer metabolic reprogramming in 3D culture that is required for energy and biomass maintenance and that restricts oxidative cell death. Thus, our results provide a rationale for targeting CXCL5 as a promising therapeutic strategy.