Context-Dependent Cancer Vulnerabilities: CRISPR Screening under Inflammatory Stress.

Abstract

Genome-wide CRISPR screens have systematically identified genes required for cancer cell survival, yet these studies are typically performed under standardized conditions that do not fully recapitulate the physiologic stresses encountered within the tumor microenvironment. In a recent issue of Nature Genetics, Cheruiyot and colleagues perform genome-wide loss-of-function screens under inflammatory conditions induced by interferon (IFN) β, IFNγ, and tumor necrosis factor (TNF), revealing that distinct cytokines impose different genetic requirements for tumor cell survival. The study shows that inflammatory signaling reshapes the genetic dependency landscape in a cytokine-specific manner. Mechanistic analyses identify the glycosylphosphatidylinositol (GPI) transamidase complex and Fitm2 as representative examples of genes that become selectively required under inflammatory stress by maintaining membrane protein maturation, endoplasmic reticulum homeostasis, and resistance to oxidative stress. These findings broaden our understanding of how inflammatory cytokines influence tumor cell biology beyond transcriptional regulation and immune recognition. More broadly, the study highlights the value of incorporating physiologically relevant conditions into functional genetic screens, suggesting that conventional dependency maps capture only part of the genetic requirements for tumor survival. Applying similar approaches to other microenvironmental stresses-including hypoxia, metabolic competition, extracellular matrix remodeling, and stromal signaling-may uncover additional therapeutic opportunities for cancer immunotherapy.