Genome-wide CRISPR screen identifies a cytokine-enhancer circuit driving HIF-2α activation in renal cancer.

Abstract

Resistance to HIF-2α inhibitors such as belzutifan underscores the need to better understand how HIF-2α is transcriptionally regulated in clear cell renal cell carcinoma (ccRCC). Here, we uncover a cytokine-driven enhancer mechanism that sustains HIF-2α expression through the JAK1/STAT3 signaling pathway. Using a genome-wide CRISPR screen in von Hippel-Lindau-deficient (VHL-deficient) ccRCC cells, we identified SOCS3 as a key negative regulator of HIF-2α. Mechanistically, loss of SOCS3 activates JAK1/STAT3 signaling, leading to the recruitment of STAT3 to distal enhancers upstream of endothelial PAS domain-containing protein (EPAS1) that physically loop to its promoter to drive HIF-2α transcription. This cytokine-enhancer circuit was recapitulated in samples from patients with ccRCC and functionally validated using CRISPR interference (CRISPRi), which disrupted enhancer-promoter looping and reduced tumor growth in HIF-2α-dependent models. SOCS3 overexpression or pharmacologic inhibition of JAK1/STAT3 markedly suppressed HIF-2α expression and tumor progression both in vitro and in vivo. Unlike prior studies focusing on VHL/HIF occupancy-driven enhancer activation, this work defines a trans-acting cytokine-JAK1/STAT3 pathway that transcriptionally controls EPAS1. Together, these findings reveal a targetable enhancer mechanism that sustains HIF-2α expression and suggest that combined inhibition of JAK1/STAT3 and HIF-2α may overcome therapeutic resistance in kidney cancer.