USP20-Driven Cholesterol Metabolism Links Inflammatory Signaling to Malignancy and Stromal Coevolution in Pancreatic Cancer.

[UNLABELLED] Inflammatory signaling, metabolic reprogramming, and stromal complexity have emerged as core hallmarks of pancreatic ductal adenocarcinoma (PDAC). Cross-talk between these programs could represent potential targets to concurrently perturb multiple tumor-promoting processes. By integrating multiomics data from clinical cohorts, patient-derived organoids, and autochthonous models, we uncovered tumor-intrinsic inflammatory cascades in PDAC as master regulators of mevalonate pathway hijacking, which drove both malignant progression and stromal coevolution. TNFSF13B+ tumor-associated macrophages activated STAT3 signaling in neoplastic epithelia, leading to the transcriptional upregulation of USP20. This deubiquitinase stabilized HMGCR to potentiate mevalonate flux, resulting in cholesterol and geranylgeranyl pyrophosphate overproduction. Stimulation of YAP/TAZ signaling induced by the USP20-mediated metabolic alterations promoted tumor cell proliferation and triggered the activation of cancer-associated fibroblasts. Genetic ablation or pharmacologic inhibition of USP20 using a selective inhibitor reversed tumor metabolic dysregulation, suppressing both tumor growth and stromal desmoplasia. Furthermore, the combination of USP20 inhibition and anti-PD-1/anti-CTLA4 immunotherapy resulted in enhanced antitumor efficacy. These findings reveal the STAT3-USP20-HMGCR axis as a central coordinator of PDAC malignancy and position USP20 inhibition as a strategy to suppress oncogenic signaling, perturb metabolic reprogramming, and reverse microenvironmental remodeling.

[SIGNIFICANCE] Targeting USP20 disrupts coevolution of pancreatic ductal adenocarcinoma and the tumor microenvironment and enhances immune checkpoint inhibitor efficacy by blocking mevalonate metabolism rewiring, providing a dual-action therapeutic approach for pancreatic cancer.