Immune Protein cGAS Found to Regulate Cellular Metabolism and Cancer Progression
Scientists at UNC Lineberger Comprehensive Cancer Center discovered that the innate immune protein cGAS plays a previously unknown role in regulating cholesterol levels and gene expression within the cell nucleus. This dual function links immune defense with metabolic control, offering new insights into cancer cell adaptation and potential treatment strategies.
In November 2026, researchers at the University of North Carolina Lineberger Comprehensive Cancer Center published findings in the *Journal of Clinical Investigation* revealing that cGAS—a protein previously known only for its role in detecting foreign DNA and triggering immune responses—also functions within the cell nucleus to regulate gene expression and cholesterol metabolism. Using CUT&RUN analysis, scientists mapped cGAS’s genomic distribution and discovered it binds to specific regions independent of its DNA- or nucleosome-binding abilities. This nuclear activity leads to increased production of LGALS3 (galectin-3), a protein that reduces acetyl-CoA levels, thereby limiting cholesterol synthesis. When cGAS is absent, cells accumulate excess cholesterol, altering membrane composition and activating growth-promoting pathways linked to tumor progression and therapy resistance. Experiments in lab-grown cancer cells and mouse models confirmed that cGAS-deficient tumors grow faster and respond poorly to chemotherapy like doxorubicin and statins, while restoring either cGAS or LGALS3 reversed these effects. The study also showed this regulatory mechanism extends beyond cancer cells to immune cells and epithelial cells. Senior author Pengda Liu emphasized the dual nature of cGAS—acting both as an immune sensor and a transcriptional regulator—and highlighted the need to understand how its function shifts during tumor development and treatment resistance.
The discovery builds
This discovery could reshape how oncologists approach therapy resistance, particularly in cancers where metabolic reprogramming is a hallmark. By linking immune function to cholesterol regulation, it suggests that targeting cGAS or LGALS3 might enhance the efficacy of existing treatments—especially statins and chemotherapies—without requiring new drug classes. Patients with tumors exhibiting low cGAS activity may benefit from therapies designed to restore this pathway, potentially improving survival outcomes. The findings may also influence drug development in metabolic diseases, given cholesterol’s central role in conditions like atherosclerosis. A comparable precedent is the discovery of immune checkpoint proteins like PD-1, which transformed cancer treatment by revealing how immune regulation affects tumor growth—this cGAS finding could similarly open a new class of targets. However, it remains uncertain whether modulating cGAS will be safe across tissues, as its role in immunity an