Liver-specific Arid1a deficiency drives MASH/HCC development through dysregulated bile acid metabolism and gut microbiota restructuring via the ARID1A-FXR-bile acid-gut microbiota axis.
Liver-specific Arid1a deficiency promotes MASH and HCC development in mice.
Gut microbiota depletion using an antibiotic cocktail attenuates MASH progression and reduces HCC incidence in liver-specific Arid1a-deficient mice.
LPS accumulation due to gut barrier dysfunction promotes HCC progression but does not significantly affect MASH activity or tumor initiation in Arid1a-deficient mice.
ARID1A deficiency reduces chromatin accessibility and impairs SWI/SNF complex binding at the FXR promoter, suppressing FXR transcription.
Arid1a-deficient mice display altered gut microbiota composition enriched in bile salt hydrolase (BSH) genes.
Arid1a-deficient mice exhibit elevated levels of the secondary bile acid taurodeoxycholic acid (TDCA) in their bile acid profiles.
TDCA administration exacerbates liver inflammation and fibrosis specifically in Arid1a-deficient mice by promoting neutrophil infiltration and hepatic stellate cell activation.
Therapeutic interventions targeting the gut microbiota-bile acid axis substantially ameliorate MASH pathology in Arid1a-deficient mice.
This research suggests that loss of a protein called ARID1A specifically in liver cells sets off a chain of events leading to serious liver disease. When ARID1A is absent, it disrupts the activity of a key regulator called FXR, which normally keeps bile acids—digestive chemicals made by the liver—in balance. Without proper FXR function, the composition of gut bacteria shifts toward types that convert bile acids into a harmful form called TDCA. This elevated TDCA then triggers inflammation and scarring in the liver, particularly in the context of ARID1A loss, and can ultimately contribute to liver cancer development. The study also found that different aspects of liver disease are driven by different factors. While TDCA and the microbiota appear to be the main drivers of the initial liver inflammation and scarring (MASH), a separate factor—bacterial toxins (LPS) leaking through a damaged gut barrier—appears to accelerate the progression to liver cancer once tumors have already begun to form. This distinction helps clarify how ARID1A mutations can contribute to multiple stages of liver disease through related but distinct mechanisms. Importantly, the research identified three different treatment strategies—an antibiotic (vancomycin) to reduce harmful gut bacteria, a drug (obeticholic acid) to reactivate FXR, and a bile acid binder (cholestyramine)—that each reduced liver disease in mice lacking ARID1A. This research suggests that patients with ARID1A mutations might benefit from therapies targeting the gut microbiota or bile acid pathways, and it establishes a clear biological pathway (the ARID1A-FXR-bile acid-gut microbiota axis) as a potential target for treating a subset of patients with these specific genetic changes.
Song S, Wang L, Li L, Bai S, Zhu X, Zhang X, et al.. (2026). Arid1a deficiency promotes metabolic dysfunction-associated steatohepatitis and hepatocellular carcinoma by disrupting the FXR-gut microbiota-bile acid axis.. Cancer letters. https://doi.org/10.1016/j.canlet.2026.218567