Gut microbial metabolite butyrate improves anticancer therapy by regulating intracellular calcium homeostasis

Gut microbiota are recognized to be important for anticancer therapy, yet the underlying mechanism is not clear. Herein, we demonstrate that gut microbial metabolite butyrate improves anticancer therapy efficacy by regulating intracellular calcium homeostasis. Butyrate metabolism is activated in hepatocellular carcinoma (HCC) patients. Butyrate supplementation or depletion of short-chain Acyl-CoA dehydrogenase (ACADS), a key enzyme for butyrate metabolism, significantly inhibit HCC proliferation and metastasis. Profiling analysis of genes upregulated by butyrate supplementation or ACADS knockdown reveal that calcium signaling pathway is activated, leading to dysregulation of intracellular calcium homeostasis and production of reactive oxygen species (ROS). Butyrate supplementation improves the therapy efficacy of a tyrosine kinase inhibitor sorafenib. Butyrate and sorafenib co-encapsulated monomethoxy (polyethylene glycol)-poly (D, L-lactide-co-glycolide)-poly(L-lysine)-glypican 3 (PEAL-GPC3) nanoparticles significantly reduce HCC progression. Our findings provide new insight into the mechanisms that the gut microbial metabolites inhibit HCC progression and suggest a translatable therapeutics approach to enhance the clinical targeted therapeutic efficacy. The gene expression profiles of sodium butyrate treatment and ACADS knockdown Hep3B cells were compared with those in control Hep3B cells