GSE202279
ACSS2 inhibitors act as metabo-immunomodulators in triple negative breast cancer [RNA-Seq]
Acetate metabolism is an important metabolic pathway in many types of cancers and is primarily controlled by acetyl-CoA synthetase 2 (ACSS2), an enzyme that catalyzes the conversion of acetate to acetyl-CoA. However, the consequences of inhibiting tumor acetate metabolism on the tumor microenvironment and anti-tumor immunity are unknown. Herein we demonstrate that the growth of ACSS2 deficient triple negative breast cancer is severely impaired when host immunity is intact and, in many instances, ACSS2 deficient tumors are fully cleared by the immune system. Pharmacological inhibition of ACSS2 using a potent small molecule inhibitor reproduces these effects and enhances the efficacy of standard of care chemotherapy for TNBC. Single cell RNA sequencing of vehicle versus ACSS2 inhibitor treated tumors indicates differentiation and activation of T cells suggesting a crosstalk between acetate metabolism and immune cells in the tumor microenvironment. Our data suggest that blocking ACSS2 and acetate metabolism in tumors increases the availability of acetate in the tumor microenvironment. Tumor infiltrating T cells can then use acetate as a fuel source due to the relatively high expression of acetyl-CoA synthetase 1 (ACSS1), which is impervious to ACSS2 inhibitors. In this manner, ACSS1-driven oxidation of acetate in T cells helps to metabolically bolster anti-tumor immune responses. Based on our findings, we propose a completely novel paradigm for ACSS2 inhibitors as metaboimmunomodulators that dually act as inhibitors of tumor cell metabolism and modulators of tumor immunity. Overall design: RNA-seq of different Bmal1 status