Role of ATP citrate lyase and its complementary partner on fatty acid synthesis in gastric cancer.

ATP citrate lyase (ACLY) and acyl-CoA short-chain synthetases 2 (ACSS2) are key enzymes in lipid metabolism. We explored the role of ACLY in gastric cancer (GC) and the effect of ACLY and ACSS2 compensation on GC growth. We used immunohistochemistry to verify the expression level of ACLY in GC, shRNA to stably knock down the expression level of ACLY in GC cells. The expression levels of lipid metabolizing enzymes were verified by qPCR and WB, and targeted lipidomics and quantification of lipid metabolism-related indicators helped us to understand the changes in lipid metabolism. Finally, subcutaneous graft tumors validate our findings from in vitro experiments. ACLY is upregulated in GC tissues, downregulation of ACLY reduced lipid accumulation and inhibited GC proliferation, migration, and invasion in vitro. ACSS2 maintains cell growth by compensatory elevation to maintain fatty acid synthesis activity in ACLY-depleted GC cells. Inhibition of ACSS2 enhanced the inhibitory effect of downregulation of ACLY on the growth of transplanted tumors in nude mice. Downregulation of ACLY inhibited GC cell growth in vitro and in vivo. ACSS2 was compensated to increase to maintain cell growth in ACLY-depleted GC cells.