TMEM97 regulates cholesterol biosynthesis and mitochondrial metabolism in gastric carcinoma

Cancer cells regulate cholesterol levels to sustain proliferation and metabolic adaptation. Here, we show that TMEM97 coordinates cholesterol sensing with oxidative phosphorylation in gastric cancer. Loss of TMEM97 reduced in vitro proliferation and impaired xenograft tumor growth. TMEM97 deficiency disrupted cholesterol homeostasis, causing accumulation of the post-lanosterol intermediate follicular fluid meiosis-activating sterol (FF-MAS) under both normal and lipoprotein-deficient serum conditions. Metabolomic and transcriptomic analyses further revealed altered tricarboxylic acid (TCA) cycle activity under lipoprotein-deficient conditions. Structural analysis identified a conserved cholesterol recognition amino acid consensus (CARC) motif in TMEM97, and its deletion reduced cholesterol binding. Collectively, TMEM97 regulates sterol regulatory element binding protein (SREBP)-associated lipid programs, post-lanosterol cholesterol biosynthesis, and mitochondrial bioenergetics. These findings identify TMEM97 as a regulator of cholesterol-dependent metabolic adaptation in gastric cancer and support TMEM97-associated cholesterol regulation as a potential therapeutic vulnerability.