Suppression of de novo lipogenesis and dietary PUFA supplementation inhibit prostate cancer progression.

Prostate cancer progression is characterized by dysregulated lipid metabolism, with fatty acid synthase (FASN), the rate-limiting step in de novo lipogenesis (DNL), resulting in significant accumulation of saturated lipids. Here, we investigate whether pharmacologic FASN inhibition creates a metabolic state that increases reliance on exogenous polyunsaturated fatty acids (PUFAs). Inhibition of FASN profoundly alters membrane phospholipid composition, driving compensatory incorporation of PUFAs into membrane phospholipids, thus increasing susceptibility to lipid peroxidation and oxidative damage. Combined FASN inhibition and PUFA exposure increased reactive oxygen species, induced mitochondrial hyperpolarization, and enhanced lipid peroxidation in both hormone-sensitive and castration-resistant prostate cancer models. Marked inhibition of human and murine prostate cancer organoids is achieved ex vivo . In genetically engineered, DNL-reliant Hi-Myc mice, a diet enriched in PUFAs significantly inhibited invasive carcinoma compared to a saturated fat-enriched diet. Environmental PUFAs modulate and enhance the therapeutic efficacy of FASN-targeted strategies. These findings set the stage for pharmacologic and dietary intervention in prostate cancer patients.