Fatty Acid Synthase as a Potential Metabolic Vulnerability in Ocular Adnexal Sebaceous Carcinoma

Background: MYC dysregulation is frequent in ocular adnexal sebaceous carcinoma (SebCA), an aggressive malignancy without precision therapy. Fatty acid synthase (FASN) expression and lipid metabolism are commonly perturbed in high-MYC-expressing tumors; however, the role of MYC and FASN in the coregulation of lipid biosynthesis and tumorigenesis in SebCA is unknown. Methods: The aim of this study was to characterize the effects of FASN inhibition on MYC expression, oncogenic processes, and lipid profiles in vitro, using non-neoplastic human Meibomian gland epithelial cells (HMGECs) and three primary SebCA cell lines, and in vivo, utilizing a conditionally MYC-overexpressing mouse model. Results: FASN inhibition reduced cell viability, proliferation, and clonogenicity and altered the saturation profile of fatty acids across multiple lipid classes. The relative saturation of ceramides was the most variable between treatment conditions. MYC overexpression in the murine Meibomian gland promoted proliferation while suppressing sebaceous differentiation. Subsequent topical FASN inhibition further reduced sebaceous differentiation, attenuated PLIN2 expression, and induced apoptotic cell death. Conclusions: Collectively, these findings suggest that MYC expression in SebCA is responsive to FASN inhibition. Pharmacologic targeting of FASN reveals a metabolic vulnerability that may serve as a target for future therapeutic development.