Lipid synthesis seems to drive proliferation in Men1 mouse adrenals and human adrenocortical cell lines

Adrenocortical carcinoma (ACC) is a devastating disease with few effective treatments. The underlying molecular pathways remain largely unknown. To identify potential pathways and drivers relevant to ACC pathogenesis, we utilized histologically normal adrenals from heterozygous multiple endocrine neoplasia type 1 (Men1) mice to study early adrenocortical tumorigenesis. Employing mass spectrometry-based proteomic profiling, we identified 681 proteins, of which 52 displayed significant differential regulation in the adrenal tissues of heterozygous Men1 mice in comparison with their wild-type counterparts. Among these were fatty acid synthase (FASN) and ATP-citrate lyase (ACLY), two enzymes previously shown to be upregulated in several other types of tumors. To assess the functional impact of ACLY and FASN in ACC, we used H295R cells as the primary model. Cells were treated with SB-204990 (ACLY inhibitor) or C75 (FASN inhibitor), which both showed a dose-dependent antiproliferative effect. Lipidomic analysis revealed a significant reduction in palmitic acid and palmitoleic acid in treated cells compared to controls, supporting a mechanistic link between ACLY/FASN activity and lipid biosynthesis. Finally, data from The Cancer Genome Atlas showed significantly diminished survival outcomes among ACC patients exhibiting high ACLY or FASN expression. These findings underscore the potential importance of exploring the inhibition of lipid synthesis as a promising avenue for further research in the context of human ACC.