Abstract 1849: Lipid metabolites as potential diagnostic biomarkers for stearoyl-CoA desaturase 1 targeting therapy in hepatocellular carcinoma (HCC)

Abstract New effective therapies should be developed for the treatment of hepatocellular carcinoma (HCC). One of the very promising strategies is blocking the activity of stearoyl-CoA desaturase 1 (SCD1). SCD1 is the enzyme responsible for de novo fatty acid (FAs) synthesis by converting saturated fatty acids (SFAs) into monounsaturated fatty acids (MUFAs). In our laboratory, we developed a novel, highly specific SCD1inhibitor - SSI-4. We have tested the biological activity of SSI-4 against different HCC cell lines and patient-derived xenografts (PDX) mouse models. Of the twelve tested HCC cell lines, four were highly sensitive to SSI-4 (IC50 1-50 nM). Other cell lines showed moderate or no sensitivity to SSI-4. We conducted analysis of the enzymatic protein levels involved in de novo fatty acid synthesis. Protein expression levels for these enzymes don’t predict response to therapy. To determine whether lipid metabolites predict response to SSI-4 therapy, lipidomic analysis was investigated. Our studies showed thatSSI-4 sensitive cells when exposed to SSI-4 had a higher baseline level of key lipid metabolites such as phospholipids (PL), diglycerides (DAG), diglycerides (TAG), ceramides (CE), and free fatty acids (FFA),compared to insensitive cells. We are currently validating these results in our in vivo models at the tumor tissue and blood levels. Additionally, mechanistic studies are in progress to determine if SREBP1c, an AKT regulated transcription factor known to regulate each of the fatty acid synthetic enzymes plays a role in HCC fatty acid synthesis and sensitivity to SCD1 inhibition. Citation Format: Justyna Joanna Gleba. Lipid metabolites as potential diagnostic biomarkers for stearoyl-CoA desaturase 1 targeting therapy in hepatocellular carcinoma (HCC) [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 1849.