Modulation of SCD1 activity in hepatocyte cell lines: evaluation of genomic stability and proliferation

Author(s)

de Lima Luna, Arthur Cassio ^[1] ; Forti, Fabio Luis ^[1]

Affiliation

^[1] Univ Sao Paulo, Inst Chem, Dept Biochem, Lab Biomol Syst Signaling, Av Prof Lineu Prestes 748, Bl 09i Sl 922, BR-05508900 Sao Paulo, SP - Brazil

• Document type: Journal article
• Source: Molecular and Cellular Biochemistry; v. 476, n. 9, p. 3393-3405, SEP 2021.
• Web of Science Citations: 0

Abstract

Stearoyl-CoA desaturase (SCD) is a central lipogenic enzyme for the synthesis of monounsaturated fatty acids (MUFA). SCD1 overexpression is associated with a genetic predisposition to hepatocarcinogenesis in mice and rats. This work hypothesized possible roles of SCD1 to genomic stability, lipogenesis, cell proliferation, and survival that contribute to the malignant transformation of non-tumorigenic liver cells. Therefore, HepG2 tumor cells were treated with the SCD1 inhibitor (CAY10566) to ensure a decrease in proliferation/survival, as confirmed by a lipidomic analysis that detected an efficient decrease in the concentration of MUFA. According to that, we switched to a model of normal hepatocytes, the HepaRG cell line, where we: (i) overexpressed SCD1 (HepaRG-SCD1 clones), (ii) inhibited the endogenous SCD1 activity with CAY10566, or (iii) treated with two monounsaturated (oleic OA and/or palmitoleic PA) fatty acids. SCD1 overexpression or MUFA stimulation increased cell proliferation, survival, and the levels of AKT, phospho-AKT(Ser473), and proliferating cell nuclear antigen (PCNA) proteins. By contrast, opposite molecular and cellular responses were observed in HepaRG cells treated with CAY10566. To assess genomic stability, HepaRG-SCD1 clones were treated with ionizing radiation (IR) and presented reduced levels of DNA damage and higher survival at doses of 5 Gy and 10 Gy compared to parental cells. In sum, this work suggests that modulation of SCD1 activity not only plays a role in cell proliferation and survival, but also in maintaining genomic stability, and therefore, contributes to a better understanding of this enzyme in molecular mechanisms of hepatocarcinogenesis projecting SCD1 as a potential translational target. (AU)

• FAPESP's process: 18/01753-6 - Identification and functional investigation of proteins that interact with Cdc42 and DUSP12 enzymes in human cells under conditions of genomic instability: a proteomic approach
• Grantee: Fábio Luis Forti
• Support Opportunities: Regular Research Grants
• FAPESP's process: 17/12775-8 - EVALUATION OF THE INDUCTION OF GENOMIC INSTABILITY AND METABOLIC ALTERATIONS BY SCD1 ENZYME IN HEPATOCYTE CELL LINES
• Grantee: Arthur Cassio de Lima Luna
• Support Opportunities: Scholarships in Brazil - Post-Doctoral