Role of Adipose Triglyceride Lipase (ATGL) in Cell Proliferation

Previously viewed simply as a static form of energy storage, the lipid droplet has recently become the focus of intense research due to the discovery of its involvement in numerous cellular metabolic processes. It is currently hypothesized that regulation of lipid droplet metabolism within the cell may have significant effect on cell signaling and disease development, including diabetes and cancer. In this project, we investigate a lipid droplet-associated lipase, adipose triglyceride lipase (ATGL), which catalyzes the first step of fatty acid breakdown by converting triglyceride to diglyceride. This lipase has previously been implicated in regulating cellular energetics and possibly cell growth. In this study, we first investigated various methods for plasmid insertion into proliferating cells and established several stable lines expressing ATGL. We show that ATGL overexpression reduces lipid droplet formation in cells, consistent with its catabolic role in lipid metabolism. We further show that addition of fatty acid to culture media attenuates the growth promoted by increased fetal bovine serum (FBS) and that cell growth is reduced with ATGL overexpression especially when grown in the presence of serum. These findings shed light on the links between lipid metabolism and cell growth and may provide evidence that lipid droplet metabolisms may influence cancer development or progression.This research was supported by the Undergraduate Research Opportunities Program (UROP)