Abstract
Fatty acid synthase (FASN) is a novel therapeutic target for cancer as it has increased expression in many different types of cancers. There has been significant understanding that cancer cells can hijack and modify tightly regulated metabolic pathway for its own survival. FASN is the enzyme that synthesizes palmitate from malonyl-CoA for energy storage, structure and biomolecules. FASN expression is low to undetectable in normal cells with the exception of liver and adipose tissue. In this study, we investigated the role of FASN in breast cancer cells. We observed that in highly expressing FASN breast cancer cells, TVB-3166, FASN inhibitor, results in a decrease in cellular proliferation and an increase in cellular death. FASN inhibition increased reactive oxygen species (ROS) and altered NADPH/NADP+ ratio. Increase in ROS and NADPH have been linked to the intrinsic apoptosis pathway. Additionally, there is an increase in expression of the BH3-only proteins Bim, Puma and Noxa, leading to the permeabilization of the mitochondria and the release of cytochrome c. Furthermore, after prolong exposure to TVB-3166 a number of cells enter into a senescent state. This was observed the in detection of β-galactosidase and confirmed by the expression of senescent markers including ARF, INK4A, and CIP. Additionally, when the cells were treated with a CDK4/6 inhibitor in combination with the FASN inhibitor TVB-3166, an increase in stress induced premature senescence was observed. Our data demonstrates that inhibition of FASN induces intrinsic apoptosis while it stimulates cellular senescence to the apoptotic resistant cells. Therefore, the ability for TVB-3166 to both eradicate and overturn cell growth makes it potential therapeutic modality.
Citation Format: Travis Van der Steen, George Kemble, Ruth Lupu. Targeting fatty acid synthase induces apoptosis and senescence [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 708.