title: FASN regulates cellular response to genotoxic treatments by increasing PARP-1 expression and DNA repair activity via NF-κB and SP1.
abstract: Fatty acid synthase (FASN), the sole cytosolic mammalian enzyme for de novo lipid synthesis, is crucial for cancer cell survival and associates with poor prognosis. FASN overexpression has been found to cause resistance to genotoxic insults. Here we tested the hypothesis that FASN regulates DNA repair to facilitate survival against genotoxic insults and found that FASN suppresses NF-κB but increases specificity protein 1 (SP1) expression. NF-κB and SP1 bind to a composite element in the poly(ADP-ribose) polymerase 1 (PARP-1) promoter in a mutually exclusive manner and regulate PARP-1 expression. Up-regulation of PARP-1 by FASN in turn increases Ku protein recruitment and DNA repair. Furthermore, lipid deprivation suppresses SP1 expression, which is able to be rescued by palmitate supplementation. However, lipid deprivation or palmitate supplementation has no effect on NF-κB expression. Thus, FASN may regulate NF-κB and SP1 expression using different mechanisms. Altogether, we conclude that FASN regulates cellular response against genotoxic insults by up-regulating PARP-1 and DNA repair via NF-κB and SP1.
authors: Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, IN 46202.
authors: Xi
authors: X
authors: Wu
authors: Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, IN 46202.
authors: Zizheng
authors: Z
authors: Dong
authors: Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, IN 46202.
authors: Chao J
authors: CJ
authors: Wang
authors: Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, IN 46202.
authors: Lincoln James
authors: LJ
authors: Barlow
authors: Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, IN 46202.
authors: Valerie
authors: V
authors: Fako
authors: Department of Biomedical Sciences, Quillen College of Medicine, East Tennessee State University, Johnson City, TN 37614.
authors: Moises A
authors: MA
authors: Serrano
authors: Department of Biomedical Sciences, Quillen College of Medicine, East Tennessee State University, Johnson City, TN 37614.
authors: Yue
authors: Y
authors: Zou
authors: Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, IN 46202.|Department of Computer and Information Science, Indiana University-Purdue University, Indianapolis, IN 46202.
authors: Jing-Yuan
authors: JY
authors: Liu
authors: Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, IN 46202; jianzhan@iu.edu.|IU Simon Cancer Center, Indiana University School of Medicine, Indianapolis, IN 46202.
authors: Jian-Ting
authors: JT
authors: Zhang
keywords: DNA repair; drug resistance; fatty acid synthase; radiation resistance; transcription regulation