title: Ceestatin, a novel small molecule inhibitor of hepatitis C virus replication, inhibits 3-hydroxy-3-methylglutaryl-coenzyme A synthase.
abstract: BACKGROUND
  Hepatitis C virus (HCV) chronically infects >170 million persons worldwide and is a leading cause of cirrhosis and hepatocellular carcinoma. The identification of more effective and better-tolerated agents for treating HCV is a high priority. We have reported elsewhere the discovery of the anti-HCV compound ceestatin using a high-throughput screen of a small molecule library.
  
  
  METHODS
  To identify host or viral protein targets in an unbiased fashion, we performed affinity chromatography, using tandem liquid chromatography/mass spectrometry to identify specific potential targets. RESULTS. Ceestatin binds to 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) synthase and irreversibly inhibits HMG-CoA synthase in a dose-dependent manner. Ceestatin's anti-HCV effects are reversed by addition of HMG-CoA, mevalonic acid, or geranylgeraniol. Treatment with small interfering RNA against HMG-CoA synthase led to a substantial reduction in HCV replication, further validating HMG-CoA synthase as an enzyme essential for HCV replication.
  
  
  CONCLUSIONS
  Ceestatin therefore exerts its anti-HCV effects through inhibition of HMG-CoA synthase. It may prove useful as an antiviral agent, as a probe to study HCV replication, and as a cholesterol-lowering agent. The logical stepwise process employed to discover the mechanism of action of ceestatin can serve as a general experimental strategy to uncover the targets on which novel uncharacterized anti-HCV compounds act.
authors.affiliation: Gastrointestinal Unit, Department of Medicine, Massachusetts General Hospital, Boston, Massachusetts 02114, USA.
authors.forename: Lee F
authors.initials: LF
authors.lastname: Peng
authors.forename: Esperance A K
authors.initials: EA
authors.lastname: Schaefer
authors.forename: Nicole
authors.initials: N
authors.lastname: Maloof
authors.forename: Andrew
authors.initials: A
authors.lastname: Skaff
authors.forename: Andrew
authors.initials: A
authors.lastname: Berical
authors.forename: Craig A
authors.initials: CA
authors.lastname: Belon
authors.forename: Julie A
authors.initials: JA
authors.lastname: Heck
authors.forename: Wenyu
authors.initials: W
authors.lastname: Lin
authors.forename: David N
authors.initials: DN
authors.lastname: Frick
authors.forename: Todd M
authors.initials: TM
authors.lastname: Allen
authors.forename: Henry M
authors.initials: HM
authors.lastname: Miziorko
authors.forename: Stuart L
authors.initials: SL
authors.lastname: Schreiber
authors.forename: Raymond T
authors.initials: RT
authors.lastname: Chung
mesh_terms: D000998:Antiviral Agents / Q000494:pharmacology*; D019086:Bridged Bicyclo Compounds, Heterocyclic / Q000494:pharmacology*; D002460:Cell Line; D002846:Chromatography, Affinity; D016174:Hepacivirus / Q000187:drug effects* / Q000502:physiology; D006801:Humans; D006904:Hydroxymethylglutaryl-CoA Synthase / Q000037:antagonists & inhibitors*; D007783:Lactones / Q000494:pharmacology*; D013058:Mass Spectrometry; D011485:Protein Binding; D034622:RNA Interference; D034741:RNA, Small Interfering; D014779:Virus Replication / Q000187:drug effects*
chemical_list: D000998:Antiviral Agents; D019086:Bridged Bicyclo Compounds, Heterocyclic; D007783:Lactones; D034741:RNA, Small Interfering; C561489:ceestatin; D006904:Hydroxymethylglutaryl-CoA Synthase