title: Inhibition of epidermal growth factor receptor tyrosine kinase by chalcone derivatives.
abstract: In our previous study, butein, a chalcone derivative, was found to be an inhibitor of tyrosine kinases and the inhibition was ATP-competitive. In this work, chalcone and seven chalcone derivatives were used to analyse the relationship between the structure of these compounds and their inhibition of tyrosine kinase activity. Three of chalcone derivatives, including butein, marein and phloretin, were found to have an ability to inhibit the tyrosine kinase activity of epidermal growth factor receptor (EGFR) in vitro. IC(50) was 8 microM for butein, 19 microM for marein and 25 microM for phloretin. The structural characterisations of these inhibitors suggest that the hydroxylations at C4 and C4' of these molecules may be required for them to act as EGFR tyrosine kinase inhibitors. The inhibition of EGF-induced EGFR tyrosine phosphorylation by butein was also observed in human hepatocellular carcinoma HepG2 cells, while marein and phloretin were inactive at the doses tested. Molecular modelling suggests that butein, marein and phloretin can be docked into the ATP binding pocket of EGFR. Hydrogen bonds and hydrophobic interaction appear to be important in the binding of these inhibitors to EGFR.
authors.affiliation: Department ofExperimental Surgery, Singapore General Hospital, Outram Road, Singapore 169608, Singapore. gesyeb@sgh.gov.sg
authors.forename: E B
authors.initials: EB
authors.lastname: Yang
authors.forename: Y J
authors.initials: YJ
authors.lastname: Guo
authors.forename: K
authors.initials: K
authors.lastname: Zhang
authors.forename: Y Z
authors.initials: YZ
authors.lastname: Chen
authors.forename: P
authors.initials: P
authors.lastname: Mack
mesh_terms: D000595:Amino Acid Sequence; D001665:Binding Sites; D015153:Blotting, Western; D002599:Chalcone / Q000031:analogs & derivatives* / Q000494:pharmacology; D047188:Chalcones; D004797:Enzyme-Linked Immunosorbent Assay; D004815:Epidermal Growth Factor / Q000494:pharmacology; D066246:ErbB Receptors / Q000037:antagonists & inhibitors*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D010693:Phloretin / Q000494:pharmacology; D010726:Phosphodiesterase Inhibitors / Q000494:pharmacology; D010766:Phosphorylation; D016415:Sequence Alignment; D013329:Structure-Activity Relationship
chemical_list: D047188:Chalcones; D010726:Phosphodiesterase Inhibitors; C040918:butein; D002599:Chalcone; D004815:Epidermal Growth Factor; D066246:ErbB Receptors; D010693:Phloretin