title: Assessment of epidermal growth factor receptor (EGFR, ErbB1) and HER2 (ErbB2) protein expression levels and response to lapatinib (Tykerb, GW572016) in an expanded panel of human normal and tumour cell lines.
abstract: OBJECTIVE
  Lapatinib (Tykerb, GW572016), a potent inhibitor of the catalytic activities of epidermal growth factor receptor (EGFR) and human epidermal growth factor receptor 2 (HER2) (ErbB2), inhibits population growth of selected EGFR and HER2 overexpressing cell lines. Previous studies with a small number of cell lines suggest a correlation between overexpression of EGFR and/or HER2 and sensitivity to growth inhibition by lapatinib; however, the precise determinants of lapatinib selectivity for tumour and/or other cells remain unclear.
  
  
  METHODS
  To clarify the determinants of its selectivity in cultured cells, lapatinib-induced cell population growth inhibition and relative EGFR and HER2 protein expression were quantified in 61 different human tumour cell lines from 12 tumour types, two oncogene transformed human cell lines and two normal human cell cultures. Using statistical tools to analyse the data, a model describing the relationship between lapatinib IC(50) (the response variable) and EGFR and HER2 expression and tissue type (explanatory variables) was derived.
  
  
  CONCLUSIONS
  The results suggest that simultaneous consideration of EGFR and HER2 expression, as well as tissue type yields the best determinant of lapatinib selectivity in cultured cells.
authors.affiliation: Translational Medicine, GlaxoSmithKline, King of Prussia, PA, USA. david.w.rusnak@gsk.com
authors.forename: D W
authors.initials: DW
authors.lastname: Rusnak
authors.forename: K J
authors.initials: KJ
authors.lastname: Alligood
authors.forename: R J
authors.initials: RJ
authors.lastname: Mullin
authors.forename: G M
authors.initials: GM
authors.lastname: Spehar
authors.forename: C
authors.initials: C
authors.lastname: Arenas-Elliott
authors.forename: A-M
authors.initials: AM
authors.lastname: Martin
authors.forename: Y
authors.initials: Y
authors.lastname: Degenhardt
authors.forename: S K
authors.initials: SK
authors.lastname: Rudolph
authors.forename: T F
authors.initials: TF
authors.lastname: Haws
authors.forename: B L
authors.initials: BL
authors.lastname: Hudson-Curtis
authors.forename: T M
authors.initials: TM
authors.lastname: Gilmer
mesh_terms: D000970:Antineoplastic Agents / Q000494:pharmacology*; D002460:Cell Line; D002461:Cell Line, Transformed; D045744:Cell Line, Tumor; D066246:ErbB Receptors / Q000378:metabolism*; D006801:Humans; D000077341:Lapatinib; D015233:Models, Statistical; D047428:Protein Kinase Inhibitors / Q000494:pharmacology*; D011799:Quinazolines / Q000494:pharmacology*; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000378:metabolism*
chemical_list: D000970:Antineoplastic Agents; D066246:ErbB Receptors; D000077341:Lapatinib; D047428:Protein Kinase Inhibitors; D011799:Quinazolines; D018719:Erb-b2 Receptor Tyrosine Kinases; C508053:ERBB2 protein, human