title: Decreased internalisation of erbB1 mutants in lung cancer is linked with a mechanism conferring sensitivity to gefitinib.
abstract: A majority of gefitinib (IRESSA)-responsive tumours in non-small cell lung cancer have been found to carry mutations in ErbB1. Previously, it has been observed that internalisation-deficient ErbB1 receptors are strong drivers of oncogenesis. Using a computational model of ErbB1 trafficking and signalling, it is found that a deficiency in ErbB1 internalisation is sufficient to explain the observed signalling phenotype of these gefitinib-responsive ErbB1 mutants in lung cancer cell lines. Experimental tests confirm that gefitinib-sensitive cell lines with and without ErbB1 mutations exhibit markedly slower internalisation rates than gefitinib-insensitive cell lines. Moreover, the computational model demonstrates that reduced ErbB1 internalisation rates are mechanistically linked to upregulated AKT signalling. Experimentally it is confirmed that impaired internalisation of ErbB1 is associated with increased AKT activity, which can be blocked by gefitinib. On the basis of these experimental and computational results, it is surmised that gefitinib sensitivity is a marker of a reliance on AKT signalling for cell survival that may be brought about by impaired ErbB1 internalisation.
authors.affiliation: Pathways Capability, AstraZeneca R and D Boston, Waltham, MA 02451, USA.
authors.forename: B S
authors.initials: BS
authors.lastname: Hendriks
authors.forename: G J
authors.initials: GJ
authors.lastname: Griffiths
authors.forename: R
authors.initials: R
authors.lastname: Benson
authors.forename: D
authors.initials: D
authors.lastname: Kenyon
authors.forename: M
authors.initials: M
authors.lastname: Lazzara
authors.forename: J
authors.initials: J
authors.lastname: Swinton
authors.forename: S
authors.initials: S
authors.lastname: Beck
authors.forename: M
authors.initials: M
authors.lastname: Hickinson
authors.forename: J M
authors.initials: JM
authors.lastname: Beusmans
authors.forename: D
authors.initials: D
authors.lastname: Lauffenburger
authors.forename: D
authors.initials: D
authors.lastname: de Graaf
mesh_terms: D000970:Antineoplastic Agents / Q000008:administration & dosage; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D003198:Computer Simulation; D066246:ErbB Receptors / Q000235:genetics* / Q000378:metabolism*; D000077156:Gefitinib; D006801:Humans; D008175:Lung Neoplasms / Q000188:drug therapy* / Q000503:physiopathology*; D008954:Models, Biological; D009154:Mutation; D011799:Quinazolines / Q000008:administration & dosage*; D015398:Signal Transduction / Q000187:drug effects*
chemical_list: D000970:Antineoplastic Agents; D011799:Quinazolines; D066246:ErbB Receptors; D000077156:Gefitinib