title: Flow cytometric FRET analysis of erbB receptor interaction on a cell-by-cell basis.
abstract: Lateral interaction of c-erbB family receptors resulting in dimer formation is the key event initiating signal transduction. Consequently cross-activation and intracellular signaling is triggered with immediate impact on cell proliferation, migration, cell survival, and differentiation. In order to elucidate the connection of signal input (receptor activation) and signal output (altered cellular behavior) we dynamically assessed cell proliferation of BT474 and SK-BR-3 breast cancer cell lines. We quantitated c-erbB2 receptor homodimerization upon treatment with the therapeutic monoclonal anti-c-erbB2 antibodies trastuzumab (Herceptin) and pertuzumab by flow cytometric FRET (FCET) measurements on a cell-by-cell basis and calculated the extent of antibody-induced cell cycle exit. The results confirm that trastuzumab does not decrease c-erbB2 homodimers despite its strong potency to drive c-erbB2-overexpressing cells into quiescence. Pertuzumab, however, is able to prevent c-erbB2 homodimerization and thereby enhance the antiproliferative effect of trastuzumab when administered in combination.
authors.affiliation: Institute of Pathology, University of Regensburg, Franz-Josef-Strauss Allee 11, 93053 Regensburg, Germany. simone.diermeier@uni-r.de
authors.forename: Simone
authors.initials: S
authors.lastname: Diermeier-Daucher
authors.forename: Max
authors.initials: M
authors.lastname: Hasmann
authors.forename: Gero
authors.initials: G
authors.lastname: Brockhoff
mesh_terms: D000911:Antibodies, Monoclonal / Q000494:pharmacology; D061067:Antibodies, Monoclonal, Humanized; D000970:Antineoplastic Agents / Q000494:pharmacology; D001943:Breast Neoplasms / Q000378:metabolism / Q000473:pathology; D001973:Bromodeoxyuridine / Q000494:pharmacology; D002453:Cell Cycle; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D002470:Cell Survival; D019281:Dimerization; D005434:Flow Cytometry / Q000379:methods*; D006801:Humans; D008954:Models, Biological; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000737:chemistry*; D015398:Signal Transduction; D000068878:Trastuzumab
chemical_list: D000911:Antibodies, Monoclonal; D061067:Antibodies, Monoclonal, Humanized; D000970:Antineoplastic Agents; D001973:Bromodeoxyuridine; D018719:Erb-b2 Receptor Tyrosine Kinases; D000068878:Trastuzumab; C485206:pertuzumab