title: Quantification of ErbB3 receptor density on human breast cancer cells, using a stable radio-labeled mutant of NRG1beta.
abstract: ErbB3 transactivation can make tumor cells resistance to ErbB1/ErbB2 targeting drugs. This urges for a reliable method to determine cell surface ErbB3 levels, but in our hands iodinated NRG1beta is unstable and tends to underestimate the number of ErbB3 receptors in a radio-receptor assay. Here we show by the use of a radio-labeled high affinity neuregulin mutant NRG/YYDLL that ErbB3 levels can be determined in a reliable manner by Scatchard analysis. Furthermore we show by differential competition with unlabeled NRG/YYDLL and betacellulin that the number of ErbB3 and ErbB4 receptors can be quantified separately on cultured human breast cancer cells.
authors.affiliation: Department of Cell Biology, Radboud University Nijmegen, Faculty of Science, Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands.
authors.forename: Sebastian P
authors.initials: SP
authors.lastname: van der Woning
authors.forename: Everardus J J
authors.initials: EJ
authors.lastname: van Zoelen
mesh_terms: D000818:Animals; D066259:Betacellulin; D001667:Binding, Competitive; D015153:Blotting, Western; D001943:Breast Neoplasms / Q000378:metabolism*; D019008:Drug Resistance, Neoplasm; D066246:ErbB Receptors / Q000032:analysis / Q000378:metabolism; D005434:Flow Cytometry; D006801:Humans; D036341:Intercellular Signaling Peptides and Proteins / Q000378:metabolism; D007457:Iodine Radioisotopes / Q000737:chemistry; D007553:Isotope Labeling; D051379:Mice; D009154:Mutation; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000378:metabolism*; D020890:Neuregulin-1; D016133:Polymerase Chain Reaction; D011869:Radioligand Assay; D020893:Receptor, ErbB-3 / Q000032:analysis* / Q000378:metabolism; D066247:Receptor, ErbB-4; D014407:Tumor Cells, Cultured
chemical_list: C587851:BTC protein, human; D066259:Betacellulin; C587852:Btc protein, mouse; D036341:Intercellular Signaling Peptides and Proteins; D007457:Iodine Radioisotopes; C094131:NRG1 protein, human; D009419:Nerve Tissue Proteins; D020890:Neuregulin-1; C587689:ERBB4 protein, human; D066246:ErbB Receptors; C587690:Erbb4 protein, mouse; D020893:Receptor, ErbB-3; D066247:Receptor, ErbB-4