Effects of ErbB2 Overexpression on the Proteome and ErbB Ligand-specific Phosphosignaling in Mammary Luminal Epithelial Cells.
Most breast cancers arise from luminal epithelial cells, and 25-30% of these tumors overexpress the ErbB2/HER2 receptor that correlates with disease progression and poor prognosis. The mechanisms of ErbB2 signaling and the effects of its overexpression are not fully understood. Herein, stable isotope labeling by amino acids in cell culture (SILAC), expression profiling, and phosphopeptide enrichment of a relevant, non-transformed, and immortalized human mammary luminal epithelial cell model were used to profile ErbB2-dependent differences in protein expression and phosphorylation events triggered via EGF receptor (EGF treatment) and ErbB3 (HRG1β treatment) in the context of ErbB2 overexpression. Bioinformatics analysis was used to infer changes in cellular processes and signaling events. We demonstrate the complexity of the responses to oncogene expression and growth factor signaling, and we identify protein changes relevant to ErbB2-dependent altered cellular phenotype, in particular cell cycle progression and hyper-proliferation, reduced adhesion, and enhanced motility. Moreover, we define a novel mechanism by which ErbB signaling suppresses basal interferon signaling that would promote the survival and proliferation of mammary luminal epithelial cells. Numerous novel sites of growth factor-regulated phosphorylation were identified that were enhanced by ErbB2 overexpression, and we putatively link these to altered cell behavior and also highlight the importance of performing parallel protein expression profiling alongside phosphoproteomic analysis.
From the ‡Women's Cancer, Institute for Women's Health, University College London, Gower Street, London WC1E 6BT, United Kingdom.
Jenny
J
Worthington
From the ‡Women's Cancer, Institute for Women's Health, University College London, Gower Street, London WC1E 6BT, United Kingdom.
Georgia
G
Spain
From the ‡Women's Cancer, Institute for Women's Health, University College London, Gower Street, London WC1E 6BT, United Kingdom john.timms@ucl.ac.uk.
John F
0000-0002-4507-835X
JF
Timms
D002448:Cell Adhesion; D018929:Cell Culture Techniques; D002460:Cell Line; D002465:Cell Movement; D049109:Cell Proliferation; D019295:Computational Biology / Q000379:methods; D004815:Epidermal Growth Factor / Q000494:pharmacology; D004847:Epithelial Cells / Q000166:cytology* / Q000378:metabolism; D005260:Female; D005784:Gene Amplification; D020869:Gene Expression Profiling / Q000379:methods*; D006801:Humans; D007553:Isotope Labeling; D008024:Ligands; D042361:Mammary Glands, Human / Q000166:cytology / Q000378:metabolism*; D020890:Neuregulin-1 / Q000494:pharmacology; D010750:Phosphoproteins / Q000378:metabolism*; D060066:Protein Interaction Maps; D040901:Proteomics / Q000379:methods*; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000235:genetics* / Q000378:metabolism; D015398:Signal Transduction; D015854:Up-Regulation
D004815:Epidermal Growth Factor; D008024:Ligands; D020890:Neuregulin-1; D010750:Phosphoproteins; D018719:Erb-b2 Receptor Tyrosine Kinases; C087230:heregulin beta1; C508053:ERBB2 protein, human