title: Cellular glycosylation affects Herceptin binding and sensitivity of breast cancer cells to doxorubicin and growth factors.
abstract: Alterations in protein glycosylation are a key feature of oncogenesis and have been shown to affect cancer cell behaviour perturbing cell adhesion, favouring cell migration and metastasis. This study investigated the effect of N-linked glycosylation on the binding of Herceptin to HER2 protein in breast cancer and on the sensitivity of cancer cells to the chemotherapeutic agent doxorubicin (DXR) and growth factors (EGF and IGF-1). The interaction between Herceptin and recombinant HER2 protein and cancer cell surfaces (on-rate/off-rate) was assessed using a quartz crystal microbalance biosensor revealing an increase in the accessibility of HER2 to Herceptin following deglycosylation of cell membrane proteins (deglycosylated cells Bmax: 6.83 Hz; glycosylated cells Bmax: 7.35 Hz). The sensitivity of cells to DXR and to growth factors was evaluated using an MTT assay. Maintenance of SKBR-3 cells in tunicamycin (an inhibitor of N-linked glycosylation) resulted in an increase in sensitivity to DXR (0.1 μM DXR P < 0.001) and a decrease in sensitivity to IGF-1 alone and to IGF-1 supplemented with EGF (P < 0.001). This report illustrates the importance of N-linked glycosylation in modulating the response of cancer cells to chemotherapeutic and biological treatments and highlights the potential of glycosylation inhibitors as future combination treatments for breast cancer.
authors.affiliation: Attana AB, Bjornnasvagen 21, SE-11419, Stockholm, Sweden.
authors.forename: Diluka
authors.initials: D
authors.lastname: Peiris
authors.affiliation: Division of Surgery and Interventional Science, UCL Medical School Royal Free Campus, Rowland Hill Street, London, NW3 2PF, UK.
authors.forename: Alexander F
authors.initials: AF
authors.lastname: Spector
authors.affiliation: Department of Biomedical Sciences, Faculty of Science and Technology, University of Westminster, 115 New Cavendish St, W1W 6UW, UK.
authors.forename: Hannah
authors.initials: H
authors.lastname: Lomax-Browne
authors.affiliation: Department of Biomedical Sciences, Faculty of Science and Technology, University of Westminster, 115 New Cavendish St, W1W 6UW, UK.
authors.forename: Tayebeh
authors.initials: T
authors.lastname: Azimi
authors.affiliation: Division of Surgery and Interventional Science, UCL Medical School Royal Free Campus, Rowland Hill Street, London, NW3 2PF, UK.
authors.forename: Bala
authors.initials: B
authors.lastname: Ramesh
authors.affiliation: Division of Surgery and Interventional Science, UCL Medical School Royal Free Campus, Rowland Hill Street, London, NW3 2PF, UK.
authors.forename: Marilena
authors.initials: M
authors.lastname: Loizidou
authors.affiliation: Division of Surgery and Interventional Science, UCL Medical School Royal Free Campus, Rowland Hill Street, London, NW3 2PF, UK.
authors.forename: Hazel
authors.initials: H
authors.lastname: Welch
authors.affiliation: Department of Biomedical Sciences, Faculty of Science and Technology, University of Westminster, 115 New Cavendish St, W1W 6UW, UK.
authors.forename: Miriam V
authors.initials: MV
authors.lastname: Dwek
mesh_terms: D000970:Antineoplastic Agents / Q000494:pharmacology*; D001943:Breast Neoplasms / Q000378:metabolism / Q000473:pathology; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects*; D003208:Concanavalin A / Q000378:metabolism; D004317:Doxorubicin / Q000494:pharmacology*; D004357:Drug Synergism; D004815:Epidermal Growth Factor / Q000494:pharmacology*; D005260:Female; D006031:Glycosylation / Q000187:drug effects; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000494:pharmacology*; D007700:Kinetics; D008856:Microscopy, Fluorescence; D011485:Protein Binding; D058525:Quartz Crystal Microbalance Techniques; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000235:genetics / Q000378:metabolism; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D000068878:Trastuzumab / Q000378:metabolism*; D014415:Tunicamycin / Q000494:pharmacology
chemical_list: D000970:Antineoplastic Agents; D003208:Concanavalin A; D004317:Doxorubicin; D004815:Epidermal Growth Factor; D007334:Insulin-Like Growth Factor I; D018719:Erb-b2 Receptor Tyrosine Kinases; D011994:Recombinant Proteins; D000068878:Trastuzumab; D014415:Tunicamycin