Cleavage of the extracellular domain of junctional adhesion molecule-A is associated with resistance to anti-HER2 therapies in breast cancer settings

Title: Cleavage of the extracellular domain of junctional adhesion molecule-A is associated with resistance to anti-HER2 therapies in breast cancer settings
Authors: Leech, Astrid O.Vellanki, Sri HariKrishnaRutherford, Emily J.Jahns, Hanneet al.
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Date: 20-Nov-2018
Online since: 2020-11-05T09:39:28Z
Abstract: BACKGROUND: Junctional adhesion molecule-A (JAM-A) is an adhesion molecule whose overexpression on breast tumor tissue has been associated with aggressive cancer phenotypes, including human epidermal growth factor receptor-2 (HER2)-positive disease. Since JAM-A has been described to regulate HER2 expression in breast cancer cells, we hypothesized that JAM-dependent stabilization of HER2 could participate in resistance to HER2-targeted therapies. METHODS: Using breast cancer cell line models resistant to anti-HER2 drugs, we investigated JAM-A expression and the effect of JAM-A silencing on biochemical/functional parameters. We also tested whether altered JAM-A expression/processing underpinned differences between drug-sensitive and -resistant cells and acted as a biomarker of patients who developed resistance to HER2-targeted therapies. RESULTS: Silencing JAM-A enhanced the anti-proliferative effects of anti-HER2 treatments in trastuzumab- and lapatinib-resistant breast cancer cells and further reduced HER2 protein expression and Akt phosphorylation in drug-treated cells. Increased epidermal growth factor receptor expression observed in drug-resistant models was normalized upon JAM-A silencing. JAM-A was highly expressed in all of a small cohort of HER2-positive patients whose disease recurred following anti-HER2 therapy. High JAM-A expression also correlated with metastatic disease at the time of diagnosis in another patient cohort resistant to trastuzumab therapy. Importantly, cleavage of JAM-A was increased in drug-resistant cell lines in conjunction with increased expression of ADAM-10 and -17 metalloproteases. Pharmacological inhibition or genetic silencing studies suggested a particular role for ADAM-10 in reducing JAM-A cleavage and partially re-sensitizing drug-resistant cells to the anti-proliferative effects of HER2-targeted drugs. Functionally, recombinant cleaved JAM-A enhanced breast cancer cell invasion in vitro and both invasion and proliferation in a semi-in vivo model. Finally, cleaved JAM-A was detectable in the serum of a small cohort of HER2-positive patients and correlated significantly with resistance to HER2-targeted therapy. CONCLUSIONS: Collectively, our data suggest a novel model whereby increased expression and cleavage of JAM-A drive tumorigenic behavior and act as a biomarker and potential therapeutic target for resistance to HER2-targeted therapies.
Funding Details: Health Research Board
Science Foundation Ireland
metadata.dc.description.othersponsorship: Breast Cancer Ireland
Beaumont Hospital Cancer Research and Development Trust
Type of material: Journal Article
Publisher: Springer
Journal: Breast Cancer Research
Volume: 20
Copyright (published version): 2018 the Authors
Keywords: Breast cancerDrug resistanceHER2HER2-targeted therapiesHerceptinJAM-ALapatinibTight junctionTrastuzumabImmunological antineoplastic agentsTumor biomarkersBreast NeoplasmsCell Adhesion MoleculesChorioallantoic MembraneNeoplasm invasivenessRNA, Small InterferingErbB-2 receptorRecombinant ProteinsDrug resistance
DOI: 10.1186/s13058-018-1064-1
Language: en
Status of Item: Peer reviewed
ISSN: 1465-5411
Appears in Collections:Veterinary Medicine Research Collection

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