Nicastrin and Notch4 drive endocrine therapy resistance and epithelial to mesenchymal transition in MCF7 breast cancer cells

Title: Nicastrin and Notch4 drive endocrine therapy resistance and epithelial to mesenchymal transition in MCF7 breast cancer cells
Authors: Lombardo, Y
Faronato, M
Filipovic, A
Vircillo, V
Magnani, L
Coombes, RC
Item Type: Journal Article
Abstract: Introduction Resistance to anti-estrogen therapies is a major cause of disease relapse and mortality in estrogen receptor alpha (ERα)-positive breast cancers. Tamoxifen or estrogen withdrawal increases the dependence of breast cancer cells on Notch signalling. Here, we investigated the contribution of Nicastrin and Notch signalling in endocrine-resistant breast cancer cells. Methods We used two models of endocrine therapies resistant (ETR) breast cancer: tamoxifen-resistant (TamR) and long-term estrogen-deprived (LTED) MCF7 cells. We evaluated the migratory and invasive capacity of these cells by Transwell assays. Expression of epithelial to mesenchymal transition (EMT) regulators as well as Notch receptors and targets were evaluated by real-time PCR and western blot analysis. Moreover, we tested in vitro anti-Nicastrin monoclonal antibodies (mAbs) and gamma secretase inhibitors (GSIs) as potential EMT reversal therapeutic agents. Finally, we generated stable Nicastrin overexpessing MCF7 cells and evaluated their EMT features and response to tamoxifen. Results We found that ETR cells acquired an epithelial to mesenchymal transition (EMT) phenotype and displayed increased levels of Nicastrin and Notch targets. Interestingly, we detected higher level of Notch4 but lower levels of Notch1 and Notch2 suggesting a switch to signalling through different Notch receptors after acquisition of resistance. Anti-Nicastrin monoclonal antibodies and the GSI PF03084014 were effective in blocking the Nicastrin/Notch4 axis and partially inhibiting the EMT process. As a result of this, cell migration and invasion were attenuated and the stem cell-like population was significantly reduced. Genetic silencing of Nicastrin and Notch4 led to equivalent effects. Finally, stable overexpression of Nicastrin was sufficient to make MCF7 unresponsive to tamoxifen by Notch4 activation. Conclusions ETR cells express high levels of Nicastrin and Notch4, whose activation ultimately drives invasive behaviour. Anti-Nicastrin mAbs and GSI PF03084014 attenuate expression of EMT molecules reducing cellular invasiveness. Nicastrin overexpression per se induces tamoxifen resistance linked to acquisition of EMT phenotype. Our finding suggest that targeting Nicastrin and/or Notch4 warrants further clinical evaluation as valid therapeutic strategies in endocrine-resistant breast cancer.
Issue Date: 11-Jun-2014
Date of Acceptance: 2-Jun-2014
URI: http://hdl.handle.net/10044/1/43013
DOI: https://dx.doi.org/10.1186/bcr3675
ISSN: 1465-542X
Publisher: BioMed Central
Journal / Book Title: Breast Cancer Research
Volume: 16
Issue: 3
Copyright Statement: © Lombardo et al.; licensee BioMed Central Ltd. 2014. This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.
Sponsor/Funder: Cancer Research UK
Funder's Grant Number: C37/A12011
Keywords: Science & Technology
Life Sciences & Biomedicine
Oncology
ESTROGEN-RECEPTOR
TAMOXIFEN RESISTANCE
SIGNALING PATHWAYS
STEM-CELLS
GROWTH
TUMORIGENESIS
METASTASIS
INHIBITION
MODULATION
ACTIVATION
Amyloid Precursor Protein Secretases
Antibodies, Monoclonal
Antigens, CD24
Antigens, CD44
Antineoplastic Agents, Hormonal
Breast Neoplasms
Cell Movement
Drug Resistance, Neoplasm
Epithelial-Mesenchymal Transition
Estrogen Receptor alpha
Female
Gene Expression Regulation, Neoplastic
Humans
MCF-7 Cells
Membrane Glycoproteins
Neoplasm Invasiveness
Proto-Oncogene Proteins
RNA Interference
RNA, Small Interfering
Receptor, Notch1
Receptor, Notch2
Receptors, Notch
Selective Estrogen Receptor Modulators
Spheroids, Cellular
Tamoxifen
Tetrahydronaphthalenes
Tumor Cells, Cultured
Valine
Oncology & Carcinogenesis
1112 Oncology And Carcinogenesis
Publication Status: Published
Article Number: ARTN R62
Appears in Collections:Division of Surgery
Chemistry
Biological and Biophysical Chemistry
Division of Cancer
Faculty of Medicine
Faculty of Natural Sciences



Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.

Creative Commonsx