Breast cancer cells develop resistance to endocrine therapies by shifting between estrogen receptor (ER)-regulated and growth factor receptor (GFR)-regulated survival signaling pathways. To study this switch, we propose a mathematical model of crosstalk between these pathways. The model explains why MCF7 sub-clones transfected with HER2 or EGFR show three GFR-distribution patterns, and why the bimodal distribution pattern can be reversibly modulated by estrogen. The model illustrates how transient overexpression of ER activates GFR signaling and promotes estrogen-independent growth. Understanding this survival-signaling switch can help in the design of future therapies to overcome resistance in breast cancer.
Keywords: 17β-estradiol; AKT; Breast cancer; CCS; CSC; E2; E2-bound estrogen receptor; E2:ER; EGFR; ER; ER-P; Endocrine resistance; Estrogen receptor signaling; FCS; GFR; Growth factor receptor signaling; HER2; MAPK; Mathematical modeling; NFκB; PI3K; a serine/threonine-specific protein kinase, also known as Protein Kinase B (PKB); cancer stem cell; charcoal-stripped fetal-calf serum; epidermal growth factor receptor; estrogen receptor; fetal calf serum; growth factor receptor; human epidermal growth factor receptor-2; mTOR; mammalian target of rapamycin; mitogen activated protein kinases; nuclear factor kappa-light-chain-enhancer of activated B cells; phosphatidylinositide 3-kinases; phosphorylated estrogen receptor.
Copyright © 2013 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.