Morphologic transformation of human breast epithelial cells MCF-10A: dependence on an oxidative microenvironment and estrogen/epidermal growth factor receptors

Abstract

BackgroundMCF-10A, immortalized but non-transformed human breast epithelial cells, are widely used in research examining carcinogenesis. The studies presented here were initiated with the observation that MCF-10A cells left in continuous culture for prolonged periods without re-feeding were prone to the development of transformed foci. We hypothesized that the depletion of labile culture components led to the onset of processes culminating in the observed cell transformation. The purpose of this study was to define the factors which promoted transformation of this cell line.ResultsChanges in levels of phenol red (PHR), hydrocortisone (HC), and epidermal growth factor (EGF) with or without estrogen treatment indicated that both oxidative stress- and estrogen receptor alpha (ERα)-mediated pathways contribute to cell transformation. Gene array and Western blotting analyses of cells maintained in our laboratory and of those from other sources documented detectable ERα and ERbeta (ERβ) in this ERα-negative cataloged cell line. Results also indicate the possibility of a direct association of EGF receptor (EGFR) and ERα in these cells as well as the formation and high induction of a novel ternary complex that includes ERβ (ERα/ERβ/EGFR) in cells grown under conditions facilitating transformation.ConclusionsOur studies resulted in the development of a growth protocol where the effects of chronic, physiologically relevant alterations in the microenvironment on cellular transformation were examined. From our results, we were able to propose a model of transformation within the MCF-10A cell line in which oxidative stress, ER and EGFR play essential roles. Overall, our work indicates that the immediate microenvironment of cells exerts powerful growth cues which ultimately determine their transformation potential.

Runx1 stabilizes the mammary epithelial cell phenotype and prevents epithelial to mesenchymal transition

“…We used a cell model that is independent of exogenous TGFβ. It has been previously shown that withdrawal from MCF10A medium of specific factors required for optimal cell growth (insulin, EGF, Hydrocortisone and Cholera Toxin), changed cell morphology from cobblestone to spindle like [20]. Here we demonstrate that this morphological change (Figure 4A) resembles an EMT process.…”

Role of thioredoxin reductase 1 in dysplastic transformation of human breast epithelial cells triggered by chronic oxidative stress

“…Moreover, we observed the appearance of focal changes of MCF-10A cells after 6-week continuous exposure to H 2 O 2 (Fig. 2b), which seems to be the MCF-10A transformed foci associated with oxidative microenvironment described in previous study20.…”

IL6-Mediated Suppression of miR-200c Directs Constitutive Activation of Inflammatory Signaling Circuit Driving Transformation and Tumorigenesis

“…MCF-10a cells are generally considered ERα negative. However, it has been reported that they express low levels of ERα (Yusuf and Frenkel, 2010). Using western blot we confirmed the presence of low but detectable expression level of ERα in MCF-10a, but not in MCF-10a-T cells (Figure 6A).…”