Selection for EGFR gene amplification in a breast epithelial cell line with basal-like phenotype and hereditary background

Abstract

An epithelial cell line, referred to as A163, was established from breast carcinoma derived from a patient with a strong family history of breast cancer but no known breast cancer susceptibility mutation. A163 was propagated in a serum-free culture medium including the epidermal growth factor. Immunophenotypic characterization demonstrated a mixed luminal and basal-like phenotype. When epidermal growth factor was excluded from the culture medium, A163 entered a quiescent period followed by a period of increased cell proliferation in a subpopulation of the cells. The epidermal growth factor-independent subpopulation retained the basal-like phenotype of the parental cell line. Karyotype and fluorescent in situ hybridization analysis showed an amplification of epidermal growth factor receptor on 7q in A163-S1 only, resulting in high expression of total and phosphorylated epidermal growth factor receptor. The A163-S1 sub-line piles up in culture, indicating a loss of contact inhibition. When grown on transwell filters, A163 shows basal expression of P63 and cytokeratin 14, whereas A163-S1 expresses P63 ubiquitously, and has lost the basal specific expression of cytokeratin 14, indicating a loss of polarity. Furthermore, when cultured in reconstituted basement membrane matrix, A163 form polarized normal like acini. In contrast, A163-S1 form large disorganized structures with lack of polarity. These cell lines may prove useful to understand molecular changes in breast cancer progression, in particular basal-like breast cancer subtype with bad prognosis and no current treatment options.

S-Nitrosylation of EGFR and Src Activates an Oncogenic Signaling Network in Human Basal-Like Breast Cancer

“…EGFR and STAT3 activation and CD44 overexpression are hallmarks of the basal-like phenotype (13, 24) and are characteristic of a breast cancer stem cell-like phenotype (25, 26). To examine the effect of NO signaling on EGFR and STAT3 phosphorylation and CD44 expression in a non-basal-like (HER2+) breast cancer cell line, serum-starved SKBR3 cells were treated with DETANO or EGF for 24 hours.…”

Mammary Microvessels are Sensitive to Menstrual Cycle Sex Hormones

“…Although generating mammary microvessels from other donors would be of significant interest, isolating breast endothelial cells from reduction mammaplasties has a very low success rate and they do not typically survive in culture. [35] Blood flow is necessary for the delivery of oxygen, immune cells, and nutrient delivery. Changes in vascular dynamics are well-known to affect the behavior of endothelial cells, which has been recapitulated in vitro.…”