当前位置： SCI文献检索 > BMC CANCER期刊下所有文献 > Characterization of MCF mammary epithelial cells overexpressing the Arylhydrocarbon receptor (AhR).

Characterization of MCF mammary epithelial cells overexpressing the Arylhydrocarbon receptor (AhR).

Abstract：

BACKGROUND:Recent reports indicate the existence of breast cancer cells expressing very high levels of the Arylhydrocarbon receptor (AhR), a ubiquitous intracellular receptor best known for mediating toxic action of dioxin and related pollutants. Positive correlation between the degree of AhR overexpression and states of increasing transformation of mammary epithelial cells appears to occur in the absence of any exogenous AhR ligands. These observations have raised many questions such as why and how AhR is overexpressed in breast cancer and its physiological roles in the progression to advanced carcinogenic transformation. To address those questions, we hypothesized that AhR overexpression occurs in cells experiencing deficiencies in normally required estrogen receptor (ER) signaling, and the basic role of AhR in such cases is to guide the affected cells to develop orchestrated cellular changes aimed at substituting the normal functions of ER. At the same time, the AhR serves as the mediator of the cell survival program in the absence of ER signaling. METHODS:We subjected two lines of Michigan Cancer Foundation (MCF) mammary epithelial cells to 3 different types ER interacting agents for a number of passages and followed the changes in the expression of AhR mRNA. The resulting sublines were analyzed for phenotypical changes and unique molecular characteristics. RESULTS:MCF10AT1 cells continuously exposed to 17-beta-estradiol (E2) developed sub-lines that show AhR overexpression with the characteristic phenotype of increased proliferation, and distinct resistance to apoptosis. When these chemically selected cell lines were treated with a specific AhR antagonist, 3-methoxy-4-nitroflavone (MNF), both of the above abnormal cellular characteristics disappeared, indicating the pivotal role of AhR in expressing those cellular phenotypes. The most prominent molecular characteristics of these AhR overexpressing MCF cells were found to be overexpression of ErbB2 and COX-2. Furthermore, we could demonstrate that suppression of AhR functions through anti-AhR siRNA or MNF causes the recovery of ERalpha functions. CONCLUSION:One of the main causes for AhR overexpression in these MCF breast cancer cells appears to be the loss of ERalpha functions. This phenomenon is likely to be based on the mutually antagonistic relationship between ER and AhR.

journal_name

BMC Cancer

journal_title

BMC cancer

authors

Wong PS,Li W,Vogel CF,Matsumura F

doi

10.1186/1471-2407-9-234

subject

Has Abstract

pub_date

2009-07-15 00:00:00

pages

234

issn

1471-2407

pii

1471-2407-9-234

journal_volume

pub_type

杂志文章

在线工具

Characterization of MCF mammary epithelial cells overexpressing the Arylhydrocarbon receptor (AhR).