Document Type

Article

Date of Original Version

2008

Department

Biomedical and Pharmaceutical Sciences

Abstract

Cadmium (Cd), an endocrine disruptor, can induce a variety of signaling events including the activation of ERK1/2 and AKT. In this study, the involvement of estrogen receptors (ER) in these events was evaluated in three human breast caner cell lines, MCF-7, MDA-MB-231, and SK-BR-3. The Cd-induced signal activation patterns in the three cell lines mimicked those exhibited in response to 17β-estradiol. Specifically, treatment of MCF-7 cells, that express ERα, ERβ and GPR30, to 0.5–10 μM Cd for only 2.5 min resulted in transient phosphorylation of ERK1/2. Cd also triggered a gradual increase and sustained activation of AKT during the 60 min treatment period. In SK-BR-3 cells, that express only GPR30, Cd also caused a transient activation of ERK1/2, but not of AKT. In contrast, in MDA-MB-231 cells, that express only ERβ, Cd was unable to cause rapid activation of either ERK1/2 or AKT. A transient phosphorylation of ERα was also observed within 2.5 min of Cd exposure in the MCF-7 cells. While the estrogen receptor antagonist, ICI 182,780, did not prevent the effect of Cd on these signals, specific siRNA against hERα significantly reduced Cd-induced activation of ERK1/2 and completely blocked the activation of AKT. It is concluded that Cd, like estradiol, can cause rapid activation of ERK1/2 and AKT and that these signaling events are mediated by possible interaction with membrane ERα and GPR30, but not ERβ.

Creative Commons License

Creative Commons License
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 4.0 License.

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