Role of an Estrogen Receptor-Dependent Mechanism in the Regulation of Estrogen Receptor mRNA in MCF-7 Cells

Saceda, Miguel; Lippman, Marc E.; Lindsey, Ralph K.; Puente, Montserrat; Martin, Mary Beth

doi:10.1210/mend-3-11-1782

Cited by 83 publications

(28 citation statements)

References 18 publications

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“…Thus, significant tissue-, gender-and species-differences have been identified in sex steroid receptor mRNA and protein expression, as well as in sex hormone binding activity, nuclear uptake and/or retention in nonocular sites (Abdelgadir et al 1990;Asaithambi et al 1997;Bergman et al 1987;Campbell et al 1990;Godwin & Crews 1999;Roselli & Resko 1997;Sheridan & Weaker 1982;Young et al 1995;Zhang et al 1989). Sex steroids may also up-or down-regulate the levels of their own or other sex steroid receptors (Blanchere et al 1998;Clark et al 1992;Saceda et al 1989). Consequently, it is quite possible that sex steroid receptor mRNA expression in ocular tissues may increase or decrease in response to changes in the sex hormone environment, such as occur during the estrous/menstrual cycles and aging (Asaithambi et al 1997;Bergman et al 1987).…”

Section: Discussionmentioning

confidence: 99%

Identification of androgen, estrogen and progesterone receptor mRNAs in the eye

Wickham

Gao

Toda

et al. 2000

Acta Ophthalmologica Scandinavica

311

213

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ABSTRACT.Purpose: Previous research has demonstrated that sex steroids exert a significant influence on the structure and function of numerous ocular tissues. To begin to explore the underlying basis of this hormone action, we examined whether various anterior and posterior tissues of the eye contain androgen, estrogen and progesterone receptor mRNAs. Methods: Tissue samples were obtained from adult male and female rats, rabbits and humans, processed for the isolation of total RNA and analyzed by RT-PCR, agarose gel electrophoresis and Southern blot hybridization. All PCR amplifications included positive and negative controls. Results: Our findings showed that androgen, estrogen and/or progesterone receptor mRNAs are present in the lacrimal gland, lacrimal gland acinar epithelial cells, meibomian gland, lid, palpebral and bulbar conjunctivae, cornea, iris/ciliary body, lens, retina/uvea, retina/choroid and retinal pigment epithelial cells of rats, rabbits or humans.Conclusions: Our findings demonstrate that sex steroid receptor mRNAs exist in a variety of ocular tissues and suggest that these sites may represent target organs for androgens, estrogens and/or progestins.

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Section: Discussionmentioning

confidence: 99%

Identification of androgen, estrogen and progesterone receptor mRNAs in the eye

Wickham

Gao

Toda

et al. 2000

Acta Ophthalmologica Scandinavica

311

213

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“…Regulation of ER expression in breast cancer cell lines is a complex process involving transcriptional as well as post-transcriptional events controlled by estradiol, anti-estrogens, and activators of protein kinase C (14,22,38). Treatment of MCF-7 cells with TPA results in a decrease in the concentration of ER (14,15).…”

Section: Discussionmentioning

confidence: 99%

Effects of 12-O-Tetradecanoylphorbol-13-acetate on Estrogen Receptor Activity in MCF-7 Cells

Martin

García-Morales

Stoica

et al. 1995

Journal of Biological Chemistry

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The effects of long term treatment with 12-O-tetradecanoylphorbol-13-acetate (TPA) on estrogen receptor (ER) expression in the human breast cancer cell line, MCF-7, were studied. This study demonstrates that treatment of cells with the phorbol ester blocked estrogen receptor activity. Treatment of cells with 100 nM TPA resulted in an 80% decrease in the level of ER protein and a parallel decrease in ER mRNA and binding capacity. Following removal of TPA from the medium, the level of ER protein and mRNA returned to control values; however, the receptor failed to bind estradiol. These cells also failed to induce progesterone receptor in response to estradiol. In addition, TPA treatment blocked transcription from an estrogen response element in transient transfection assays and inhibited ER binding to its response element in a DNA mobility shift assay. The estrogen receptor in treated cells was recognized by two monoclonal anti-ER antibodies and was not quantitatively different from ER in control cells. RNase protection analysis failed to detect any qualitative changes in the ER mRNA transcript. Mixing experiments suggest that TPA induces/activates a factor which interacts with the ER to block binding of estradiol. The effects of TPA on ER levels and binding capacity were concentration-dependent. Low concentrations of TPA inhibited estradiol binding without a decrease in the level of protein, whereas higher concentrations were required to decrease the level of ER protein. The effects of TPA appear to be mediated by activation of protein kinase C since the protein kinase C inhibitors, H-7 and bryostatin, block the effects of TPA on estradiol induction of progesterone receptor. TPA treatment had no effect on the level or binding capacity of the glucocorticoid receptor, indicating that the effects are not universal for steroid receptors. These data demonstrate that activation of the protein kinase C signal transduction pathway modulates the estrogen receptor pathway. The long term effect of protein kinase C activation is to inhibit estrogen receptor function through induction/ activation of a factor which interacts with the receptor.

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“…The biochemical details of modulation of mRNA stability are reviewed elsewhere (Kracht and Saklatvala, 2002;Ing, 2005) and involve, in part, transcriptional regulation of estrogen-regulated mRNA stabilizing factor (Kawagoe et al, 2003). For the purpose of this review, it is important to emphasize that estrogen may autoregulate the stability of mRNA for its own receptor in some tissues (Saceda et al, 1989;Adams et al, 2007). Therefore, differences in efficacy of SERMs may reflect differences in the ability of the SERM-bound receptor complex to alter estrogen receptor expression.…”

Section: Post-transcriptional and Translational Modulation Of Protmentioning

confidence: 99%