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- Palmieri, C, et al.
(författare)
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Estrogen receptor beta in breast cancer
- 2002
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Ingår i: Endocrine-related cancer. - : Bioscientifica. - 1351-0088. ; 9:1, s. 1-13
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Tidskriftsartikel (refereegranskat)abstract
- Estrogen is essential for normal growth and differentiation in the mammary gland. It also supports growth of approximately 50% of primary breast cancers. For this reason, removal of estrogen or blocking of its action with the anti-estrogen, tamoxifen, is the main treatment for estrogen receptor alpha (ERalpha)-positive tumors. In 1996, when oncologists became aware of a second ER, ERbeta, there was some doubt as to whether this receptor would be of importance in breast cancer because the clinical consensus was that responsiveness to tamoxifen is related to the presence of ERalpha in breast cancer. Today we know that ERalpha and ERbeta have distinct cellular distributions, regulate separate sets of genes and can oppose each other's actions on some genes. We also know that ERbeta is widely expressed in both the normal and malignant breast and that there are proliferating cells in the breast which express ERbeta. In this review we summarize what is known about ERbeta in breast cancer and examine the possibility that ERbeta-selective ligands may well represent a useful class of pharmacological tools with a novel target, namely proliferating cells expressing ERbeta.
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| 4. |
- Palmieri, C, et al.
(författare)
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The expression of oestrogen receptor (ER)-beta and its variants, but not ERalpha, in adult human mammary fibroblasts
- 2004
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Ingår i: Journal of molecular endocrinology. - : Bioscientifica. - 0952-5041 .- 1479-6813. ; 33:1, s. 35-50
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Tidskriftsartikel (refereegranskat)abstract
- Whilst oestrogen receptor (ER)-alpha and ERbeta have been shown to be important in the development of the mammary gland, the cell-specific expression pattern of these two receptors within the human breast is not clear. Although it is well established that in the developing rodent mammary gland stromal ERalpha mediates the secretion of growth factors which stimulate the proliferation of the ductal epithelium, the expression of ERalpha in human adult breast stromal fibroblasts is controversial, and the expression of ERbeta has not been properly defined. In the present study, we have evaluated the expression of ERalpha and ERbeta by immunohistochemistry in normal tissue samples, and in purified human breast fibroblasts by Western blotting, RT-PCR analysis and ligand-binding sucrose gradient assay. Our data clearly demonstrated that ERbeta variants, including ERbeta1, ERbeta2, ERbeta5, ERbetadelta and ERbetains, but not ERalpha, are expressed in human adult mammary fibroblasts. These results are supported by the findings that an ERbeta-selective ligand, BAG, but not the ERalpha high-affinity ligand oestradiol, can induce fibroblast growth factor-7 release and activate transcription from an oestrogen-responsive element promoter in these adult human mammary fibroblasts. Together, these observations revealed that, in the adult breast and in breast cancer, the proliferative signals derived from the stroma of adult mammary glands in response to oestrogen are not mediated by ERalpha and provide new insights into the nature of stromal-epithelial interactions in the adult mammary gland. In addition, the expression of these ERbeta variants in cells where there is no ERalpha suggested that these ERbeta splice forms may have functions other than that of modulating ERalpha activity.
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