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Cekanova M, Woraratphoka J, Sukhthankar M, Dharmawardhana S, Siriwardana N, Moustaid-Moussa N, Strom A, Baek SJ, Wong Q, Zou M, Donnell R, Wimalasena J. Abstract 4591: Estrogen receptor beta controls a wide variety of functions in breast cancer cells. Cancer Res 2010. [DOI: 10.1158/1538-7445.am10-4591] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
The role of ER alpha as the mediator of estrogen action in breast cancer (BC) cells is well known, however, the role of ER beta is controversial. The majority of BC expressing ER alpha also express ER beta. Some clinical studies suggest that ER beta expression is a good prognosticator; however, in others, especially where expression levels of ER beta > ER alpha, ER beta may be associated with more advanced BC. Previously, we showed that ER beta may regulate a number of signaling pathways (AACR, 2008). Our recent work demonstrates that ER beta has even wider actions in MCF7 and T47D cells stably overexpressing ER beta. Thus, ER beta decreased phospho (p)/ total Stat1, p Stat3, p Stat5/total Stat5. Expression of the oncogenic miR cluster 17-92 was highly reduced (p<0.01) when ER beta overexpressing vs. control cells were compared. ER beta also decreased PPAR gamma, superoxide dismutase, as well as the concentration of the mRNA processing factor, RBM5, and the activated form of AMPK. All these changes were significant (p<0.05) in triplicate measurements. While ER beta overexpression increased migration through Matrigel, it significantly decreased CXCR4 expression (p<0.05, n=4). All of these effects of ER beta were estrogen-independent. On the other hand, estrogen increased CXCR4 expression in MCF7 cells significantly. In our study, we analyzed the expression of ER beta and BAD using tissue microarrays with normal and neoplastic breast tissue. Our immunohistochemical (IHC) data revealed a significant increase of ER beta cytoplasmic staining in neoplastic cells compared to normal cells (p<0.001). In addition, the nuclear expression of ER beta was significantly decreased in neoplastic cells compared to normal cells (p<0.01). From our correlation analysis of IHC data obtained from tissue microarray, we identified that cytoplasmic expression of BAD was negatively correlated with cytoplasmic expression of ER beta. In addition, the nuclear expression of BAD was significantly positively correlated with nuclear ER beta.
These results suggest that ER beta has a wide variety of actions in BC cells, as predicted by the regulation of 62 miRs (p<0.01) as determined by Exiqon Inc. Taken together our results suggest that ER beta may have a multitude of actions in breast cancer and that the ratio of ER alpha/beta may determine the prognostic outcome.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 4591.
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Affiliation(s)
| | | | | | - S Dharmawardhana
- 2University of Puerto Rico Medical Sciences, San Juan, Puerto Rico
| | | | | | | | | | - Q Wong
- 4University of Oklahoma, Medical Center, Oklahoma City, OK
| | - M Zou
- 4University of Oklahoma, Medical Center, Oklahoma City, OK
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