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ER-α36, a Novel Variant of ER-α, Mediates Estrogen-Stimulated Proliferation of Endometrial Carcinoma Cells via the PKCδ/ERK Pathway

BACKGROUND: Recently, a variant of ER-α, ER-α36 was identified and cloned. ER-α36 lacks intrinsic transcription activity and mainly mediates non-genomic estrogen signaling. The purpose of this study was to investigate the function and the underlying mechanisms of ER-α36 in growth regulation of endom...

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Autores principales: Tong, Jing-Shan, Zhang, Qing-Hua, Wang, Zhen-Bo, Li, Sen, Yang, Cai-Rong, Fu, Xue-Qi, Hou, Yi, Wang, Zhao-Yi, Sheng, Jun, Sun, Qing-Yuan
Formato: Texto
Lenguaje:English
Publicado: Public Library of Science 2010
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2973969/
https://www.ncbi.nlm.nih.gov/pubmed/21079811
http://dx.doi.org/10.1371/journal.pone.0015408
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author Tong, Jing-Shan
Zhang, Qing-Hua
Wang, Zhen-Bo
Li, Sen
Yang, Cai-Rong
Fu, Xue-Qi
Hou, Yi
Wang, Zhao-Yi
Sheng, Jun
Sun, Qing-Yuan
author_facet Tong, Jing-Shan
Zhang, Qing-Hua
Wang, Zhen-Bo
Li, Sen
Yang, Cai-Rong
Fu, Xue-Qi
Hou, Yi
Wang, Zhao-Yi
Sheng, Jun
Sun, Qing-Yuan
author_sort Tong, Jing-Shan
collection PubMed
description BACKGROUND: Recently, a variant of ER-α, ER-α36 was identified and cloned. ER-α36 lacks intrinsic transcription activity and mainly mediates non-genomic estrogen signaling. The purpose of this study was to investigate the function and the underlying mechanisms of ER-α36 in growth regulation of endometrial Ishikawa cancer cells. METHODS: The cellular localization of ER-α36 and ER-α66 were determined by immunofluorescence in the Ishikawa cells. Ishikawa endometrial cancer control cells transfected with an empty expression vector, Ishikawa cells with shRNA knockdown of ER-α36 (Ishikawa/RNAiER36) and Ishikawa cells with shRNA knockdown of ER-α66 (Ishikawa/RNAiER66) were treated with E2 and E2-conjugated to bovine serum albumin (E2-BSA, membrane impermeable) in the absence and presence of different kinase inhibitors HBDDE, bisindolylmaleimide, rottlerin, H89 and U0126. The phosphorylation levels of signaling molecules and cyclin D1/cdk4 expression were examined with Western blot analysis and cell growth was monitored with the MTT assay. RESULTS: Immunofluorescence staining of Ishikawa cells demonstrated that ER-α36 was expressed mainly on the plasma membrane and in the cytoplasm, while ER-α66 was predominantly localized in the cell nucleus. Both E2 and E2-BSA rapidly activated PKCδ not PKCα in Ishikawa cells, which could be abrogated by ER-α36 shRNA expression. E2-and E2-BSA-induced ERK phosphorylation required ER-α36 and PKCδ. However, only E2 was able to induce Camp-dependent protein kinase A (PKA) phosphorylation. Furthermore, E2 enhances cyclin D1/cdk4 expression via ER-α36. CONCLUSION: E2 activates the PKCδ/ERK pathway and enhances cyclin D1/cdk4 expression via the membrane-initiated signaling pathways mediated by ER-α36, suggesting a possible involvement of ER-α36 in E2-dependent growth-promoting effects in endometrial cancer cells.
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spelling pubmed-29739692010-11-15 ER-α36, a Novel Variant of ER-α, Mediates Estrogen-Stimulated Proliferation of Endometrial Carcinoma Cells via the PKCδ/ERK Pathway Tong, Jing-Shan Zhang, Qing-Hua Wang, Zhen-Bo Li, Sen Yang, Cai-Rong Fu, Xue-Qi Hou, Yi Wang, Zhao-Yi Sheng, Jun Sun, Qing-Yuan PLoS One Research Article BACKGROUND: Recently, a variant of ER-α, ER-α36 was identified and cloned. ER-α36 lacks intrinsic transcription activity and mainly mediates non-genomic estrogen signaling. The purpose of this study was to investigate the function and the underlying mechanisms of ER-α36 in growth regulation of endometrial Ishikawa cancer cells. METHODS: The cellular localization of ER-α36 and ER-α66 were determined by immunofluorescence in the Ishikawa cells. Ishikawa endometrial cancer control cells transfected with an empty expression vector, Ishikawa cells with shRNA knockdown of ER-α36 (Ishikawa/RNAiER36) and Ishikawa cells with shRNA knockdown of ER-α66 (Ishikawa/RNAiER66) were treated with E2 and E2-conjugated to bovine serum albumin (E2-BSA, membrane impermeable) in the absence and presence of different kinase inhibitors HBDDE, bisindolylmaleimide, rottlerin, H89 and U0126. The phosphorylation levels of signaling molecules and cyclin D1/cdk4 expression were examined with Western blot analysis and cell growth was monitored with the MTT assay. RESULTS: Immunofluorescence staining of Ishikawa cells demonstrated that ER-α36 was expressed mainly on the plasma membrane and in the cytoplasm, while ER-α66 was predominantly localized in the cell nucleus. Both E2 and E2-BSA rapidly activated PKCδ not PKCα in Ishikawa cells, which could be abrogated by ER-α36 shRNA expression. E2-and E2-BSA-induced ERK phosphorylation required ER-α36 and PKCδ. However, only E2 was able to induce Camp-dependent protein kinase A (PKA) phosphorylation. Furthermore, E2 enhances cyclin D1/cdk4 expression via ER-α36. CONCLUSION: E2 activates the PKCδ/ERK pathway and enhances cyclin D1/cdk4 expression via the membrane-initiated signaling pathways mediated by ER-α36, suggesting a possible involvement of ER-α36 in E2-dependent growth-promoting effects in endometrial cancer cells. Public Library of Science 2010-11-04 /pmc/articles/PMC2973969/ /pubmed/21079811 http://dx.doi.org/10.1371/journal.pone.0015408 Text en Tong et al. http://creativecommons.org/licenses/by/4.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are properly credited.
spellingShingle Research Article
Tong, Jing-Shan
Zhang, Qing-Hua
Wang, Zhen-Bo
Li, Sen
Yang, Cai-Rong
Fu, Xue-Qi
Hou, Yi
Wang, Zhao-Yi
Sheng, Jun
Sun, Qing-Yuan
ER-α36, a Novel Variant of ER-α, Mediates Estrogen-Stimulated Proliferation of Endometrial Carcinoma Cells via the PKCδ/ERK Pathway
title ER-α36, a Novel Variant of ER-α, Mediates Estrogen-Stimulated Proliferation of Endometrial Carcinoma Cells via the PKCδ/ERK Pathway
title_full ER-α36, a Novel Variant of ER-α, Mediates Estrogen-Stimulated Proliferation of Endometrial Carcinoma Cells via the PKCδ/ERK Pathway
title_fullStr ER-α36, a Novel Variant of ER-α, Mediates Estrogen-Stimulated Proliferation of Endometrial Carcinoma Cells via the PKCδ/ERK Pathway
title_full_unstemmed ER-α36, a Novel Variant of ER-α, Mediates Estrogen-Stimulated Proliferation of Endometrial Carcinoma Cells via the PKCδ/ERK Pathway
title_short ER-α36, a Novel Variant of ER-α, Mediates Estrogen-Stimulated Proliferation of Endometrial Carcinoma Cells via the PKCδ/ERK Pathway
title_sort er-α36, a novel variant of er-α, mediates estrogen-stimulated proliferation of endometrial carcinoma cells via the pkcδ/erk pathway
topic Research Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2973969/
https://www.ncbi.nlm.nih.gov/pubmed/21079811
http://dx.doi.org/10.1371/journal.pone.0015408
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