Calcium Activation of the Androgen Receptor in Prostate Cells

Background. Although prostate cancer patients initially respond to androgen deprivation therapy, most patients progress to a resistant phenotype. Castration resistance is due, in part, to intratumoral and/or adrenal synthesis of androgens, overexpression or mutation of the androgen receptor (AR), st...

Full description

Saved in:
Bibliographic Details
Main Authors: Zeina W. Sharawi, Sawsan M. Khatrawi, Qiaochu Wang, Hongzhao Zhou, Kedra Cyrus, Gai Yan, Becky Hoxter, Bassem R. Haddad, Mary Beth Martin
Format: Article
Language:English
Published: Wiley 2023-01-01
Series:International Journal of Endocrinology
Online Access:http://dx.doi.org/10.1155/2023/9907948
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1832546704233070592
author Zeina W. Sharawi
Sawsan M. Khatrawi
Qiaochu Wang
Hongzhao Zhou
Kedra Cyrus
Gai Yan
Becky Hoxter
Bassem R. Haddad
Mary Beth Martin
author_facet Zeina W. Sharawi
Sawsan M. Khatrawi
Qiaochu Wang
Hongzhao Zhou
Kedra Cyrus
Gai Yan
Becky Hoxter
Bassem R. Haddad
Mary Beth Martin
author_sort Zeina W. Sharawi
collection DOAJ
description Background. Although prostate cancer patients initially respond to androgen deprivation therapy, most patients progress to a resistant phenotype. Castration resistance is due, in part, to intratumoral and/or adrenal synthesis of androgens, overexpression or mutation of the androgen receptor (AR), stabilization of AR by chaperones, and ligand-independent activation of AR. Increasing evidence also links disruption of calcium homeostasis to progression of prostate cancer. Our previous study shows that heavy metal cadmium activates the AR through a ligand-independent mechanism. Cadmium mimics calcium in biological systems due to their similar ionic charge and radius. This study determines whether calcium activates AR and whether first- and second-generation antiandrogens block the ability of calcium to activate the receptor. Methods. The expression of androgen-responsive genes and calcium channels was measured in prostate cells using a quantitative real-time polymerase chain reaction assay. Cell growth was measured. Results. To ask whether calcium activates AR, prostate cells were treated with calcium in the absence and presence of the first-generation antiandrogens hydroxyflutamide and bicalutamide and the second-generation antiandrogen enzalutamide, and the expression of androgen-responsive genes and cell growth was measured. In the normal PWR-1E cells and HEK293T cells transiently expressing AR, treatment with calcium increased the expression of androgen-responsive genes by approximately 3-fold. The increase was blocked by enzalutamide but was not consistently blocked by the first-generation antiandrogens. In LNCaP cells which contain a mutant AR, treatment with calcium also increased the expression of androgen-responsive genes by approximately 3-fold, and the increase was more effectively blocked by enzalutamide than by hydroxyflutamide or bicalutamide. Treatment with calcium also increased cell growth that was blocked by enzalutamide. To ask whether dysregulation of calcium channels is associated with castration resistance, calcium channels were measured in the normal PWR-1E prostate cells, the hormone-responsive LNCaP cells, and the castration-resistant VCaP and 22RV1 cells. Compared to normal prostate cells, the hormone-responsive and hormone-resistant cells overexpressed several calcium channels. Conclusions. The results of this study show that calcium activates AR and increases cell growth and that calcium channels are overexpressed in hormone-responsive and hormone-resistant prostate cancer cells. Taken together, the results suggest a novel role of calcium in the castration-resistant phenotype.
format Article
id doaj-art-e83e340fd7324457bb0b27bd46f34b0d
institution Kabale University
issn 1687-8345
language English
publishDate 2023-01-01
publisher Wiley
record_format Article
series International Journal of Endocrinology
spelling doaj-art-e83e340fd7324457bb0b27bd46f34b0d2025-02-03T06:47:29ZengWileyInternational Journal of Endocrinology1687-83452023-01-01202310.1155/2023/9907948Calcium Activation of the Androgen Receptor in Prostate CellsZeina W. Sharawi0Sawsan M. Khatrawi1Qiaochu Wang2Hongzhao Zhou3Kedra Cyrus4Gai Yan5Becky Hoxter6Bassem R. Haddad7Mary Beth Martin8Departments of OncologyDepartments of Biochemistry, Molecular and Cellular BiologyDepartments of Biochemistry, Molecular and Cellular BiologyDepartments of Biochemistry, Molecular and Cellular BiologyDepartments of OncologyDepartments of OncologyDepartments of OncologyDepartments of OncologyDepartments of OncologyBackground. Although prostate cancer patients initially respond to androgen deprivation therapy, most patients progress to a resistant phenotype. Castration resistance is due, in part, to intratumoral and/or adrenal synthesis of androgens, overexpression or mutation of the androgen receptor (AR), stabilization of AR by chaperones, and ligand-independent activation of AR. Increasing evidence also links disruption of calcium homeostasis to progression of prostate cancer. Our previous study shows that heavy metal cadmium activates the AR through a ligand-independent mechanism. Cadmium mimics calcium in biological systems due to their similar ionic charge and radius. This study determines whether calcium activates AR and whether first- and second-generation antiandrogens block the ability of calcium to activate the receptor. Methods. The expression of androgen-responsive genes and calcium channels was measured in prostate cells using a quantitative real-time polymerase chain reaction assay. Cell growth was measured. Results. To ask whether calcium activates AR, prostate cells were treated with calcium in the absence and presence of the first-generation antiandrogens hydroxyflutamide and bicalutamide and the second-generation antiandrogen enzalutamide, and the expression of androgen-responsive genes and cell growth was measured. In the normal PWR-1E cells and HEK293T cells transiently expressing AR, treatment with calcium increased the expression of androgen-responsive genes by approximately 3-fold. The increase was blocked by enzalutamide but was not consistently blocked by the first-generation antiandrogens. In LNCaP cells which contain a mutant AR, treatment with calcium also increased the expression of androgen-responsive genes by approximately 3-fold, and the increase was more effectively blocked by enzalutamide than by hydroxyflutamide or bicalutamide. Treatment with calcium also increased cell growth that was blocked by enzalutamide. To ask whether dysregulation of calcium channels is associated with castration resistance, calcium channels were measured in the normal PWR-1E prostate cells, the hormone-responsive LNCaP cells, and the castration-resistant VCaP and 22RV1 cells. Compared to normal prostate cells, the hormone-responsive and hormone-resistant cells overexpressed several calcium channels. Conclusions. The results of this study show that calcium activates AR and increases cell growth and that calcium channels are overexpressed in hormone-responsive and hormone-resistant prostate cancer cells. Taken together, the results suggest a novel role of calcium in the castration-resistant phenotype.http://dx.doi.org/10.1155/2023/9907948
spellingShingle Zeina W. Sharawi
Sawsan M. Khatrawi
Qiaochu Wang
Hongzhao Zhou
Kedra Cyrus
Gai Yan
Becky Hoxter
Bassem R. Haddad
Mary Beth Martin
Calcium Activation of the Androgen Receptor in Prostate Cells
International Journal of Endocrinology
title Calcium Activation of the Androgen Receptor in Prostate Cells
title_full Calcium Activation of the Androgen Receptor in Prostate Cells
title_fullStr Calcium Activation of the Androgen Receptor in Prostate Cells
title_full_unstemmed Calcium Activation of the Androgen Receptor in Prostate Cells
title_short Calcium Activation of the Androgen Receptor in Prostate Cells
title_sort calcium activation of the androgen receptor in prostate cells
url http://dx.doi.org/10.1155/2023/9907948
work_keys_str_mv AT zeinawsharawi calciumactivationoftheandrogenreceptorinprostatecells
AT sawsanmkhatrawi calciumactivationoftheandrogenreceptorinprostatecells
AT qiaochuwang calciumactivationoftheandrogenreceptorinprostatecells
AT hongzhaozhou calciumactivationoftheandrogenreceptorinprostatecells
AT kedracyrus calciumactivationoftheandrogenreceptorinprostatecells
AT gaiyan calciumactivationoftheandrogenreceptorinprostatecells
AT beckyhoxter calciumactivationoftheandrogenreceptorinprostatecells
AT bassemrhaddad calciumactivationoftheandrogenreceptorinprostatecells
AT marybethmartin calciumactivationoftheandrogenreceptorinprostatecells