TY - JOUR
T1 - Biochemical characterization of nuclear receptors for vitamin D3 and glucocorticoids in prostate stroma cell microenvironment
AU - Hidalgo, Alejandro A.
AU - Montecinos, Viviana P.
AU - Paredes, Roberto
AU - Godoy, Alejandro S.
AU - McNerney, Eileen M.
AU - Tovar, Heribelt
AU - Pantoja, Diego
AU - Johnson, Candace
AU - Trump, Donald
AU - Onate, Sergio A.
N1 - Funding Information:
This study was supported by the Fondecyt (1080261), American Cancer Society (RGS-012301-TBE), and the Concern Foundation to Sergio A. Onate. The authors would like to acknowledge the support from the Translational Research Tissue Resource and the Pathology core facilities at Roswell Park Cancer Institute for providing prostate tissue from the organ donor program.
PY - 2011/8/19
Y1 - 2011/8/19
N2 - The disruption of stromal cell signals in prostate tissue microenvironment influences the development of prostate cancer to androgen independence. 1α,25-Dihydroxyvitamin D3 (1,25D3) and glucocorticoids, either alone or in combination, have been investigated as alternatives for the treatment of advanced prostate cancers that fails androgen therapies. The effects of glucocorticoids are mediated by the intracellular glucocorticoid receptor (GR). Similarly, the effect of 1,25D3 is mediated by the 1,25D3 nuclear receptor (VDR). In this study, fibroblasts from benign- (BAS) and carcinoma-associated stroma (CAS) were isolated from human prostates to characterize VDR and GR function as transcription factors in prostate stroma. The VDR-mediated transcriptional activity assessed using the CYP24-luciferase reporter was limited to 3-fold induction by 1,25D3 in 9 out of 13 CAS (70%), as compared to >10-fold induction in the BAS clinical sample pair. Expression of His-tagged VDR (Ad-his-VDR) failed to recover the low transcriptional activity of the luciferase reporter in 7 out of 9 CAS. Interestingly, expression of Ad-his-VDR successfully recovered receptor-mediated induction in 2 out of the 9 CAS analyzed, suggesting that changes in the receptor protein itself was responsible for decreased response and resistance to 1,25D3 action. Conversely, VDR-mediated transcriptional activity was more efficient in 4 out of 13 CAS (30%), as compared to the BAS sample pair. Consistent with the reduced response to 1,25D3 observed in CAS, chromatin immunoprecipitation (ChIP) assays indicated decreased recruitment of coactivators SRC-1/CBP, without major changes in the recruitment of VDR to the CYP24 promoter. In addition, we observed that GR-mediated transcriptional activity was also altered in CAS, as compared to BAS. Disruption of coactivators SRC-1/CBP recruitment may promote hormone resistance in CaP, and highlights the relevance of molecular diagnosis and drug design in tumor cell microenvironment.
AB - The disruption of stromal cell signals in prostate tissue microenvironment influences the development of prostate cancer to androgen independence. 1α,25-Dihydroxyvitamin D3 (1,25D3) and glucocorticoids, either alone or in combination, have been investigated as alternatives for the treatment of advanced prostate cancers that fails androgen therapies. The effects of glucocorticoids are mediated by the intracellular glucocorticoid receptor (GR). Similarly, the effect of 1,25D3 is mediated by the 1,25D3 nuclear receptor (VDR). In this study, fibroblasts from benign- (BAS) and carcinoma-associated stroma (CAS) were isolated from human prostates to characterize VDR and GR function as transcription factors in prostate stroma. The VDR-mediated transcriptional activity assessed using the CYP24-luciferase reporter was limited to 3-fold induction by 1,25D3 in 9 out of 13 CAS (70%), as compared to >10-fold induction in the BAS clinical sample pair. Expression of His-tagged VDR (Ad-his-VDR) failed to recover the low transcriptional activity of the luciferase reporter in 7 out of 9 CAS. Interestingly, expression of Ad-his-VDR successfully recovered receptor-mediated induction in 2 out of the 9 CAS analyzed, suggesting that changes in the receptor protein itself was responsible for decreased response and resistance to 1,25D3 action. Conversely, VDR-mediated transcriptional activity was more efficient in 4 out of 13 CAS (30%), as compared to the BAS sample pair. Consistent with the reduced response to 1,25D3 observed in CAS, chromatin immunoprecipitation (ChIP) assays indicated decreased recruitment of coactivators SRC-1/CBP, without major changes in the recruitment of VDR to the CYP24 promoter. In addition, we observed that GR-mediated transcriptional activity was also altered in CAS, as compared to BAS. Disruption of coactivators SRC-1/CBP recruitment may promote hormone resistance in CaP, and highlights the relevance of molecular diagnosis and drug design in tumor cell microenvironment.
KW - Cellular microenvironment
KW - Coactivators
KW - Corepressors
KW - Glucocorticoids receptor
KW - Prostate cancer
KW - Transcription regulation
KW - Vitamin D receptor
UR - http://www.scopus.com/inward/record.url?scp=80051786893&partnerID=8YFLogxK
U2 - 10.1016/j.bbrc.2011.06.181
DO - 10.1016/j.bbrc.2011.06.181
M3 - Article
C2 - 21763285
AN - SCOPUS:80051786893
SN - 0006-291X
VL - 412
SP - 13
EP - 19
JO - Biochemical and Biophysical Research Communications
JF - Biochemical and Biophysical Research Communications
IS - 1
ER -