Cancer Res; 70(14); OF1–10. ©2010 AACR.
Published OnlineFirst June 29, 2010; doi: 10.1158/0008-5472.CAN-10-0617
1. Wei Luo1,
2. Adam R. Karpf1,
3. Kristin K. Deeb1,
4. Josephia R. Muindi2,
5. Carl D. Morrison3,
6. Candace S. Johnson1, and
7. Donald L. Trump2
1. Authors' Affiliations: Departments of 1Pharmacology and Therapeutics, 2Medicine, and 3Pathology, Roswell Park Cancer Institute, Buffalo, New York
1. Corresponding Author:
Donald L. Trump, Department of Medicine, Roswell Park Cancer Institute, Elm and Carlton Streets, Buffalo, NY 14263. Phone: 716-845-5772; Fax: 716-845-8261; E-mail: donald.trump at roswellpark.org.
1. W. Luo and A.R. Karpf contributed equally to this work.
Calcitriol, a regulator of calcium homeostasis with antitumor properties, is degraded by the product of the CYP24A1 gene, which is downregulated in human prostate cancer by unknown mechanisms. We found that CYP24A1 expression is inversely correlated with promoter DNA methylation in prostate cancer cell lines. Treatment with the DNA methyltransferase inhibitor 5-aza-2?-deoxycytidine (DAC) activates CYP24A1 expression in prostate cancer cells. In vitro methylation of the CYP24A1 promoter represses its promoter activity. Furthermore, inhibition of histone deacetylases by trichostatin A (TSA) enhances the expression of CYP24A1 in prostate cancer cells. Quantitative chromatin immunoprecipitation-PCR (ChIP-qPCR) reveals that specific histone modifications are associated with the CYP24A1 promoter region. Treatment with TSA increases H3K9ac and H3K4me2 and simultaneously decreases H3K9me2 at the CYP24A1 promoter. ChIP-qPCR assay reveals that treatment with DAC and TSA increases the recruitment of vitamin D receptor to the CYP24A1 promoter. Reverse transcriptase-PCR analysis of paired human prostate samples revealed that CYP24A1 expression is downregulated in prostate malignant lesions compared with adjacent histologically benign lesions. Bisulfite pyrosequencing shows that CYP24A1 gene is hypermethylated in malignant lesions compared with matched benign lesions. Our findings indicate that repression of CYP24A1 gene expression in human prostate cancer cells is mediated in part by promoter DNA methylation and repressive histone modifications.
Note: Supplementary data for this article are available at Cancer Research Online (http://cancerres.aacrjournals.org/).
* Received February 19, 2010, Revision received April 26, 2010, Accepted May 14, 2010.
* ©2010 American Association for Cancer Research.
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