|Budget Amount *help
¥3,600,000 (Direct Cost : ¥3,600,000)
Fiscal Year 2000 : ¥1,600,000 (Direct Cost : ¥1,600,000)
Fiscal Year 1999 : ¥2,000,000 (Direct Cost : ¥2,000,000)
1. Immunohistochemical analysis of Vitamin A related receptors in human prostates : Expression of retinoic acid receptor (RAR)-α, β, γ, retinoid X receptor (RXR)-α, β, and γ was analyzed in formalin-fixed paraffin-embedded tissue sections from 15 patients with benign prostatic hyperplasia (BPH) and 15 with prostate cancer (PCa) using each polyclonal antibody. RARs-α and γ were detected in all BPH and PCa samples, RXRs-α and γ in all BPH samples and 80% of PCa samples, RXR-β in 13% of both samples, and RAR-β in all BPH and 13% of PCa samples. 2.Analysis of Vitamin A related receptor mRNAs in human prostates : A nonradioactive mRNA in situ hybridization technique using digoxigenin-labeled probe for RAR-α, β, γ were analyzed in five BPH and five PCa samples. RAR-α, and γ mRNA were detected in all BPH and PCa samples while RAR-β not detected. Thus, RAR-β mRNA was examined by RT-PCR in the microdisected samples, showing that 20% of PCa and 80% of BPH samples had RAR-β mRNA.3. Analysis of regulation in RAR-β2 gene expression in human prostates : Regulation mechanisms of RAR-β2 gene were analyzed because PCa showed dramatically decreasing expression of RAR-β gene. (1) PCR-SSCP analysis showed no abnormal band in 10 PCa samples, suggesting that there may be no mutation in any exons of the RAR-β gene. (2) Using bisulfite PCR methods, methylation status was analyzed within the RAR-β promoter region. Aberrant methylation was detected in 83% of the 24 PCa samples while no methylation in BPH samples. These results suggest that one of Vitamin A related receptors, RAR-β, especially β2 may play an important role in carcinogenesis of the prostate, and the possibility that this gene may become a tumor marker or a target for gene therapy.