Developmental changes in DNA methylation around prostatic steroid-binding protein genes.

R White,M Parker

doi:10.1016/s0021-9258(18)32148-3

Abstract

The state of DNA methylation around prostatic steroid-binding protein genes has been investigated at CCGG sites by using the restriction enzymes MspI and HpaII. In the ventral prostate, these sites change from being completely methylated around the C1, C2, and one of two C3 genes in 10-day-old animals to being unmethylated in 28-day-old animals. The second C3 gene is always methylated and probably transcriptionally inactive, and all four genes are hypermethylated in other tissues. Hormone withdrawal from mature animals results in methylation of approximately 50% of CCGG sites in the ventral prostate which correlates with an increase in the number of stromal cells relative to epithelial cells. This suggests that the state of DNA methylation in epithelial cells, where prostatic steroid-binding protein is expressed, is unchanged. Thus, the inverse correlation between gene expression and DNA methylation is valid during development but probably not during subsequent hormone withdrawal.

Highlights

The state of DNA methylation around prostatic ste- site resistant to HpaII digestion but not MspI digestion
Prostaticsteroid-bindingprotein is undetectableinrats until 15-20 days of age [20, 21], after which there is a progressive increase in protein levels
The transcriptional activitoyf genes appears tobe inversely correlated with their state of DNA methylation [16, 17], and it hasbeen postulated that changes in DNA methylactoiuolnd was carried out at 65 “C for 16 h in solution C containing a nicktranslated [26] 32P-labeledDNA probe at 5 X lo5dpm/ml

Summary

Roger White and Malcolm Parker

From the Imperial Cancer Research Fund, Lincoln’s Inn Fields, London WC2A 3PX, England. The state of DNA methylation around prostatic ste- site resistant to HpaII digestion but not MspI digestion. Preparation of Cell DNA-Total cell DNA was isolated from tissues by the method of Blin and Stafford ( 2 3 ) except in the case of rat sperm from the cauda epididymidis which was prepared by the method of Borenfreund et al [24] In those preparations where digestion with and C3 and the other subunit containing pthoelypeptides C2 restriction enzymes proved difficult, the DNA was further purified and C3 [7]. The transcriptional activitoyf genes appears tobe inversely correlated with their state of DNA methylation [16, 17], and it hasbeen postulated that changes in DNA methylactoiuolnd was carried out at 65 “C for 16 h in solution C containing a nicktranslated [26] 32P-labeledDNA probe at 5 X lo5dpm/ml. Occurs in the 5‘ position of cytosine usually in the sequence CpG [18].The isoschizomeric restriction enzymes HpaII and

RESULTS

DNA MethySliatetison AssociatePdrowsittahtic

MHMHMHMHMHMHMH Kb