Objective      To investigate the correlation of expression of DNA methyltransferase 1 (DNMT1) and the methylation status of glutathione S transferase P1 (GSTP1) and adenomatous polyposis coli (APC) promoter CpG island in prostate cancer and its clinical significance.      Methods      RT-PCR method was used to detect the expression of DNMT1

GSTP1

and APC in 56 cases of prostate cancer and 10 cases of benign prostatic hyperplasia. Mutagenivcally separated-PCR (MS-PCR) was used to detect the methylation status of CpG island of promoter of GSTP1 and APC.      Results      DNMT1 mRNA was highly expressed in most of the prostate cancer tissue (the positive rate in the poorly-differentiated cancer tissues was 90.0%)

but mildly expressed in benign prostatic hyperplasia (the positive rate was 40.0%). GSTP1 and APC mRNA was slightly expressed in most of the prostate cancer tissue (the positive rate of poor-differentiation was 23.3% and 33.3% respectively

P0.05)

but strongly expressed in most benign prostatic hyperplasia tissue (the positive rate was 90.0% and 80.0% respectively). GSTP1 and APC were in hypermethylated status in most  prostate cancer tissues (the positive rate of poor-differentiation was 83.3% and 73.3% respectively)

but in hypomethylated status (or demethylation) in benign prostatic hyperplasia (the positive rate was 10.0% and 20.0% respectively

P0.05).      Conclusion      Silence of GSTP and APC in prostate cancer may be related with hypermethylation of DNMT1 promoter CpG island due to its high expression.