Genomic hypomethylation and CpG island hypermethylation in prostatic intraepithelial neoplasm.
Altered DNA methylation in cancer cells is characterized by focal CpG island hypermethylation and diffuse genomic hypomethylation. Both types of aberrant methylation are frequently found in human prostate adenocarcinoma (PCa). Prostatic intraepithelial neoplasm (PIN), a precursor lesion of PCa, has been demonstrated to contain CpG island hypermethylation, but little is known about the role of DNA hypomethylation. We analyzed the methylation status at 12 CpG island loci and at two repetitive DNA elements (LINE-1 and SAT2) from normal prostate (n = 20), PIN (n = 25), and PCa (n = 35) tissues using MethyLight assay or combined bisulfite restriction analysis. The methylation levels in LINE-1 and SAT2 decreased with progression of lesion types from normal prostate to PIN to PCa (P < 0.05), whereas promoter CpG island loci displayed increased methylation. Ten genes were found to be hypermethylated in a cancer-specific manner and were further analyzed in another set of PCa tissues (n = 64). The number of methylated genes was closely associated with TNM stage, Gleason sum, and preoperative serum PSA levels (P = 0.020, 0.073, 0.033, respectively). These results suggest that genomic hypomethylation and CpG island hypermethylation, common among PCas, are early events in prostate carcinogenesis and may be implicated in the development of PIN.
Cho
Nam-Yun
NY
Laboratory of Epigenetics, Cancer Research Institute, Seoul National University College of Medicine, Seoul, South Korea.
Kim
Jung Ho
JH
Moon
Kyung Chul
KC
Kang
Gyeong Hoon
GH
D000123:Acetyltransferases / Q000235:genetics; D000230:Adenocarcinoma / Q000097:blood / Q000235:genetics / Q000473:pathology; D000368:Aged; D016022:Case-Control Studies; D018899:CpG Islands / Q000235:genetics*; D019175:DNA Methylation / Q000235:genetics*; D004273:DNA, Neoplasm / Q000235:genetics; D018450:Disease Progression; D006801:Humans; D020084:Long Interspersed Nucleotide Elements / Q000235:genetics; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D017430:Prostate-Specific Antigen / Q000097:blood; D019048:Prostatic Intraepithelial Neoplasia / Q000097:blood / Q000235:genetics* / Q000473:pathology; D011471:Prostatic Neoplasms / Q000097:blood / Q000235:genetics* / Q000473:pathology; D000099228:Diamine N-Acetyltransferase
D000123:Acetyltransferases; D004273:DNA, Neoplasm; D017430:Prostate-Specific Antigen; D000099228:Diamine N-Acetyltransferase