title: DNA methylation changes correlate with Gleason score and tumor stage in prostate cancer.
abstract: DNA methylation, a widely used epigenetic mark, has been associated with many tumors. However, few studies have addressed the role of cell-free plasma DNA methylation in discriminating aggressive prostate cancer (PCa) from indolent cases. We conducted a case series and a case-control study among histologically confirmed stage II/III cases and matched controls recruited at Columbia University Medical Center. The aim of this study was to investigate whether plasma DNA methylation levels are appropriate surrogate biomarker of PCa tumor tissue levels and whether these markers are associated with worse clinicopathological tumor characteristics, which correlate with poorer prognosis. Quantitative pyrosequencing was used to detect methylation levels of p16 (CDKN4A), APC, GSTP1, and LINE-1 in 24 pairs of prostate tumor and adjacent tissues, as well as 27 plasma samples of PCa patients and 24 of controls. DNA methylation levels were significantly higher in tumor tissue than in adjacent nontumor tissue for p16 (CDKN4A), GSTP1, and APC; GSTP1 had a higher average percentage methylation in tumor tissue (38.9%) compared with p16 (CDKN4A) (5.9%) and APC (14.5%). GSTP1, p16 (CDKN4A), and APC methylation in tumor tissue was statistically significantly higher for cases with Gleason score ≥7 compared with those with Gleason score <7 [49.0% vs. 21.9% (p=0.01), 6.6% vs. 4.5% (p=0.04), and 19.1% vs. 7.4% (p=0.02), respectively]. Plasma LINE-1 methylation levels were higher in those with higher Gleason (67.6%) than in those with Gleason's below 7 (64.6%, p=0.03). Significant plasma-tissue correlations were observed for GSTP1 and LINE-1 methylation. These data, although preliminary, suggest that aberrant methylation may be a useful marker to identify PCa patients with clinically aggressive disease.
authors.affiliation: Department of Environmental Health Sciences, Mailman School of Public Health, Columbia University, 650 West 168th Street, New York, NY 10032, USA.
authors.forename: Lissette
authors.initials: L
authors.lastname: Delgado-Cruzata
authors.forename: Gregory W
authors.initials: GW
authors.lastname: Hruby
authors.forename: Karina
authors.initials: K
authors.lastname: Gonzalez
authors.forename: James
authors.initials: J
authors.lastname: McKiernan
authors.forename: Mitchel C
authors.initials: MC
authors.lastname: Benson
authors.forename: Regina M
authors.initials: RM
authors.lastname: Santella
authors.forename: Jing
authors.initials: J
authors.lastname: Shen
mesh_terms: D000368:Aged; D002277:Carcinoma / Q000175:diagnosis / Q000235:genetics* / Q000473:pathology*; D016022:Case-Control Studies; D019941:Cyclin-Dependent Kinase Inhibitor p16 / Q000235:genetics / Q000378:metabolism; D019175:DNA Methylation / Q000502:physiology; D003850:Deoxyribonuclease I / Q000235:genetics / Q000378:metabolism; D015972:Gene Expression Regulation, Neoplastic / Q000502:physiology; D017491:Genes, APC; D051549:Glutathione S-Transferase pi / Q000235:genetics / Q000378:metabolism; D006801:Humans; D008297:Male; D008875:Middle Aged; D060787:Neoplasm Grading; D009367:Neoplasm Staging; D011471:Prostatic Neoplasms / Q000175:diagnosis / Q000235:genetics* / Q000473:pathology*
chemical_list: D019941:Cyclin-Dependent Kinase Inhibitor p16; D051549:Glutathione S-Transferase pi; D003850:Deoxyribonuclease I; C538849:LINE-1 endonuclease, human