title: Epigenetic progression of columnar cell lesions of the breast to invasive breast cancer.
abstract: Promoter hypermethylation of several tumour suppressor genes often occurs during breast carcinogenesis, but little is known about epigenetic silencing in the possible precursor columnar cell lesion (CCL). Promoter hypermethylation of 50 different tumour suppressor genes was assessed in normal breast tissue (N = 10), CCL (N = 15), ductal carcinoma in situ (DCIS) grade I originating in CCL (N = 5) and paired CCL (N = 15) with DCIS (N = 7) and/or invasive carcinoma (N = 14) by Methylation-specific multiplex ligation-dependent probe amplification. Increasing mean cumulative methylation levels were found from normal breast tissue to CCL to DCIS and invasive carcinoma (P < 0.001) with similar methylation levels in DCIS and invasive carcinoma. Methylation levels and frequencies (in the overall analysis and analysis of only the synchronous lesions) were the highest for RASSF1, CCND2, ID4, SCGB3A1 and CDH13. The methylation levels of ID4, CCND2, and CDH13 increased significantly from normal breast tissue to CCL and to DCIS/invasive carcinoma. RASSF1, SCGB3A1 and SFRP5 had significant higher methylation levels in CCL compared to normal breast tissue, but showed no significant differences between CCL, DCIS and invasive carcinoma. Also, no difference was found between CCLs with and without atypia, or CCLs with or without synchronous cancer. In conclusion, promoter hypermethylation for several established tumour suppressor genes is already present in CCLs, underlining that promoter hypermethylation is an early event in breast carcinogenesis. Atypia in CCL or the presence of synchronous more advanced lesions does not seem to be accompanied by higher methylation levels.
authors.affiliation: Department of Pathology, University Medical Center Utrecht Cancer Center, PO Box 85500, 3508 GA Utrecht, The Netherlands.
authors.forename: Anoek H J
authors.initials: AH
authors.lastname: Verschuur-Maes
authors.forename: Peter C
authors.initials: PC
authors.lastname: de Bruin
authors.forename: Paul J
authors.initials: PJ
authors.lastname: van Diest
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001943:Breast Neoplasms / Q000235:genetics* / Q000473:pathology* / Q000601:surgery; D015820:Cadherins / Q000235:genetics; D002285:Carcinoma, Intraductal, Noninfiltrating / Q000235:genetics* / Q000473:pathology / Q000601:surgery; D056742:Cyclin D2 / Q000235:genetics; D016207:Cytokines / Q000235:genetics; D019175:DNA Methylation; D044127:Epigenesis, Genetic; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D016147:Genes, Tumor Suppressor; D006801:Humans; D051796:Inhibitor of Differentiation Proteins / Q000235:genetics; D042361:Mammary Glands, Human / Q000473:pathology* / Q000601:surgery; D008875:Middle Aged; D060885:Multiplex Polymerase Chain Reaction; D011230:Precancerous Conditions / Q000235:genetics* / Q000601:surgery; D011401:Promoter Regions, Genetic; D012016:Reference Values; D025521:Tumor Suppressor Proteins / Q000235:genetics
chemical_list: C080336:CCND2 protein, human; D015820:Cadherins; D056742:Cyclin D2; D016207:Cytokines; C099972:H-cadherin; C490128:ID4 protein, human; D051796:Inhibitor of Differentiation Proteins; C411762:RASSF1 protein, human; C434732:SCGB3A1 protein, human; D025521:Tumor Suppressor Proteins