title: The DNA methylome of benign and malignant parathyroid tumors.
abstract: The role of DNA methylation of CpG islands in parathyroid tumorigenesis has not been analyzed in an unbiased, systematic fashion. DNA was isolated from normal and pathologic parathyroid tissues, bisulphite modified and analyzed using the Infinium HumanMethylation27 BeadChip. Distinct hierarchical clustering of genes with altered DNA methylation profiles in normal and pathologic parathyroid tissue was evident. Comparing normal parathyroid tissue with parathyroid adenomas, 367 genes were significantly altered, while 175 genes significantly differed when comparing parathyroid carcinomas and normal parathyroid tissues. A comparison between parathyroid adenomas and parathyroid carcinomas identified 263 genes with significantly distinct methylation levels. Results were confirmed for certain genes in a validation cohort of 40 parathyroid adenomas by methylation-specific PCR. Genes of known or putative importance in the development of parathyroid tumors showed significant and frequent hypermethylation. DNA hypermethylation of CDKN2B, CDKN2A, WT1, SFRP1, SFRP2, and SFRP4 was associated with reduced gene expression in both benign and malignant parathyroid tumors. Treatment with 5-aza-2'-deoxycytidine of primary cell cultures restores expression of hypermethylated genes in benign and malignant parathyroid tumors. In conclusion, the unbiased, genome-wide study of the parathyroid tumor DNA methylome identified a number of genes with altered DNA methylation patterns of putative importance to benign and malignant parathyroid tumorigenesis.
authors.affiliation: Department of Surgery, Yale University , New Haven, CT; Yale Endocrine Neoplasia Laboratory, 333 Cedar Street, New Haven, CT 06520, USA.
authors.forename: Lee F
authors.initials: LF
authors.lastname: Starker
authors.forename: Jessica
authors.initials: J
authors.lastname: Svedlund
authors.forename: Robert
authors.initials: R
authors.lastname: Udelsman
authors.forename: Henning
authors.initials: H
authors.lastname: Dralle
authors.forename: Göran
authors.initials: G
authors.lastname: Akerström
authors.forename: Gunnar
authors.initials: G
authors.lastname: Westin
authors.forename: Richard P
authors.initials: RP
authors.lastname: Lifton
authors.forename: Peyman
authors.initials: P
authors.lastname: Björklund
authors.forename: Tobias
authors.initials: T
authors.lastname: Carling
mesh_terms: D000236:Adenoma / Q000235:genetics* / Q000473:pathology; D001374:Azacitidine / Q000494:pharmacology; D002277:Carcinoma / Q000235:genetics* / Q000473:pathology; D019175:DNA Methylation; D015254:DNA Modification Methylases / Q000037:antagonists & inhibitors; D044127:Epigenesis, Genetic; D015972:Gene Expression Regulation, Neoplastic; D052138:Genes, Neoplasm; D006801:Humans; D010282:Parathyroid Neoplasms / Q000235:genetics* / Q000473:pathology; D014158:Transcription, Genetic; D014407:Tumor Cells, Cultured
chemical_list: D015254:DNA Modification Methylases; D001374:Azacitidine