title: Single nucleotide polymorphism microarray analysis in cortisol-secreting adrenocortical adenomas identifies new candidate genes and pathways.
abstract: The genetic mechanisms underlying adrenocortical tumor development are still largely unknown. We used high-resolution single nucleotide polymorphism microarrays (Affymetrix SNP 6.0) to detect copy number alterations (CNAs) and copy-neutral losses of heterozygosity (cnLOH) in 15 cortisol-secreting adrenocortical adenomas with matched blood samples. We focused on microalterations aiming to discover new candidate genes involved in early tumorigenesis and/or autonomous cortisol secretion. We identified 962 CNAs with a median of 18 CNAs per sample. Half of them involved noncoding regions, 89% were less than 100 kb, and 28% were found in at least two samples. The most frequently gained regions were 5p15.33, 6q16.1, 7p22.3-22.2, 8q24.3, 9q34.2-34.3, 11p15.5, 11q11, 12q12, 16q24.3, 20p11.1-20q21.11, and Xq28 (≥20% of cases), most of them being identified in the same three adenomas. These regions contained among others genes like NOTCH1, CYP11B2, HRAS, and IGF2. Recurrent losses were less common and smaller than gains, being mostly localized at 1p, 6q, and 11q. Pathway analysis revealed that Notch signaling was the most frequently altered. We identified 46 recurrent CNAs that each affected a single gene (31 gains and 15 losses), including genes involved in steroidogenesis (CYP11B1) or tumorigenesis (CTNNB1, EPHA7, SGK1, STIL, FHIT). Finally, 20 small cnLOH in four cases affecting 15 known genes were found. Our findings provide the first high-resolution genome-wide view of chromosomal changes in cortisol-secreting adenomas and identify novel candidate genes, such as HRAS, EPHA7, and SGK1. Furthermore, they implicate that the Notch1 signaling pathway might be involved in the molecular pathogenesis of adrenocortical tumors.
authors.affiliation: Unit of Endocrinology, Department of Internal Medicine I, University Hospital of Würzburg, Würzburg, Germany. cry_ronchi@yahoo.it
authors.forename: Cristina L
authors.initials: CL
authors.lastname: Ronchi
authors.forename: Ellen
authors.initials: E
authors.lastname: Leich
authors.forename: Silviu
authors.initials: S
authors.lastname: Sbiera
authors.forename: Dirk
authors.initials: D
authors.lastname: Weismann
authors.forename: Andreas
authors.initials: A
authors.lastname: Rosenwald
authors.forename: Bruno
authors.initials: B
authors.lastname: Allolio
authors.forename: Martin
authors.initials: M
authors.lastname: Fassnacht
mesh_terms: D000306:Adrenal Cortex Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D018246:Adrenocortical Adenoma / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D000328:Adult; D000368:Aged; D002471:Cell Transformation, Neoplastic / Q000235:genetics; D002869:Chromosome Aberrations; D055028:Comparative Genomic Hybridization; D056915:DNA Copy Number Variations; D005260:Female; D052138:Genes, Neoplasm; D006801:Humans; D006854:Hydrocortisone / Q000378:metabolism; D019656:Loss of Heterozygosity; D008297:Male; D008875:Middle Aged; D020411:Oligonucleotide Array Sequence Analysis; D020641:Polymorphism, Single Nucleotide; D015203:Reproducibility of Results; D015398:Signal Transduction; D014158:Transcription, Genetic
chemical_list: D006854:Hydrocortisone