Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
2000-6-16
pubmed:abstractText
It has been previously shown that adrenocortical tumors (ACT) in adults exhibit structural abnormalities in tumor DNA in approximately 30% of cases. These abnormalities involve chromosome 11p15 and include loss of heterozygosity, paternal isodisomy, and overexpression of the gene for insulin-like growth factor II (IGF2), correlating with DNA demethylation at this locus. It has been hypothesized that these events occur late in the tumorigenic process in adults and seem to correlate with a worse prognosis. We present 4 pediatric cases of ACT diagnosed at 2.5 yr, 10 months, 12 yr, and 2.2 yr. All 4 patients presented with virilization, and 1 patient also showed signs and symptoms of glucocorticoid excess. The youngest patient's maternal aunt had surgical excision of a more than 15-cm ACT 18 yr previously, but the aunt is doing well at age 23 yr. They all had surgical removal of their tumors. The 2.5-yr-old child also received chemotherapy and radiotherapy because of capsular rupture and, after 3 local recurrences, died 3.3 yr after initial presentation. We investigated all 4 tumors for chromosome 11 structural abnormalities (11p15.5 to 11q23), IGF2 and H19 expression by competitive RT-PCR analysis, and IGF2 methylation patterns by Southern analysis. All 4 tumors (100%) showed a combination of structural abnormalities at the 11p15 locus with mosaic loss of heterozygosity involving 11p. All tumors also had significantly increased IGF2 messenger ribonucleic acid levels relative to normal adrenal (up to 36-fold) and significant IGF2 demethylation (mean, 87%). H19 messenger ribonucleic acid levels were undetectable in 3 of 4 tumors, explained in part by mosaic loss of the actively expressed maternal allele for this imprinted gene. By immunohistochemistry we were able to confirm increased IGF-II peptide levels within the tumor tissue in 10 pediatric patients, including the 4 patients described above. Concomitantly, we also observed nuclear accumulation of p53, suggesting somatic mutations. For the 10-month-old patient, sequencing revealed a p53 germline mutation. We therefore conclude that in pediatric ACT, structural abnormalities of tumor DNA and IGF2 overexpression as well as p53 mutations are very common and are therefore less useful for prognosis than in adults. Our findings support the theory that pediatric ACT, whose IGF2 expression and steroidogenesis evoke the phenotype of the fetal adrenal cortex, may arise because of defective apoptosis.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
AIM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0021-972X
pubmed:author
pubmed:issnType
Print
pubmed:volume
85
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
2048-56
pubmed:dateRevised
2011-10-7
pubmed:meshHeading
pubmed-meshheading:10843195-Adrenal Cortex Neoplasms, pubmed-meshheading:10843195-Adult, pubmed-meshheading:10843195-Child, pubmed-meshheading:10843195-Child, Preschool, pubmed-meshheading:10843195-Chromosome Mapping, pubmed-meshheading:10843195-Chromosomes, Human, Pair 11, pubmed-meshheading:10843195-Female, pubmed-meshheading:10843195-Gene Expression Regulation, Neoplastic, pubmed-meshheading:10843195-Genes, Tumor Suppressor, pubmed-meshheading:10843195-Genomic Imprinting, pubmed-meshheading:10843195-Haplotypes, pubmed-meshheading:10843195-Humans, pubmed-meshheading:10843195-Infant, pubmed-meshheading:10843195-Insulin-Like Growth Factor II, pubmed-meshheading:10843195-Loss of Heterozygosity, pubmed-meshheading:10843195-Male, pubmed-meshheading:10843195-Muscle Proteins, pubmed-meshheading:10843195-Nuclear Family, pubmed-meshheading:10843195-RNA, Untranslated, pubmed-meshheading:10843195-Reverse Transcriptase Polymerase Chain Reaction, pubmed-meshheading:10843195-Virilism
pubmed:year
2000
pubmed:articleTitle
Pediatric adrenocortical tumors: molecular events leading to insulin-like growth factor II gene overexpression.
pubmed:affiliation
Sainte-Justine Hospital Research Center, Department of Pediatrics, Université de Montréal, Québec, Canada.
pubmed:publicationType
Journal Article, Review, Case Reports, Research Support, Non-U.S. Gov't