Lack of evidence for mutations or deletions in the CDKN2A/p16 and CDKN2B/p15 genes of Brazilian neuroblastoma patients
Braz. j. med. biol. res
; 37(11): 1683-1687, Nov. 2004. tab
Article
em En
| LILACS
| ID: lil-385883
Biblioteca responsável:
BR1.1
RESUMO
Neuroblastoma, the most common extracranial tumor in childhood, has a wide spectrum of clinical and biological features. The loss of heterozygosity within the 9p21 region has been reported as a prognostic factor. Two tumor suppressor genes located in this region, the CDKN2B/p15 and CDKN2A/p16 (cyclin-dependent kinase inhibitors 2B and 2A, respectively) genes, play a critical role in cell cycle progression and are considered to be targets for tumor inactivation. We analyzed CDKN2B/p15 and CDKN2A/p16 gene alterations in 11 patients, who ranged in age from 4 months to 13 years (male/female ratio was 1.21). The most frequent stage of the tumor was stage IV (50 percent), followed by stages II and III (20 percent) and stage I (10 percent). The samples were submitted to the multiplex PCR technique for homozygous deletion analysis and to single-strand conformation polymorphism and nucleotide sequencing for mutation analysis. All exons of both genes were analyzed, but no deletion was detected. One sample exhibited shift mobility specific for exon 2 in the CDKN2B/p15 gene, not confirmed by DNA sequencing. Homozygous deletions and mutations are not involved in the inactivation mechanism of the CDKN2B/p15 and CDKN2A/p16 genes in neuroblastoma; however, these two abnormalities do not exclude other inactivation pathways. Recent evidence has shown that the expression of these genes is altered in this disease. Therefore, other mechanisms of inactivation, such as methylation of promoter region and unproperly function of proteins, may be considered in order to estimate the real contribution of these genes to neuroblastoma genesis or disease progression.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
LILACS
Assunto principal:
DNA de Neoplasias
/
Deleção de Genes
/
Proteínas de Ciclo Celular
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Inibidor p16 de Quinase Dependente de Ciclina
/
Proteínas Supressoras de Tumor
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Mutação
/
Neuroblastoma
Tipo de estudo:
Prognostic_studies
Limite:
Adolescent
/
Child
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Child, preschool
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Female
/
Humans
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Infant
/
Male
País/Região como assunto:
America do sul
/
Brasil
Idioma:
En
Revista:
Braz. j. med. biol. res
Ano de publicação:
2004
Tipo de documento:
Article