RESUMO
Los astrocitomas son el grupo de tumores intracraneales más frecuentes. De ellos, el glioblastoma es el más agresivo. En esta revisión nos centramos en describir las anomalías genéticas más frecuentes en astrocitomas. Para ello hacemos referencia a los genes del preceptor del factor de crecimiento epidérmico (EGFR) p53, p16, PTEN y DMBT1. Asimismo presentamos ciertos aspectos genéticos que influyen en la progresión tumoral hacia glioblastomas (AU)
Assuntos
Adulto , Feminino , Masculino , Humanos , Astrocitoma/genética , Neoplasias Encefálicas/genética , Glioblastoma/genética , Progressão da Doença , Biologia Molecular/métodos , Inibidor p16 de Quinase Dependente de Ciclina/genéticaRESUMO
Astrocytomas are the most frequent group of intracranial tumors. Among them, glioblastoma is the most aggressive one. In this review we will describe the most common genetic abnormalities found out in astrocytomas. We will refer to the epidermal growth factor receptor (EGFR), p53, p16, PTEN and DMBT1 genes. We will also present certain genetic aspects that influence the progression to glioblastoma.
RESUMO
Alterations of the short arm of chromosome 1 are recurrently found in cytogenetic analysis of malignant gliomas, and deletions of 1p36-p32 region characterize at least the higher-grade tumors, glioblastoma multiforme. Molecular analysis of tumor-derived and normal genomic DNA from 57 cases of gliomas, using a panel of chromosome 1-specific DNA probes showed LOH in 16 tumors. Allelic losses on 1p were primarily restricted to glioblastoma multiforme (2/11) and to tumors with a major oligodendroglial component: grade II oligodendrogliomas (6/6), grade III anaplastic oligodendrogliomas (5/6) and grade II-III mixed oligo-astrocytomas (2/3). Losses for 1q markers were detected in only 1 tumor (glioblastoma multiforme). Our data suggest that anomalies of 1p primarily characterize oligodendrogliomas, whereas they are rare events in astrocytic tumors and indicate that a tumor-suppressor gene on 1p36-p32 is involved in the development of brain tumors with oligodendroglial differentiation.