RESUMO

Craniopharyngioma is the most common childhood tumor and thought to arise from embryonic remnants of Rathke's pouch. The paucity of published data on the molecular basis of these tumors prompted us to examine 22 adamantinomatous craniopharyngiomas looking for genetic abnormalities. Using the X-linked polymorphic androgen receptor gene as a tool for X-chromosome inactivating analysis, we found that a subset of craniopharyngiomas are monoclonal and therefore are probably due to acquired somatic genetic defects. Thus, we investigated these tumours for mutations within three candidate genes, Gsalpha, Gi2alpha and patched (PTCH). Using single stranded conformational polymorphism (SSCP), denaturing gradient gel electrophoresis and direct sequencing, the presence of somatic mutations in these genes could not be demonstrated in any tumor. Our data indicate that a subset of craniopharyngiomas are monoclonal and the mutations in the PTCH, Gsalpha, and Gi2alpha contribute little if any to craniopharyngioma development.

Assuntos

Adenoma/genética , Neoplasias Encefálicas/genética , Craniofaringioma/genética , Subunidades alfa Gi-Go de Proteínas de Ligação ao GTP/genética , Subunidades alfa Gs de Proteínas de Ligação ao GTP/genética , Proteínas Proto-Oncogênicas/genética , Adenoma/patologia , Anticorpos Monoclonais , Neoplasias Encefálicas/patologia , Craniofaringioma/patologia , Primers do DNA , Éxons/genética , Subunidade alfa Gi2 de Proteína de Ligação ao GTP , Humanos , Mutação/genética , Polimorfismo Conformacional de Fita Simples , Desnaturação Proteica , Reação em Cadeia da Polimerase Via Transcriptase Reversa