RESUMEN

Gastrointestinal stromal tumors (GISTs) are mesenchymal tumors characterized by mutations of KIT or PDGFRA. The objectives of this study were to evaluate BRAF mutations in GISTs and then to correlate BRAF mutational status in the tumor with clinical parameters, with B-raf expression, and with activation of some cellular pathways. BRAF mutation was screened in 321 GISTs with 70 wild-type GISTs. BRAF V600E was detected in 9 (13%) of 70 wild-type GISTs. No mutations were detected in GISTs bearing KIT or PDGFRA mutations. BRAF V600E detection in the tumor does not induce a higher expression of the B-raf protein or the preferential activation of the p42/44 mitogen-activated protein kinase (MAPK) signaling pathway compared with GISTs without the BRAF mutation. In comparison with the GIST group with KIT or PDGFRA mutation or the wild-type GIST group without BRAF mutation, the wild-type GIST group with a BRAF mutation is not different in terms of B-raf expression or the p44/42 MAPK- or AKT-activated signaling pathway.

Asunto(s)

Tumores del Estroma Gastrointestinal/genética , Mutación , Proteínas Proto-Oncogénicas B-raf/genética , Adulto , Anciano , Anciano de 80 o más Años , Biomarcadores de Tumor/metabolismo , Western Blotting , Niño , Cromatografía Líquida de Alta Presión , Análisis Mutacional de ADN , ADN de Neoplasias/análisis , Femenino , Tumores del Estroma Gastrointestinal/metabolismo , Tumores del Estroma Gastrointestinal/patología , Regulación Neoplásica de la Expresión Génica , Humanos , Técnicas para Inmunoenzimas , Masculino , Persona de Mediana Edad , Proteína Quinasa 1 Activada por Mitógenos/biosíntesis , Proteína Quinasa 1 Activada por Mitógenos/genética , Desnaturalización de Ácido Nucleico , Proteínas Proto-Oncogénicas B-raf/metabolismo , Transducción de Señal , Adulto Joven