Your browser doesn't support javascript.
loading
BACKGROUND: Cutaneous squamous-cell carcinomas and keratoacanthomas are common findings in patients treated with BRAF inhibitors. METHODS: We performed a molecular analysis to identify oncogenic mutations (HRAS, KRAS, NRAS, CDKN2A, and TP53) in the lesions from patients treated with the BRAF inhibitor vemurafenib. An analysis of an independent validation set and functional studies with BRAF inhibitors in the presence of the prevalent RAS mutation was also performed. RESULTS: Among 21 tumor samples, 13 had RAS mutations (12 in HRAS). In a validation set of 14 samples, 8 had RAS mutations (4 in HRAS). Thus, 60% (21 of 35) of the specimens harbored RAS mutations, the most prevalent being HRAS Q61L. Increased proliferation of HRAS Q61L-mutant cell lines exposed to vemurafenib was associated with mitogen-activated protein kinase (MAPK)-pathway signaling and activation of ERK-mediated transcription. In a mouse model of HRAS Q61L-mediated skin carcinogenesis, the vemurafenib analogue PLX4720 was not an initiator or a promoter of carcinogenesis but accelerated growth of the lesions harboring HRAS mutations, and this growth was blocked by concomitant treatment with a MEK inhibitor. CONCLUSIONS: Mutations in RAS, particularly HRAS, are frequent in cutaneous squamous-cell carcinomas and keratoacanthomas that develop in patients treated with vemurafenib. The molecular mechanism is consistent with the paradoxical activation of MAPK signaling and leads to accelerated growth of these lesions. (Funded by Hoffmann-La Roche and others; ClinicalTrials.gov numbers, NCT00405587, NCT00949702, NCT01001299, and NCT01006980.).
Asunto(s)

Texto completo: 1 Colección: 01-internacional Base de datos: MEDLINE Asunto principal: Neoplasias Cutáneas / Sulfonamidas / Carcinoma de Células Escamosas / Genes ras / Proteínas Proto-Oncogénicas B-raf / Inhibidores de Proteínas Quinasas / Indoles / Mutación Tipo de estudio: Prognostic_studies Límite: Aged / Aged80 / Animals / Female / Humans / Male / Middle aged Idioma: En Revista: N Engl J Med Año: 2012 Tipo del documento: Article País de afiliación: Estados Unidos Pais de publicación: Estados Unidos

Texto completo: 1 Colección: 01-internacional Base de datos: MEDLINE Asunto principal: Neoplasias Cutáneas / Sulfonamidas / Carcinoma de Células Escamosas / Genes ras / Proteínas Proto-Oncogénicas B-raf / Inhibidores de Proteínas Quinasas / Indoles / Mutación Tipo de estudio: Prognostic_studies Límite: Aged / Aged80 / Animals / Female / Humans / Male / Middle aged Idioma: En Revista: N Engl J Med Año: 2012 Tipo del documento: Article País de afiliación: Estados Unidos Pais de publicación: Estados Unidos