Mutational analysis of the BRAF, RAS and EGFR genes in human adrenocortical carcinomas.
Endocr Relat Cancer
; 16(2): 565-72, 2009 Jun.
Article
em En
| MEDLINE
| ID: mdl-19190079
ABSTRACT
The serine/threonine kinase B-Raf plays a key role in the Ras/Raf/MEK/ERK pathway that relays extracellular signals for cell proliferation and survival. Several types of human malignancies harbor activating BRAF mutations, most frequently a V600E substitution. The epidermal growth factor receptor (EGFR), a transmembrane tyrosine kinase (TK) receptor that mediates proliferation and survival signaling, is expressed in a wide variety of normal and neoplastic tissues. EGFR inhibitors have produced objective responses in patients with non-small cell lung carcinomas harboring activating EGFR TK domain somatic mutations. We evaluated the presence of mutations in BRAF (exons 11 and 15), KRAS (exons 1 and 2), NRAS (exons 1 and 2), and EGFR (exons 18-21) in adrenal carcinomas (35 tumor specimens and two cell lines) by DNA sequencing. BRAF mutations were found in two carcinomas (5.7%). Four carcinomas (11.4%) carried EGFR TK domain mutations. One specimen carried a KRAS mutation, and another carried two NRAS mutations. No mutations were found in the two adrenocortical cell lines. BRAF- and EGFR-mutant tumor specimens exhibited stronger immunostaining for the phosphorylated forms of the MEK and ERK kinases than their wild-type counterparts. EGFR-mutant carcinomas exhibited increased phosphorylation of EGFR (Tyr 992) compared with wild-type carcinomas. We conclude that BRAF, RAS, and EGFR mutations occur in a subset of human adrenocortical carcinomas. Inhibitors of the Ras/Raf/MEK/ERK and EGFR pathways represent candidate targeted therapies for future clinical trials in carefully selected patients with adrenocortical carcinomas harboring respective activating mutations.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Genes ras
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Proteínas Proto-Oncogênicas
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Carcinoma Adrenocortical
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Proteínas ras
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Proteínas Proto-Oncogênicas B-raf
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Receptores ErbB
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Mutação
Tipo de estudo:
Observational_studies
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Risk_factors_studies
Limite:
Adolescent
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Adult
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Aged
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Aged80
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Child
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Female
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Humans
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Male
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Middle aged
Idioma:
En
Ano de publicação:
2009
Tipo de documento:
Article