B-raf and Ha-ras mutations in chemically induced mouse liver tumors.

摘要: The mitogen-activated protein kinase signalling pathway is a central regulator of tumor growth, which constitutively activated in chemically induced mouse liver tumors. In about 30–50% cases this effect can be related to activation the Ha-ras gene by point mutations, whereas remaining mutations may occur other members within pathway, such as Raf kinases. Recently, B-raf has been shown frequently mutated human melanomas and certain cancers, with V599E amino-acid change representing most predominant mutation type. We now screened 82 N-nitrosodiethylamine-induced tumors from C3H/He mice for hotspot positions genes. About 50% (39/82) showed codon 61 16 (∼20%) harbored at 624 gene, corresponds 599 B-raf. None was both high prevalence striking contrast hepatocellular cancers very infrequently harbor two These fundamental differences between biology man toxicological relevance.