%0 Journal Article
%T Concurrent mutation in exons 1 and 2 of the K-ras oncogene in colorectal cancer
%A Raffaele Palmirotta
%A Annalisa Savonarola
%A Giorgia Ludovici
%A Maria Laura De Marchis
%J Folia Histochemica et Cytobiologica
%D 2012
%I Polish Histochemical and Cytochemical Society
%R 10.5603/14737
%X The K-ras gene is frequently mutated in colorectal cancer and has been associated with tumor initiation and progression; approximately 90% of the activating mutations are found in codons 12 and 13 of exon 1 and just under 5% in codon 61 located in exon 2. These mutations determine single aminoacidic substitutions in the GTPase pocket leading to a block of the GTP hydrolytic activity of the K-ras p21 protein, and therefore to its constitutive activation. Point mutations in sites of the K-ras gene, other than codons 12, 13 and 61, and other types of genetic alterations, may occur in a minority of cases, such as in the less frequent cases of double mutations in the K-ras gene. However, all mutations in this gene, even those which occur in non-canonical sites or double mutations, are relevant oncogenic alterations in colorectal cancer and may underlie K-ras pathway hyperactivation. In the present study, we report the case of a patient with colorectal cancer presenting a concurrent point mutation in exons 1 and 2 of the K-ras gene, a GGT to TGT substitution (Glycine to Cysteine) at codon 12, and a GAC to AAC substitution (Aspartic Acid to Asparagine) at codon 57. In addition, we found in the same patient¡¯s sample a silent polymorphism at codon 11 (Ala11Ala) of exon 1. (Folia Histochemica et Cytobiologica 2011; Vol. 49, No. 4, pp. 729¨C733)
%K colorectal cancer
%K K-ras
%K double mutation
%U http://czasopisma.viamedica.pl/fhc/article/view/14737