Previous molecular genetics studies of colorectal cancer have identified multiple mutations in the c-K-ras gene (also known as KRAS2) in all phases of its development.
Point mutations in codon 12, 13, and 61 of the K-ras gene are an early event in tumorigenesis of colorectal cancer, but the impact of number, type, and position of such mutations on the progression of adenomas as well as the clinical behaviour of colorectal carcinomas is not clearly established.
Point mutations in codons 12, 13, and 61 of the K-ras gene occur early in the development of colorectal cancer and are preserved throughout the course of tumor progression.
Mutations in the K-ras gene detected in the plasma of 64 (28%) of 232 patients were statistically significantly associated with colorectal cancer risk factors (P =.0002).
Detection of tumor cells in blood using CD45 magnetic cell separation followed by nested mutant allele-specific amplification of p53 and K-ras genes in patients with colorectal cancer.
A recombinant adenovirus vector expressing an antisense or sense K-ras gene fragment (AxCA-AS-K-ras or AxCA-S-K-ras) was first transduced into seven human colorectal cancer cell lines.
Codon 12 K-RAS mutations were examined in DNA extracted from the serum of 35 patients with colorectal cancer and were compared with the K-RAS status in the corresponding primary tumor.
Determination of microsatellite instability, p53 and K-RAS mutations in hepatic metastases from patients with colorectal cancer: relationship with response to 5-fluorouracil and survival.
Although no statistically significant correlation was observed between the disease progression, histopathologic findings, gender and age, we suppose that assessment of K-RAS gene mutations might be of clinical value in the prognosis of colorectal cancer.
We investigated the role of p14 in colorectal cancer by determining its methylation status in cancers that were studied previously for microsatellite instability, CIMP, and mutations of p53 and K-RAS.
It has been assumed that mutations in the K-ras gene induce gastrin gene expression and that gastrin stimulates the growth of colorectal cancer in an autocrine fashion by coexpressing gastrin and cholecystokinin (CCK)2 receptors.
Our results suggest that GSTT1 and GSTP1 could play a role in the occurrence of KRAS2 and TP53 mutations in colorectal cancer and generate a hypothesis on the dietary factors that could be incriminated.
Collectively, our results provide support for the idea that activation of the MAP kinase pathway, especially via BRAF and KRAS mutations, is of critical importance for the development of colorectal cancer.