Mutations of the Ki-ras oncogene in endometrial carcinoma have been reported in Japan, but the prevalence and clinical significance of such mutations in the United States remains unclear. DNA extracted from paraffin sections of 112 carcinomas of the endometrium was amplified by the polymerase chain reaction with mismatched primers that generated a BstNI recognition site with the wild-type codon...

approximately 5-10% of all thyroid cancers are medullary thyroid carcinomas (mtc). mtc is mainly sporadic in nature, but 20-30% of cases are hereditary. genetic testing for hereditary mtc is very important for the patient and his family, but the patients must be receiving appropriate genetic counseling. about 98% of patients with hereditary mtc have germline mutations in exons 10, 11, 13, 14, 1...

PURPOSE Mutations in the ras genes often occur during tumorigenesis. In malignant melanoma, the most common ras alterations are N-ras codon 61 mutations. This study was aimed to measure the frequency of such mutations in a large series of paired primary and metastatic melanomas to determine their role in melanoma initiation and progression. EXPERIMENTAL DESIGN Seventy-four primary melanomas a...

BACKGROUND Accumulation of molecular alterations, including mutations in Kirsten-ras (K-ras), p53, and adenomatous polyposis coli (APC), contribute to colorectal carcinogenesis. Our group has previously characterised a panel of sporadic colorectal adenocarcinomas for mutations in these three genes and has shown that p53 and K-ras mutations rarely occur in the same colorectal tumour. This sugges...

To assess a possible role in tumor progression, the occurrence and type of K- and N-RAS mutations were determined in purified tumor cells, including samples from patients with premalignant monoclonal gammopathy of undetermined significance (MGUS), multiple myeloma (MM), and extramedullary plasma cell (PC) tumors (ExPCTs). Immunophenotypic aberrant PCs were flow sorted from 20 MGUS, 58 MM, and 1...

Laryngeal cancer is a rare type of neoplasia, constituting approximately 2% of all human cancers. Mutations of the ras gene family is one of the main activating mechanisms in human cancer. Their involvement in head and neck cancer has been mainly demonstrated at the level of the overexpression whereas ras mutations in these cancers are rare in the Western world. In the present study we explored...

DNA from bone marrow and peripheral blood samples of 44 chronic myelogenous leukemia (CML) patients were analyzed for the presence of mutations of codons 12, 13 or 61 of the N-ras, H-ras, or K-ras genes. In seven patients, samples were available from both their chronic phase and blast crisis. A total of 29 samples examined were at chronic phase and 22 were at blast crisis (eight lymphoid, eight...

The aim of this study was to compare the ratio of K-ras codon 12 and 13 mutations in various tissues of colorectal cancer patients. Multiple samples of inconspicuous mucosa and a sample of carcinoma tissue were taken from 36 colorectal cancer patients (group I) and these results were compared with those from polyp and carcinoma tissues of another 48 colorectal cancer patients (group II). A poly...

We analyzed 66 non-small cell lung cancer cell lines for mutations at codons 12, 13, and 61 of all three ras genes and correlated the findings with patient survival. We used designed restriction fragment-length polymorphisms to detect mutations after amplification of ras-specific sequences by the polymerase chain reaction. We found 19 mutations of ras genes (29%), and 11 of these 19 (58%) were ...

The ras family consists of three evolutionarily conserved genes, H-ras, N-ras, and K-ras. The ras genes code for 21-kDa proteins that mediate signal transduction between cell surface receptors and intracellular regulatory molecules. The proteins attach to the inner surface of the cytoplasmic membrane via a posttranslationally added farnesyl group. This lipid modification is essential for functi...