abstract :  reovirus (respiratory enteric orphan virus), a naturally occurring benign human pathogen, has an inherent ability to target transformed and cancerous cells and cause their lysis, while leaving non-transformed cells relatively unaffected.  the efficiency of this innate oncolytic activity of reovirus correlates with expression of the ras oncogene.  cells expressing activated ras and t...

To determine what the role of RAS oncogene is in radiation-induced leukemia, we investigated the frequency of mutations and the sites of the base substitution of activated N- and K-RAS oncogenes in 25 leukemic patients who had been exposed to the atomic bomb and compared the results with those for 47 non-exposed leukemic patients. To detect the presence of mutated RAS oncogene, we used the PCR ...

The induction of tumors with chemicals and the production of transgenic animals are two experimental approaches to study oncogene involvement in carcinogenesis. The combination of both strategies offers an excellent model system to study tumor development. This study analyzes the potential cooperation of N-methylnitrosourea (MNU) treatment and N-ras proto-oncogene overexpression in tumorigenesi...

Human tumor cells containing ras oncogenes display enhanced sensitivity to 1-beta-D-arabinofuranosylcytosine (Ara-C) and other deoxycytidine analogues (H-M. Koo, et al., Cancer Res., 56: 5211-5216, 1996). Human tumor cell lines with or without a ras oncogene as well as a pair of isogenic cell lines with one containing an activated ras oncogene were used to study the basis for differential sensi...

Products of ras genes are putative elements of growth factor signal transduction. However, the mechanism of action of these proteins in normal and malignant growth is as yet obscure. To test for functional consequences of ras oncogene expression, electrophysiological experiments were performed on NIH-3T3 fibroblasts transfected with a transforming Ha-ras MMTV-LTR construct expressing the oncoge...

The ability to detect K-ras oncogene may provide additional information for the management of patients with non-small cell lung cancer (NSCLC). In the present study, we detected the K-ras oncogene in 76 patients with NSCLC by two methods: direct sequencing of K-ras in tumor tissues and membrane array detection of the gene overexpression specific for activated K-ras in peripheral blood. The resu...

Using polymerase chain reaction and sequence-specific oligonucleotide hybridization, the frequency of three ras oncogene mutations (N-ras, Ha-ras, and K-ras) in thyroid tumors (25 adenomas, 16 follicular carcinomas, and 22 papillary carcinomas) was investigated in both iodide-deficient and iodide-sufficient areas. The ras oncogene mutation rate was significantly higher in the iodide-deficient a...

Although it has been more than 20 yr since its discovery, the ras family of genes has not yet lost its impact on basic and clinical oncology. These genes remain central to the field of molecular oncology as tools for investigating carcinogenesis and oncogenic signaling, as powerful biomarkers for the identification of those who have or are at high risk of developing cancer, and as oncogene targ...