title: Expression of Ha-ras oncogene product in rat gastrointestinal carcinomas induced by chemical carcinogens.
abstract: The expression of Ha-ras oncogene product in rat gastrointestinal carcinomas induced by N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) or 1, 2-dimethylhydrazine (DMH) was studied by Western blotting and immunohistochemistry using anti-Ha-ras p 21 oncoprotein antibody. In Western blotting, high levels of c-Ha-ras p 21 were found in serially transplantable rat duodenal carcinomas induced by MNNG and rat colon carcinomas induced by DMH. Immunohistochemically, c-Ha-ras p 21 immunoreactivity was detected in 3 (16.7%) of 17 MNNG-induced stomach carcinomas and in 21 (63.6%) of 33 DMH-induced colon carcinomas, respectively. In the colon carcinomas, c-Ha-ras p 21 immunoreactivity in deeply invasive tumors was stronger than that in superficially invasive tumors and was expressed in all subserosal tumors. Moreover, all of the metastatic colon carcinomas had c-Ha-ras p 21 immunoreactive tumor cells. These findings suggest that c-Ha-ras p 21 expression plays an important role in tumor proliferation, invasion and metastasis of DMH-induced colon carcinoma.
mesh_terms: D000230:Adenocarcinoma / Q000139:chemically induced / Q000235:genetics* / Q000473:pathology; D000818:Animals; D003110:Colonic Neoplasms / Q000139:chemically induced / Q000235:genetics* / Q000473:pathology; D004127:Dimethylhydrazines; D008769:Methylnitronitrosoguanidine; D015689:Oncogene Protein p21(ras); D009856:Oncogene Proteins, Viral / Q000032:analysis*; D011519:Proto-Oncogenes; D051381:Rats; D011919:Rats, Inbred Strains; D013274:Stomach Neoplasms / Q000139:chemically induced / Q000235:genetics* / Q000473:pathology
chemical_list: D004127:Dimethylhydrazines; D009856:Oncogene Proteins, Viral; D008769:Methylnitronitrosoguanidine; D015689:Oncogene Protein p21(ras)