Immunocytochemical localization of C-myc and C-jun oncoproteins in hamster kidney and estrogen-induced kidney tumors.
The chronic administration of 17beta-estradiol to male Syrian hamsters for 6-7 months induces kidney tumors which express high levels of c-fos, c-myc and c-jun mRNA compared to surrounding tissue or untreated controls. In this study, we have investigated, by immunocytochemical methods, the cellular localization of c-myc and c-jun oncoproteins in estrogen-dependent kidney tumors, in kidney tissue of hamsters treated with 17beta-estradiol for 6 months and in the kidneys of age-matched controls. The c-myc oncoprotein was strongly expressed in tumors, in smooth muscle layers of arteries and in parietal epithelial cells of the glomerulus. In age-matched untreated kidneys, there was little or no staining in the glomerulus, arteries or kidney tubular cells. The c-jun oncoprotein was detected in kidney tumors and in the tubular epithelium of surrounding tissue. The immunoreactivity for c-jun oncoprotein was highest in the tumor, intermediate in estrogen-treated kidney tissue and lowest in kidney tubular cells of controls. It is concluded that the high expression of c-myc in estrogen-induced kidney tumors, in the smooth muscle layer of arteries, and in glomerular parietal epithelial cells in the kidneys of 17beta-estradiol-treated hamsters, but poor expression in control kidneys indicate an involvement of this oncoprotein in the tumorigenic process. In contrast, c-jun is expressed in untreated, in 17beta-estradiol-treated kidneys and in tumors, and may not serve as a prognostic marker in the transformation of these cells to the malignant phenotype.
Bhat
H K
HK
Department of Pharmacology, University of Texas Medical Branch, Galveston 77555-1031, U.S.A.
Springer
I
I
Rajaraman
S
S
Liehr
J G
JG
D000818:Animals; D006224:Cricetinae; D004958:Estradiol / Q000494:pharmacology; D004967:Estrogens / Q000494:pharmacology*; D007150:Immunohistochemistry; D007668:Kidney / Q000502:physiology*; D007680:Kidney Neoplasms / Q000139:chemically induced / Q000235:genetics*; D008297:Male; D016755:Proto-Oncogene Proteins c-jun / Q000032:analysis* / Q000187:drug effects / Q000276:immunology; D016271:Proto-Oncogene Proteins c-myc / Q000032:analysis* / Q000187:drug effects / Q000276:immunology
D004967:Estrogens; D016755:Proto-Oncogene Proteins c-jun; D016271:Proto-Oncogene Proteins c-myc; D004958:Estradiol