Elevated concentrations of gamma-enolase in renal cell tumors in rats: similarity to renal cell carcinoma in man.
Concentrations of enolase isozymes in normal kidney and renal cell tumors in rats were determined using a highly sensitive enzyme immunoassay, and the isozymes were immunohistochemically localized in tissue sections. Levels of alpha-enolase in renal cell tumors were significantly lower than in normal kidney, whereas those of gamma-enolase were significantly elevated (mean +/- SD: 211 +/- 129 ng/mg protein, n = 15, as compared to 27.1 +/- 2.9 ng/mg protein, n = 7). The proportion of gamma-enolase in the total enolases in the tumor tissues (1.6 +/- 0.5%) was significantly higher than in normal kidney (0.15 +/- 0.05%). Immunohistochemistry revealed epithelial cells of all nephron segments to be positive for the alpha-isozyme, whereas gamma-enolase staining was strongly positive only in the loops of Henle, being faint in the distal tubules and absent in the proximal tubules. Both alpha- and gamma-enolases demonstrated positive immunostaining in all of the seven renal cell tumors studied. These findings indicate that an isozyme switch from alpha- to gamma-enolase occurs during rat kidney carcinogenesis, taking into account the derivation from proximal tubules, consistent with the findings for renal cell carcinomas in man.
Takashi
M
M
Department of Urology, Nagoya University School of Medicine, Japan.
Sakata
T
T
Inaguma
Y
Y
Kato
K
K
D000818:Animals; D002292:Carcinoma, Renal Cell / Q000201:enzymology*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D007668:Kidney / Q000201:enzymology; D007680:Kidney Neoplasms / Q000201:enzymology*; D009994:Osmolar Concentration; D010751:Phosphopyruvate Hydratase / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012016:Reference Values; D014018:Tissue Distribution
D010751:Phosphopyruvate Hydratase