lmmunogold analysis of antioxidant enzymes in common renal cancers

Abstract

Immunogold studies of normal human kidney and common human kidney cancers were performed using polyclonal antibodies to antioxidant enzymes, including antibodies to copper, zinc and manganese superoxide dismutases, catalase, glutathione peroxidase, and glutathione S-transferases and their subunits. Normal tissue adjacent to human renal tumors had the same antioxidant enzyme immunoreactive protein profiles as normal human kidney, thus establishing that the presence of tumor does not alter the levels of antioxidant enzyme immunoreactive proteins in adjacent kidney tissue. Levels of immunoreactive protein for antioxidant enzymes were determined in four common types of malignant renal cancer. In general, tumors had low levels of antioxidant enzymes; however, certain histologic types of renal tumors had high levels of immunoreactive protein for glutathione S-transferase subunits, which could affect their susceptibility to chemotherapy. Studies of transitional carcinoma of the renal pelvis were especially informative since it was possible to compare levels of antioxidant enzyme immunoreactive protein with adjacent normal transitional epithelium; the majority of antibodies resulted in lower levels of immunoreactive protein in transitional cell carcinoma than in adjacent normal transitional epithelium. Our results are discussed in relation to the response of renal tumors to therapy.