13 research outputs found
An immunohistochemical analysis of antioxidant and glutathione S-transferase enzyme levels in normal and neoplastic human lung
Samples of normal human lung and six major
types of human lung carcinomas were immunostained
for antioxidant enzymes (manganese and copper, zinc
superoxide dismutases, catalase, and glutathione
peroxidase) and six isoenzymes of glutathione Stransferase
staining was generally low in tumor cells
compared with the high level of staining noted in
respiratory epithelium. A notable exception was
heterogeneity in immunostaining for manganese
superoxide dismutase in lung adenocarcinoma, which
showed both positive and negative cells in the same
tumor. Tumor stromal cells (fibroblast-appearing cells)
often showed strong immunostaining for manganese
superoxide dismutase, while stromal cells were negative
for other antioxidant and glutathione S-transferase
enzymes. None of the carcinomas studied had significant
levels of catalase or glutathione peroxidase; this finding
has potential clinical relevance since it indicates that
these tumors cannot detoxify hydrogen peroxide. The
low levels of antioxidant and glutathione S-transferase
enzymes in tumor cells is consistent with the hypothesis
that these enzymes are markers of cell differentiation