Abstract
We made a study on the localization of manganese superoxide dismutase (Mn SOD) and copper-zinc superoxide dismutase (Cu-Zn SOD) in normal lung tissue and lung cancer by immunohistochemical study and quantitative analysis by enzyme immunoassay. In normal lung tissue, both SODs were localized mainly in the bronchiolar epithelial cells. In lung cancer, both SODs were stained intensely in the cytoplasm of cancer cells. Mn SOD and Cu-Zn SOD were immunohistochemically demonstrated in 87% (40 of 46) and 93% (43 of 46) of cases of lung cancer, respectively. The concentrations of Mn SOD and Cu-Zn SOD in tissue of lung cancer (n=73) were significantly higher than those in normal lung tissue (n=26), regardless of the histological type (p<0.01). The Mn SOD contents in non-small cell lung cancer were significantly higher than those in small cell lung cancer. In the sera (n=62) of patients with lung cancer, neither of the SODs was indicated as a useful tumor marker for lung cancer. This indicates that lung cancer tissues have increased levels of Mn SOD and Cu-Zn SOD.
