Activity and tissue localization of cathepsin D in non small cell lung cancer

Activity and tissue localization of cathepsin D were examined in tumors deriving from 80 patients with non small cell lung cancer. Activity of the enzyme was higher in sediments and supernatants of tumors than in non invaded lung parenchyma. In all histological types of tumors cathepsin D activity in sediments was three times lower and in lung parenchyma five times lower than in supernatants. The immunohistochemical technique was used for enzyme localization. We observed seemingly the lack of correlation between activity of cathepsin D examined in tumors and immunohistochemical reaction intensity in neoplasm cells. Different numbers of macrophages and quantity of tumor stroma could explain this effect in examined histological types of cancer. Results of our explanations indicates for relations between cathepsin D activity versus histological type and degree of tumor differentiation. We did not observe correlation between cathepsin D activity versus lymph node metastases and clinical stages.