42 P - Activity of cathepsin D in non small cell lung cancer

Abstract

The aim of the present study was to evaluate the cathepsin D activity in NSCLC depending to the morphologic pattern and stage of the disease. The material for examinations was obtained intraoperative from patients with lung carcinoma (35 men and 4 women, aged between 40-70 years). The activity of cathepsin D was assayed in supernatants and sediments of tissues homogenates obtained by the centrifuge, using the denaturated hemoglobin. The enzyme activity was evaluated On the ground of the amount of liberated tyrosine assayed by the method of Folin and Ciocalteau. The protein level was determind by the method of Lowry. The activity of cathepsin D in supernantants and sediments of neoplastic tumors as well as of lung tissue surrounding a tumor was significantly higher than the enzyme activity in nonmalignant lung diseases (tuberculoma, emphysema)/p<0.051/. The supernatant of lung cancer reveals the activity of cathepsin D: 102.35±23.2Tyr nM/g protein for macrocellular carcinoma, 74.3±14.3Tyr nM/g protein for planoepithelial carcinoma, 65.43±38.8Tyr nM/g protein for adenocarcinoma. The sediment of lung cancer reveals the activity of cathepsin D : 38.86±15.8 Tyr nM/g protein for macrocellular carcinoma, 33.3±10.6 Tyr nM/g protein for adenocarcinoma and 20.76±9.8 Tyr nM/g protein for planoepithelial carcinoma. Increasing activity of the enzyme was not depend on the stage of the disease. The study suggests that activity of cathepsin D in lung cancer tissue depend on the degree of tumor differentiation.