CATHEPSIN-D ACTIVITY LEVELS IN COLORECTAL-CANCER - CORRELATION WITH CATHEPSIN-B AND CATHEPSIN-L AND OTHER BIOLOGICAL AND CLINICAL-PARAMETERS

Cathepsin D, B and L activity levels were determined in colorectal can cer and correlated with a number of biological and clinical parameters . Our studies have evidenced significant higher activity levels of the se lysosomal enzymes in tumor cytosol compared to paired normal mucosa as well as an evident increase of tumor specific cathepsin D activity in Dukes' stage A tumors compared to later stages (B, C and D). Furth ermore, significant higher cathepsin B and L activity levels were obse rved in Dukes' stage A compared to Dukes' stage D tumors while signifi cant higher cathepsin B activity levels were observed in tumors less t han or equal to 5 cm than in those >5 cm as well as in moderately diff erentiated tumors (G2) than in well differentiated (G1) ones. No furth er correlation between tumor specific cathepsin B activity levels and other parameters examined i.e., anatomical site, nodal status, DNA plo idy, and proliferation rate (S-phase fraction) or between tumor specif ic cathepsin D and L and all these parameters were observed. These res ults indicate that cathepsin D, B and L may be involved in colorectal tumor progression by acting, probably, at different levels of this pro cess and suggest that the altered tumor specific activity of these pro teinases may be of interest as independent, prognostic factor of malig nant progression of this neoplastic disease.