OCCURRENCE OF AN ACTIVE FORM OF GELATINASE IN HUMAN GASTRIC AND COLORECTAL-CARCINOMA TISSUES

Profiles of gelatinases released during 4 h incubation of explants from human carcinoma tissues (15 gastric and 15 colorectal carcinomas) in serum-free RPMI 1640 medium were compared with those of corresponding normal tissue specimens obtained 2 and 10 cm apart from tumor periphery. All the culture supernatants of both tumor and normal tissues contained gelatinase species of 200, 130, 92 and 72 kDa as detected by zymography with gelatin as a substrate. Besides these gelatinase species, all carcinoma tissue culture supernatants had an additional 66-kDa gelatinase, an active form of the 72-kDa gelatinase. This gelatinase was not detectable in the normal tissues 10 cm apart from the tumor mass, with an exceptional case of gastric carcinoma of Borrmann type 4. These results suggest that the presence of active form of gelatinase might be one of the characteristic properties of these malignant human tumors.