Association Between Expression of Activated 72-Kilodalton Gelatinase and Tumor Spread in Non-Small-Cell Lung Carcinoma

Background: Matrix metalloproteinases, in particular the 92-kd and 72-kd gelatinases, have been implicated in the progression of breast, colorectal, and gastric carcinomas, but involvement of the gelatinases in progression of non-small-cell lung carcinoma has not been documented. Immunohistochemical studies have measured the overall expression of these enzymes in tumor tissue but have failed to determine the proportion of active enzyme to latentproenzyme. Because the conversion of the latent proenzyme to active enzyme results in removal of a 10-kd amino-terminal domain, the expression of each proteinase can be determined by zymography, which separates substances according to molecular weight