PRODUCTION OF MATRIX METALLOPROTEINASE-2 (GELATINASE TYPE-IV COLLAGENASE) AND 3 (STROMELYSIN) BY CULTURED ORAL SQUAMOUS-CELL CARCINOMA

Matrix metalloproteinases (MMPs) are believed to play an important role in tumor invasion and metastasis. MMPs have been identified as proforms of malignant tumor-associated enzymes, such as procollagenase (proMMP-1) of M(r) = 53,000, progelatinase (proMMP-2) of M(r) = 72,000, proMMP-9 of M(r) = 92,000, and prostromelysin (proMMP-3) of M(r) = 59,000. Here we report that two cell lines of squamous cell carcinoma (SCC9 and SCC25) produce at least two matrix metalloproteinases (MMPs) in zymogen form, which have been identified as proMMP-2 and 3 by indirect immunofluorescence technique, immunoblot analysis, and gelatin-substrate gel enzymography. Additionally, a 92-kDa gelatinolytic metalloproteinase (proMMP-9) was detected by gelatin-substrate gel enzymography. We propose that the ability of these tumor cells to secrete MMPs plays an important role in the malignant behavior of oral squamous cell carcinomas.