EXPRESSION OF MATRIX METALLOPROTEINASES AND TISSUE INHIBITOR OF METALLOPROTEINASES IN HEAD AND NECK SQUAMOUS-CELL CARCINOMA

Matrix metalloproteinases (MMPs) are a family of proteolytic enzymes i mplicated in the invasion and metastasis of many cancers. In situ hybr idization techniques were used to reveal sites of expression of collag enase (MMP-1), gelatinase 72 kd (MMP-2), gelatinase 92kd (MMP-9), and tissue inhibitor of metalloproteinase-1 (TIMP-1) in head and neck carc inomas (N=21). Both TIMP-1 and gelatinase 72 kd were expressed in near ly all tumors, whereas the expression of collagenase and gelatinase 92 kd showed variability. Tumor-associated expression of MMPs was strong est in stromal cells near advancing margins. No differences in express ion levels were detected between primary and metastatic sites. This pa per reviews the literature and discusses the significance and possible implications of MMPs in head and neck squamous cell carcinoma.