Matrix metalloproteinase-2 expression in laryngeal preneoplastic and neoplastic lesions

Matrix metalloproteinase-2 (MMP-2), a member of gelatinases, is particularly important in the digestion of nonfibrillary and denaturated collagens; thus, it may play a role in tissue remodeling and in the invasion of malignant cells. The expression of MMP-2 has not yet been described in preneoplastic lesions of the larynx thus far. The purpose of this study was to evaluate whether the expression of MMP-2 plays a role in early laryngeal carcinogenesis. Laryngectomy specimens of 20 invasive carcinoma cases were studied. The slides with atypical hyperplasia, carcinoma in situ, and invasive carcinoma were selected from laryngectomy specimens. On these slides, 23 atypical hyperplasia and 17 carcinoma in situ areas were identified. MMP-2 expression was scored immunohistochemically on paraffin tissue sections using the avidin-biotin-peroxidase method. MMP-2 expression in all three groups was statistically different. A sequential increase in MMP-2 expression correlated significantly with the hypothesis of multistep carcinogenesis. In contrast, MMP-2 expression was not related to tumor stage, lymph node metastasis, or differentiation in squamous cell carcinomas. In conclusion, this sequential increase in MMP-2 expression points to an altered expression of MMP-2 in early neoplastic transformation in laryngeal mucosa, followed by an increasing expression during the progression of the disease.