Expression of MMP-1, TIMP-1, and type I collagen in laryngeal carcinoma

Matrix metalloproteinases (MMPs) are thought to play an important role in tumor invasion and metastasis. To our knowledge, however, no previous report examined the histologic localization of matrix metalloproteinase-1 (MMP-1), tissue inhibitor of metalloproteinase-1 (TIMP-1) and Type I collagen in laryngeal carcinoma from the same samples. In this study, immunohistochemical staining for MMP-1, TIMP-1, and Type I collagen was performed on paraffin-embedded sections from 83 laryngeal squamous cell carcinomas. Twenty of the 83 tumors were examined for MMP-1 and TIMP-1 mRNA using in situ hybridization (ISH). Immunohistochemical and ISH analyses indicated that squamous cancer cells as well as stromal cells such as fibroblasts, macrophages, and mononuclear and endothelial cells expressed MMP-1 and TIMP-1 in the area adjacent to the tumor. The localization of MMP- 1 and TIMP-1 protein is similar to that of their respective transcripts. Dense or moderate patterns of Type I collagen were associated with a tendency toward positivity for TIMP-1 and negativity for MMP-1 (P < .002). A sparse pattern of Type I collagen was associated with a tendency toward positivity for MMP-1 and negativity for TIMP-1 (P < .004). The patterns of Type I collagen staining correlated significantly with imbalances in MMP-1 and TIMP- 1 expression (P < .001). Matrix degradation and remodeling in squamous cell carcinoma of the larynx might be attributable to an imbalance in the expression of MMP-1 and TIMP-1.