Immunoexpression of MMP-9 in Metastasis of Oral Squamous Cell Carcinoma

摘要

Introduction: Oral squamous cell carcinoma (OSCC) is the most common malignancy of the head and the neck. The unfavorable prognosisof OSCC is mainly due to extensive local invasion and frequent spread to the lymph node. Studies have supported that the metastaticpotential of carcinoma might correlate with the degree of enzymatic degradation of basement membrane type IV collagen. MMP-9 afamily member of zinc-dependent endopeptidases causes degradation of type IV collagen and plays a relevant role in tumor invasionand metastasis.Aim and objective: To evaluate the role of MMP-9 in the invasion and metastasis of OSCC and to examine whether high levels of MMP-9expression have any prognostic potential.Materials and methods: MMP-9 expression was examined using the immunohistochemistry procedure in 30 OSCC cases with and withoutlymph node metastasis and in 10 normal controls. One set from each case and control was stained with the hematoxylin and eosin stain. Theexpression of MMP-9 was scored according to staining intensity and staining area. The relationship between MMP-9 expression and nodalmetastasis was determined and statically analyzed.Results: The staining for MMP-9 was observed in the cytoplasm of malignant keratinocytes within all the primary tumors as well as in the excisedlymph nodes. MMP-9 positive expression was seldom found (less than 10% of cells) in the control group.Conclusion: Higher MMP-9 expression in tumor proper and lymph node-positive cancers and overexpression in metastasized malignant cellsindicate that MMP-9 plays an important role in invasion and metastasis of OSCC.