Immunohistochemical Expression of MMP-9, TIMP-1, and Vimentin and its Correlation With Inflammatory Reaction and Clinical Parameters in Oral Epithelial Dysplasia.

The aim of this study was to investigate the immunoexpression of matrix metalloproteinase 9 (MMP-9), tissue inhibitor of metalloproteinase 1 (TIMP-1), and vimentin (VIM) and its association with the inflammatory reaction (IR) and clinical parameters in oral epithelial dysplasia (ED). The sample was composed of 66 cases of ED, 27 oral squamous cell carcinoma (OSCC), and 28 non-neoplastic epithelium (NNE). ED was graded according to the binary system as low-risk ED (n=42) and high-risk epithelial dysplasia (HRED: n=24). The IR was defined as the median number of inflammatory cells present on the connective tissue in 5 consecutive fields. Tissue sections of paraffin-embedded samples were immunohistochemically stained; MMP-9 and TIMP-1 expression was analyzed separately in the epithelium and the connective tissue; VIM was analyzed in the epithelium. Clinical parameters such as age, sex, lesion site and clinical presentation, alcohol/tobacco use, and malignant transformation of ED were retrospectively obtained from medical records. Nonhomogeneous leukoplakia presented higher odds (3.857; 95% confidence interval: 1.16-12.85) of being graded as HRED than did homogeneous lesions. The IR was higher in OSCC and ED than in NNE, and correlated with the epithelial expression of VIM. HRED and nonhomogeneous leukoplakias presented higher IR than did low-risk ED and homogeneous leukoplakias. Alcohol users had higher IR than nonalcohol users. Smokers had higher epithelial expression of MMP-9 and VIM. High IR in OSCC and HRED, and its positive correlation with VIM expression suggest a contribution of the IR in the progression of OSCC. Moreover, the high expression of MMP-9 and VIM in smokers implies its involvement in tobacco carcinogenesis.