Immunohistochemical correlation of matrix metalloproteinase-2 and tissue inhibitors of metalloproteinase-2 in tobacco associated epithelial dysplasia.

AIM: To study the immunohistochemical expression of matrix metalloproteinase and tissue inhibitors of matrix metalloproteinase-2 in different histological grades of tobacco associated epithelial dysplasia and correlate the association between these proteases. Potentially malignant oral disorders (PMODs) progressing to oral cancer are related to the severity of epithelial dysplasia. METHODS: A retrospective immunohistochemical study was carried out on 30 clinically and histologically proven cases of leukoplakia with dysplasia and 10 cases of normal buccal mucosa using anti-MMP-2 and anti-TIMP-2 monoclonal antibodies. RESULTS: Mann Whitney U test, for comparing the expression of both MMP-2 and TIMP-2 in normal mucosa with dysplasia, was highly significant (P < 0.001). Kruskal-Wallis test to compare the median score of MMP-2 and TIMP-2 in different grades of dysplasia showed statistical significance (P < 0.001), and a Spearman's correlation between MMP-2 and TIMP-2 through different grades of dysplasia and cells observed showed positive correlation. CONCLUSION: Concomitant increase in the expression of both MMP-2 and TIMP-2 suggested that the activation of MMP-2 is dependent on TIMP-2 acting as a cofactor. Changes in TIMP-2 levels are considered important because they directly affect the level of MMP-2 activity.

Role of immunomarkers in the clinicopathological analysis of unicystic ameloblastoma.

PURPOSE: The clinical behavior of unicystic ameloblastoma varies according to its subtype. The assessment of its proliferative capacity, neovascularization, and invasiveness using relevant immunomarkers may aid in appropriate surgical therapeutic protocol. METHODS: 18 cases of clinically and histologically confirmed unicystic ameloblastoma, categorized as luminal, intraluminal, or mural subtypes, were analyzed retrospectively. Immunomarkers such as Ki-67, CD34, MMP-2, and MMP-9 were studied to evaluate their behavior. RESULTS: Labeling index of Ki-67 was 4.25% in the intraluminal subtype, compared with 2.14% in the luminal and 4.04% in the mural variant (P = 0.3). CD34 immunostaining was significantly higher in the mural variant (43 per high power field) than the other two subtypes (P = 0.04). MMP-2 and MMP-9 were strongly expressed in mural, moderately in intraluminal, and weakly to absent in luminal variant. CONCLUSIONS: High proliferative index, angiogenesis, and protease activity in the mural ameloblastoma, ascertained by the expression of these markers, confirm its aggressive phenotype. The intraluminal and luminal subtype exhibiting decreased expression are compatible with their indolent clinical behavior.