Atividade gelatinolítica in situ e imuno-expressão das metaloproteinases 2 e 9 em lesões potencialmente malignas e carcinomas espinocelulares bucais / In situ gelatinolytic activity and immunoexpression of metalloproteinases 2 and 9 in oral potentially malignant lesions and squamous cell carcinomas

AUTOR(ES)
FONTE

IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia

DATA DE PUBLICAÇÃO

28/02/2012

RESUMO

The transition from normal oral mucosa to invasive carcinoma has a complex and multifactorial etiology. Oral leukoplakia (OL) is regarded as the most prevalent potentially malignant oral lesion, with a higher tendency for malignant transformation if compared to normal oral mucosa. Although an increased activity of matrix metalloproteinases (MMPs) 2 and 9 in oral mucosa presenting varying degrees of epithelial dysplasia and oral squamous cell carcinomas (OSCCs) has been suggested, but further investigation is necessary for confirming such association. Therefore, the aim of this research is to evaluate the immunohistochemical expression and the total in situ gelatinolytic activity of MMP-2 and MMP-9 in OL and OSCC, as well as to evaluate the integrity of the basal lamina through the expression of collagen IV, correlating the results obtained with clinical and pathological features. Immunohistochemical, immunofluorescent and in situ zymography reactions were carried out in 5 normal oral epithelium, 12 cases presenting hyperkeratosis and acanthosis with no epithelial dysplasia, 8 mild/moderate epithelial dysplasia, 8 severe epithelial dysplasia, 10 well differentiated and 4 poorly differentiated OSCC s. It was found that MMP-2 expression was higher in oral epithelium devoid of dysplasia, if compared to dysplastic and neoplastic oral epitheliums. In addition, despite both MMPs were expressed in the stroma of severe epithelial dysplasia and OSCC s samples, MMP-9 expression revealed to be more pronounced, especially in poorly differentiated OSCCs. in situ gelatinolytic activity was higher in normal epithelium and those presenting only hyperkeratosis and acanthosis, co-localizing only with MMP-2. All cases of OSCC and 63% of lesions with severe epithelial dysplasia showed discontinuity of the basal lamina, revealing co-localization of MMPs with in situ gelatinolytic activity in regions with continuous and discontinuous basal lamina. Taken together, the results obtained revealed that a low gelatinolytic activity in the parenchyma of dysplastic lesions and OSCC correlated with disruption of the basal lamina and with an increased expression of MMPs in the stroma, suggesting that MMP s expressed in the stroma of the lesions would be more related with tumor progression than MMP s expressed in the lesional parenchyma.

ASSUNTO(S)

leucoplasia zimografia imunoistoquímica imunofluorescência leucoplaklia zymography immunohistochemistry immunofluorescence antibody technique

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