Toll-like receptor 2 is present in the microenvironment of oral squamous cell carcinoma.

<bold>Background: </bold>The aim of this study was to investigate the expression of toll-like receptor 2 (TLR2) on cells associated with oral squamous cell carcinoma, epithelial dysplasia and irritative hyperplasia, using immunohistochemistry.<bold>Results: </bold>More immune cells expressed TLR2 in carcinoma and dysplasia than in hyperplasia (P<0.001). No hyperplastic samples showed positive TLR2 staining on keratinocytes, whereas keratinocytes in 64% of cases of carcinoma and 74% of cases of dysplasia were TLR2 positive.<bold>Conclusion: </bold>Positive TLR2 expression in the microenvironment suggests activation of immune surveillance against the altered epithelium, whereas TLR2 expression by malignant keratinocytes may be indicative of resistance to apoptosis as a pro-survival mechanism. [ABSTRACT FROM AUTHOR]