Role of Integrins in the Carcinogenesis of Squamous Cell Carcinoma of the Tongue and Lower Lip

Abstract

This study analyzed the distribution, intensity, and pattern of immunohistochemical expression of α2β1, α3β1, and α5β1 integrins in squamous cell carcinoma (SCC) of the lower lip and tongue to identify biomarkers that reflect the clinical course of this cancer. Immunoexpression was compared considering prognostic parameters such as anatomic site, metastasis, and histologic grade of malignancy. Immunohistochemical analysis at the invasion front showed a predominance of granular cytoplasmic expression of the integrins studied. In most cases, immunopositive cells were diffusely distributed in the tumors, irrespective of their location, except for α3β1 integrin-positive cells which were focally distributed in 53.3% of tongue SCC cases. With respect to staining intensity, positive staining for α2β1 integrin was observed in 80% of lower lip SCCs and in 93.3% of tongue SCCs. Staining for α3β1 integrin was moderately positive in 60% of lower lip and tongue SCCs. The staining intensity of α5β1 integrin was moderately and strongly positive in 53.3% and 46.7% of lower lip SCCs, respectively, and in 46.7% and 53.3% of tongue SCCs. The strong immunoreactivity for integrins α2β1, α3β1, and α5β1 seen in the oral SCC cases studied suggests a significant participation of these proteins in oral carcinogenesis. However, their expression does not reflect the clinical course of this cancer.