Expression of the extracellular matrix protein tenascin in laryngeal epithelial lesions: correlation with fibronectin, CD44, cathepsin D and proliferation indices.

Tenascin (TN) is an extracellular matrix glycoprotein expressed in areas of epithelial-mesenchymal interactions during embryogenesis and in neoplasia. We studied the expression of TN in a series of 35 squamous cell invasive carcinomas of the larynx, 13 in situ carcinomas, 41 cases of dysplasia, 10 papillomas and 18 cases of keratosis using the monoclonal antibody TN2 on paraffin-embedded tissue. TN expression was correlated with the expression of fibronectin, CD44 and cathepsin D (CD) proteins, with the proliferation indices Ki-67 and proliferating cell nuclear antigen (PCNA) as well as with conventional clinicopathological variables. Malignant tumours showed a significantly greater stromal TN staining than benign lesions. In invasive carcinomas, the immunoreactivity was statistically higher than that in situ (P=0.01), dysplastic lesions (P<0.0001), papillomas (P=0.004) and keratosis (P<0.0001). A statistically significant difference of TN expression between in situ and dysplastic lesions was observed (P=0.001). In invasive lesions, TN expression was statistically correlated with CD44 expression (P=0.02) and a trend for correlation with CD of tumour cells and fibronectin expression was found (P=0.06 and P=0.09, respectively). The relationship of TN expression with the histological grade and the proliferative activity was insignificant. In conclusion, stromal TN expression may be involved in the complex mechanism of development of laryngeal lesions and may help to predict the risk of progression of pre-cancerous lesions to cancer. [ABSTRACT FROM AUTHOR]