Differential expression of ezrin in epithelial skin tumors: cytoplasmic ezrin immunoreactivity in squamous cell carcinoma.

Background: Ezrin is a cytoskeleton linker protein that is actively involved in regulating the growth and metastatic capacity of cancer cells. The purpose of the study was to assess the expression pattern of ezrin in normal skin and various epithelial neoplasms.
Methods: We used immunohistochemical techniques to examine the expression of ezrin in paraffin-embedded tissues of squamous cell carcinoma (n = 23), basal cell carcinoma (n = 10), Bowen's disease (n = 10), actinic keratosis (n = 10), keratoacanthoma (n = 9), seborrheic keratosis (n = 5), psoriasis vulgaris (n = 5), and normal control skin (n = 5).
Results: In Bowen's disease, actinic keratosis, keratoacanthoma, and seborrheic keratosis, ezrin was dominantly expressed in the cell membrane except for the cornified layer. In squamous cell carcinoma (SCC) specimens, the percentage of ezrin-positive cells was increased compared with Bowen's disease, actinic keratosis, keratoacanthoma, and seborrheic keratosis. Especially in SCC samples, ezrin expression was markedly expressed in the cytoplasm. In addition, there was a correlation between the pattern of ezrin expression and tumor differentiation in SCC. Basal cell carcinoma showed intense and diffuse staining especially in the solid growth pattern.
Conclusions: Our findings suggest that dysregulation of ezrin may be important in the development of cutaneous epithelial malignancies and tumor grade. We suggest that the cytoplasmic localization of ezrin may be useful in the diagnosis of skin SCC.