Immunohistochemical Study of GLI-1 Expression in the Basal Cell Carcinoma of Sun-Exposed and Non-Exposed Areas

Seo, Young Ju; Kim, Chul Woo; Kim, Kwang Ho; Kim, Kwang Joong; Park, Hye Rim; Kim, Yong Sun

Abstract

BACKGROUND
Basal cell carcinoma (BCC) is the most prevalent cancer in the western world, showing a rapid increase in incidence. Activation of the Sonic hedgehog/Patched (PTCH) and is sisnalling pathway, due to PTCH inactivation, is a key event in sporadic and familial BCC development in humans and is associated with transcriptional activation of specific target genes, including GLI-1. Recently, PTCH inactivation by UV-specific mutation has been reported to develop BCC. OBJECTIVE: To evaluate the expression pattern of GLI-1 oncogene in BCC of sun-exposed and non-exposed areas of skin. METHOD: We examined 20 cases of BCC, and 4 cases of BCC occurring in sun-exposed and non-exposed areas, using an immunohistochemical method with paraffin-embedded sections. RESULTS: The results were as follows. 1. All cases of BCC showed a positive staining for GLI-1 protein. 2. In the staining pattern of GLI-1 protein, BCC in both sun-exposed and non-exposed areas showed diffuse staining throughout the tumor lobules. Moreover, the degree of staining was not found to be different between the BCC of sun-exposed and non-exposed areas. CONCLUSION: These results suggest that increased GLI-1 expression is important for BCC development. And multiple factors, including PTCH mutation due to UV irradiation, may affect GLI-1 expression.