EXPRESSION OF THE SONIC HEDGEHOG PATHWAY IN SQUAMOUS CELL CARCINOMA OF THE SKIN AND THE MUCOSA OF THE HEAD AND NECK

Background. Activation of the hedgehog pathway may contribute to carcinogenesis. This study characterizes the expression pattern in squamous cell carcinoma of the skin and the head and neck. Methods. Tissue microarrays were constructed with samples of squamous cell carcinoma of the skin and the head and neck. All tissue samples were immunohistochemically stained for 7 Hedgehog pathway molecules. Results. Significant (p <.0001) overexpression of all evaluated molecules could be observed in the tumor samples compared with healthy control tissues. Expression of Gli-2 showed significant upregulation and that of Smoothened and Patched significant downregulation in head and neck compared with skin carcinoma. High expression of Sonic hedgehog correlates significantly (p =.001) with poor overall survival in patients with head and neck cancer. Conclusions. Hedgehog signaling is differentially regulated in squamous cell carcinomas of the skin and the head and neck. Sonic hedgehog expression may serve as a prognostic factor in patients with head and neck cancer. (C) 2010 Wiley Periodicals, Inc. Head Neck 33: 244-250, 2011