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.