Molecular profiling of tumor progression in head and neck cancer

Objective: To assess gene expression changes associated with tumor progression in patients with squamous cell carcinoma of the oral cavity. Design: A microarray containing 17840 complementary DNA clones was used to measure gene expression changes associated with tumor progression in 9 patients with squamous cell carcinoma of the oral cavity. Samples were taken for analysis from the primary tumor, nodal metastasis, and "normal" mucosa from the patients' oral cavity. Setting: Tertiary care facility. Patients: Nine patients with stage III or stage IV untreated oral cavity squamous cell carcinoma. Results: Our analysis to categorize genes based on their expression patterns has identified 140 genes that consistently increased in expression during progression from normal tissue to invasive tumor and subsequently to metastatic node (in at least 4 of the 9 cases studied). A similar list of 94 genes has been identified that decreased in expression during tumor progression and metastasis. We validated this gene discovery approach by selecting moesin (a member of the ezrin/radixin/ moesin [ERM] family of cytoskeletal proteins) and one of the genes that consistently increased in expression during tumor progression for subsequent immunohistochemical analysis using a head and neck squamous cell carcinoma tissue array. Conclusion: A distinct pattern of gene expression, with progressive up- or down-regulation of expression, is found during the progression from histologically normal tissue to primary carcinoma and to nodal metastasis.