Hypoxia, metabolism, and growth factor signaling in head and neck squamous cell carcinoma: correlation between primary and xenograft tumors.

Hypoxia, metabolism, and growth factor signaling are important prognostic features in most solid tumors. The purpose of this study was to determine whether head and neck squamous cell carcinoma (HNSCC) xenografts show similar biological and molecular characteristics as the primary tumor they originate from. Eighteen HNSCC primary tumor-xenograft pairs were immunofluorescently stained for pimonidazole (hypoxia), carbonic anhydrase IX (CAIX), glucose transporter-1 (GLUT-1), monocarboxylate transporter-1 (MCT-1), monocarboxylate transporter-4 (MCT-4), epidermal growth factor receptor (EGFR), and phosphorylated protein kinase B (pAKT). Although no correlation was found for the amount of hypoxia, significant correlations between primary tumors and xenografts were observed for both the percentage of cells positive for expression and the hypoxia-related expression pattern of CAIX, GLUT-1, and MCT-1. For EGFR and MCT-4, the intensity of expression was correlated. No correlation was observed for pAKT. Xenografts did not always resemble the primary tumor they originate from, but the xenografts did represent the variability in expression levels and patterns observed in the primary tumors.