Abstract
PURPOSE: To validate the association of phosphorylated (p)AKT with lymph node metastasis in an independent, homogeneous cohort of patients with larynx cancer. METHODS AND MATERIALS: Seventy-eight patients with laryngeal cancer were included. Epidermal growth factor receptor, pAKT, vimentin, E-cadherin, hypoxia, and blood vessels were visualized in biopsy material using immunohistochemistry. Positive tumor areas and spatial relationships between markers were assessed by automated image analysis. In 6 laryngeal cancer cell lines, E-cadherin and vimentin messenger RNA was quantified by real-time polymerase chain reaction and by immunohistochemistry before and after treatment with the pAKT inhibitor MK-2206. RESULTS: A significant correlation was found between low pAKT in the primary tumor and positive lymph node status (P=.0005). Tumors with lymph node metastases had an approximately 10-fold lower median pAKT value compared with tumors without lymph node metastases, albeit with large intertumor variations, validating our previous results. After inhibition of pAKT in laryngeal cancer cells with MK-2206, up-regulation of vimentin and a downregulation of E-cadherin occurred, consistent with epithelial-mesenchymal transition. CONCLUSION: Low pAKT expression in larynx tumors is associated with lymph node metastases. Further, inhibition of pAKT in laryngeal cancer induces epithelial-mesenchymal transition, predisposing for an increased metastatic risk.
