Up-regulated miR-221 expression as a molecular diagnostic marker in laryngeal squamous cell carcinoma and its correlation with Apaf-1 expression

BACKGROUND: Despite the improvement in the diagnosis and the management of laryngeal squamous cell carcinoma (LSCC), many patients with advanced-stage have poor prognosis in the form of recurrence, metastasis or death. So, recognition of new molecular markers would facilitate the development of targeted therapies. OBJECTIVES: To investigate miR-221 expression in LSCC and its possible correlation to apoptotic protease activating factor-1 (Apaf-1). Also, we aimed to investigate the association between miR-221 and Apaf-1 expressions and the clinicopathological features of LSCC. METHODS: We investigated the expression of miR-221 (by qRT-PCR) and Apaf-1 (by qRT-PCR and immunohistochemistry) in primary LSCC and adjacent normal tissues. RESULTS: We found significant up-regulation of miR-221 and significant down-regulation of Apaf-1 expression in LSCC tissues compared to normal nearby laryngeal tissues. In addition, significant associations between up-regulated miR-221 and downregulated Apaf-1 expressions and clinical stage and lymph node (LN) metastasis (P < 0.001 for each) were found. Furthermore, there was a negative correlation between miR-221 gene expression and Apaf-1 gene expression (r = 0.73, P < 0.001). CONCLUSION: miR-221 can be considered as a diagnostic marker in LSCC and Apaf-1 may be considered as a possible target of miR-221.