Roles of KAI1 and nm23 in lymphangiogenesis and lymph metastasis of laryngeal squamous cell carcinoma

BACKGROUND Lymphatic metastasis contributes to the poor prognosis of laryngeal squamous cell carcinoma (LSCC). This study aimed to investigate the roles of two metastasis suppressor genes, KAI1 and nm23, in lymphangiogenesis and lymph metastasis of LSCC. METHODS A total of 45 LSCC patients were enrolled in this study. The positive expression rates of KAI1 and nm23 protein were detected via immunohistochemistry in 45 LSCC and 22 normal laryngeal mucosa adjacent to LSCC. Micro-lymphatic vessel density (MLVD) was detected via immunohistochemistry with the specific antibody D2-40. Associations between KAI1 and nm23 expression and clinical characteristics of LSCC were then evaluated. RESULTS The positive expression rates of KAI1 and nm23 were significantly lower in LSCC than normal laryngeal mucosa (P < 0.05). Significantly lower positive rates of KAI1 and nm23 were found in LSCC with lymphatic metastasis than those without lymphatic metastasis (P < 0.05), whereas MLVD was negatively correlated with the expression of KAI1 and nm23 (P < 0.05). However, no significant associations were found between KAI1 and nm23 expression and clinical characteristics of LSCC (sex, age, disease position, differentiation, and T-stage). CONCLUSIONS Both KAI1 and nm23 can inhibit lymphangiogenesis and lymphatic metastasis in LSCC.