Correlation between expression of extracellular matrix metalloproteinase inducer and matrix metalloproteinase-2 and cervical lymph node metastasis of nasopharyngeal carcinoma.

OBJECTIVES: We evaluated the expression of extracellular matrix metalloproteinase inducer (EMMPRIN) and matrix metalloproteinase-2 (MMP-2) in nasopharyngeal carcinoma (NPC) and studied their relationship with cervical lymph node metastasis. METHODS: Immunohistochemical staining was used to detect the expression of EMMPRIN and MMP-2 in specimens from patients with chronic nasopharyngitis (CN), nonmetastastic NPC (NM-NPC), and lymph node-metastatic NPC (LNM-NPC). RESULTS: The rates of positive EMMPRIN expression in CN, NM-NPC, and LNM-NPC were 13.3%, 30.0%, and 66.7%, respectively. Significant differences were found between the rates in CN and LNM-NPC (p <0.01) and between the rates in NM-NPC and LNM-NPC (p = 0.01). In the LNM-NPC group, NPC cells had a higher rate of expression of EMMPRIN in tumor metastases than in the primary tumor (81.8% versus 66.7%; p = 0.01). The rates of positive MMP-2 expression in CN, NM-NPC, and LNM-NPC were 13.3%, 35.0%, and 60.6%, respectively. A significant difference was found between the rates in CN and LNM-NPC (p < 0.01). In the LNM-NPC group, NPC cells had a higher rate of MMP-2 expression in tumor metastases than in the primary tumor (72.7% versus 60.6%; p <0.01). The expressions of MMP-2 and EMMPRIN were highly correlated (rs = 0.466; p <0.01). CONCLUSIONS: Nasopharyngeal carcinoma cells may attain enhanced metastastic capability through the expression of MMP-2 induced by EMMPRIN.