Expression of matrix metalloproteinase 9 in nasopharyngeal carcinoma and association with Epstein-Barr virus infection.

Abstract

To evaluate the expression of matrix metalloproteinase-9 (MMP9) in nasopharyngeal carcinoma and the association between MMP9 and Epstein-Barr virus infection. The MMP9 expression was studied by immunohistochemical analysis; and Epstein-Barr virus encoded small nuclear mRNA-1 (EBER-1) produced by in situ hybridization were examined in 41 nasopharyngeal carcinoma sections, and the relation between them, and the associations of MMP9 with clinical features were statistically analyzed. Positive expression rate of MMP9 was 73.17%. The expression of MMP9 showed significant positive correlation with the expression of EBER-1 (gamma=0.483, P=0.001). There was significant association of MMP9 expression with lymph nodes metastasis and clinical stage (P<0.001), non-significant association with age, gender, pathological classification and T classification. The highly pronounced expression of MMP9 is associated with cervical lymph nodes metastasis. Epstein-Barr virus can enhance NPC metastasis by up-regulating the expression of MMP9.