Objective: To investigate the expression of matrix metalloproteinase 9 (MMP9) in mucosal natural killer/T cell and mature T cell lymphomas and its relation to Epstein-Barr virus (EBV) infection.
Methods: The expression of MMP9 and EBV-encoded RNA (EBER) were detected by immunohistochemistry and in situ hybridization in 59 cases of mucosal natural killer/T cell and mature T cell lymphomas.
Results: The positivity rates of MMP9 and EBERs were 83.05% and 72.88% respectively. The positivity rate of EBERs was correlated with histopathological subtype (P<0.05), but not with clinical stage, vascular invasion or the patients' survival time (P>0.05). The expression level of MMP9 was not correlated with the clinical stage, vascular invasion or survival time (P>0.05). No significant correlation was found between MMP9 expression and EBV infection.
Conclusion: EBV may play an important role in the development of mucosal natural killer/T cell and mature T cell lymphomas and promote disease progression by up-regulating MMP9 expression indirectly. Elimination of EBV infection may be helpful to prevent the development of lymphoma.