Extranodal NK/T-cell lymphoma, nasal type (ENKTL) is recognized as a distinct clinical pathological entity of non-Hodgkin’s lymphoma, and develops more frequently in East Asia and Central America than in the West
[1, 2]. ENKTL was previously described as lethal midline granuloma or midline reticulosis, which most commonly invades the nasal cavity and other mucosal sites of the upper aerodigestive tract. Although ENKTL can be diagnosed at early stage, it is characterized by a strongly aggressive lymphoma in advanced stage and resistance to different treatments
. Currently, ENKTL is mainly treated by concurrent chemoradiotherapy
[4–6], but the overall survival is frustratingly poor
. Among the risk factors of ENKTL development, Epstein-Barr virus (EBV) latent infection has been shown to play an important role, and ENKTL is closely associated with EBV infection
EBV is a member of the g-herpes- virus family which approximately infects 90% of the adult population in the world. A variety of molecules are involved in EBV latent infection, including EBV-encoded nuclear antigens (EBNAs); EBNA leader protein (EBNA-LP); latent membrane protein (LMP) 1, LMP2A, and LMP2B; and EBV encoded RNAs (EBERs) EBER1 and EBER2
. Among these, LMP1 is essential for EBV-mediated growth transformation of infected cells, and the C-terminal region of LMP1 protein can regulate a variety of cellular signaling pathways such as TNF receptor, NF-κB and JAK/STAT to regulate the proliferation, immortalization, and invasion of lymphoma cells
[13–15]. Therefore, LMP1 has been suggested to have oncogenic effects in the development and progression of EBV-related lymphomas. On the other hand, LMP2A is one of the most commonly present EBV encoding proteins and is widely expressed in EBV-infected cells within the infected human host and EBV-associated malignancies. LMP2A is the only one membrane protein expressed in the reservoir of circulating, latently EBV-infected resting B-cells
. LMP2A contributes to malignant transformation by intervening with multiple signaling pathways, especially the cell cycle and apoptotic pathways, thus plays important role in viral latency and tumorigenesis
[17, 18]. The ability of LMP2A to influence the balance of survival factors in B lymphocytes could be functionally important in Burkitt lymphoma and LMP2A expression in EBV-infected B cells may lead to the induction and maintenance of an activated, proliferative state that could ultimately result in the development of Hodgkin lymphoma
[19, 20]. However, the correlation between the expression of LMP1 and LMP2A in ENKTL and patient prognosis is poorly understood.
In this study, we examined the expression profiles of LMP1 and LMP2A in ENKTL patients by immunohistochemistry analysis. Moreover, we analyzed the correlation of LMP1 and LMP2A expression with the clinicopathologic features and outcomes of ENKTL. Our results suggest that LMP1 and LMP2A are potential biomarkers for the diagnosis and prognosis of patients with ENKTL.