Background and aims: A prominent clinical feature of nasopharyngeal carcinoma (NPC) is its ability to easily invade local tissues and metastasize. In this field, latent membrane protein-1 (LMP-1), which is the principal Epstein-Barr virus-encoded oncoprotein, induces a set of factors that mediates angiogenesis and invasion. Matrix metalloproteinase-1 (MMP-1) and Ets-1 transcription factor are two other major factors that play crucial roles in tumor progression and may thus contribute to invasiveness of NPC cells. The aim of this study was to investigate the prognostic relevance of LMP-1 and its relationship with MMP-1 and Ets-1 expression in NPC biopsies.
Methods: The expressions of LMP-1, MMP-1 and Ets-1 were immunohistochemically examined in 39 undifferentiated NPC specimens from Tunisian patients and the correlation between these proteins and clinicopathological parameters of the disease was statistically determined.
Results: A significant association of LMP-1 expression with high T categories, as well as with the young age onset of NPC, has been found (p = 0.003). The expression of MMP-1 correlated with lymph node metastasis (p = 0.035), whereas a significant association between Ets-1 and high T categories, as well as distant metastasis, has been retrieved (p = 0.008; p = 0.047, respectively). In addition, the expression of LMP-1 showed a significant correlation with the expression of MMP-1 (p = 0.02).
Conclusions: The results of the current study suggest that LMP-1 may contribute to invasion and metastasis of undifferentiated NPCs through the induction of MMP-1.