Background. Spleen tyrosine kinase (Syk) is a nonreceptor tyrosine kinase and often aberrantly expressed in human cancers. However, Syk expression pattern has not yet been investigated in nasopharyngeal carcinoma (NPC). Methods. Samples of 223 NPC tissues were immunohistochemically stained for Syk expression and survival analysis was then performed. Interaction and co-localization of Syk with Epstein-Barr virus encoded latent membrane protein 2A (LMP2A) was explored. Results. High expression of Syk was detected in 24% of NPC cases, and correlated significantly with T classification, local recurrence, a lower 5- year survival rate, and a lower 5-year disease-free survival (DFS) rate. Syk expression was a significant, independent prognosis predictor for patients with NPC. LMP2A induced Syk expression in NPC and LMP2A high expression correlated with Syk high expression in NPC clinical samples. Conclusion. High expression of Syk, which results partly from LMP2A expression in NPC, is associated with tumor recurrence and poor prognosis of patients with NPC. V C 2012 Wiley Periodicals, Inc. Head Neck 34: 1456-1464, 2012
