Elevated serum levels of transforming growth factor β1 in Epstein‐Barr virus‐associated nasopharyngeal carcinoma patients

Abstract

Nasopharyngeal carcinomas (NPCs) of non-keratinizing type are strongly associated with Epstein-Barr virus (EBV). EBV and its gene products induce the synthesis and/or release of transforming growth factor β1 (TGF-β1) from human cells and platelets. TGF-β1 is an immunosuppressive cytokine, and many tumors are known to secrete it, to counter the host immune response. To determine the potential role of this cytokine in the pathogenesis of NPC, 53 serum samples from patients with EBV-associated NPC and 20 from healthy donors were analyzed for total and active TGF-β content using ELISA. Serum samples for TGF-β content were also analyzed from NPC patients at different clinical stages of the tumors. Significantly higher (p < 0.01) levels of active and total TGF-β were found in the sera of NPC patients than in control sera. The ratio of active:total TGF-β was also significantly (p < 0.01) increased in the NPC sera. Levels of this cytokine were also significantly higher (p < 0.05) in the sera of patients with advanced stages of tumor compared to patients with earlier stages. Furthermore, higher levels were seen in patients with relapsing than with remitting tumors; even higher levels were observed in NPC patients who died of the tumor. Our data suggest a role of this cytokine in the pathogenesis of NPC; therefore, it may prove to be a valuable biomarker molecule for the diagnosis and prognosis of NPC. Int. J. Cancer (Pred. Oncol.) 84:396–399, 1999. © 1999 Wiley-Liss, Inc.