The latent membrane protein 1 (LMP1),which is encoded by the Epstein-Barr virus (EBV) has been suggested to be one of the major oncogenic factors in nasopharyngeal carcinoma (NPC).In previous studies,we experimentally demonstrated that down-regulation of LMP1 expression by targeting EBV-LMP1 DNAzyme (Dzl) could increase the radiosensitivity of NPC.However,how Dzl contributes to the radiosensitivity in NPC is still not clear.In the present study,we confirmed that Dzl decreases LMP1 expression and down-regulates the expression of the catalytic subunit of telomerase (hTERT) both at the protein and mRNA levels (p<0.01),and therefore,consequently inhibitstelomerase activity (p<0.05) in LMPl-positive NPC cells.