【Objective】 To investigate the mutation of latent membrane protein 1 (LMP1) distal promoter L1-TR in nasopharyngeal carcinoma (NPC) tissue and the influence on promoter activity. 【Methods】 The L1-TR fragments of Epstein-Barr virus (EBV) genome in B95.8 cells and fresh NPC tissue cells were amplified by using polymerase chain reaction (PCR) and the difference between their nucleotides sequence were compared by direct sequencing. The luciferase reporter containing mutant or prototype L1-TR promoter was constructed and transfected into the HaCat

B95.8

and C666-1 cells respectively to compare the transcriptional activity. 【Results】 The nucleotides insertion

deletion and point mutations were found in L1-TR promoter derived from NPC tissue compared with B95.8 prototype

and activity of the mutant L1-TR promoter was reduced markedly (P < 0.05). 【Conclusions】 The activity of the LMP1 promoter in NPC tissue is significantly lower than that of B95.8 prototype L1-TR

which might contribute to the immune evasion mechanism of EBV.