Background & objective: Epstein-Barr virus (EBV) is associated with genesis of many human tumors, including non-Hodgkin's lymphoma (NHL). Latent membrane protein 1 (LMP1) gene is considered as an oncogene of EBV. Recent researches have suggested that LMP1 polymorphisms, especially C-terminal 30bp-deletion (del-LMP1), might be associated with carcinogenicity of EBV, and play important roles in tumorigenesis. This study was to detect expression of del-LMP1 gene in NHL patients and healthy people, and explore relationship of del-LMP1 gene to tumorigenesis and prognosis of NHL.
Methods: LMPl gene segments (including the 30 bp deletion) in 48 NHL patients and 60 healthy people were amplified by polymerase chain reaction (PCR) with sequence-specific primers. PCR products were randomly chosen,and sequenced to confirm their specificities and to detect other mutations of LMP1 gene. The distributions of del-LMPl in NHL patients and healthy people were compared. Relationship of del-LMP1 gene to prognosis of NHL was analyzed.
Results: (1) LMP1 gene was detected in 23 of 48 NHL patients, 18 of 23 (78%) harbored del-LMPl; LMP1 gene was detected in 32 of 60 healthy people, 13 of 32 (41%) harbored del-LMPl. Positive rate of del-LMPl gene in NHL patients was significantly higher than that in healthy people (P < 0.05). (2) Among 23 EBV-related NHL patients, 15 belonged to high risk group (IPI>/=3), and del-LMPl was detected in 14 of them (93%); 8 belonged to low risk group (IPI<3), and del-LMPl was detected in 4 of them (50%). Positive rate of del-LMP1 in IPI>/=3 group was significantly higher than that in IPI < 3 group (P<0.05). (3)Sequencing confirmed that the 30 bp-deletion located at 168 285-168 256 nt (355-346 aa), and most C-terminal mutations located at 168 357-168 225 nt.
Conclusion: Del-LMPl gene exists commonly in EBV-related NHL, and might correlate with prognosis of NHL.