Analysis of Epstein-Barr Virus LMP1 Gene Deletion in Patients of Nasopharyngeal Carcinoma in Northern Part of China
Nasopharyngeal carcinoma (NPC)incidence occurs with a striking geographic difference and is endemic in southern part of ChinaThe LMP1 gene encoded by EpsteinBarr virus(EBV)is a typical oncogene due to its ability to transform rodent fibroblasts and B lymphocytesIt was originally shown that the LMP1 gene from NPC harbours a nucleotide deletion of 30bp in C terminusHowever,this deletion is also present in EBV in healthy people in the NPC endemic areasFor studying the LMP1 gene C terminus deletion of NPC patients in northern China and the carcinogenic effect on NPC,we collected paraffin embedded tissues of 22 NPC cases and peripheral blood of 26 nonNPC cases from northern ChinaThe LMP1 gene C terminus sequence was amplified by PCR,and the sequence with deleted LMP1 was cloned and sequencedThe results showed that the region covering delLMP1 was amplified successfully from 19 of 22 NPC cases(86%)and the LMP1 deletion was found in 8 of 19 cases(42%)The LMP1 was amplified successfully from 24 of 26 nonNPC cases(9231%)and none of LMP1 deletion was foundSequencing was performed on 4 LMP1 gene C terminus deleted cases,they showed the presence of the 30bp deletionSequence analysis revealed that the EBV LMP1 gene C terminus deleted in NPC and nonNPC patients in northern China was obviously different from that in southern prevalent areas like Guangdong and Guangxi Provinces