Loss of an XhoⅠ- site within N- terminal Region of Epstein- Barr Virus LMP1 Gene in Nasopharyngeal Carcinoma
10.3321/j.issn:1000-467X.2003.11.005
- VernacularTitle:鼻咽癌中EB病毒LMP1基因N端XhoⅠ酶切位点的丢失
- Keywords:
Nasopharyngeal neoplasm;
Epstein- Barr virus(EBV);
Latent membrane protein 1(LMP1)gene;
XhoⅠ
- From:Chinese Journal of Cancer
2003;22(11):1147-1151
- CountryChina
- Language:Chinese
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Abstract:
BACKGROUND ＆ OBJECTIVE: It is well known that Epstein- Barr virus(EBV) LMP1 gene is involved in nasopharyngeal carcinogenesis. This research was designed to investigate the loss of an XhoⅠ- site within the N- terminus of Epstein- Barr virus(EBV) latent membrane protein 1(LMP1) gene isolated from nasopharyngeal carcinoma(NPC) in Guangdong for further understanding the sequence variation of LMP1 gene involved in carcinogenesis. METHODS: Sixty- three fresh nasopharyngeal biopsies taken from the patients with nasopharyngeal carcinoma were collected in Cancer Center of Sun Yat- sen University. The peripheral blood mononuclear cells (PBMCs) obtained from 10 healthy EBV carriers were as control. The QIAamp DNA Mini Kits were used for extracting the DNA of biopsies and PBMCs. The N- terminus of EBV LMP1 gene was amplified using nested polymerase chain reaction(PCR) and then followed by XhoⅠ enzyme digestion. Bidirectional solid- phase sequencing of the PCR products was performed using four- colored fluorescence terminator sequencing method. RESULTS: No loss of an XhoⅠ- site within N- terminus of EBV LMP1 gene (wt- XhoⅠ ) was detected in PBMCs of all 10 carriers. The loss of an XhoⅠ- site (XhoⅠ- loss) was demonstrated in 50 cases (50/63, 79.36％ ) and the partial loss was demonstrated in 4 cases (4/63, 6.35％ ). The loss of an XhoⅠ- site was not found in 9 cases (9/63, 14.29％ ). Besides loss of an XhoⅠ- site (nt:169423- 169428; GAGCTC→ GATCTC), 4 additional missense point mutations were found. CONCLUSION: According to the results obtained from this investigation, the PBMCs of 10 EBV carriers residing in Guangdong merely contain EBV variant with wt- XhoⅠ . On the contrary, the EBV variant with XhoⅠ- loss becomes the predominant variant detected in NPC tissues. So, the genomic variation within N- terminus (loss of an XhoⅠ- site and other missense point mutations) of EBV LMP1 gene might be developed in the process of nasopharyngeal carcinogenesis.
