title: V-val subtype of Epstein-Barr virus nuclear antigen 1 preferentially exists in biopsies of nasopharyngeal carcinoma.
abstract: Epstein-Barr virus (EBV) has been suggested to be involved in pathogenesis of nasopharyngeal carcinoma (NPC). However, EBV infection is ubiquitous, whereas NPC occurs with strong geographic and racial distribution. Whether a substrain of EBV contributes to this phenomenon remains uncertain. Epstein-Barr virus nuclear antigen 1 (EBNA-1) is one of the most frequently detected EBV proteins in NPC tissues. Based on the polymorphism of amino acids at position 487, EBNA-1 is classified into five subtypes: P-ala, P-thr, V-val, V-leu and V-pro. To examine the relationship between subtypes of EBNA-1 and NPC, we determined the subtypes of EBNA-1 in biopsies of NPC, peripheral blood lymphocytes (PBL), and throat washings (TWs) obtained in endemic and non-endemic areas of NPC within China. The results revealed that V-val was the only subtype detected in NPC tissue, whereas three subtypes of EBNA-1, V-val, P-ala, and P-thr, were detected in PBL and TWs irrespective of origin, and mixed infection of V-val and P-ala was also observed. In addition, the variations of V-val derived from biopsies of NPC were identical to those derived from PBL and TWs in the context of N-terminus and C-terminus of EBNA-1. These facts indicate that a substrain of EBV with V-val subtype of EBNA-1 infects NPC preferentially and a susceptibility to a particular EBV isolate in the nasopharynx may exist during development of NPC.
authors.affiliation: Department of Experimental Research, Cancer Center, Sun Yat-sen University, 651 Dongfeng Road East, Guangzhou 510060, People's Republic of China.
authors.forename: Xiao-Shi
authors.initials: XS
authors.lastname: Zhang
authors.forename: Hong-He
authors.initials: HH
authors.lastname: Wang
authors.forename: Li-Fu
authors.initials: LF
authors.lastname: Hu
authors.forename: Ang
authors.initials: A
authors.lastname: Li
authors.forename: Ru-Hua
authors.initials: RH
authors.lastname: Zhang
authors.forename: Hai-Qiang
authors.initials: HQ
authors.lastname: Mai
authors.forename: Jian-Chuan
authors.initials: JC
authors.lastname: Xia
authors.forename: Li-Zheng
authors.initials: LZ
authors.lastname: Chen
authors.forename: Yi-Xin
authors.initials: YX
authors.lastname: Zeng
mesh_terms: D001483:Base Sequence; D001706:Biopsy; D019309:Epstein-Barr Virus Nuclear Antigens / Q000145:classification* / Q000235:genetics; D004854:Herpesvirus 4, Human / Q000235:genetics* / Q000276:immunology; D008214:Lymphocytes / Q000821:virology; D025202:Molecular Diagnostic Techniques; D009303:Nasopharyngeal Neoplasms / Q000821:virology*; D010614:Pharynx; D011110:Polymorphism, Genetic; D007507:Therapeutic Irrigation
chemical_list: D019309:Epstein-Barr Virus Nuclear Antigens; C417029:EBV-encoded nuclear antigen 1