EB病毒基因BARF1在鼻咽癌中的表达及其意义

目的 EB病毒与鼻咽癌(特别是低分化鳞癌)密切相关。BARF1基因是EBV裂解期中的早期基因，本研究通过检测BARF1基因在鼻咽癌组织中的表达，希望能进一步揭示EB病毒与鼻咽癌的关系及致癌的可能机制。方法 对经病理确诊的47例鼻咽低分化鳞癌病人分别取癌组织、癌旁组织及相对正常鼻咽黏膜和13例其他头颈部恶性肿瘤癌组织及8例正常人鼻咽黏膜组织(均证实有EB病毒潜伏感染)，采用巢式-PCR技术检测BARF1在这些组织中的表达情况。结果 鼻咽癌组织BARF1基因表达率为91．5％(43／47)，其中39例相对强表达，4例弱表达；癌旁组织BARF1基因表达率为46．8％(22／47)，其中儿例相对强表达，儿例弱表达；相对正常黏膜BARF1基因表达率为6．4％(3／47)，3例均为弱表达；携带EB病毒的其他头颈部恶性肿瘤组织、正常人鼻咽黏膜组织均未检测到：BARY1基因表达。结论 从相对正常鼻咽黏膜到癌旁组织再到鼻咽癌组织BARF1基因的表达趋势为从不表达到表达，从弱表达到强表达。说明EB病毒与鼻咽癌的发生确实存在密切相关性；提示启动BARF1基因的表达有可能是EB病毒致鼻咽癌的重要条件之一。

Epstein-barr virus gene BARF1 expression and its role in nasopharyngeal carcinoma

Objective Epstein-Barr virus (EBV) is highly related to Nasopharyngeal carcinoma (NPC), especially to Nasopharyngeal poorly differentiated squamous cell carcinoma. BamH1-A right frame 1 (BARF1), an early stage gene in lytic cycle of EBV, may have ability to immortalize human or monkey kidney epithelial cells and induce tumors. Hopefully, the study on BARF1 expression of epithelial cell of NPC may ascertain the relationship between EBV and NPC, and identify the possible mechanism of EBV inducing NPC. Methods The study consisted of carcinoma tissues, adjacent tissues, and normal Nasopharyngeal tissues from 47 patients with nasopharyngeal poorly differentiated squamous cell carcinoma (NPDSCC), carcinoma tissues from 13 head and neck carcinoma (HNC) patients and nasopharyngeal tissues from another 8 healthy subjects. EBV latent infection of all specimens had been confirmed, and then BARF1 expression levels of all specimens were detected by using nested PCR. Results: Expressive rates of BARF1 gene were as below: carcinoma tissues of NPC patients being 91.5% (43/47) with strong expression of 39 specimens and weak expression of 4 specimens; adjacent tissues being 46.8% (22/47) with strong expression of 11 specimens and weak expression of 11 specimens; and normal nasopharyngeal tissues being 6.4% (3/47) with weak expression of 3 specimens. Tissues from other HNC and health subjects can not detect the presence of BARF1 gene expression. Conclusion The expression level of BARF1 gene is increasing from relative normal tissues to adjacent tissues, to carcinoma tissues of NPC patients. This result indicates that EBV is highly related to the development of NPC, suggesting that activating BARF1 gene expression may play an important role in inducing NPC by EBV.