Toll样受体基因多态性与EBV感染相关胃癌的易感性

目的： 探讨Toll样受体(TLR)家族成员TLR2基因启动子区-196~-174 del和TLR4基因 Thr399Ile位点多态性与EBV相关胃癌(EBVaGC)及EBV阴性胃癌(EBVnGC)易感性的关系。方法：采用PCR技术检测52例EBVaGC，157例EBVnGC以及94例正常对照人群TLR2(-196~-174 del)基因多态性；PCR-限制性片段长度多态性(PCR-RELP)技术检测50例EBVaGC，67例EBVnGC以及71例正常对照TLR4 Thr399Ile位点基因型及等位基因分布；分析2种基因多态性与EBVaGC及EBVnGC易感性的关系。结果：胃癌组与对照组比较TLR2(-196~-174 del)基因型分布无显著差异(χ2=3.180，P=0.075)，胃癌组del等位基因频率明显高于对照组(χ2=4.875， P=0.027)，del等位基因携带者的罹患危险性明显高于非携带者(OR=1.491，95%CI=1.045~2.126)；EBVaGC组和EBVnGC组中，TLR2(-196~-174 del)3种基因型以及del等位基因频率差异无统计学意义(χ2=0.05，P=0.867)。EBVaGC组、EBVnGC组和正常对照组中均未发现TLR4基因Thr399Ile位点的多态，其基因型分布及等位基因频率差异均无统计学意义(P>0.05)。结论：TLR2(-196~-174 del)等位基因可能是胃癌发病危险因素，且在EBVaGC和EBVnGC两种胃癌发生中产生相同的影响。未发现TLR2(-196~-174 del)和TLR4基因Thr399Ile基因型分布与EBVaGC的易感性相关。

Toll-like receptors gene polymorphism and susceptibility to EBV-associated gastric carcinoma

OBJECTIVE： To explore the relationship of Toll-like receptors 2 （TLR2） and TLR4 Thr399Ile gene polymorphism and the susceptibility to EBV-associated gastric carcinoma （EBVaGC） and EBV-negative gastric carcinoma（EBVnGC）. METHODS：TLR2 gene promoter region-196 to-174 del polymorphism was detected by using the allele-specific polymerase chain reaction in 52 EBVaGCs,157 EBVnGCs and 94 normal controls. TLR4 gene Thr399Ile genotype and allele distribution were evaluated by PCR and restriction fragment length polymorphism （PCR-RFLP） in 50 EBVaGCs,67 EBVnGCs and 71 normal controls. The relationship between gene polymorphism in TLR2 and TLR4 coding genes and the susceptibility to EBVaGC and EBVnGC was analysed. RESULTS：There was no significant 2difference （ X^2=3.180,P=0.075） between gastric cancer group and control group in genotype distribution of TLR2（-196 to-174 del）,but the del allele frequency of gastric cancer group was obviously higher than that of control group 2（ =4.875,P=0.027）,The risk of developing gastric carcinoma in del allele carriers was significantly higher than that in controls（OR=1.491,95%CI=1.045-2.126）. TLR2 （-196 to-174 del） genotype and the frequency of del allele showed no 2significant difference in EBVaGC and EBVnGC group （ =0.05,P=0.867）. TLR4 gene Thr399Ile locus mutation was not found in EBVaGC,EBVnGC or normal control groups. The genotype distribution and allele frequency also revealed no statistical differences . CONCLUSION：TLR2-196 to-174 del alleles could be risk factors for gastric carcinoma,butχχχits effects were not different in EBVaGC and EBVnGC. There was no obvious correlation in the genotype distribution of TLR2（-196 to-174 del） and TLR4 gene Thr399Ile and EBVaGC genetic susceptibility.