摘要目的 探讨锰超氧化物歧化酶(MnSOD)基因单核苷酸多态性与食管癌的发生及病变进展的关系.方法 采用聚合酶链反应-限制性片段长度多态性(PCR-RFLP)方法,分析103例食管癌患者(食管癌组)和195例正常对照人群(对照组)的MnSOD基因启动子区上游第9位点单核苷酸多态性,比较不同基因型与食管癌发病风险以及病变部位、病变长度、最大直径和临床分期之间的关系.结果 在食管癌组中,MnSOD基因启动子区上游第9位点变异基因型(TC+CC)分布的频率为28.2%,明显高于对照组(17.4%;X~2=4.645,P＜0.05);与携带TT基因型者相比,携带C等位基因(TC+CC)的个体患食管癌的风险增加了1.889倍(95%CI为1.052～3.391).食管癌组中,病变长度≤5 cm者,变异基因型分布的频率为16.3%;病变长度＞5 cm者,变异基因型分布的频率为36.7%,差异有统计学意义(X~2=5.147,P＜0.05).MnSOD 9 T→C变异与食管癌的病变长度呈正相关,但与食管癌的病变部位、最大直径以及临床分期之间无明显的相关性.结论 MnSOD 9 T→C变异增加了食管癌的发病风险,其可以作为食管癌遗传易感性的标志物,用于易感个体的预警,并且该基因的多态性可能与食管癌病变的纵向进展相关.

abstractsObjective To investigate the association of single nucleotide polymorphism(SNP)of manganese superoxide dismutase(MnSOD)gene with carcinogenesis and progression of esophageal squmous cell carcinoma.Methods The MnSOD9 T→C SNP was genotyped by polymerase chain reactionrestriction fragment length polymorphism(PCR-RFLP)analysis in 103 patients with esophageal squamous cell carcinoma and 195 healthy controls.Results A significant difference was observed in the MnSOD allelotype distribution among esophageal squamous cell carcinomas and healthy controls(X~2=4.645,P＜0.05).Individuals with the 9 C allele had a signiflcandy higher risk to develop esophageal squamous cell carcinoma compared with those with the TT allele.The frequency of C allelotype among patients witll lesions of different lengths(≤5 cm and＞5 cm)was 16.3%and 36.7%,respectively.A significant difierence was observed in the MnSOD alhiotype distribution between patients with lesions of different lengths(X~2=5.147,P＜0.05).No significant association of the MnSOD polymorphism at 9 T→C with the tumor site,maximal length and chnical staging was found in esophageal squamous cell carcinoma.Conclusion Single nucleotide polymorphism(SNP)of MnSOD gene may be correlated with the susceptibility and disease progression of esophageal squamous cell carcinoma,and may become a tumor marker for prediction of this cancer.