let-7基因多态与中国汉族人群头颈癌易感性的关联研究

Investigation of correlation between genetic polymorphism of let-7 and genetic susceptibility to head and neck cancer risk in Han Chinese

目的：探讨 let-7基因多态与中国汉族人群头颈癌易感性的关联。方法：采用病例-对照研究设计，以经确诊的503例头颈部癌患者作为病例组，选取900例健康人群作为对照组。对病例-对照进行流行病学调查，内容包括：一般人口学特征、疾病史、肿瘤家族史、吸烟、饮酒情况，并进行体格检查。收集研究对象血液标本5 mL，提取基因组 DNA。以 let-7 rs10877887和rs13293512为研究位点，应用TaqMan探针方法进行多态性检测，并用logistic 回归计算比值比（odds ratio，OR）及其95％可信区间（confidence interval，CI），比较不同基因型与头颈癌患病风险的关系。结果：rs10877887位点3种基因型 TT、CT及 CC 在病例组分布频率分别为45．7％（227/503）、42．9％（213/503）及11．4％（57/503）；在对照组中分别为40．8％（361/900）、47．7％（422/900）及11．5％（101/900）。rsl3293512位点3种基因型 TT、CT 及 CC 在病例组分布频率分别为31．9％（157/503）、52．3％（257/503）及15．8％（78/503），在对照组中分别为30．2％（270/900）、49．2％（439/900）及20．6％（194/900）。多因素 logistic 回归分析显示，携带 rs10877887位点至少1个突变等位基因 C 的个体与携带 TT基因型的个体相比，头颈部肿瘤患病风险差异无统计学意义（CC ＋CT/TT调整 OR＝0．82，95％ CI：0．90～1．23，P＝0．087）；与携带 TT＋CT基因型个体相比较，携带 rs13293512位点2个突变等位基因 C 的个体头颈部肿瘤患病风险显著降低（CC/TT＋CT 调整 OR＝0．73，95％ CI：0．55～0．98，P＝0．039）。结论：let-7 rs13293512位点多态可影响中国汉族人群的罹患头颈癌的风险。

Objective：To discuss the association between single nucleotide polymorphisms in let-7 and genetic susceptibility to head and neck cancer （HNC）in Han Chinese.Methods：In this case-control study,503 newly and histologically confirmed HNC patients were consecutively recruited as cases and 900 cancer-free controls were randomly selected as controls.Designed questionnaires were used to ac-quire patients′information on demographic data and age,sex,smoking,and alcohol consumption.Approximate 5 ml of venous blood sample was collected from each subject for DNA extraction and genotyping.We used TaqMan allelic discrimination assay to genotype two polymor-phisms of rs10877887 and rs13293512 in let-7.The associations of SNPs with HNC risks were estimated by computing the crude and adjus-ted odds ratios （ORs）and their 95% confidence intervals （CIs）using logistic regression analyses.Results：The frequencies of genotype TT,CT and CC of rs10877887 were 45.7% （227/503）,42.9% （213/503）and 11.4% （57/503）in case group;while separately 40. 8% （361/900）,47.7% （422/900）and 11.5% （101/900）in control group.The frequencies of genotype TT,CT and CC of rs13293512 were 31.9% （157/503）,52.3% （257/503）and 15.8% （78/503）;while separately 30.2% （270/900）,49.2% （439/900）and 20. 6% （194/900）in control group.Logistic regression analyses showed that there was no statistic significe in the relationship between rs10877887 and susceptibility to HNC （CC＋CT/TT：adjusted OR=0.82,95% CI：0.90-1.23,P=0.087）,while rs13293512 CC geno-type significantly decreased susceptibility to HNC （CC/TT＋CT：adjusted OR=0.73,95% CI：0.55 -0.98,P=0.039）.Conclusions：The polymorphism of rs13293512 in let-7 may be a biomarker of susceptibility to HNC in Han Chinese.