王春芳 雷茗 龐曉霞 黃華佗 王俊利 韋貴將 韋葉生
【摘要】目的分析miR181基因rs16927589位點單核苷酸多態性(single nucleotide polymorphism,SNP)在中國廣西地區人群中的分布特點,并比較其基因型和等位基因頻率與其他種族和地區人群間的分布差異。方法采用SNaPshot SNP技術和DNA測序技術檢測299例中國廣西人群rs16927589位點SNPs,用統計學方法分析其基因型和等位基因頻率與國際人類基因組單體型圖(Haplotype map,HapMap)計劃公布的北京人群(HapMapHCB)、日本人群(HapMapJPT)、肯尼亞人群(HapMapLWK)、印度人群(HapMapGIH)及歐洲人群(HapMapCEU)間的差異。結果中國廣西人群存在miR181基因rs16927589多態性,有TT、TC和CC三種基因型,其頻率分別為73.6%、25.4%和10%,含T和C兩種等位基因,頻率分別為86.3%和13.7%,兩者男女組間比較差異無統計學意義(P>0.05);與HapMapHCB人群比較差異無統計學意義(P>0.05),但與HapMapGIH、HapMapLWK、HapMapJPT及HapMapCEU比較差異均有統計學意義(P<0.05或0.01)。結論在中國廣西人群存在miR181基因rs16927589多態性,且在不同地域和種族人群間比較存在差異。不同種族和地區人群SNP差異可能是miR181基因相關疾病在臨床表現和發病率不同的重要因素之一。
【關鍵詞】miR181基因;單核苷酸多態性;種族
中圖分類號:R394 文獻標識碼:ADOI:10.3969/j.issn.10031383.2018.02.001
Distribution character of SNP at rs16927589 locus of
miR181 gene in Guangxi population of China
WANG Chunfang,LEI Ming,PANG Xiaoxia,HUANG Huatuo,WANG Junli,WEI Guijiang,WEI Yesheng
(Department of Laboratory Medicine,Affiliated Hospital of Youjiang Medical University for Nationalities,Baise 533000,China)
【Abstract】ObjectiveTo analyze the distribution character of (single nucleotide polymorphism,SNP) at rs16927589 locus of miR181 gene in Guangxi population of China,and to compare the genotypes and allele frequencies of them with those of other races and regions.MethodsSNaPshot SNP and DNA sequencing were used to detect SNPs at rs16927589 loci in 299 Guangxi population of China.And statistical method was used to analyze differences of genotypes and allele frequencies between Guangxi population,HapMapHCB,HapMapJPT,HapMapLWK,HapMapGIH and HapMapCEU published by (Haplotype map,HapMap).ResultsThere was rs16927589 polymorphism of miR181 gene in Guangxi population of China.There were three genotypes(TT,TC and CC),the frequencies of which were 73.6%, 25.4% and 1.0%,respectively,and there were two allels(T and C),the frequencies of which were 86.3% and 13.7%,respectively.Difference of genotypes and allele frequencies of rs16927589 polymorphism between men and women was statistically significant(P>0.05),difference between Guangxi population and HapMapHCB was not statistically significant(P>0.05),but that between Guangxi population,HapMapGIH,HapMapLWK,HapMapJPT and HapMapCEU was statistically significant(P<0.05 or 0.01).ConclusionRs16927589 polymorphism of miR181 gene exists in Guangxi population of China,and there are differences between varied regions and ethnic groups.The difference of SNP in varied ethnic groups and regions may be one of the important factors of different clinical manifestations and morbidity of miR181 gene related diseases.
【Key words】miR181 gene;SNP;race
microRNA(miRNA)是一類長度約為22 nt的調控性小分子,作為非編碼家族的新成員之一,沒有開放閱讀框架,但在細胞增殖、分化、發育、代謝和應激等過程中具有多種生物學行為[1]。多數學者認為單核苷酸多態性與系統性紅斑狼瘡(SLE)的發生存在遺傳易感性,并與其表達存在相關性[2~4]。病例研究發現,primiR34b/c rs4938723 SNP顯著增加了宮頸癌發病的風險[4]。miR143/145啟動子區rs4705342 SNP顯著降低了缺血性腦卒中的發病風險[3]。miR181通過影響T細胞、B細胞發育等在SLE發生和發展中起著至關重要的作用,如導致免疫復合物清除能力下降、細胞凋亡增加[5~7]。但至今miR181基因多態性與SLE的遺傳易感性研究尚未見報道。本研究采用SNaPshot SNP分型和DNA測序技術對中國廣西地區299例健康人群rs16927589多態性進行檢測,其結果與HapMap公布的不同種族和地區人群的結果進行比較,分析不同地域和種族人群間rs16927589多態性的分布差異情況,為后期miR181基因參與的相關疾病防治的研究及人類群體遺傳學研究提供參考資料。
1對象與方法1.1對象篩選本地來我院體檢的無親緣關系的健康人群299例,女261例,男38例,年齡24~67歲,實驗室檢查各項指標及臨床體檢均無異常,排除患有感染、心腦血管及腫瘤等疾病。
1.2方法
1.2.1基因組DNA提取EDTAK2抗凝管采集體檢者靜脈血3 ml,置于-70℃冰箱保存備用;采用人類全血DNA提取試劑盒(深圳亞能)提取樣本DNA,置于-70℃冰箱保存備用。
1.2.2引物設計與合成應用生物信息學軟件,根據NCBI中Genebank基因庫人miR181基因的全長序列,選取包含rs16927589位點的適宜長度DNA片段,用primer 30軟件設計引物,由上海天昊生物科技有限公司合成。rs16927589上游引物序列為:5TAATTAGGGGCAAGGGGAGGAT3,下游引物序列為:5TATGTGGGGATATGTGGGCACT3,延伸引物為:5TTTTTTTTTTTTTTTTTTCAAAGTGAAATGTGATAAGAACTGTC3。
1.2.3PCR擴增及測序對miR181基因rs16927589進行PCR擴增,總體系為20 μL,其中含1x GCI buffer(Takara)2.0 μL,0.3 mmol/L dNTPs 20 μL,上、下游引物各1.0 μL, TaqDNA聚合酶1.0 U,模板DNA 1.0 μL,用純水補至20 μL體系后進行多重PCR擴增。PCR產物經2 U外切酶I(EXO I,Epicentre公司)和5 U蝦堿酶(SAP,Promega公司提供)純化后,應用SNaPshot Multiplex Kit (ABI 公司提供)進行延伸反應,最后經1 U SAP酶純化延伸產物上樣ABI3130XL電泳儀測序。測序結果用GeneMapper 4.1 (AppliedBiosystems Co.,Ltd.,USA)分析。
1.3統計學方法用SPSS 23.0軟件包分析實驗結果,采用直接計數法計算基因型和等位基因的頻率,用四格表χ2和行×列表χ2檢驗計算比較各組間基因型及等位基因頻率,檢驗水準:α=0.05。
2結果2.1miR181基因rs16927589分型miR181基因rs16927589PCR擴增產物片段大小為167 bp,其分型結果顯示,rs16927589位點存在TT、TC和CC三種基因型,頻率分別為73.6%、25.4%和1.0%,等位基因T和C的頻率分別為86.3%和13.7%。DNA測序證實基因型結果一致。見圖1。
2.2廣西人群miR181基因rs16927589多態性在不同性別的比較經χ2檢驗,本研究納入人群miR181基因rs16927589基因型數據符合哈迪溫伯格平衡(HardyWeinberg equilibrium,HWE)定律(P=0200),說明研究對象具有群體代表性。統計結果顯示,rs16927589位點基因型和等位基因頻率在廣西人群男女性別間比較差異均無統計學意義(P>005)。見表1。
2.3廣西地區人群miR181基因rs16927589基因型和等位基因頻率與其他不同地域和種族人群的比較 廣西人群miR181基因rs16927589基因型及等位基因頻率與HapMapJPT、HapMapLWK、HapMapGIH及HapMapCEU人群比較差異均有統計學意義(P<0.05或0.01),但與HapMapHCB人群比較差異無統計學意義 (P>0.05)。見表2和表3。注:①、②、③箭頭指向分別表示TT、TC、CC基因型
3討論miR181基因簇由miR181a、miR181b、miR181c和miR181d組成,前兩者分別位于1號和9號染色體上,后兩者則位于19號染色體上。人類基因組單體型圖計劃研究發現,miR181基因存在多個功能性SNPs 位點,這些位點多態性改變可能會引起miR181編碼活性及miR181基因相關疾病遺傳易感性發生改變,最終導致miR181相關疾病的發生和發展。前期關于基因多態性與疾病的相關性研究主要集中在蛋白編碼基因上[8~10],較少涉及非編碼基因。近年來,越來越多的研究表明微小RNA基因多態性與疾病的發病相關[11~13]。我們課題組前期研究發現[3],miR143/145基因rs4705342位點多態性與缺血性腦卒中的遺傳易感性相關,TT和CT基因型可顯著降低缺血性腦卒中的發病風險(TC vsTT:adjusted OR=0.74,95% CI,0.57~0.97; CC vsTT:adjusted OR=0.53,95% CI,0.34~0.83)。目前關于miR181基因多態性與疾病的遺傳易感性研究尚未見文獻報道。基因多態性多因種族、環境、地理位置、飲食和生活習慣等不同呈現不同程度差異,而同一SNP位點在不同種族、地區人群間對疾病遺傳易感性的影響也表現出很大區別[14]。例如,Geng等[15]發現IL17A基因rs2275913多態性與冠心病的發病相關,然而墨西哥學者VargasAlarcon等[16]卻發現rs2275913多態性與冠心病的遺傳易感性無關。由此可見,不同種族和地區人群間正常人群基因多態性研究可為我們提供這些地區人群的遺傳背景資料,為其與相關疾病的遺傳多態性研究提供基礎理論依據和數據支持。
本研究檢測了中國廣西地區正常人群miR181基因rs16927589 存在多態性的分布情況,結果顯示其有TT、TC和CC三種基因型,含T和C兩種等位基因,以TT基因型(73.6%)與等位基因T (86.3%)常見,兩者在性別間比較差異無統計學意義,表明廣西人群rs16927589無性別間差異。而與HapMap公布的不同人群SNP比較分析發現,我國廣西健康人群miR181基因rs16927589基因型及等位基因頻率與HapMapJPT、HapMapLWK、HapMapGIH及HapMapCEU人群比較差異均有統計學意義,與HapMapHCB人群比較差異無統計學意義。廣西人群rs16927589 T和C等位基因頻率為86.3%和13.7%,與HapMapJPT(T,93.6%;C,10.4%)、HapMapLWK(T,95.6%;C,4.4%)、HapMapGIH(T,98.7%;C,13%)及HapMapCEU(T,100%)相差較大,與同是亞洲人的HapMapHCB(T,89.5%;C,10.5%)相差較小,結果吻合“親緣關系越近,基因型分布差異越小”的基因遺傳定律。結果也表明,基因多態性存在民族、種族和地域差異,同時與各地地理位置、環境、氣候、飲食和生活習慣相關。
綜上所述,中國廣西人群存在miR181基因rs16927589多態性,其基因型和等位基因頻率在不同種族和不同地區人群之間比較存在不同程度的差異。對中國廣西人群miR181基因rs16927589多態性研究,不僅有助于辨析miR181家族基因與其相關疾病的發生在不同種族、不同地域表現的差異,而且進一步為相關疾病防治的研究及人類群體遺傳學研究提供參考資料。參考文獻[1]Vidigal JA,Ventura A.The biological functions of miRNAs:lessons from in vivo studies[J].Trends Cell Biol,2015,25(3):137147.
[2]Talaat RM,Alrefaey SA,Bassyouni IH,et al.Genetic polymorphisms of interleukin 6 and interleukin 10 in Egyptian patients with systemic lupus eythematosus[J].Lupus,2016,25(3):255264.
[3]Wei YS,Xiang Y,Liao PH,et al.An rs4705342 T>C polymorphism in the promoter of miR143/145 is associated with a decreased risk of ischemic stroke[J].Sci Rep,2016,6:34620.
[4]Yuan F,Sun R,Chen P,et al.Combined analysis of primiR34b/c rs4938723 and TP53 Arg72Pro with cervical cancer risk[J].Tumour Biol,2016,37(5):62676273.
[5]Neilson JR,Zheng GX,Burge CB,et al.Dynamic regulation of miRNA expression in ordered stages of cellular development[J].Genes Dev,2007,21(5):578589.
[6]Shen N,Jiang L,Li Q,et al.The epigenetic effect of microRNA in BCRABL1positive microvesicles during the transformation of normal hematopoietic transplants[J].Oncol Rep,2017,38(5);32783284.
[7]Carlsen AL,Schetter AJ,Nielsen CT,et al.Circulating microRNA expression profiles associated with systemic lupus erythematosus[J].Arthritis Rheum,2013,65(5):13241334.
[8]Mohamed HT,ElHusseiny N,ElGhonaimy EA,et al.IL10 correlates with the expression of carboxypeptidase B2 and lymphovascular invasion in inflammatory breast cancer:The potential role of tumor infiltrated macrophages[J].Curr Probl Cancer,2018,pii:s01470272(17)3012030124.
[9]Shehjar F,Afroze D,Misgar RA,et al.Association of polymorphic variants of IL1beta and IL1RN genes in the development of Graves disease in Kashmiri population (North India)[J].Hum Immunol,2018,79(4):228232.
[10]Mustafa S,Fatima H,Fatima S,et al.Association of single nucleotide polymorphism in CD28(C/TI3 + 17) and CD40 (C/T1) genes with the Graves disease[J].J Pak Med Assoc,2018,68(1):39.
[11]Cai MY,Cheng J,Zhou MY,et al.The association between premiR27a rs895819 polymorphism and myocardial infarction risk in a Chinese Han population[J].Lipids Health Dis,2018,17(1):7.
[12]Danesh H,Hashemi M,Bizhani F,et al.Association study of miR100,miR1241,miR2182,miR301b,miR605,and miR4293 polymorphisms and the risk of breast cancer in a sample of Iranian population[J].Gene,2018,647:7378.
[13]Wu F,Li M,You W,et al.A Genetic Variant in miR124 Decreased the Susceptibility to Esophageal Squamous Cell Carcinoma in a Chinese Kazakh Population[J].Genet Test Mol Biomarkers,2018,22(1):2934.
[14]黃華佗,王榮,陸玉蘭,等.白細胞介素17A基因rs3748067位點單核苷酸多態性在廣西人群中的分布特點[J].右江醫學,2017,45(4):389393.
[15]Geng GY,Liu HL,Zhao YJ,et al.Correlation between polymorphisms in the IL17A and IL17F genes and development of coronary artery disease[J].Genet Mol Res,2015,14(3):1148811494.
[16]VargasAlarcon G,AngelesMartinez J,VillarrealMolina T,et al.Interleukin17A gene haplotypes are associated with risk of premature coronary artery disease in Mexican patients from the Genetics of Atherosclerotic Disease (GEA) study[J].PLoS One,2015,10(1):e0114943.
(收稿日期:2018-01-25修回日期:2018-0321)
(編輯:梁明佩)