长链非编码RNA遗传变异与结直肠癌风险的分子流行病学研究

发布时间：2018-12-30 12:45

【摘要】：研究背景和目的结直肠癌(colorectal cancer, CRC)是最常见的消化系统恶性肿瘤之一。据国际癌症研究中心统计,2012年全球约有结直肠癌新发病例136万例,结直肠癌死亡病例69万例。近几十年来,结直肠癌发病率在全球的分布情况发生了很大的变化,我国在上世纪仍属于结直肠癌低发国家,然而,随着经济社会的发展和生活方式的转变,结直肠癌的发病率呈现明显的上升趋势,已成为严重威胁我国居民健康和生命质量的重大公共卫生问题。结直肠癌的发生发展是环境因素与遗传因素共同作用下的多阶段、多步骤的过程。基因组的遗传变异,可通过改变基因结构而影响其功能,从而在环境因素的作用下发挥不同的效应,导致个体结直肠癌易感性发生改变。长链非编码RNA (long non-coding RNA, lncRNA)是一类长度在200nt～100kb之间的不编码或很少编码蛋白质的RNA分子。鉴于其保守的二级结构、剪切形式、亚细胞定位,及其在多种层面上调控蛋白编码基因的表达水平和在肿瘤细胞增殖、凋亡、迁移等肿瘤发生发展过程中所起的重要生物学功能,lncRNA遗传多态位点中的某些位点可能与结直肠癌的发生发展相关,可作为结直肠癌遗传易感性评价的生物标志物。材料和方法本研究采用了最新的生物信息学方法,系统研究基因组lncRNA遗传多态位点的分布特征,并在浙江省嘉善县通过以自然人群为基础的两阶段病例对照研究设计,分析lncRNA遗传多态性与结直肠癌发病之间的关联。病例对照的纳入分为两个阶段,一阶段共纳入病例对照320例和319例；二阶段共纳入结直肠癌病例501例和538例。研究采用现场入户问卷调查方法,通过面对面的访谈获取研究对象相关信息,建立数据库。同时收集外周静脉血5 ml,抽提基因组DNA,采用基于Sequenom平台的MassARRAY对筛选出的102个lncRNA遗传多态位点进行分型检测。本研究统计分析过程主要采用了SAS9.2、Stata 11.2以及R2.13.0等统计软件。结果本研究两阶段合并病例对照研究最终纳入分析的研究对象为病例组821例,对照组857例。病例组和对照组在婚姻状况、家族肿瘤史以及饮茶情况的分布上存在有统计学意义的差异,在性别、年龄、BMI、职业、教育程度、吸烟以及饮酒情况上未见有统计学意义的差异。应用最新的人类lncRNA数据库和课题组前期研究基础中获得的lncRNA表达谱数据库的相关信息,建立信息完备的基因组lncRNA SNPs数据库和结直肠癌潜在相关lncRNA SNPs数据库。对筛选出的遗传多态位点进行检测分型的结果如下：RP11-650L12.2 rs149941240多态位点不同基因型的分布与直肠癌风险呈正相关,与TTCC/TTCC基因携带者相比,rs149941240 TTCC/DEL基因型携带者发生结直肠癌的风险升高47.1%,TTCC/DEL基因型和DEL/DEL基因型携带者发生结直肠癌的风险升高40.6%。RP11-392P7.6 rs10845671多态位点不同基因型的分布与直肠癌风险呈正相关,与CC基因携带者相比,rs 10845671 CA基因型携带者发生结直肠癌的风险升高41.6%。RP5-884M6.1 rs60226884和rs10250402多态位点不同基因型的分布也与直肠癌风险呈正相关,与T/T基因携带者相比,rs60226884 T/DEL基因型携带者发生结直肠癌的风险升高32.8%；与GG基因携带者相比,rs10250402 GT基因型携带者发生结直肠癌的风险升高34.3%。此外,RP11-3N2.1 rs13230517多态位点不同基因型的分布与直肠癌风险呈负相关,与GG基因携带者相比,rs 13230517 GA基因型携带者发生结直肠癌的风险降低26.1%。按吸烟、饮酒和饮茶等生活方式特征进行分层分析后发现,lncRNA基因多态性与上述生活方式特征之间存在交互作用。结论本研究分析了lncRNA遗传多态性与人群结直肠癌易感性的关联。主要研究结论如下：(1)基因组lncRNA SNPs数据库中共有11780个lncRNA上的801173个SNP位点；结直肠癌潜在相关lncRNA SNPs数据库中共有1065个lncRNA上的65805个SNP。(2) lncRNA RP11-650L12.2 rsl49941240, RP11-392P7.6 rs10845671, RP'5-884M6.1 rs60226884, rs 10250402不同基因型的分布会增加结直肠癌的发生风险；RP11-3N2.1 rs13230517的遗传多态位点不同基因型的分布会降低结直肠癌的发生风险。(3) lncRNAMAGI2-AS3 rs6949538不同基因型的分布与吸烟和饮茶情况之间存在着复杂的交互作用。这些证据提示,lncRNA可能参与了结直肠癌的发生,其遗传多态性作为结直肠癌易感性的分子标志物具有一定潜力。这些发现仍有待于基于自然人群的大样本前瞻性队列研究以及功能学研究的进一步验证。
[Abstract]:Background and objective colorectal cancer (CRC) is one of the most common malignant tumors of the digestive system. According to the International Center for Cancer Research, there are 136 new cases of colorectal cancer in the world in 2012, and 69 cases of colorectal cancer deaths. In recent decades, the incidence of colorectal cancer has changed greatly in the world, and China is still a low-developing country of colorectal cancer in the last century. However, with the development of economic and social development and the transformation of the lifestyle, the incidence of colorectal cancer has increased significantly. It has become a major public health problem which is a serious threat to the health and the quality of life of our residents. The development of colorectal cancer is a multi-stage and multi-step process of environmental factors and genetic factors. The genetic variation of the genome can influence the function of the gene by changing the structure of the gene so as to exert different effects under the influence of the environmental factors, leading to the change of the susceptibility of the individual colorectal cancer. Long-chain non-coding RNA (lncRNA) is a class of RNA molecules that do not encode or rarely encode proteins between 200nt and 100kb. in view of the conservative secondary structure, the shear form, the subcellular localization, and the important biological functions of the expression level of the regulatory protein coding gene at various levels and in the development of tumor cell proliferation, apoptosis, migration and the like, Some of the sites of the ncRNA genetic polymorphism may be associated with the development of colorectal cancer and may be used as a biomarker for the assessment of genetic susceptibility to colorectal cancer. Materials and Methods The latest bioinformatics methods were used in this study to study the distribution characteristics of the genomic lncRNA genetic polymorphism sites and to design a two-stage case-control study based on the natural population in Jiashan County, Zhejiang Province. To analyze the association between the genetic polymorphism of lncRNA and the incidence of colorectal cancer. The inclusion of case-control was divided into two phases: a total of 320 cases and 319 cases were included in one stage, and 501 cases and 538 cases of colorectal cancer were included in two stages. The method of site-to-house survey was used to obtain the relevant information of the study object through face-to-face interview, and the database was established. At the same time, 5 ml of peripheral venous blood was collected, the genomic DNA was extracted, and the screened 102 ncRNA genetic polymorphism sites were detected by MassARRAY based on the Sequenom platform. The statistical software of S9.2, Stata 11.2 and R.13. 0 was used in the statistical analysis of this study. Results The results of the two-stage combined case-control study in this study included 821 cases of the case group and 857 in the control group. There was a statistically significant difference in the distribution of marital status, family tumor history and tea-drinking conditions in the case group and control group, and there was no statistically significant difference in sex, age, BMI, occupation, education level, smoking, and alcohol consumption. Using the latest human lncRNA database and the relevant information of the ncRNA expression profile database obtained from the previous research base of the research group, the information-complete genomic lncRNA SNPs database and the potential related lncRNA SNPs database of colorectal cancer were established. The results of the detection and classification of the screened genetic polymorphism sites are as follows: the distribution of the different genotypes of the polymorphic sites of the RP11-650L12. 2 rs149941240 is positively related to the risk of the rectal cancer, and the risk of colorectal cancer in the rs149941240 TTCC/ DEL-type carrier is increased by 47.1% compared with the TTCC/ TTC gene carrier, The risk of colorectal cancer in the TMCC/ DEL genotype and the DEL/ DEL genotype carriers increased by 40.6%. The distribution of the different genotypes of the polymorphic sites of the RP11-392P7.6 rs10845671 was positively correlated with the risk of the rectal cancer, and compared with the CC gene carrier, RP5-884M6. 1rs60226884 and rs10250402 polymorphism loci have a positive correlation with the risk of rectal cancer. Compared with the T/ T gene carrier, the risk of colorectal cancer in the rs60226884 T/ DEL-type carrier is 32.8%, compared with that of the GG gene carrier, The risk of colorectal cancer in rs10250402GT genotype was 34.3%. In addition, the distribution of P11-3N2. 1rs13230517 polymorphic site was negatively correlated with the risk of rectal cancer. Compared with the GG gene, the risk of colorectal cancer in the rs 13230517GA-type carrier decreased by 26. 1%. It was found that there was an interaction between the polymorphism of lncRNA gene and the above-mentioned lifestyle characteristics after the stratified analysis according to the characteristics of the living methods such as smoking, drinking and drinking tea. Conclusion The association between the genetic polymorphism of lncRNA and the susceptibility to colorectal cancer is analyzed in this study. The main findings are as follows: (1) There are 1173 SNP sites in the total of 11780 lncRNA in the genomic lncRNA SNPs database, and 65805 SNPs in the potential related lncRNA SNPs database of colorectal cancer have 1065 ncRNA. (2) The distribution of different genotypes of lncRNA RP11-650L12. 2rsl49941240, RP11-392P7. 6rs10845671, RP '5-884M6. 1rs60226884, rs 10250402 may increase the risk of colorectal cancer; the distribution of different genotypes of the genetic polymorphism sites of RP11-3N3.1 rs13230517 will reduce the risk of colorectal cancer. (3) There is a complex interaction between the distribution of the different genotypes of lncRNAMAGE2-AS3 rs6949538 and the conditions of smoking and tea drinking. These evidence suggests that lncRNA may be involved in the occurrence of colorectal cancer and its genetic polymorphism has potential as a molecular marker for colorectal cancer susceptibility. These findings remain to be further validated based on large sample prospective cohort studies and functional studies of the natural population.
【学位授予单位】：浙江大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：R735.34

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