miR-143/145启动子区SNPs与云南汉族人群宫颈癌发病的关联研究

Cervical cancer is the second most common cancer among women in our country and the incidence trend of younger patients increasing obviously. Accumulating evidence suggest that the occurrence of cervical cancer is associated with genetic factors. Nevertheless, a number of studies focused on coding regions, paid little attention to non-coding region, especially the promoter region of miRNA gene. Our previous study has confirmed: miR - 143/145 was low expressed in cervical cancer and have the function of the tumor-suppressor genes. We also found rs4705343 polymorphism is associated with the occurrence of cervical cancer, the single-base mutation can cause miR - 143/145 transcription level changes. Therefore this study intends to predict miR - 143/145 promoter region and identify 12 SNPs by bioinformatics methods. Further, case - control study to find out the SNPs differentially expression in cervical cancer group and the control group. Finally, we plan to use dual luciferase reporter gene detection assay,electrophoretic mobility shift assay, chromatin immunoprecitation, real-time fluorescent quantitative PCR and western blot to clarify these SNPs pathogenesis in cervical cancer. We aim to identify new susceptibility genes, find new molecular markers and to provide evidence to clarify the role of the SNPs in the promoter region of miR - 143/145 playing in the development of cervical cancer.

宫颈癌是威胁我国女性健康的第二大肿瘤，发病趋势明显年轻化。多项证据显示，宫颈癌的发生与遗传因素有关，但大多数研究均集中于编码区，很少关注非编码区尤其是miRNA启动子区的遗传变异。本研究前期已证实：miR-143/145在宫颈癌中表达下调，发挥类似抑癌基因的作用，同时发现rs4705343多态性与宫颈癌的发生有关，该位点单碱基变异可引起 miR-143/145转录活性变化。因此本研究采用生物信息学方法预测启动子区并确定12个多态性位点，通过病例-对照研究筛选宫颈癌组和对照组中具有统计学差异的miR-143/145启动子区SNPs，运用双荧光素酶报告基因系统、凝胶迁移电泳、免疫共沉淀、实时荧光定量PCR和免疫印迹等方法研究这些SNPs对宫颈癌发病的影响。通过本研究，拟鉴定出新的易感基因，找到宫颈癌诊治新的靶点，为阐明miR-143/145启动子区SNPs在宫颈癌发生发展中的作用提供依据。

宫颈癌是威胁我国女性健康的第二大肿瘤，发病趋势明显年轻化。多项证据显示，宫颈癌的发生与遗传因素有关，但是对于 miR-143/145 的研究主要体现在其对肿瘤发生发展中的调控作用，而对其自身异常表达的内在原因探讨研究较少。由于 miR-143/145 可通过与其启动子区结合，调控下游靶基因，进而影响细胞增殖、侵袭、迁移和凋亡等生物学过程，参与肿瘤形成。因此，有理由推测，宫颈癌中 miR-143/145 启动子区遗传变异,例如单核苷酸多态性，可能影响其差异性表达，并影响不同个体对宫颈癌的易感性。.单核苷酸多态性与肿瘤的易感性研究是热点，但以往的研究多集中于编码区，对miRNA启动子区的遗传变异研究甚少。目前尚未见miR-143/145启动子区SNPs与宫颈癌发生发展的相关研究报道。.本课题组研究证实miR-143/145在宫颈癌组织中呈低表达，发挥类似抑癌基因作用，且miRNA启动子区SNP与肿瘤易感性有关，位点rs3733846 A/G多态位点AG基因型、rs4705343T/C多态位点TC基因型、rs4705341 A/G多态位点AG基因型、rs1723799 T/C多态位点TC基因型增加了宫颈癌的发病风险，rs353292 T/C多态位点TC基因型、rs4705342 C/T多态位点CC基因型降低了宫颈癌的发病风险，与宫颈癌的易感性有一定相关性。候选位点频率分布与宫颈癌临床特征有一定相关性。miR-143/145启动子区SNP位点rs4705343，PGL3- rs4705343C等位基因的荧光素酶活性显著低于rs4705343T等位基因的荧光素酶活性，是探索肿瘤病因病机的新方向。本研究揭示了宫颈癌中miR-143/145异常表达的分子机理，可能探索出宫颈癌临床诊断的新的分子标记物，为有效防治宫颈癌的发展，早期诊治奠定一定基础。