TET介导的组蛋白修饰参与艾灸干预CAC炎-癌转化的机制研究

DNA methylating enzyme TET family in colitis-associated carcinogenesis (CAC) tumor tissue low expression, and β-catenin overexpression, which is one of the important mechanisms of "inflammation-cancer transformation". Our previous studies suggested that moxibustion could decrease the high expression of IL-6 and β-catenin on CAC rats. The project intends to focus on DNA hydroxymethylase TET family closely related UC and CAC. Combined with UC and CAC model, with molecular biology techniques, ChIP-qPCR, gene knockout and other methods, to explore the mechanisms of moxibustion on inhibition colonic inflammation and suppression colorectal cancer，we will explore the interaction between the TET family and histone modification on UC and CAC, and explain TET family-mediated histone modification is the mechanism of moxibustion, which inhibititon the activity of SPRY2 protein and regulation the expression of IL-6 and β-catenin. Moxibustion could inhibit colonic inflammation and suppresses colorectal cancer. All of these provide experimental data and scientific basis for colon "inflammation-cancer transformation" of moxibustion in clinical application.

结肠炎相关性癌变组织中DNA羟甲基化酶TET家族低表达、β-catenin过表达，是“炎-癌转化”重要机制之一。前期研究结果提示艾灸能逆转结肠炎及CAC大鼠结肠组织高表达的IL-6和β-catenin。本项目拟从DNA羟甲基化酶TET家族与UC及其癌变密切相关为切入点，结合UC炎症和CAC肿瘤模型，应用分子生物学技术、ChIP-qPCR、基因敲除等方法，研究旨在从TET家族影响组蛋白修饰的角度，阐释艾灸通过TET家族介导的组蛋白修饰，抑制SPRY2蛋白活性，调控促炎症因子IL-6和促癌因子β-catenin表达的机制，拟证实艾灸改变结肠炎及其癌变组织的TET介导的组蛋白乙酰化修饰，以达到艾灸抑制结肠炎症、阻遏结肠炎癌变之目的，以期为艾灸在结肠“炎-癌转化”的临床应用提供实验资料和科学依据。

结肠炎相关性肠癌（CAC）与溃疡性结肠炎（UC）密切相关，UC的结肠慢性炎症反复发作是导致CAC 的关键环节之一，艾灸抑制UC肠道炎症反应有助于降低CAC的发病率。10-11转位蛋白（TET）家族在UC及结肠炎相关癌变CAC组织中低表达，β-catenin过表达，是“炎-癌转化”的重要机制之一。本项目基于前期针灸对UC组蛋白修饰的免疫调节的研究基础上，采用ChIP-PCR、RNA-seq、WB、IHC、IF和Real-time PCR等技术和方法，结合RNA干扰和TET2基因敲除技术，构建AOM-DSS诱导的UC和CAC大鼠及小鼠动物模型，研究聚焦DNA羟甲基化酶TET2在炎症和肿瘤中的作用，开展了针灸对UC及CAC的抗炎和抑制肿瘤生长的效应机制研究。研究结果提示温和灸和电针均有抑制UC结肠炎症、抑制CAC结肠肿瘤生长的作用，其机制与针灸能调节DNA羟甲基化酶TET2的表达，促进组蛋白去乙酰化酶HDAC2在结肠白介素6启动子区域富集，继而抑制结肠白介素6的转录水平，减少了损伤部位炎性介质的释放，针灸能调节5mC、5hmC，以及H3和H4的乙酰化水平，通过DNA羟甲基化酶TET2介导的HDAC2组蛋白乙酰化，抑制结肠β-catenin的激活，抑制结肠肿瘤生长达到抑制结肠上皮细胞从慢性炎症向异型增生的“炎-癌转化”。本研究结果阐释了针灸能促进结肠炎及其癌变组织的TET2介导的组蛋白修饰，作用于组蛋白去乙酰化酶HDAC2，调控UC结肠组织IL-6和CAC结肠组织β-catenin表达，纠正UC结肠黏膜病变，实现针灸抑制肠道炎症、阻遏结肠炎相关性癌变之目的，为针灸在结肠“炎-癌转化”的临床应用提供了实验资料和科学依据，为针灸在临床的应用推广提供理论基础。