胃黏膜高级别上皮内瘤变组织的增强子重塑及其对增殖相关基因CD24表达的影响  

Remodeling of enhancers in high-grade epithelial dysplasia of gastric mucosa and its effect on expression of proliferation-related gene CD24

作　　者：薛锐 潘雨薇 谭玉婷 储召乐 刘碧颖 李先锋 王涛[3] 王斌 张璇[4] 沈艾 XUE Rui;PAN Yuwei;TAN Yuting;CHU Zhaole;LIU Biying;LI Xianfeng;WANG Tao;WANG Bin;ZHANG Xuan;SHEN Ai(Medical College of Chongqing University,Chongqing,400044;Hepatobiliary and Pancreatic Tumor Center,Affiliated Cancer Hospital of Chongqing University,Chongqing;Department of Gastroenterology,Chongqing Key Laboratory of Precise Prevention and Treatment of Digestive Malignancies,Army Medical Center of PLA/Daping Hospital of Third Military Medical University,Chongqing;Department of Oncology,Chongqing Hospital of Traditional Chinese Medicine,Chongqing,China)

机构地区：[1]重庆大学医学院,重庆 [2]重庆大学附属肿瘤医院肝胆胰肿瘤中心,重庆 [3]陆军特色医学中心(第三军医大学大坪医院)消化内科,消化系统肿瘤精准防治重庆市重点实验室,重庆 [4]重庆市中医院肿瘤科,重庆

出　　处：《陆军军医大学学报》2025年第5期426-434,共9页Journal of Army Medical University

基　　金：国家自然科学基金优秀青年科学基金(81822032);重庆市自然科学基金杰出青年基金(CSTC2019JCYJJQX0027)。

摘　　要：目的通过绘制胃黏膜高级别上皮内瘤变(high-grade intraepithelial neoplasia,HGIN)组织中组蛋白H3K27ac修饰标记的增强子图谱,探究表观调控对HGIN发生发展的影响。方法收集2022年6月至2023年6月来自陆军特色医学中心消化内科的14例正常胃黏膜组织(Nor组)、31例胃黏膜高级别上皮内瘤变组织(HGIN组)和17例胃癌(gastric cancer,GC)组织(GC组),利用染色质靶向捕获测序(cleavage under targets and tagmentation,CUT&Tag)技术捕获组蛋白H3K27ac修饰的增强子区域;联合多组学分析筛选HGIN组织特异的活性增强子及其潜在调控的基因;采用免疫组化染色观察目的基因在不同类型临床样本中的表达差异,并通过CRISPR-dCas9基因编辑技术沉默活性增强子,观察目的基因的表达水平,并验证潜在调控关系。结果表观多组学测序数据质量较好,3组样本组间H3K27ac修饰的全基因组分布特征无显著差异,但H3K27ac增强子在HGIN、GC组织中发生明显重塑(P<0.05)。联合转录组数据分析发现,增强子重塑可能上调HGIN组织增殖相关靶基因CD24表达;抑制增强子活性,则CD24表达水平显著降低(P<0.05)。免疫组化结果显示,CD24表达与Ki-67呈正相关(P<0.001)。结论H3K27ac标记的增强子重塑是HGIN的重要表观遗传学特征,H3K27ac标记的活性增强子上调CD24表达,可能促进HGIN增殖。Objective To identify the enhancer profile marked by histone H3K27ac modification in high-grade intraepithelial neoplasia(HGIN)in order to reveal the novel regulatory mechanism of HGIN pathogensis.Methods Gastric tissue samples were collected from Department of Gastroenterology of Army Medical Center of PLA between June 2022 and June 2023,including 14 normal gastric tissues(Nor group),31 HGIN tissues(HGIN group)and 17 gastric cancer tissues(GC group).Cleavage under targets and tagmentation(CUT&Tag)technique was employed to capture enhancer regions modified by histone H3K27ac.Multi-omics analysis was performed to identify HGIN-specific active enhancers and their potentially regulated genes.Immunohistochemical profiling was performed to assess differential expression of the gene of interest across clinically stratified specimens,combined with CRISPR-dCas9-mediated ablation of active enhancers to monitor the gene of interest transcriptional dynamics and validate enhancer-mediated regulatory mechanisms.Results Epigenomic sequencing obtained the data with excellent quality,and indicated that obvious remodeling was observed in H3K27ac enhancers in HGIN and GC groups(P<0.05),though no significant difference in the genome-wide distribution of H3K27ac modification among the 3 groups.Combining transcriptome data revealed that enhancer remodeling may up-regulate the expression of the proliferation-related target gene,CD24,in the HGIN tissue;while,inhibiting enhancer activity can notably reduce CD24 expression level(P<0.05).Immunohistochemical assay displayed a positive correlation between the expression levels of CD24 and Ki-67(P<0.001).Conclusion The remodeling of H3K27ac enhancer represents a significant epigenetic feature of the transformation from normal condition to HGIN.Remodeling of H3K27ac enhancer up-regulates CD24,which may facilitate the abnormal proliferation of gastric epithelial cells.

关 键 词：胃癌 高级别上皮内瘤变 表观遗传 增强子 肿瘤增殖 

分 类 号：R394.3[医药卫生—医学遗传学] R730.23[医药卫生—基础医学] R735.2