长链非编码RNA HNF1A-AS1在胃癌发生发展中的作用及其诊断价值分析

Gastric cancer is one of the most common carcinomas in China. The five-year survival rate is low, which makes gastric cancer the second leading cause of death of all cancers. Currently, long non-coding RNA (lncRNA) has been known to be associated with the development and progression of carcinomas. It is also regarded as a potential tumor biomarker. Our preliminary results showed that lncRNA HNF1A-AS1 was markedly up-regulated in the tissues of human primary gastric cancer patients compared to normal gastric tissue, and it could also be detected in the patient's plasma. Knockdown of HNF1A-AS1 expression decreased the proliferation and migration of gastric cancer cells in vitro. Bioinformatics analysis suggested that HNF1A-AS1 may promote the formation and progress of gastric cancer through epigenetically modulating the chromosome and chromatin. As proposed in this project, we will test this hypothesis by utilizing technologies including RNA interfering, adenovirus mediated over-expression, RIP and RNA pull-down to explore the role of HNF1A-AS1 in the assembly and modulation of chromatin and histone at the molecular, cellular and system levels. The expressions of HNF1A-AS1 in different tissues and plasma samples will be further compared between normal control, gastritis, precancerous lesion and gastric carcinoma. These studies will help establish the potential candidacy of HNF1A-AS1 as a biomarker for gastric carcinoma, facilitating the diagnosis and treatment monitoring of this devastating disease in the clinic.

胃癌发病率一直高居我国各种恶性肿瘤前列，五年生存率低，死亡率居第二。目前已知长链非编码RNA(lncRNA)与恶性肿瘤发生发展密切相关，是一类潜在的肿瘤分子标志物。我们前期的实验发现lncRNA HNF1A-AS1在胃癌组织中的表达较正常组织明显上调，并可在血浆中检测到，在胃癌细胞中敲降HNF1A-AS1表达可减弱细胞的增殖和迁移。经生物信息学分析，提示HNF1A-AS1可能通过表观遗传修饰调节核小体和染色质的组装，从而促进胃癌的发生和发展。为验证这一假说，本项目将采用RNA干扰、导入过表达载体、RIP、RNA pull-down等技术，从分子水平、细胞实验和动物实验等方面探讨HNF1A-AS1是否参与染色质组装及其作用机制；并比较正常人、胃炎、胃癌前病变和胃癌患者组织中HNF1A-AS1的表达水平，探讨作为生物标志物的可行性，为其在胃癌诊断和治疗监测的潜在临床应用提供理论依据和实验基础。

胃癌是消化系统最常见的恶性肿瘤之一，长链非编码RNA是近年来一类广泛受到关注的RNA分子，大量现有研究已经预示着LncRNA具备可作为肿瘤标志物，治疗靶点等的潜能。目前，已发现胃癌组织中存在异常表达LncRNA，且在胃癌发生发展、转移复发等中发挥重要的作用。然而，关于LncRNA在胃癌中的具体作用机制尚未完全阐明，有待进一步探讨。我们前期发现LncRNA HNF1A-AS1，lncRNA GHET1以及lncRNA SNHG16在胃癌患者血清或血浆中均能被检出，且表达异常与胃癌相关，这都提示GHET1具有作为无创胃癌标志物的潜质，但它们在胃癌的发生发展中起到什么作用，并未有深入研究。本项目研究了GHET1在胃癌发生发展中的作用；并进一步评价GHET1在胃癌中的临床诊断效能。采用qRT-PCR确立GHET1表达的检测体系；检测正常胃粘膜细胞及胃癌细胞、胃癌组织及癌旁组织以及血浆样本中GHET1的表达；采用划痕、Transwell、Western blot等实验、研究GHET1对胃癌细胞行为的影响；证实GHET1是通过上调P21表达和下调细胞周期蛋白和CDK表达以抑制细胞周期由G0/G1期进入S期。在裸鼠胃癌细胞移植瘤模型中检测GHET1的调控表达及作用，为GHET1开发为胃癌标志物提供实验基础和理论依据。对lncRNA SNHG16的研究，我们同样证实了在胃癌组织中的表达水平明显高于正常组织，且通过RNA干扰技术，发现敲低胃癌细胞HGC-27中SNHG16基因，可抑制胃癌细胞增殖、侵袭、迁移能力。表明lncRNASNHG16可能在一定程度上参与胃癌的发生发展。本项目研究lncRNA影响胃癌侵袭和转移的发生发展机制，并初步阐明了多个lncRNA参与的调节机制，为进一步研究胃癌靶向治疗和标志物提供新的可能思路。