circRNA-miR-29s-VEGF信号通路介导胃癌不同生长方式的机制研究

Based on patterns of growth and invasion, gastric cancer was concisely classified into expanding and infiltrative types according to Ming's classification. These two types of gastric cancer showed obviously differential clinical prognosis，but little was known about the molecular regulatory mechanism in this process. Differently expression of circRNA and miRNA in these two types of gastric cancer was found in our preliminary study using highthrought sequencing and chip analysis. Clinical sample validation showed that the circRNA-miR-29s paired interactor was related to the Ming's subtype and the prognosis in gastric cancer. Bioinformatics prediction and cell experiments have preliminarily confirmed that these interacting molecules mainly impact angiogenesis through the VEGF signaling pathway in gastric microenvironment. This study will subsequently use RIP, RNA pull-down,LUC and a series of techniques to elucidate the molecular mechanism of the circRNA-miR-29s-VEGF pathway in gene regulatory network; By interfering with this network, the transformation of growth pattern, marker protein and angiogenesis were analyzed in these two types of gastric cancer and establish growth pattern specific tumor model to clarify this biological process in gastric cancer. This project is expected to reveal new molecular mechanisms regulating the growth pattern of gastric cancer and better understand the complex regulatory network in the development of gastric cancer, which could provide new ideas for further development of better targeted strategies.

根据不同生长方式，胃癌分为膨胀型和浸润型（Ming氏分型），二者临床预后截然不同，但对于其形成的调控机制仍然知之甚少。本课题通过前期的高通量测序及芯片分析证实：circRNA和miRA在两型胃癌中均存在差异表达；临床样本验证表明其中circRNA-miR-29s这一互作分子与Ming氏分型及预后相关；生信预测及细胞实验初步证实这一互作分子主要通过VEGF信号通路来影响胃癌微环境血管发生能力的改变。本课题后续将通过RIP、RNA pull-down及LUC等技术阐明circRNA-miR-29s-VEGF这一调控网络中的分子机制；通过干扰该网络，分析两型在生长方式、标志蛋白及血管生成方面的转变；建立胃癌生长方式特异性荷瘤模型来明确其在诱导胃癌不同生长方式过程中的生物学功能。该项目可望揭示调控胃癌生长方式新的分子机制，加深认识胃癌发展过程中复杂的调控网络，为研究更有针对性的防治策略提供新思路。

本课题志在寻找影响其生长方式的调控分子有利于探究不同类型胃癌的发生机制，准确鉴定与胃癌生物学特性相关的分子标记。通过筛选与鉴定胃癌不同生长方式相关的miRNA，探索其主要的生物作用途径和细胞功能，进而揭示这些miRNA与靶基因调控机制在胃癌组织学分型等病理发生中的作用，探讨它们与胃癌临床病理特征的关系，以期能够寻找到调控上述胃癌Ming分型相关miRNAs的circRNA分子，鉴定circRNA-miRNA-mRNA调控轴靶基因在胃癌疾病进展和预后评估中的临床意义。在本研究中，我们发现胃癌不同生长方式相关的miR-29s通过靶向调节ECM-receptor interaction途径中COL4A1基因来影响胃癌细胞迁移、浸润等生物学功能，进而参与了胃癌组织不同生长方式的形成。靶基因COL4A1有望成为能够预测胃癌恶性分级、进展分期和疾病预后的生物学标记，具有重要的潜在临床价值。此外，本课题研究表明circHIPK3-miR-124/miR-29b 调控轴可以影响胃癌细胞增殖，该调控轴的靶基因表达与胃癌的临床进展有关。对circHIPK3 的调控网络进行系统化地识别和鉴定有助于我们进一步认识胃癌不同组织病理学起源中的转录机制。上述一系列结果表明胃癌的不同生长方式与miRNA的调控有密切的关系，这类miRNA 通过调节靶基因的功能来影响胃癌的组织学分型和肿瘤的病理进展。circRNA-miRNA-mRNA调控轴也参与了胃癌不同生长方式的发生，由circRNA调控网络介导的转录调控机制拓展了对胃癌发病机制的认识，该调控网络中的靶基因表达水平对于评估胃癌的疾病进程有重要的临床价值。本课题研究结果从circRNA-miRNA调控网络的角度阐释了不同生长方式胃癌的发生发展机制，推动了对胃癌致病机理的深入理解，为胃癌的防治策略提供了新思路。