外泌体来源TRIM3在胃癌进展中作用机制及诊断应用研究

Both specific, sensitive, non-traumatic markers for gastric cancer diagnosis and therapy are deficiency. Exosomal protein, as emerging non-invasive markers for the diagnosis and therapy of cancers, have attracted increasing attention. The proteomic profile of exosomes from the serum of gastric cancer patients was detected by using LC-MS/MS. The expression of TRIM3 in exosome from the serum of gastric cancer patients was much lower than that from the healthy control. This study intends to detect the expression of exosomal TRIM3 from the serum of gastric cancer patients and healthy controls, and to analyze the correlation between TRIM3 and clinical pathological characteristics. The expression of exosomal TRIM3 from the serum of patients with gastric cancer, gastritis, gastric ulcer and other digestive system tumors was compared, and analyze the sensitivity and specificity of exosomal TRIM3. To reveal the clinical significance of exosomal TRIM3 in the diagnosis, treatment and prognosis of gastric cancer. The roles and mechanisms of exosomal TRIM3 will be explored by using cell and animal models via Lentiviral vector and CRISPR/Cas9 technique. Our study will provide new methods and novel biomarkers for gastric cancer diagnosis, reveal the roles and mechanisms of exosomal TRIM3 in cancer progression, and provide new therapeutic targets.

胃癌缺乏特异、敏感的非创伤性诊断指标。血液外泌体（exosome）内蛋白分子作为一种新的非创伤性分子标志物在肿瘤诊疗中的作用备受关注。我们通过液质联用质谱分析胃癌患者血液来源exosome内蛋白表达谱，筛选出低表达差异蛋白TRIM3。本研究拟检测胃癌患者血液exosome内TRIM3表达水平，结合患者临床病理特征、病历资料进行相关性分析，并与胃炎、胃溃疡及其他消化系统肿瘤患者血清exosome内TRIM3表达水平进行对比，分析其敏感性和特异性；揭示exosome内TRIM3在胃癌诊断、疗效观察及预后判断中的临床意义。采用过表达慢病毒及CRISPR/Cas9基因敲除技术实现TRIM3在胃癌细胞中的过表达和沉默，结合动物模型，解析TRIM3对胃癌细胞生物学功能的影响，揭示TRIM3涉及的信号通路，阐明其参与胃癌进展的作用及机制。将为胃癌诊疗提供新的分子标志，为胃癌防治提供新靶标，具有重要意义。

胃癌缺乏特异、敏感的非创伤性诊断指标。血液外泌体（exosome）内蛋白分子作为一种新的非创伤性分子标志物在肿瘤诊疗中的作用备受关注。分析及鉴定胃癌来源exosome的形态、直径大小及浓度，筛选其exosome内差异表达蛋白。. 胃癌血清来源的exosome，具有典型的“碟状”或“杯状”形态，且浓度显著高于健康对照组，两组exosome的直径大小无差异；胃癌细胞培养上清来源exosome的浓度较GES-1来源的exosome高。我们通过液质联用质谱分析胃癌患者血液来源exosome内蛋白表达谱，筛选出低表达差异蛋白TRIM3。扩大样本量验证发现胃癌患者血清exosome内TRIM3的表达明显低于健康人。 . TRIM3过表达可以抑制胃癌细胞在体内外的增殖和迁移，使干细胞转录因子表达减弱，抑制EMT发生。TRIM3干扰可以增强胃癌细胞在体内外的增殖和迁移能力，使干细胞转录因子表达上调，促进EMT发生。TRIM3过表达的胃癌细胞可以通过exosome传递大量的TIRM3到靶细胞，能抑制胃癌细胞的增殖、迁移能力，使干细胞转录因子表达下调，抑制EMT发生。. 生物信息学预测发现TRIM3为miRNA-20a的直接靶基因。胃癌患者血清来源的exosome及胃癌组织内miRNA-20a呈高表达，且与TRIM3表达水平呈负相关。TRIM3的表达下调可以使Wnt/β-catenin信号通路中的Wnt4和β-catenin的表达增强。. 胃癌患者血清exosome的浓度及exosome内容物与健康者有显著差异；血清exosome和exosome内TRIM3可能成为胃癌辅助诊断的新型标志物；exosome携载的TRIM3在胃癌的增殖和迁移中具有明显的作用，且与血清miRNA-20a呈负相关；TRIM3参与胃癌发生、发展的机制与Wnt/β-catenin信号通路有关。本研究为胃癌的诊断与治疗提供了新的思路和依据。