原癌基因RON在胃癌中对bata-catenin的激活作用及双靶向治疗的研究

Our previous researches have shown that receptor tyrosine kinase Recepteur d'Origine Nantais (RON) gene and its variants are overexpressed and are abnormally activated in gastric cancer. Furthermore,its activation level has a positive corelation with lymphatic metastasis and pathological stage. Recently, we have found that the overexpression of RON will increase the phosphorylation level of ?-catenin. We therefore infer that the abnormal expression of RON and its variants may be one of the main factors causing the activation of ?-catenin of gastric cancer cell, which plays an important role in the carcinogenesis and development of gastric cancer. The project is to prove the role of RON in activating ?-catenin of gastric cancer cell by cell and animal experiment results. It is planned to prove the interaction between RON and ?-catenin protein with laser scanning confocal microscopy (LSCM) and co-immunoprecipitation and study the relation between the common activation of the pathways of RON and ?-catenin in gastric carcinoma tissues and the clinical and pathological characteristics of the gastric cancer patients. It discusses and compares the inhibitory effect of blocking RON and ?-catenin pathways separately or jointly on the grwoth of tumor cell with in vitro and animal experiments. The research will generate innovative results in the areas of the pathogenesis of gastric cancer and new therapeutic target, having important theoretical value and potential application prospect.

我们前期研究表明受体酪氨酸激酶RON基因及其变异型在胃癌中过度表达和异常激活，且其激活程度与淋巴结转移和病理分期等呈正相关。新近，我们发现RON的过表达能使?-catenin磷酸化水平增加。我们推测RON及其变异型异常表达可能是导致胃癌细胞?-catenin活化的主要因素之一，其在胃癌发生、发展中起着重要作用。本项目拟从细胞和动物实验水平证实RON在胃癌细胞中对?-catenin的激活作用。应用激光共聚焦和免疫共沉淀实验证实RON和?-catenin蛋白间的相互作用。研究胃癌组织RON和?-catenin途径的共同激活与胃癌患者临床、病理特征的关系。探索和比较在体外和动物实验中单独或联合阻断RON和?-catenin通路对肿瘤细胞生长抑制作用。本研究将在胃癌发病机制和治疗新靶点研究方面获得创新性成果，具有重要的理论价值和潜在的应用前景。

RON在多种恶性肿瘤中表达异常，β-catenin的激活导致细胞粘附力下降促使肿瘤细胞迁移，RON和β-catenin都在肿瘤发生和发展过程中起重要作用。本研究详细探讨了RON及其变异体RONΔ160在多种胃癌细胞系和人体胃癌及正常胃粘膜组织中的表达情况，并利用免疫共沉淀和激光共聚焦等技术验证了RON和RONΔ160对β-catenin的激活作用，同时探索了胃癌裸鼠荷瘤模型的双靶向治疗，并得出以下结论：（1）RON, RONΔ160, β-catenin及其下游基因在胃癌组织和旁癌组织中的表达上调；（2）RON和RONΔ160的表达上调能引起β-catenin及其下游基因的表达上调；（3）RONΔ160的过表达可引起胃癌细胞形态学改变，通过调控细胞周期促进细胞增殖、迁移、侵袭并且可以在体内促进肿瘤生长；（4）RON和RONΔ160能与β-catenin结合产生相互作用，并促使β-catenin向细胞核内转移；（5）单独或者联合抑制RON和β-catenin基因，在体内和体外都能抑制胃癌细胞增殖和迁移，同时能有效抑制c-Myc和cyclin D1的表达。以期本研究工作可为临床筛选相关胃癌治疗靶点、延缓胃癌进展提供理论依据和工作基础。