钙调蛋白激酶CaMKIIγ促进结直肠癌发生发展的机制研究

CaMKIIγ is a downstream kinase of the non-canonical Wnt/Ca2+ pathway which plays an essential role in the growth and proliferation of many tumors. Our previous results showed that CaMKIIγ promoted the development of colitis-associated cancer by stimulating the proliferation of intestinal epithelial cells, but not the inflammation. However, the tumor-promoting mechanism of CaMKIIγ in colorectal cancer (CRC) is still obscure. In this proposal, we have managed to screen many unreported CaMKIIγ interactive proteins by BioID method. CaMKIIγ may exert its functions through these key interacting proteins. We will confirm the relationship between CaMKIIγ and its interacting proteins by co-immunoprecipitation and in vitro kinase experiments. We will also investigate the function of CaMKIIγ in the development of CRC by using the CaMKIIγ-/- mouse, APC Min/+ mouse and the AOM-induced CRC model, as well as the application of the CaMKIIγ specific inhibitor, KN93. The results will be further verified in human CRC tissues. In brief, our project will decipher the underlying mechanism of CaMKIIγ in the development of CRC, to provide a potential therapeutic target of CRC.

钙调蛋白激酶CaMKIIγ是非经典Wnt/Ca2+通路下游激酶，在多种肿瘤致病过程中发挥重要作用。我们前期研究发现CaMKIIγ可促进小鼠炎症相关性结直肠癌的发生发展，机制在于其促进了肠上皮细胞增殖而非调控炎症反应。CaMKIIγ调控肠癌增殖的分子机制及其在非肠炎相关结直肠癌(Colorectal Cancer, CRC)发生发展中的作用仍不清楚。我们前期筛选到多个新的CaMKIIγ互作蛋白，提示其可能通过它们发挥功能。本研究将通过免疫共沉淀，体外激酶实验等研究CaMKIIγ与互作蛋白的作用方式；利用CaMKIIγ敲除小鼠、APC Min/+小鼠及AOM诱导的小鼠CRC模型，结合使用CaMKIIγ抑制剂KN93，深入研究CaMKIIγ及其关键互作蛋白在CRC发生发展中的作用；并用临床CRC组织验证。本研究将阐明CaMKIIγ促进CRC发生发展的分子机理，为临床诊疗该疾病提供潜在药物靶标。

钙调蛋白激酶CaMKIIγ是非经典Wnt/Ca2+通路下游激酶，我们前期研究发现CaMKIIγ可促进AOM/DSS诱导的炎性肠癌，但CaMKIIγ在结直肠癌发生发展中的作用仍不清楚，本项目由此开展以下工作：1）确认CaMKIIγ与DVL2及TIPRL存在相互作用，提示CaMKIIγ可能通过与DVL2互作反馈调控Wnt信号通路，并可能通过与TIPRL相互作用参与肿瘤细胞凋亡调控。此外还发现CaMKIIγ与脂肪酸氧化反应限速酶CPT1A存在相互作用，提示CaMKIIγ 可能调控脂质代谢促进结直肠癌的发生发展。2）利用CaMKIIγ敲除小鼠、APCMin/+小鼠及AOM诱导的小鼠肠癌模型，结合使用CaMKIIγ抑制剂KN93，确定CaMKIIγ在肠癌发生发展中的促进作用；3）检测肠癌患者的肿瘤及癌旁组织中CaMKIIγ及其互作蛋白的表达水平。本研究将阐明CaMKIIγ促进肠癌发生发展的分子机理，为临床诊疗该疾病提供潜在药物靶标。