P300对aPKC-ι信号通路调控下的肝癌侵袭转移的作用机制研究

The Epithelial-Mesenchymal Transition (EMT) and repolarization of cancer cells is the key link of invasion and metastasis. In our previous research, we demonstrated that aPKC-ι pathway plays an important promote role in EMT, and ATM, which is a specific inhibitor of aPKC-ι, could reduce the invasion of hepatocellular carcinoma cells via reversing the EMT. However, it is one great difficulty and the key to suppress the EMT at initial step of hepatocellular carcinoma. There are reports that the P300 with endogenic histone acetyltransferase (HAT) activity catalyzes substrates lysine which covalently bound to the ethanoyl of acetoacetyl CoA in order to regulate the EMT of hepatocellular carcinoma at transcriptional level. Based on the previous works, this project will further investigate the effects of P300 on the invasion and metastasis and prognosis of hepatocellular carcinoma. The P300-siRNA will be structured for researching the mechanism of P300 regulating the EMT of hepatocellular carcinoma via aPKC-ι pathway. In vivo, the nude mouse model of hepatocellular carcinoma cell line transfected by lentivirus containing P300-siRNA was established to observe the EMT. And the small molecular that act on target P300 was screened by the high throughput drug screening system in order to investigate the invasion and metastasis mechanism of hepatocellular carcinoma combining with ATM. Ultimately, the mechanism of the genesis, invasion and metastasis of solid tumor supressed by inhibiting P300 activation was studied to provide a novel method for the treatment of hepatocellular carcinoma.

肿瘤侵袭转移的核心环节是肿瘤细胞的上皮细胞-间质细胞转化和极化重建。我们研究发现aPKC-ι信号通路的激活对肝癌EMT有促进作用，其特异性抑制剂ATM可以一定程度逆转EMT并降低肝癌细胞的侵袭力。但在肿瘤的起始阶段抑制EMT的发生是困扰研究者的难题。研究发现P300具有内在的乙酰转移酶（HAT）活性，催化乙酰辅酶A的乙酰基共价结合底物蛋白的赖氨酸残基，可在转录水平调控肝癌EMT的发生。基于前期工作，本项目拟进一步探讨P300对肝癌侵袭转移和预后的影响。运用分子干预，构建阻遏P300活化的siRNA，探讨P300对肝癌EMT关键通路aPKC-ι的影响和机制。并在动物实验中以携带有阻遏P300基因的慢病毒感染肝癌EMT移植瘤模型的裸鼠，运用高通量药物筛选出以P300为靶点的小分子化合物，在实体瘤中探讨P300抑制剂与ATM联合作用对肝癌侵袭转移的影响和机制，为治疗肝癌提供新的思路。