胆汁酸通过1-磷酸鞘氨醇受体2（S1PR2）促进胆管癌发生发展的作用和机制研究

Chronic cholestasis is a vital stimulus of the process of cholangiocarcinoma. Sphingosine 1-phosphate receptors (S1PRs) is a kind of membrane derived lipid mediators receptor, and has been reported to be involved in a variety of malignant tumor cell proliferation, inflammation and metastasis. However, the role and mechanism of S1PR2 in the process of cholangiocarcinoma is still not clear. Our previous study found that the expression of S1PR2 is high in human and rat cholangiocarcinoma cells, S1PR2 specific inhibitor block ERK1/2 and AKT pathway and cholangiocarcinoma cells proliferation and migration induced by bile acid, and the computer simulation shows that between TCA and S1PR2 may exist direct combination. We hypothesized that S1PR2 may play an important mediating role in cholangiocarcinoma development induced by bile acid. In this project, we proposed to use the SPR, 3D cell co-culture, siRNA gene silencing, bile duct ligation and DEN induced, S1PR2 knockout mice and other technology to clarify the mechanism of S1PR2 in cholangiocarcinoma development induced by bile acid and downstream signaling pathways in the cell and animal models, and confirm that S1PR2 is TCA direct receptor in the cholangiocarcinoma cells. The project will explain the mechanism of cholangiocarcinoma development induced by bile acid, and provide new targets for the treatment of cholangiocarcinoma.

慢性胆汁酸淤积是胆管癌发生发展的一个重要刺激物。1-磷酸鞘氨醇受体（S1PRs）是一种膜衍生脂介质受体，已被报道参与了多种恶性肿瘤的细胞增殖、炎症和恶性转移。但是S1PR2在胆管癌的发生发展中的作用和机制尚不清楚。我们前期研究发现人和大鼠胆管癌细胞中S1PR2高表达，S1PR2特异性抑制剂能够抑制胆汁酸诱导的ERK1/2和AKT通路激活以及胆管癌细胞增殖和迁移；且计算机模拟发现TCA与S1PR2之间可能存在直接结合。我们假设S1PR2在胆汁酸诱导胆管癌发展中具重要的介导作用。本项目中，我们拟利用SPR、细胞3D共培养、siRNA基因沉默、胆管结扎DEN诱导、S1PR2敲除小鼠等技术，在细胞和动物层面阐明S1PR2在胆汁酸诱导胆管癌发生发展中的作用机制和下游信号通路，并确证S1PR2是胆汁酸在胆管癌细胞上的直接受体。项目将阐明胆汁酸在胆管癌发生发展中的作用机制，为胆管癌的治疗提供新的靶点。

胆管癌（CCA）具有较高的死亡率，并且发病率正在逐年上升。这一上升趋势要求我们开发更有效的CCA治疗方案。前期研究已证明CCA与鞘氨醇-1-磷酸-受体2（S1PR2）和鞘氨醇激酶2（SphK2）存在一定关联。ABC294640为一种竞争性SphK2抑制剂，I期临床研究发现ABC294640可以暂时治疗患有转移性CCA的患者，表明其具有治疗CCA的潜力。为了确定ABC294640治疗CCA的具体效果，本研究集中于探寻ABC294640对大鼠CCA细胞系的影响。我们发现ABC294640抑制CCA和CAF细胞的增殖和迁移。 3D器官共培养胆管癌模型中ABC294640减少了由CCA和CAF形成的“胆管样”结构的大小和数量。此外，CCA患者肝样本中S1PR2和SphK2表达增加，暗示了抑制SphK2治疗CCA的潜力。总之，ABC294640可以成为CCA的潜在治疗药物。