aPKC-ɩ介导的FBP1下调对肝内胆管癌细胞糖代谢及侵袭转移的调控研究

EMT is a core aspect of the initial stage of cancer cells invasion and metastasis. The applicant firstly found that aPKC-ι was overexpressed and involved in the regulation of EMT in cholangiocarcinoma. Recently, it is reported that the EMT changes of cancer cells is related to abnormal glycometabolism. The applicant previously studied that the level of aPKC-ι was positively correlated with key enzymes and product of glycolysis pathway in intrahepatic cholangiocarcinoma. Meanwhile, the level of aPKC-ι was negatively associated with FBP1, which plays a critical role in regulating glycometabolism. Based on the above, we infer that FBP1 repressed by aPKC-ι enhances the level of glycolysis level and the ability of metastasis of cancer cells. Moreover, the positive feedback of lactate on cancer cells further promotes the invasion and metastasis in intrahepatic cholangiocarcinoma. This project intends to elucidate the effect of aPKC-ι regulating glycometabolism conditions and the ability of metastasis by employing activated or silenced expression of aPKC-ι intrahepatic cholangiocarcinoma cells. Furthermore, the specific mechanism of FBP1 loss mediated by aPKC-ι will be investigated in-depth. The project is expected to clarify the molecular mechanisms on invasion and metastasis of intrahepatic cholangiocarcinoma cells from a new perspective and to provide evidences for a new therapy strategy of intrahepatic cholangiocarcinoma.

上皮-间质转化（EMT）是癌细胞侵袭转移起始阶段的核心环节。申请者首次发现：aPKC-ι在胆管癌及其转移组织中高表达，参与调控胆管癌细胞EMT。近年来认为，癌细胞EMT改变与糖代谢异常密切相关，申请者前期研究发现，肝内胆管癌细胞中aPKC-ι的表达与肿瘤糖代谢异常的核心环节糖酵解过程的关键酶及其产物呈正相关；与FBP1呈负相关，而FBP1在调节癌细胞糖代谢过程中起着至关重要的作用。申请者据此推测，aPKC-ι可能通过负性调控FBP1从而增强肝内胆管癌细胞糖酵解水平及转移能力，同时糖酵解产物正反馈作用于癌细胞，更进一步促进肝内胆管癌的侵袭和转移。本项目拟利用增强或沉默aPKC-ι表达的肝内胆管癌细胞，阐明aPKC-ι调控癌细胞糖代谢状态及转移能力的作用，并深入探讨aPKC-ι调控FBP1的具体机制。可望从新的角度阐明肝内胆管癌细胞侵袭转移的分子机制，为探索新的肝内胆管癌治疗策略提供理论依据。

肝内胆管癌在世界范围内是最常见的恶性肿瘤之一，同时也是第二常见的原发性肝脏肿瘤。目前，尚缺乏有效的治愈手段，肝内胆管癌病人的预后较差且具有较高的死亡率。我们前期研究发现：非典型性蛋白激酶C-iota(aPKC-i)，细胞极化运动调节蛋白，在原发性和转移性肝内胆管癌组织中高表达，并通过 aPKC-i/P-Sp1/Snail信号通路调控胆管癌细胞的上皮-间质转化（epithelial-mesenchymal transition, EMT）。最近有研究报道，在癌细胞的EMT过程中往往伴随着异常糖代谢状态的改变。鉴于FBP1在调节葡萄糖代谢中的重要作用，因此，我们假设aPKC-i通过Snai1途径抑制FBP1表达，促进肝内胆管癌细胞EMT并增强糖酵解水平，进而介导肝内胆管癌的侵袭和转移。本研究中，我们发现：肝内胆管癌组织中，aPKC-i与Snail高表达，FBP1低表达；此外，aPKC-ι表达与Snail水平正相关，而与FBP1呈负相关；FBP1表达与Snail水平呈负相关；aPKC-ι、Snail和FBP1为肝内胆管癌病人的预后相关；验证了FBP1参与aPKC-i调节肝内胆管癌细胞EMT同时可增强癌细胞糖酵解水平，进而促进肝内胆管癌侵袭和转移；并发现Snail通过直接与FBP1启动子直接结合，抑制FBP1的转录与表达；验证了aPKC-i通过Snail信号通路下调FBP1表达参与肝内胆管癌EMT及代谢重编程。证实了aPKC-i/Snail信号通路对肝内胆管癌侵袭和转移的调控作用。我们的发现为肝内胆管癌进展和转移的分子机制提供了新的线索，同时并为探索新的治疗策略提供理论依据。