胆管癌（CCA）是一种高度异质性和转移性恶性肿瘤，即便在根治性肝切除后，预后也很差。因此，需要研究其发病机制并确定有效的治疗靶点。在本研究中，我们发现一种丝/苏氨酸蛋白激酶TANK结合蛋白激酶1（TBK1）在小鼠自发性CCA癌变的不同阶段（增生、异型增生和CCA）中呈动态增加趋势。与非肿瘤组织相比，TBK1在人类组织包括肝内（n = 182）和肝外（n = 40）CCA组织中表达上调，且TBK1的高表达与更大的肿瘤直径、淋巴结转移和TNM分期进展相关。功能研究表明，TBK1在体内外均促进CCA的生长和转移。 TBK1直接与β-连环蛋白相互作用，促进其在S552位点的磷酸化和核定位，从而进一步激活与EMT相关的转录重编程。TBK1抑制剂GSK-8612或酶失活突变有效抑制了上述过程。此外，我们发现胆固醇内吞受体低密度脂蛋白受体（LDLR）在CCA中上调。因此，我们设计了一种胆固醇结合的DNA/RNA杂交寡核苷酸（Cho-TBK1-HDO），可以通过LDLR在CCA细胞中积累，减少TBK1 mRNA水平并抑制CCA的肝内转移。此外，在182例ICC患者的实验组中，高TBK1表达合并高核β-连环蛋白表达预测了更差的预后。总之，TBK1可能是CCA患者的潜在预后生物标志物和治疗靶点。 © 2023作者（们）。

Cholangiocarcinoma (CCA) is a highly heterogeneous and metastatic malignancy with a poor prognosis even after curative hepatectomy. Studies exploring its pathogenesis and identifying effective therapeutic targets are urgently needed. In this study, we found that TANK-binding kinase 1 (TBK1), a serine/threonine-protein kinase, showed a dynamic increase during the different stages of murine spontaneous CCA carcinogenesis (hyperplasia, dysplasia, and CCA). TBK1 was upregulated in human tissues, including intrahepatic (n = 182) and extrahepatic (n = 40) CCA tissues, compared with nontumor tissues, and the elevated expression of TBK1 was positively correlated with larger tumour diameter, lymph node metastasis, and advanced TNM stage. Functional studies indicated that TBK1 promoted CCA growth and metastasis both in vitro and in vivo. TBK1 directly interacts with β-catenin, promoting its phosphorylation at the S552 site and its nuclear translocation, which further activates EMT-related transcriptional reprogramming. GSK-8612, a TBK1 inhibitor or a kinase-inactivating mutation, effectively suppresses the above processes. In addition, we found that low-density lipoprotein receptor (LDLR), which mediates the endocytosis of cholesterol, was upregulated in CCA. Therefore, we designed a cholesterol-conjugated DNA/RNA heteroduplex oligonucleotide targeting TBK1 (Cho-TBK1-HDO), which could accumulate in CCA cells via LDLR, reduce the TBK1 mRNA level and inhibit intrahepatic metastasis of CCA. Besides, in the experimental group of 182 ICC patients, high TBK1 expression combined with high nuclear β-catenin expression predicted a worse prognosis. In summary, TBK1 might serve as a potential prognostic biomarker and therapeutic target for patients with CCA.© 2023. The Author(s).