Department of Medical Oncology, National Center for Tumor Diseases (NCT) Heidelberg, Heidelberg University Hospital, Heidelberg, Germany.
Liver Cancer Center Heidelberg, Heidelberg University Hospital, Heidelberg, Germany.
Liver Int. 2024 Nov;44(11):2950-2963. doi: 10.1111/liv.16069. Epub 2024 Aug 20.
Cholangiocarcinoma (CCA) is an aggressive malignancy arising from the intrahepatic (iCCA) or extrahepatic (eCCA) bile ducts with poor prognosis and limited treatment options. Prior evidence highlighted a significant contribution of the non-canonical NF-κB signalling pathway in initiation and aggressiveness of different tumour types. Lymphotoxin-β (LTβ) stimulates the NF-κB-inducing kinase (NIK), resulting in the activation of the transcription factor RelB. However, the functional contribution of the non-canonical NF-κB signalling pathway via the LTβ/NIK/RelB axis in CCA carcinogenesis and progression has not been established.
Human CCA-derived cell lines and organoids were examined to determine the expression of NF-κB pathway components upon activation or inhibition. Proliferation and cell death were analysed using real-time impedance measurement and flow cytometry. Immunoblot, qRT-PCR, RNA sequencing and in situ hybridization were employed to analyse gene and protein expression. Four in vivo models of iCCA were used to probe the activation and regulation of the non-canonical NF-κB pathway.
Exposure to LTα1/β2 activates the LTβ/NIK/RelB axis and promotes proliferation in CCA. Inhibition of NIK with the small molecule inhibitor B022 efficiently suppresses RelB expression in patient-derived CCA organoids and nuclear co-translocation of RelB and p52 stimulated by LTα1/β2 in CCA cell lines. In murine CCA, RelB expression is significantly increased and LTβ is the predominant ligand of the non-canonical NF-κB signalling pathway.
Our study confirms that the non-canonical NF-κB axis LTβ/NIK/RelB drives cholangiocarcinogenesis and represents a candidate therapeutic target.
胆管癌（CCA）是一种起源于肝内（iCCA）或肝外（eCCA）胆管的侵袭性恶性肿瘤，预后较差，治疗选择有限。先前的证据强调了非经典 NF-κB 信号通路在不同肿瘤类型的起始和侵袭性中的重要作用。淋巴毒素-β（LTβ）刺激 NF-κB 诱导激酶（NIK），导致转录因子 RelB 的激活。然而，LTβ/NIK/RelB 轴的非经典 NF-κB 信号通路在 CCA 癌变和进展中的功能贡献尚未确定。
研究了人 CCA 来源的细胞系和类器官，以确定 NF-κB 通路成分在激活或抑制后的表达情况。使用实时阻抗测量和流式细胞术分析增殖和细胞死亡。免疫印迹、qRT-PCR、RNA 测序和原位杂交用于分析基因和蛋白表达。使用四个 iCCA 的体内模型来探测非经典 NF-κB 通路的激活和调节。
LTα1/β2 的暴露激活了 LTβ/NIK/RelB 轴，并促进了 CCA 的增殖。小分子抑制剂 B022 抑制 NIK 的活性可有效抑制患者来源的 CCA 类器官中的 RelB 表达，以及 LTα1/β2 刺激的 CCA 细胞系中的 RelB 和 p52 的核共转位。在小鼠 CCA 中，RelB 的表达显著增加，LTβ 是非经典 NF-κB 信号通路的主要配体。
我们的研究证实，非经典 NF-κB 轴 LTβ/NIK/RelB 驱动胆管癌发生，代表了一个有希望的治疗靶点。
