Department of Microbiology and Immunology, Medical School of Southeast University, Nanjing, 210009, Jiangsu, China.
Liver Cancer Institute, Zhongshan Hospital, Fudan University and Key Laboratory of Carcinogenesis and Cancer Invasion, Ministry of Education, Shanghai, 200032, China.
J Gastroenterol. 2023 Sep;58(9):908-924. doi: 10.1007/s00535-023-02012-8. Epub 2023 Jul 11.
Therapies for cholangiocarcinoma are largely limited and ineffective. Herein, we examined the role of the FGF and VEGF pathways in regulating lymphangiogenesis and PD-L1 expression in intrahepatic cholangiocarcinoma (iCCA).
The lymphangiogenic functions of FGF and VEGF were evaluated in lymphatic endothelial cells (LECs) and iCCA xenograft mouse models. The relationship between VEGF and hexokinase 2 (HK2) was validated in LECs by western blot, immunofluorescence, ChIP and luciferase reporter assays. The efficacy of the combination therapy was assessed in LECs and xenograft models. Microarray analysis was used to evaluate the pathological relationships of FGFR1 and VEGFR3 with HK2 in human lymphatic vessels.
FGF promoted lymphangiogenesis through c-MYC-dependent modulation of HK2 expression. VEGFC also upregulated HK2 expression. Mechanistically, VEGFC phosphorylated components of the PI3K/Akt/mTOR axis to upregulate HIF-1α expression at the translational level, and HIF-1α then bound to the HK2 promoter region to activate its transcription. More importantly, dual FGFR and VEGFR inhibition with infigratinib and SAR131675 almost completely inhibited lymphangiogenesis, and significantly suppressed iCCA tumor growth and progression by reducing PD-L1 expression in LECs.
Dual FGFR and VEGFR inhibition inhibits lymphangiogenesis through suppression of c-MYC-dependent and HIF-1α-mediated HK2 expression, respectively. HK2 downregulation decreased glycolytic activity and further attenuated PD-L1 expression. Our findings suggest that dual FGFR and VEGFR blockade is an effective novel combination strategy to inhibit lymphangiogenesis and improve immunocompetence in iCCA.
胆管癌的治疗方法主要有限且无效。在此，我们研究了 FGF 和 VEGF 通路在调节肝内胆管癌（iCCA）中的淋巴管生成和 PD-L1 表达中的作用。
在淋巴管内皮细胞（LEC）和 iCCA 异种移植小鼠模型中评估了 FGF 和 VEGF 的淋巴管生成功能。通过 Western blot、免疫荧光、ChIP 和荧光素酶报告基因检测验证了 VEGF 和己糖激酶 2（HK2）之间的关系。在 LECs 和异种移植模型中评估了联合治疗的疗效。微阵列分析用于评估 FGFR1 和 VEGFR3 与人类淋巴管中 HK2 的病理关系。
FGF 通过 c-MYC 依赖性调节 HK2 表达促进淋巴管生成。VEGFC 也上调了 HK2 的表达。在机制上，VEGFC 磷酸化 PI3K/Akt/mTOR 轴的成分，在翻译水平上上调 HIF-1α 的表达，然后 HIF-1α 结合到 HK2 启动子区域激活其转录。更重要的是，用英非替尼和 SAR131675 进行双重 FGFR 和 VEGFR 抑制几乎完全抑制了淋巴管生成，并通过降低 LECs 中的 PD-L1 表达，显著抑制了 iCCA 肿瘤的生长和进展。
双重 FGFR 和 VEGFR 抑制通过抑制 c-MYC 依赖性和 HIF-1α 介导的 HK2 表达分别抑制淋巴管生成。HK2 下调降低了糖酵解活性，并进一步减弱了 PD-L1 的表达。我们的研究结果表明，双重 FGFR 和 VEGFR 阻断是抑制淋巴管生成和改善 iCCA 免疫功能的有效新联合策略。
