Wen Jing, Fu A-fu, Chen Li-Juan, Xie Xing-Jiang, Yang Guang-Li, Chen Xian-Cheng, Wang Yong-Sheng, Li Jiong, Chen Ping, Tang Ming-Hai, Shao Xi Ming, Lu You, Zhao Xia, Wei Yu-Quan
State Key Laboratory of Biotherapy, West China Hospital, West China Medical School, Sichuan University, Chengdu, China.
Int J Cancer. 2009 Jun 1;124(11):2709-18. doi: 10.1002/ijc.24244.
Lymph nodes metastasis of tumor could be a crucial early step in the metastatic process. Induction of tumor lymphangiogenesis by vascular endothelial growth factor-D may play an important role in promoting tumor metastasis to regional lymph nodes and these processes can be inhibited by inactivation of the VEGFR-3 signaling pathway. Honokiol has been reported to possess potent antiangiogenesis and antitumor properties in several cell lines and xenograft tumor models. However, its role in tumor-associated lymphangiogenesis and lymphatic metastasis remains unclear. Here, we established lymph node metastasis models by injecting overexpressing VEGF-D Lewis lung carcinoma cells into C57BL/6 mice to explore the effect of honokiol on tumor-associated lymphangiogenesis and related lymph node metastasis. The underlying mechanisms were systematically investigated in vitro and in vivo. In in vivo study, liposomal honokiol significantly inhibited the tumor-associated lymphangiogenesis and metastasis in Lewis lung carcinoma model. A remarkable delay of tumor growth and prolonged life span were also observed. In in vitro study, honokiol inhibited VEGF-D-induced survival, proliferation and tube-formation of both human umbilical vein endothelial cells (HUVECs) and lymphatic vascular endothelial cells (HLECs). Western blotting analysis showed that liposomal honokiol-inhibited Akt and MAPK phosphorylation in 2 endothelial cells, and downregulated expressions of VEGFR-2 of human vascular endothelial cells and VEGFR-3 of lymphatic endothelial cells. Thus, we identified for the first time that honokiol provided therapeutic benefit not only by direct effects on tumor cells and antiangiogenesis but also by inhibiting lymphangiogenesis and metastasis via the VEGFR-3 pathway. The present findings may be of importance to investigate the molecular mechanisms underlying the spread of cancer via the lymphatics and explore the therapeutical strategy of honokiol on antilymphangiogenesis and antimetastasis.
肿瘤的淋巴结转移可能是转移过程中至关重要的早期步骤。血管内皮生长因子-D诱导肿瘤淋巴管生成可能在促进肿瘤转移至区域淋巴结中发挥重要作用，而这些过程可通过VEGFR-3信号通路的失活来抑制。厚朴酚已被报道在多种细胞系和异种移植肿瘤模型中具有强大的抗血管生成和抗肿瘤特性。然而，其在肿瘤相关淋巴管生成和淋巴转移中的作用仍不清楚。在此，我们通过将过表达VEGF-D的Lewis肺癌细胞注射到C57BL/6小鼠中建立淋巴结转移模型，以探讨厚朴酚对肿瘤相关淋巴管生成和相关淋巴结转移的影响。在体外和体内系统地研究了其潜在机制。在体内研究中，脂质体厚朴酚显著抑制Lewis肺癌模型中的肿瘤相关淋巴管生成和转移。还观察到肿瘤生长明显延迟和寿命延长。在体外研究中，厚朴酚抑制VEGF-D诱导的人脐静脉内皮细胞（HUVECs）和淋巴管内皮细胞（HLECs）的存活、增殖和管形成。蛋白质印迹分析表明，脂质体厚朴酚抑制两种内皮细胞中的Akt和MAPK磷酸化，并下调人血管内皮细胞的VEGFR-2和淋巴管内皮细胞的VEGFR-3的表达。因此，我们首次发现厚朴酚不仅通过对肿瘤细胞的直接作用和抗血管生成提供治疗益处，还通过VEGFR-3途径抑制淋巴管生成和转移。本研究结果对于研究癌症通过淋巴管扩散的分子机制以及探索厚朴酚在抗淋巴管生成和抗转移方面的治疗策略可能具有重要意义。
