Activation of the VEGFC/VEGFR3 pathway induces cancer immune escape through tumor-associated lymphatic vessels and macrophages in colorectal cancer

Colorectal cancer (CRC) is one of the major causes of cancer-related death in Western countries and is associated with increased numbers of lymphatic vessels (LVs) and tumor-associated macrophages (TAMs). The VEGFC/VEGFR3 pathway is regarded as the principal inducer of lymphangiogenesis and it contributes to metastases; however, no data are available on its role during CRC development. We found that both VEGFC and VEGFR3 were upregulated in human non-metastatic CRC, with VEGFR3 localising on both LVs and TAMs. We further proved in different preclinical models of CRC, that VEGFC/VEGFR3 axis can shape both LECs and TAMs to synergically inhibit anti-tumor immunity and promote primary CRC growth. VEGFR3-directed therapy could be envisioned for the treatment of non-metastatic CRC. n=8 Lymphatic cell samples and n=8 Macrophage samples with or without anti-VEGFR3 treatment.