Figure S1: Anti-lymphatic compounds do not disrupt the blood vasculature. Figure S2: Simvastatin and lovastatin inhibit blood and lymphatic vessel development. Figure S3: Flunarizine causes apoptosis in parachordal lymphangioblasts. Figure S4: Bodyweight changes in mice treated with anti-lymphatic compounds. Figure S5: Bioluminescent imaging of primary tumour growth. Supplementary Table 1. VEGFR IC50 values for lymphatic inhibitors.
ARTICLE ABSTRACT
The growth of new lymphatic vessels (lymphangiogenesis) in tumors is an integral step in the metastatic spread of tumor cells, first to the sentinel lymph nodes that surround the tumor and then elsewhere in the body. Currently, no selective agents designed to prevent lymphatic vessel growth have been approved for clinical use, and there is an important potential clinical niche for antilymphangiogenic agents. Using a zebrafish phenotype-based chemical screen, we have identified drug compounds, previously approved for human use, that have antilymphatic activity. These include kaempferol, a natural product found in plants; leflunomide, an inhibitor of pyrimidine biosynthesis; and cinnarizine and flunarizine, members of the type IV class of calcium channel antagonists. Antilymphatic activity was confirmed in a murine in vivo lymphangiogenesis Matrigel plug assay, in which kaempferol, leflunomide, and flunarizine prevented lymphatic growth. We show that kaempferol is a novel inhibitor of VEGFR2/3 kinase activity and is able to reduce the density of tumor-associated lymphatic vessels as well as the incidence of lymph node metastases in a metastatic breast cancer xenograft model. However, in this model, kaempferol administration was also associated with tumor deposits in the pancreas and diaphragm, and flunarizine was found to be tumorigenic. Although this screen revealed that zebrafish is a viable platform for the identification and development of mammalian antilymphatic compounds, it also highlights the need for focused secondary screens to ensure appropriate efficacy of hits in a tumor context. Mol Cancer Ther; 13(10); 2450–62. ©2014 AACR.
