Active interaction of human A375 melanoma cells with the lymphatics in vivo

• Published in: Histochemistry and cell biology Vol. 114; no. 5; pp. 373 - 385
• Main Authors: Papoutsi, M, Siemeister, G, Weindel, K, Tomarev, S I, Kurz, H, Schächtele, C, Martiny-Baron, G, Christ, B, Marmé, D, Wilting, J
• Format: Journal Article
• Language: English
• Published: Germany Springer Nature B.V 01.11.2000
• Subjects: Allantoin - metabolism; Animals; Blotting, Northern; Capillaries; Cell Division; Cell Nucleus - ultrastructure; Cell proliferation; Chick Embryo; Chorioallantoic membrane; Coturnix; Endothelial cells; Fluorescent Antibody Technique, Indirect; Gene Expression Regulation, Neoplastic - genetics; Homeodomain Proteins - biosynthesis; Humans; Immunohistochemistry; In Situ Hybridization; Lymphatic System - pathology; Lymphatic System - ultrastructure; Melanoma; Melanoma, Experimental - genetics; Melanoma, Experimental - pathology; Melanoma, Experimental - ultrastructure; Mice; Mice, Nude; Receptor Protein-Tyrosine Kinases - metabolism; Receptors, Growth Factor - metabolism; Solid tumors; Transfection; Tumor cells; Tumor Cells, Cultured; Tumor Suppressor Proteins; Tumors; Vascular endothelial growth factor; Vascular Endothelial Growth Factor Receptor-3; Vascular endothelial growth factor receptors
• ISSN: 0948-6143; 1432-119X
• DOI: 10.1007/s004180000204

We have used the avian chorioallantoic membrane (CAM) to study the interaction of tumor cells with the lymphatics in vivo. The vascular endothelial growth factor-C (VEGF-C) has been shown to be lymphangiogenic. We have therefore grown VEGF-C-expressing human A375 melanoma cells on the CAM. These tumors induced numerous lymphatics at the invasive front, and compressed or destroyed VEGF receptor (R)-3-positive lymphatics were observed within the solid tumors. The lymphatics in the CAM and in the A375 melanomas could also be demonstrated with an antibody against Prox 1, a highly specific marker of lymphatic endothelial cells. Proliferation studies revealed a BrdU labeling index of 11.6% of the lymphatic endothelial cells in the tumors and at their margins. A great number of melanoma cells invaded the lymphatics. Such interactions were not observed with VEGF-C-negative Malme 3 M melanoma cells. Lymphangiogenesis was inhibited to some extent when A375 melanoma cells were transfected with cDNA encoding soluble VEGFR-3 (sflt4), and the BrdU labeling index of the lymphatics in these tumors was 3.9%. Invasion of lymphatics and growth of blood vascular capillaries were not inhibited by the transfection. Therefore, tumor-induced lymphangiogenesis seems to be dependent to some extent on VEGF-C/flt4 interactions, but invasion of lymphatics seems to be a distinct mechanism.