title: Vascular endothelial growth factor-C and C-C chemokine receptor 7 in tumor cell-lymphatic cross-talk promote invasive phenotype.
abstract: Most carcinomas spread to distant sites through lymphatic vessels. Several preclinical and clinical studies have shown a positive correlation between the incidence of lymph node metastasis and secretion of the lymphatic growth factor vascular endothelial growth factor-C (VEGF-C) by tumor cells, suggesting tumor lymphangiogenesis as an escape mechanism. However, recent evidence has shown VEGF receptor-3 (VEGFR-3) expression on tumor cells and autocrine signaling, which increase metastatic potential. Furthermore, there is growing evidence implicating lymphatic-homing chemokine receptors, particularly C-C chemokine receptor 7 (CCR7), in lymph node metastasis. We report here that expressions of VEGF-C and CCR7 by tumor cells act synergistically to promote their invasion toward lymphatics. First, VEGF-C acts to increase lymphatic secretion of CCL21, which in turn drives CCR7-dependent tumor chemoinvasion toward lymphatics. Second, VEGF-C acts in an autocrine fashion to increase tumor invasiveness by increasing the proteolytic activity and motility of tumor cells in a three-dimensional matrix. Both of these effects are VEGFR-3 dependent and evident only in three-dimensional environments. We further verified that VEGF-C induces lymphatic CCL21 up-regulation in vivo by direct injection of VEGF-C protein intradermally in the mouse. Taken together, these results bridge the prometastatic functions of CCR7 and VEGF-C in tumors and show that, beyond lymphangiogenesis, VEGF-C promotes tumor invasion toward lymphatics by both autocrine and CCR7-dependent paracrine signaling mechanisms, which may be a significant cause of lymph node metastasis.
authors.affiliation: Institute of Bioengineering, Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland.
authors.forename: Amine
authors.initials: A
authors.lastname: Issa
authors.forename: Thomas X
authors.initials: TX
authors.lastname: Le
authors.forename: Alexander N
authors.initials: AN
authors.lastname: Shoushtari
authors.forename: Jacqueline D
authors.initials: JD
authors.lastname: Shields
authors.forename: Melody A
authors.initials: MA
authors.lastname: Swartz
mesh_terms: D001943:Breast Neoplasms / Q000378:metabolism* / Q000473:pathology*; D045744:Cell Line, Tumor; D002465:Cell Movement / Q000502:physiology; D054421:Chemokine CCL21 / Q000378:metabolism; D042783:Endothelial Cells / Q000378:metabolism* / Q000473:pathology*; D006801:Humans; D008207:Lymphatic Metastasis; D042601:Lymphatic Vessels / Q000378:metabolism; D009361:Neoplasm Invasiveness; D020239:Receptor Cross-Talk; D054400:Receptors, CCR7 / Q000096:biosynthesis / Q000378:metabolism*; D015398:Signal Transduction; D042582:Vascular Endothelial Growth Factor C / Q000096:biosynthesis / Q000378:metabolism*; D040321:Vascular Endothelial Growth Factor Receptor-3 / Q000096:biosynthesis / Q000378:metabolism
chemical_list: C515478:CCL21 protein, human; D054421:Chemokine CCL21; D054400:Receptors, CCR7; C467486:VEGFC protein, human; D042582:Vascular Endothelial Growth Factor C; D040321:Vascular Endothelial Growth Factor Receptor-3