title: c-Myc is essential for vasculogenesis and angiogenesis during development and tumor progression.
abstract: c-Myc promotes cell growth and transformation by ill-defined mechanisms. c-myc(-/-) mice die by embryonic day 10.5 (E10.5) with defects in growth and in cardiac and neural development. Here we report that the lethality of c-myc(-/-) embryos is also associated with profound defects in vasculogenesis and primitive erythropoiesis. Furthermore, c-myc(-/-) embryonic stem (ES) and yolk sac cells are compromised in their differentiative and growth potential. These defects are intrinsic to c-Myc, and are in part associated with a requirement for c-Myc for the expression of vascular endothelial growth factor (VEGF), as VEGF can partially rescue these defects. However, c-Myc is also required for the proper expression of other angiogenic factors in ES and yolk sac cells, including angiopoietin-2, and the angiogenic inhibitors thrombospondin-1 and angiopoietin-1. Finally, c-myc(-/-) ES cells are dramatically impaired in their ability to form tumors in immune-compromised mice, and the small tumors that sometimes develop are poorly vascularized. Therefore, c-Myc function is also necessary for the angiogenic switch that is indispensable for the progression and metastasis of tumors. These findings support the model wherein c-Myc promotes cell growth and transformation, as well as vascular and hematopoietic development, by functioning as a master regulator of angiogenic factors.
mesh_terms: D042683:Angiopoietin-1; D042702:Angiopoietin-2; D000818:Animals; D002454:Cell Differentiation; D002460:Cell Line; D016228:Endothelial Growth Factors / Q000096:biosynthesis; D004920:Erythropoiesis / Q000502:physiology; D005260:Female; D036341:Intercellular Signaling Peptides and Proteins / Q000096:biosynthesis; D008222:Lymphokines / Q000096:biosynthesis; D008297:Male; D008562:Membrane Glycoproteins / Q000096:biosynthesis; D051379:Mice; D018345:Mice, Knockout; D016513:Mice, SCID; D018919:Neovascularization, Physiologic / Q000502:physiology*; D019408:Platelet Endothelial Cell Adhesion Molecule-1 / Q000378:metabolism; D014176:Protein Biosynthesis; D016271:Proto-Oncogene Proteins c-myc / Q000235:genetics / Q000502:physiology*; D013234:Stem Cells / Q000166:cytology / Q000378:metabolism; D019700:Thrombospondin 1 / Q000096:biosynthesis; D042461:Vascular Endothelial Growth Factor A; D042442:Vascular Endothelial Growth Factors
chemical_list: D042683:Angiopoietin-1; D042702:Angiopoietin-2; C467628:Angpt1 protein, mouse; D016228:Endothelial Growth Factors; D036341:Intercellular Signaling Peptides and Proteins; D008222:Lymphokines; D008562:Membrane Glycoproteins; D019408:Platelet Endothelial Cell Adhesion Molecule-1; D016271:Proto-Oncogene Proteins c-myc; D019700:Thrombospondin 1; D042461:Vascular Endothelial Growth Factor A; D042442:Vascular Endothelial Growth Factors