c-Myc is essential for vasculogenesis and angiogenesis during development and tumor progression.

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.

[1]  F. White,et al.  VEGF mRNA is reversibly stabilized by hypoxia and persistently stabilized in VEGF-overexpressing human tumor cell lines. , 1995, Growth factors.

[2]  W. Risau,et al.  Mechanisms of angiogenesis , 1997, Nature.

[3]  Lieve Moons,et al.  Abnormal blood vessel development and lethality in embryos lacking a single VEGF allele , 1996, Nature.

[4]  J. Bishop,et al.  Contrasting patterns of myc and N-myc expression during gastrulation of the mouse embryo. , 1989, Genes & development.

[5]  David Baunoch,et al.  Abnormal angiogenesis and responses to glucose and oxygen deprivation in mice lacking the protein ARNT , 1997, Nature.

[6]  O. Hankinson,et al.  ARNT-deficient mice and placental differentiation. , 1997, Developmental biology.

[7]  F. Alt,et al.  N-myc can functionally replace c-myc in murine development, cellular growth, and differentiation. , 2000, Genes & development.

[8]  Douglas Hanahan,et al.  Signaling Vascular Morphogenesis and Maintenance , 1997, Science.

[9]  F. Alt,et al.  Analysis of C-MYC function in normal cells via conditional gene-targeted mutation. , 2001, Immunity.

[10]  Kenneth Chu,et al.  Sustained Loss of a Neoplastic Phenotype by Brief Inactivation of MYC , 2002, Science.

[11]  P. Bornstein,et al.  Transformation by v-src causes transient induction followed by repression of mouse thrombospondin-1. , 1994, Cell growth & differentiation : the molecular biology journal of the American Association for Cancer Research.

[12]  J. Sedivy,et al.  Phenotypes of c-Myc-deficient rat fibroblasts isolated by targeted homologous recombination. , 1997, Cell growth & differentiation : the molecular biology journal of the American Association for Cancer Research.

[13]  Mark J. Murphy,et al.  c-Myc regulates mammalian body size by controlling cell number but not cell size , 2001, Nature.

[14]  M. Simon,et al.  Multilineage embryonic hematopoiesis requires hypoxic ARNT activity. , 1999, Genes & development.

[15]  B. Keyt,et al.  Homologous Up-regulation of KDR/Flk-1 Receptor Expression by Vascular Endothelial Growth Factor in Vitro * , 1998, The Journal of Biological Chemistry.

[16]  P. Kingsley,et al.  Initiation of hematopoiesis and vasculogenesis in murine yolk sac explants. , 1995, Blood.

[17]  E. Gabrielson,et al.  c-Myc suppresses the tumorigenicity of lung cancer cells and down-regulates vascular endothelial growth factor expression. , 2000, Cancer research.

[18]  G. Keller,et al.  A common precursor for primitive erythropoiesis and definitive haematopoiesis , 1997, Nature.

[19]  W. Risau,et al.  Molecular mechanisms of vasculogenesis and embryonic angiogenesis , 1997, Journal of cellular physiology.

[20]  Kenneth J. Hillan,et al.  Heterozygous embryonic lethality induced by targeted inactivation of the VEGF gene , 1996, Nature.

[21]  Janet Rossant,et al.  Failure of blood-island formation and vasculogenesis in Flk-1-deficient mice , 1995, Nature.

[22]  P. Carmeliet,et al.  Role of vascular endothelial growth factor and vascular endothelial growth factor receptors in vascular development. , 1999, Current topics in microbiology and immunology.

[23]  J. Bishop,et al.  The MYC protein activates transcription of the alpha‐prothymosin gene. , 1991, The EMBO journal.

[24]  D. Felsher,et al.  Reversible tumorigenesis by MYC in hematopoietic lineages. , 1999, Molecular cell.

[25]  M. Linial,et al.  Viral Myc Oncoproteins in Infected Fibroblasts Down-modulate Thrombospondin-1, a Possible Tumor Suppressor Gene* , 1996, The Journal of Biological Chemistry.

[26]  J. Ihle.  The Challenges of Translating Knockout Phenotypes into Gene Function , 2000, Cell.

[27]  G. Evan,et al.  Suppression of Myc-Induced Apoptosis in β Cells Exposes Multiple Oncogenic Properties of Myc and Triggers Carcinogenic Progression , 2002, Cell.

[28]  D. Prober,et al.  Drosophila myc Regulates Cellular Growth during Development , 1999, Cell.

[29]  G. Breier,et al.  Expression of vascular endothelial growth factor during embryonic angiogenesis and endothelial cell differentiation. , 1992, Development.

[30]  Robert S. Kerbel,et al.  Establishing a Link between Oncogenes and Tumor Angiogenesis , 1998, Molecular medicine.

[31]  K. Dameron,et al.  Sequential development of an angiogenic phenotype by human fibroblasts progressing to tumorigenicity , 1997, Oncogene.

[32]  I. Weissman,et al.  A developmental switch in thymic lymphocyte maturation potential occurs at the level of hematopoietic stem cells , 1990, Cell.

[33]  M. Neeman,et al.  Stabilization of vascular endothelial growth factor mRNA by hypoxia and hypoglycemia and coregulation with other ischemia-induced genes , 1995, Molecular and cellular biology.

[34]  J. Cleveland,et al.  Constitutive c-myc expression in an IL-3-dependent myeloid cell line suppresses cell cycle arrest and accelerates apoptosis. , 1991, Oncogene.

[35]  G. Evan,et al.  Reversible activation of c-Myc in skin: induction of a complex neoplastic phenotype by a single oncogenic lesion. , 1999, Molecular cell.

[36]  M. Kennedy,et al.  A common precursor for hematopoietic and endothelial cells. , 1998, Development.

[37]  M. Roussel,et al.  Disruption of the ARF-Mdm2-p53 tumor suppressor pathway in Myc-induced lymphomagenesis. , 1999, Genes & development.

[38]  D. Hanahan,et al.  Patterns and Emerging Mechanisms of the Angiogenic Switch during Tumorigenesis , 1996, Cell.

[39]  Gerard I. Evan,et al.  Induction of apoptosis in fibroblasts by c-myc protein , 1992, Cell.

[40]  M. Skobe,et al.  Activation of the tie2 receptor by angiopoietin-1 enhances tumor vessel maturation and impairs squamous cell carcinoma growth. , 2002, The American journal of pathology.

[41]  Jessica Lo,et al.  HIF‐1α is required for solid tumor formation and embryonic vascularization , 1998 .

[42]  J L Cleveland,et al.  The ornithine decarboxylase gene is a transcriptional target of c-Myc. , 1993, Proceedings of the National Academy of Sciences of the United States of America.

[43]  M. Gassmann,et al.  Cellular and developmental control of O2 homeostasis by hypoxia-inducible factor 1 alpha. , 1998, Genes & development.

[44]  P. Neiman,et al.  Angiogenesis is an early event in the generation of myc-induced lymphomas , 2000, Oncogene.

[45]  J. Rossant,et al.  Role of the Flt-1 receptor tyrosine kinase in regulating the assembly of vascular endothelium , 1995, Nature.

[46]  J L Cleveland,et al.  Myc signaling via the ARF tumor suppressor regulates p53-dependent apoptosis and immortalization. , 1998, Genes & development.

[47]  U. Thorgeirsson,et al.  Different regulation of vascular endothelial growth factor expression by the ERK and p38 kinase pathways in v-ras, v-raf, and v-myc transformed cells. , 2000, Biochemical and biophysical research communications.

[48]  A. Bradley,et al.  A null c-myc mutation causes lethality before 10.5 days of gestation in homozygotes and reduced fertility in heterozygous female mice. , 1993, Genes & development.

[49]  P. Carmeliet,et al.  Role of HIF-1α in hypoxia-mediated apoptosis, cell proliferation and tumour angiogenesis , 1998, Nature.

[50]  M. L. Le Beau,et al.  A tumor suppressor-dependent inhibitor of angiogenesis is immunologically and functionally indistinguishable from a fragment of thrombospondin. , 1990, Proceedings of the National Academy of Sciences of the United States of America.

[51]  L. Penn,et al.  The myc oncogene: MarvelouslY Complex. , 2002, Advances in cancer research.

[52]  P. Vernier,et al.  SPARC and thrombospondin genes are repressed by the c‐jun oncogene in rat embryo fibroblasts. , 1994, The EMBO journal.