Identification of RSK and TTK as Modulators of Blood Vessel Morphogenesis Using an Embryonic Stem Cell-Based Vascular Differentiation Assay.
Blood vessels are formed through vasculogenesis, followed by remodeling of the endothelial network through angiogenesis. Many events that occur during embryonic vascular development are recapitulated during adult neoangiogenesis, which is critical to tumor growth and metastasis. Current antiangiogenic tumor therapies, based largely on targeting the vascular endothelial growth factor pathway, show limited clinical benefits, thus necessitating the discovery of alternative targets. Here we report the development of a robust embryonic stem cell-based vascular differentiation assay amenable to small-molecule screens to identify novel modulators of angiogenesis. In this context, RSK and TTK were identified as angiogenic modulators. Inhibition of these pathways inhibited angiogenesis in embryoid bodies and human umbilical vein endothelial cells. Furthermore, inhibition of RSK and TTK reduced tumor growth, vascular density, and improved survival in an in vivo Lewis lung carcinoma mouse model. Our study suggests that RSK and TTK are potential targets for antiangiogenic therapy, and provides an assay system for further pathway screens.
Program in Developmental and Stem Cell Biology, Peter Gilgan Centre for Research and Learning, The Hospital for Sick Children, 686 Bay Street, Toronto, ON M5G 0A4, Canada.
Lamis
L
Hammoud
Program in Developmental and Stem Cell Biology, Peter Gilgan Centre for Research and Learning, The Hospital for Sick Children, 686 Bay Street, Toronto, ON M5G 0A4, Canada.
Jessica R
JR
Adams
Program in Developmental and Stem Cell Biology, Peter Gilgan Centre for Research and Learning, The Hospital for Sick Children, 686 Bay Street, Toronto, ON M5G 0A4, Canada.
Amanda J
AJ
Loch
Drug Discovery Department, Ontario Institute for Cancer Research, Toronto, ON M5G 0A3, Canada.
Richard C
RC
Marcellus
Drug Discovery Department, Ontario Institute for Cancer Research, Toronto, ON M5G 0A3, Canada.
David E
DE
Uehling
Drug Discovery Department, Ontario Institute for Cancer Research, Toronto, ON M5G 0A3, Canada.
Ahmed
A
Aman
SPARC BioCentre, The Hospital for Sick Children, Toronto, ON M5G 0A4, Canada.
Christopher
C
Fladd
Radiation Medicine Program, STTARR Innovation Centre, Princess Margaret Cancer Centre, Toronto, ON M5G 1L7, Canada.
Trevor D
TD
McKee
Program in Developmental and Stem Cell Biology, Peter Gilgan Centre for Research and Learning, The Hospital for Sick Children, 686 Bay Street, Toronto, ON M5G 0A4, Canada.
Christine E B
CEB
Jo
Drug Discovery Department, Ontario Institute for Cancer Research, Toronto, ON M5G 0A3, Canada.
Rima
R
Al-Awar
Program in Developmental and Stem Cell Biology, Peter Gilgan Centre for Research and Learning, The Hospital for Sick Children, 686 Bay Street, Toronto, ON M5G 0A4, Canada; Department of Molecular Genetics, University of Toronto, Toronto, ON M5S 1A8, Canada.
Sean E
SE
Egan
Program in Developmental and Stem Cell Biology, Peter Gilgan Centre for Research and Learning, The Hospital for Sick Children, 686 Bay Street, Toronto, ON M5G 0A4, Canada; Department of Molecular Genetics, University of Toronto, Toronto, ON M5S 1A8, Canada. Electronic address: janet.rossant@sickkids.ca.
Janet
J
Rossant
D020533:Angiogenesis Inhibitors / Q000494:pharmacology; D000818:Animals; D001808:Blood Vessels / Q000196:embryology* / Q000378:metabolism*; D018797:Cell Cycle Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism*; D002454:Cell Differentiation; D002460:Cell Line; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D055808:Drug Discovery; D053595:Embryonic Stem Cells / Q000166:cytology* / Q000378:metabolism*; D005260:Female; D006801:Humans; D051379:Mice; D009024:Morphogenesis; D009369:Neoplasms / Q000188:drug therapy / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D009389:Neovascularization, Pathologic; D018919:Neovascularization, Physiologic / Q000187:drug effects / Q000235:genetics; D038081:Organogenesis; D047428:Protein Kinase Inhibitors / Q000494:pharmacology; D017346:Protein Serine-Threonine Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D011505:Protein-Tyrosine Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D019893:Ribosomal Protein S6 Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism*
D020533:Angiogenesis Inhibitors; D018797:Cell Cycle Proteins; D047428:Protein Kinase Inhibitors; D011505:Protein-Tyrosine Kinases; D017346:Protein Serine-Threonine Kinases; D019893:Ribosomal Protein S6 Kinases; C075840:TTK protein, human