Infantile hemangioma (IH) is a common vascular tumor with a unique lifecycle of rapid blood vessel formation over the first 6-9 months of infancy, followed by a slow spontaneous involution of blood vessels over several years. For most children, IH does not pose a serious threat and therapy is unnecessary; however, in about 10% of cases, IH can enlarge dramatically, threaten organs and cause permanent disfigurement. Over the last 10 years, propranolol, a well-known non-selective ?-adrenergic receptor antagonist, has emerged as first-line therapy for endangering IH, yet how and why it works so well in reducing the vascular overgrowth in IH has remained a mystery. There is a significant need to improve propranolol therapy because up to 18% of IHs fail to respond, up to 25% resume growth when the drug is stopped, and 37% of propranolol-treated infants require surgery at 5-6 years of age to minimize deformity caused by remaining fibrofatty residua. To improve on propranolol, it is essential to elucidate it?s mechanism of action against vascular overgrowth, which will then provide a path forward to advance IH medical therapy, and potentially other neovascular diseases as well. In previous funding cycles, we identified a hemangioma stem cell (HemSC) from human IH surgical specimens that can differentiate into endothelial cells, pericytes and adipocytes and form hemangioma-like vessels within 7 days when implanted into immune-deficient mice. Subsequent studies from our lab and others validate HemSCs as the IH-initiating cell. Our recent results show that a small molecule inhibitor of the transcription factor SOX18 and propranolol both effectively block HemSC-to-endothelial differentiation. Furthermore, the R(+) enantiomer of propranolol, which lacks ?-adrenergic receptor antagonistic activity, is equally effective. This novel discovery identifies a ?-adrenergic receptor-independent, SOX18-dependent mechanism by which propranolol reduces vascular overgrowth in IH. To investigate deeply, we propose three specific aims.
Aim 1 will directly and rigorously test the requirement for SOX18 in IH vessel formation using our in vivo model in which IH-derived HemSC form IH-like blood vessels in nude mice.
Aim 2 will investigate dimerization status of SOX18 in IH (sub-aim 2a), how propranolol and the R(+) enantiomer disrupt SOX18 dimerization and sub- cellular localization (sub-aim 2b), and how this alters transcription to prevent HemSC-blood vessel formation (sub-aim 2c).
Aim 3, conducted in parallel, will analyze our existing next generation sequencing data using new bioinformatic tools to identify potential chromosomal translocations or small copy number variants that could produce fusion transcripts with new activities (sub-aim 3a) and will perform deep coverage RNA-Seq on IH tissue and freshly isolated IH cells as an alternative method to identify fusion transcripts (sub-aim 3b); once identified, the connection to SOX18 and IH vessel formation will tested in in vitro and in vivo models.

Public Health Relevance

Infantile hemangioma, a benign vascular tumor that occurs in 4-5% of children, is treated with propranolol, yet why and how propranolol is effective has remained a mystery. We have new data that uncovers a novel, unexpected mechanism of action for propranolol. In this proposal we will deeply study how propranolol reduces vascular overgrowth in infantile hemangioma with the goal of improving treatment options for infantile hemangioma, and potentially other diseases where vascular overgrowth occurs.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Project (R01)
Project #
2R01HL096384-09
Application #
9973341
Study Section
Cardiovascular Differentiation and Development Study Section (CDD)
Program Officer
Mcdonald, Cheryl
Project Start
2009-04-01
Project End
2024-04-30
Budget Start
2020-05-01
Budget End
2021-04-30
Support Year
9
Fiscal Year
2020
Total Cost
Indirect Cost
Name
Boston Children's Hospital
Department
Type
DUNS #
076593722
City
Boston
State
MA
Country
United States
Zip Code
02115
Nowak-Sliwinska, Patrycja; Alitalo, Kari; Allen, Elizabeth et al. (2018) Consensus guidelines for the use and interpretation of angiogenesis assays. Angiogenesis 21:425-532
Ye, Xi; Abou-Rayyah, Yassir; Bischoff, Joyce et al. (2016) Altered ratios of pro- and anti-angiogenic VEGF-A variants and pericyte expression of DLL4 disrupt vascular maturation in infantile haemangioma. J Pathol 239:139-51
Ayturk, Ugur M; Couto, Javier A; Hann, Steven et al. (2016) Somatic Activating Mutations in GNAQ and GNA11 Are Associated with Congenital Hemangioma. Am J Hum Genet 98:789-95
Huang, Lan; Nakayama, Hironao; Klagsbrun, Michael et al. (2015) Glucose transporter 1-positive endothelial cells in infantile hemangioma exhibit features of facultative stem cells. Stem Cells 33:133-45
Jia, Di; Huang, Lan; Bischoff, Joyce et al. (2015) The endogenous zinc finger transcription factor, ZNF24, modulates the angiogenic potential of human microvascular endothelial cells. FASEB J 29:1371-82
Nakayama, Hironao; Huang, Lan; Kelly, Ryan P et al. (2015) Infantile hemangioma-derived stem cells and endothelial cells are inhibited by class 3 semaphorins. Biochem Biophys Res Commun 464:126-32
Smadja, David M; Levy, Marilyne; Huang, Lan et al. (2015) Treprostinil indirectly regulates endothelial colony forming cell angiogenic properties by increasing VEGF-A produced by mesenchymal stem cells. Thromb Haemost 114:735-47
Lee, D; Boscolo, E; Durham, J T et al. (2014) Propranolol targets the contractility of infantile haemangioma-derived pericytes. Br J Dermatol 171:1129-37
Smadja, David M; Dorfmüller, Peter; Guerin, Coralie L et al. (2014) Cooperation between human fibrocytes and endothelial colony-forming cells increases angiogenesis via the CXCR4 pathway. Thromb Haemost 112:1002-13
Gelfand, Maria V; Hagan, Nellwyn; Tata, Aleksandra et al. (2014) Neuropilin-1 functions as a VEGFR2 co-receptor to guide developmental angiogenesis independent of ligand binding. Elife 3:e03720

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