title: Targeting SRPK1 to control VEGF-mediated tumour angiogenesis in metastatic melanoma.
abstract: BACKGROUND
  Current therapies for metastatic melanoma are targeted either at cancer mutations driving growth (e.g., vemurafenib) or immune-based therapies (e.g., ipilimumab). Tumour progression also requires angiogenesis, which is regulated by VEGF-A, itself alternatively spliced to form two families of isoforms, pro- and anti-angiogenic. Metastatic melanoma is associated with a splicing switch to pro-angiogenic VEGF-A, previously shown to be regulated by SRSF1 phosphorylation by SRPK1. Here, we show a novel approach to preventing angiogenesis-targeting splicing factor kinases that are highly expressed in melanomas.
  
  
  METHODS
  We used RT-PCR, western blotting and immunohistochemistry to investigate SRPK1, SRSF1 and VEGF expression in tumour cells, and in vivo xenograft assays to investigate SRPK1 knockdown and inhibition in vivo.
  
  
  RESULTS
  In both uveal and cutaneous melanoma cell lines, SRPK1 was highly expressed, and inhibition of SRPK1 by knockdown or with pharmacological inhibitors reduced pro-angiogenic VEGF expression maintaining the production of anti-angiogenic VEGF isoforms. Both pharmacological SRPK1 inhibitors and SRPK1 knockdown reduced growth of human melanomas in vivo, but neither affected cell proliferation in vitro.
  
  
  CONCLUSIONS
  These results suggest that selective blocking of pro-angiogenic isoforms by inhibiting splice-site selection with SRPK1 inhibitors reduces melanoma growth. SRPK1 inhibitors may be used as therapeutic agents.
authors.affiliation: Microvascular Research Laboratories, School of Physiology and Pharmacology, Preclinical Veterinary Sciences Building, University of Bristol, Southwell Street, Bristol BS2 8EJ, UK.
authors.forename: M V
authors.initials: MV
authors.lastname: Gammons
authors.affiliation: Microvascular Research Laboratories, School of Physiology and Pharmacology, Preclinical Veterinary Sciences Building, University of Bristol, Southwell Street, Bristol BS2 8EJ, UK.
authors.forename: R
authors.initials: R
authors.lastname: Lucas
authors.affiliation: Microvascular Research Laboratories, School of Physiology and Pharmacology, Preclinical Veterinary Sciences Building, University of Bristol, Southwell Street, Bristol BS2 8EJ, UK.
authors.forename: R
authors.initials: R
authors.lastname: Dean
authors.affiliation: Department of Molecular and Clinical Cancer Medicine, University of Liverpool, Liverpool, UK.
authors.forename: S E
authors.initials: SE
authors.lastname: Coupland
authors.affiliation: Microvascular Research Laboratories, School of Physiology and Pharmacology, Preclinical Veterinary Sciences Building, University of Bristol, Southwell Street, Bristol BS2 8EJ, UK.
authors.forename: S
authors.initials: S
authors.lastname: Oltean
authors.affiliation: 1] Microvascular Research Laboratories, School of Physiology and Pharmacology, Preclinical Veterinary Sciences Building, University of Bristol, Southwell Street, Bristol BS2 8EJ, UK [2] Cancer Biology, Division of Cancer and Stem Cells, School of Medicine, University of Nottingham, Queen's Medical Centre, Nottingham NG2 7UH, UK.
authors.forename: D O
authors.initials: DO
authors.lastname: Bates
mesh_terms: D020533:Angiogenesis Inhibitors / Q000494:pharmacology; D000818:Animals; D045744:Cell Line, Tumor; D055785:Gene Knockdown Techniques; D006801:Humans; D008545:Melanoma / Q000188:drug therapy / Q000378:metabolism* / Q000556:secondary; D051379:Mice; D008819:Mice, Nude; D058990:Molecular Targeted Therapy; D009389:Neovascularization, Pathologic / Q000378:metabolism*; D009536:Niacinamide / Q000031:analogs & derivatives / Q000494:pharmacology; D010880:Piperidines / Q000494:pharmacology; D017346:Protein Serine-Threonine Kinases / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D012326:RNA Splicing; D012878:Skin Neoplasms / Q000188:drug therapy / Q000378:metabolism* / Q000473:pathology; D047368:Tumor Burden; D042461:Vascular Endothelial Growth Factor A / Q000502:physiology*; D023041:Xenograft Model Antitumor Assays
chemical_list: D020533:Angiogenesis Inhibitors; D010880:Piperidines; C584061:SRPIN340; C467484:VEGFA protein, human; D042461:Vascular Endothelial Growth Factor A; D009536:Niacinamide; C087728:SRPK1 protein, human; D017346:Protein Serine-Threonine Kinases