title: Tyrosine Kinase Inhibitors as Potential Therapeutic Agents in the Treatment of Granulosa Cell Tumors of the Ovary.
abstract: OBJECTIVE
  Granulosa cell tumors of the ovary (GCTs) represent a specific subset of malignant ovarian tumors, of which there are 2 distinct subtypes, the juvenile and the adult form. Aside from surgery, no reliable therapeutic options currently exist for patients with GCT. This study sought to investigate the potential role of small molecule tyrosine kinase inhibitors (TKIs) as novel therapeutics in the clinical management of GCT.
  
  
  METHODS
  Using TKI with distinct but overlapping multitargeted specificities, cellular proliferation, viability, and apoptosis were evaluated in 2 human GCT-derived cell lines, COV434 and KGN.
  
  
  RESULTS
  Sunitinib, which targets the imatinib-inhibited tyrosine kinases of VEGFR, KIT, PDGFR, and FLT-3, was without effect in COV434 and KGN cell lines. Sorafenib, which has a high affinity for RAF1 and BRAF, dose dependently inhibited cellular proliferation and viability in both cell lines at concentrations equivalent to that seen in other systems. A RAF1 kinase inhibitor was without effect, suggesting that sorafenib is acting via inhibition of BRAF, or that aberrant signaling originates upstream of BRAF in the MAPK pathway. In the presence of a selective Src family inhibitor (SU6656), cell proliferation and cell viability responses dissociated; that is, although SU6656 dose dependently inhibited cell viability, it had limited effect on proliferation and apoptosis.
  
  
  CONCLUSIONS
  These findings implicate BRAF in the activated signaling responsible for the growth and viability of GCT and suggest that TKI already in clinical use may be a therapeutic option in the treatment of GCT.
authors.affiliation: Prince Henry's Institute of Medical Research, and the Department of Medicine, Monash University, Clayton, Victoria, Australia.
authors.forename: Stacey
authors.initials: S
authors.lastname: Jamieson
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Fuller
mesh_terms: D000328:Adult; D017209:Apoptosis / Q000187:drug effects*; D049109:Cell Proliferation / Q000187:drug effects*; D005260:Female; D006106:Granulosa Cell Tumor / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D061307:Human Umbilical Vein Endothelial Cells / Q000187:drug effects* / Q000378:metabolism; D006801:Humans; D010051:Ovarian Neoplasms / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D047428:Protein Kinase Inhibitors / Q000494:pharmacology*; D015398:Signal Transduction / Q000187:drug effects; D014407:Tumor Cells, Cultured
chemical_list: D047428:Protein Kinase Inhibitors