title: GDC-0941 inhibits metastatic characteristics of thyroid carcinomas by targeting both the phosphoinositide-3 kinase (PI3K) and hypoxia-inducible factor-1α (HIF-1α) pathways.
abstract: BACKGROUND
  Phosphoinositide 3-kinase (PI3K) regulates the transcription factor hypoxia-inducible factor-1 (HIF-1) in thyroid carcinoma cells. Both pathways are associated with aggressive phenotype in thyroid carcinomas.
  
  
  OBJECTIVE
  Our objective was to assess the effects of the clinical PI3K inhibitor GDC-0941 and genetic inhibition of PI3K and HIF on metastatic behavior of thyroid carcinoma cells in vitro and in vivo.
  
  
  METHODS
  Vascular endothelial growth factor ELISA, HIF activity assays, proliferation studies, and scratch-wound migration and cell spreading assays were performed under various O(2) tensions [normoxia, hypoxia (1 and 0.1% O(2)), and anoxia] with or without GDC-0941 in a panel of four thyroid carcinoma cell lines (BcPAP, WRO, FTC133, and 8505c). Genetic inhibition was achieved by overexpressing phosphatase and tensin homolog (PTEN) into PTEN-null cells and by using a dominant-negative variant of HIF-1α (dnHIF). In vivo, human enhanced green fluorescence protein-expressing follicular thyroid carcinomas (FTC) were treated with GDC-0941 (orally). Spontaneous lung metastasis was confirmed by viewing enhanced green fluorescence protein-positive colonies cultured from lung tissue.
  
  
  RESULTS
  GDC-0941 inhibited hypoxia/anoxia-induced HIF-1α and HIF-2α expression and HIF activity in thyroid carcinoma cells. Basal (three of four cell lines) and/or hypoxia-induced (four of four) secreted vascular endothelial growth factor was inhibited by GDC-0941, whereas selective HIF targeting predominantly affected hypoxia/anoxia-mediated secretion (P < 0.05-0.0001). Antiproliferative effects of GDC-0941 were more pronounced in PTEN mutant compared with PTEN-restored cells (P < 0.05). Hypoxia increased migration in papillary cells and cell spreading/migration in FTC cells (P < 0.01). GDC-0941 reduced spreading and migration in all O(2) conditions, whereas dnHIF had an impact only on hypoxia-induced migration (P < 0.001). In vivo, GDC-0941 reduced expression of HIF-1α, phospho-AKT, GLUT-1, and lactate dehydrogenase A in FTC xenografts. DnHIF expression and GDC-0941 reduced FTC tumor growth and metastatic lung colonization (P < 0.05).
  
  
  CONCLUSIONS
  PI3K plays a prominent role in the metastatic behavior of thyroid carcinoma cells irrespective of O(2) tension and appears upstream of HIF activation. GDC-0941 significantly inhibited the metastatic phenotype, supporting the clinical development of PI3K inhibition in thyroid carcinomas.
authors: Hypoxia and Therapeutics Group, School of Pharmacy and Pharmaceutical Sciences, University of Manchester, Oxford Road, Manchester M13 9PT, United Kingdom.
authors: Natalie
authors: N
authors: Burrows
authors: Muhammad
authors: M
authors: Babur
authors: Julia
authors: J
authors: Resch
authors: Sophie
authors: S
authors: Ridsdale
authors: Melissa
authors: M
authors: Mejin
authors: Emily J
authors: EJ
authors: Rowling
authors: Georg
authors: G
authors: Brabant
authors: Kaye J
authors: KJ
authors: Williams
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology*; D002277:Carcinoma / Q000201:enzymology / Q000473:pathology / Q000556:secondary*; D015687:Cell Hypoxia; D002465:Cell Movement / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D005260:Female; D006801:Humans; D051795:Hypoxia-Inducible Factor 1, alpha Subunit / Q000378:metabolism*; D007191:Indazoles / Q000494:pharmacology*; D051379:Mice; D051059:PTEN Phosphohydrolase / Q000378:metabolism; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism*; D015398:Signal Transduction / Q000187:drug effects*; D013449:Sulfonamides / Q000494:pharmacology*; D013964:Thyroid Neoplasms / Q000201:enzymology / Q000378:metabolism / Q000473:pathology*; D014407:Tumor Cells, Cultured; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism
chemical_list: C532162:2-(1H-indazol-4-yl)-6-(4-methanesulfonylpiperazin-1-ylmethyl)-4-morpholin-4-ylthieno(3,2-d)pyrimidine; D000970:Antineoplastic Agents; C497442:HIF1A protein, human; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D007191:Indazoles; D013449:Sulfonamides; D042461:Vascular Endothelial Growth Factor A; D019869:Phosphatidylinositol 3-Kinases; D051059:PTEN Phosphohydrolase