title: The oral multitarget tumour growth inhibitor, ZK 304709, inhibits growth of pancreatic neuroendocrine tumours in an orthotopic mouse model.
abstract: OBJECTIVE
  Current systemic therapies for neuroendocrine tumours (NETs) do not provide sufficient control of tumour growth. However, efficient evaluation of novel drugs is hindered by the lack of a suitable preclinical animal model. Here an orthotopic mouse model of pancreatic NET is established and used to study the action of ZK 304709, a first in class, oral multitarget tumour growth inhibitor. ZK 304709 is an inhibitor of cyclin-dependent kinases (Cdks) 1, 2, 4, 7 and 9, vascular endothelial growth factor receptor-type kinases (VEGF-RTKs) 1-3 and platelet-derived growth factor receptor-type kinase beta (PDGF-RTKss).
  
  
  METHODS
  BON and QGP-1 human NET cells were used to study proliferation, survival and cell cycle distribution in vitro. For induction of orthotopic NETs, BON cells were injected into the pancreas of NMRI(nu/nu) mice. Primary tumour growth and metastatic spread were recorded after 9 weeks, and apoptosis, microvessel density and lymphatic vessel density were determined.
  
  
  RESULTS
  ZK 304709 dose-dependently suppressed proliferation and colony formation of NET cells. Direct effects on NET cells were consistent with Cdk inhibition and involved G(2) cell cycle arrest and apoptosis induction, which was associated with reduced expression of MCL1 (myeloid cell leukaemia sequence 1), survivin and hypoxia-inducible factor 1alpha (HIF1alpha). Apoptosis similarly occurred in vivo in ZK 304709-treated orthotopic BON tumours, resulting in a 80% reduction of primary tumour growth. In contrast, treatment with lanreotide or 5-fluorouracil and streptozotocin failed to inhibit tumour gowth. ZK 304709 also reduced tumour microvessel density, implicating antiangiogenic mechanisms.
  
  
  CONCLUSIONS
  BON orthotopic tumours provide an informative model for preclinical drug evaluation in NETs. In this model, ZK 304709 achieved efficacious tumour growth control via induction of apoptosis and inhibition of tumour-induced angiogenesis.
authors.affiliation: Medizinische Klinik mit Schwerpunkt Hepatologie und Gastroenterologie, Charité-Universitätsmedizin Berlin, Campus Virchow-Klinikum, Berlin, Germany.
authors.forename: A
authors.initials: A
authors.lastname: Scholz
authors.forename: K
authors.initials: K
authors.lastname: Wagner
authors.forename: M
authors.initials: M
authors.lastname: Welzel
authors.forename: F
authors.initials: F
authors.lastname: Remlinger
authors.forename: B
authors.initials: B
authors.lastname: Wiedenmann
authors.forename: G
authors.initials: G
authors.lastname: Siemeister
authors.forename: S
authors.initials: S
authors.lastname: Rosewicz
authors.forename: K M
authors.initials: KM
authors.lastname: Detjen
mesh_terms: D020533:Angiogenesis Inhibitors / Q000627:therapeutic use*; D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D015415:Biomarkers / Q000032:analysis; D002467:Cell Nucleus / Q000737:chemistry; D004305:Dose-Response Relationship, Drug; D005260:Female; D005434:Flow Cytometry; D005455:Fluorescent Antibody Technique; D006651:Histocytochemistry; D006801:Humans; D051795:Hypoxia-Inducible Factor 1, alpha Subunit / Q000032:analysis; D051034:Inhibitor of Apoptosis Proteins; D008207:Lymphatic Metastasis; D051379:Mice; D008819:Mice, Nude; D008869:Microtubule-Associated Proteins / Q000032:analysis; D009389:Neovascularization, Pathologic / Q000188:drug therapy; D018358:Neuroendocrine Tumors / Q000098:blood supply / Q000188:drug therapy*; D010190:Pancreatic Neoplasms / Q000098:blood supply / Q000188:drug therapy*; D000077022:Survivin; D014407:Tumor Cells, Cultured; D023041:Xenograft Model Antitumor Assays / Q000379:methods
chemical_list: D020533:Angiogenesis Inhibitors; C107489:BIRC5 protein, human; D015415:Biomarkers; C497442:HIF1A protein, human; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D051034:Inhibitor of Apoptosis Proteins; D008869:Microtubule-Associated Proteins; D000077022:Survivin