title: FGFR3 is overexpressed waldenstrom macroglobulinemia and its inhibition by Dovitinib induces apoptosis and overcomes stroma-induced proliferation.
abstract: OBJECTIVE
  There is no standard of therapy for the treatment of Waldenström macroglobulinemia (WM), therefore there is a need for the development of new agents. Fibroblast growth factor receptor 3 (FGFR3) was shown to play a major role in several types in cancer. Dovitinib, an inhibitor of FGFR3, was effective in hematologic malignancies. In this study, we tested FGFR3 as a therapeutic target in WM and tested the effect of dovitinib on cell proliferation and apoptosis of WM cells in the context of BM microenvironment.
  
  
  METHODS
  The expression of FGFR3 in WM cells was tested using immunofluorescence and flow cytometry. Cell signaling in response to stimulation with FGF3 and stromal cells, and its inhibition by dovitinib was performed using immunoblotting. Cell survival and cell proliferation were assessed by MTT and BrdU assays. Apoptosis was measured by detection of APO-2.7 and cleavage of caspase-3 using flow cytometry. Cell cycle was performed by PI staining of cells and flow cytometry. The combinatory effect of dovitinib with other drugs was analyzed using Calcusyn software. The effect of dovitinib was tested in vivo.
  
  
  RESULTS
  FGFR3 was overexpressed in WM cells and its activation induced cell proliferation. Inhibition of FGFR3 with dovitinib decreased cell survival, increased apoptosis, and induced cell cycle arrest. Inhibition of FGFR3 by dovitinib reduced the interaction of WM to bone marrow components, and reversed its proliferative effect. Dovitinib had an additive effect with other drugs. Moreover, dovitinib reduced WM tumor progression in vivo.
  
  
  CONCLUSIONS
  We report that FGFR3 is a novel therapeutic target in WM, and suggest dovitinib for future clinical trial the treatment of patients with WM.
authors.affiliation: Department of Medical Oncology, Dana-Farber Cancer Institute and Harvard Medical School, Boston, Massachusetts, USA.
authors.forename: Abdel Kareem
authors.initials: AK
authors.lastname: Azab
authors.forename: Feda
authors.initials: F
authors.lastname: Azab
authors.forename: Phong
authors.initials: P
authors.lastname: Quang
authors.forename: Patricia
authors.initials: P
authors.lastname: Maiso
authors.forename: Antonio
authors.initials: A
authors.lastname: Sacco
authors.forename: Hai T
authors.initials: HT
authors.lastname: Ngo
authors.forename: Yang
authors.initials: Y
authors.lastname: Liu
authors.forename: Yong
authors.initials: Y
authors.lastname: Zhang
authors.forename: Brittany L
authors.initials: BL
authors.lastname: Morgan
authors.forename: Aldo M
authors.initials: AM
authors.lastname: Roccaro
authors.forename: Irene M
authors.initials: IM
authors.lastname: Ghobrial
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects*; D002448:Cell Adhesion / Q000187:drug effects; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D018450:Disease Progression; D004789:Enzyme Activation / Q000187:drug effects; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D051379:Mice; D016513:Mice, SCID; D047428:Protein Kinase Inhibitors / Q000494:pharmacology*; D051498:Receptor, Fibroblast Growth Factor, Type 3 / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism*; D017154:Stromal Cells / Q000187:drug effects* / Q000378:metabolism; D059016:Tumor Microenvironment / Q000187:drug effects; D008258:Waldenstrom Macroglobulinemia / Q000235:genetics / Q000378:metabolism*
chemical_list: D000970:Antineoplastic Agents; D047428:Protein Kinase Inhibitors; C496365:FGFR3 protein, human; D051498:Receptor, Fibroblast Growth Factor, Type 3