title: Tyrosine receptor kinase B is a drug target in astrocytomas.
abstract: Astrocytomas are the most common primary human brain tumors. Receptor tyrosine kinases (RTKs), including tyrosine receptor kinase B (TrkB, also known as tropomyosin-related kinase B; encoded by neurotrophic tyrosine kinase receptor type 2 [NTRK2]), are frequently mutated by rearrangement/fusion in high-grade and low-grade astrocytomas. We found that activated TrkB can contribute to the development of astrocytoma and might serve as a therapeutic target in this tumor type.
  
  
  
  To identify RTKs capable of inducing astrocytoma formation, a library of human tyrosine kinases was screened for the ability to transform murine Ink4a-/-/Arf-/-astrocytes. Orthotopic allograft studies were conducted to evaluate the effects of RTKs on the development of astrocytoma. Since TrkB was identified as a driver of astrocytoma formation, the effect of the Trk inhibitors AZD1480 and RXDX-101 was assessed in astrocytoma cells expressing activated TrkB. RNA sequencing, real-time PCR, western blotting, and enzyme-linked immunosorbent assays were conducted to characterize NTRK2 in astrocytomas.
  
  
  
  Activated TrkB cooperated with Ink4a/Arf loss to induce the formation of astrocytomas through a mechanism mediated by activation of signal transducer and activator of transcription 3 (STAT3). TrkB activation positively correlated with Ccl2 expression. TrkB-induced astrocytomas remained dependent on TrkB signaling for survival, highlighting a role of NTRK2 as an addictive oncogene. Furthermore, the QKI-NTRK2 fusion associated with human astrocytoma transformed Ink4a-/-/Arf-/-astrocytes, and this process was also mediated via STAT3 signaling.
  
  
  
  Our findings provide evidence that constitutively activated NTRK2 alleles, notably the human tumor-associated QKI-NTRK2 fusion, can cooperate with Ink4a/Arf loss to drive astrocytoma formation. Therefore, we propose NTRK2 as a potential therapeutic target in the subset of astrocytoma patients defined by QKI-NTRK2 fusion.
authors.affiliation: Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, Massachusetts (J.N., S.X., V.L., Y.S., P.B., R.B., T.M.R., C.D.S., R.A.S., J.J.Z.); Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts (J.N., S.X., V.L., T.M.R., J.J.Z.); Department of Medical Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, Massachusetts (S.H.R., R.B., K.L.L., W.C.H.); Broad Institute, Boston, Massachusetts (P.B., R.B., W.C.H.); Department of Pathology, Brigham and Women's Hospital, Boston, Massachusetts (S.H.R., K.L.L.); Department of Pathology, Boston Children's Hospital, Boston, Massachusetts (K.L.L.).
authors.forename: Jing
authors.initials: J
authors.lastname: Ni
authors.affiliation: Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, Massachusetts (J.N., S.X., V.L., Y.S., P.B., R.B., T.M.R., C.D.S., R.A.S., J.J.Z.); Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts (J.N., S.X., V.L., T.M.R., J.J.Z.); Department of Medical Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, Massachusetts (S.H.R., R.B., K.L.L., W.C.H.); Broad Institute, Boston, Massachusetts (P.B., R.B., W.C.H.); Department of Pathology, Brigham and Women's Hospital, Boston, Massachusetts (S.H.R., K.L.L.); Department of Pathology, Boston Children's Hospital, Boston, Massachusetts (K.L.L.).
authors.forename: Shaozhen
authors.initials: S
authors.lastname: Xie
authors.affiliation: Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, Massachusetts (J.N., S.X., V.L., Y.S., P.B., R.B., T.M.R., C.D.S., R.A.S., J.J.Z.); Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts (J.N., S.X., V.L., T.M.R., J.J.Z.); Department of Medical Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, Massachusetts (S.H.R., R.B., K.L.L., W.C.H.); Broad Institute, Boston, Massachusetts (P.B., R.B., W.C.H.); Department of Pathology, Brigham and Women's Hospital, Boston, Massachusetts (S.H.R., K.L.L.); Department of Pathology, Boston Children's Hospital, Boston, Massachusetts (K.L.L.).
authors.forename: Shakti H
authors.initials: SH
authors.lastname: Ramkissoon
authors.affiliation: Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, Massachusetts (J.N., S.X., V.L., Y.S., P.B., R.B., T.M.R., C.D.S., R.A.S., J.J.Z.); Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts (J.N., S.X., V.L., T.M.R., J.J.Z.); Department of Medical Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, Massachusetts (S.H.R., R.B., K.L.L., W.C.H.); Broad Institute, Boston, Massachusetts (P.B., R.B., W.C.H.); Department of Pathology, Brigham and Women's Hospital, Boston, Massachusetts (S.H.R., K.L.L.); Department of Pathology, Boston Children's Hospital, Boston, Massachusetts (K.L.L.).
authors.forename: Victor
authors.initials: V
authors.lastname: Luu
authors.affiliation: Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, Massachusetts (J.N., S.X., V.L., Y.S., P.B., R.B., T.M.R., C.D.S., R.A.S., J.J.Z.); Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts (J.N., S.X., V.L., T.M.R., J.J.Z.); Department of Medical Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, Massachusetts (S.H.R., R.B., K.L.L., W.C.H.); Broad Institute, Boston, Massachusetts (P.B., R.B., W.C.H.); Department of Pathology, Brigham and Women's Hospital, Boston, Massachusetts (S.H.R., K.L.L.); Department of Pathology, Boston Children's Hospital, Boston, Massachusetts (K.L.L.).
authors.forename: Yu
authors.initials: Y
authors.lastname: Sun
authors.affiliation: Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, Massachusetts (J.N., S.X., V.L., Y.S., P.B., R.B., T.M.R., C.D.S., R.A.S., J.J.Z.); Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts (J.N., S.X., V.L., T.M.R., J.J.Z.); Department of Medical Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, Massachusetts (S.H.R., R.B., K.L.L., W.C.H.); Broad Institute, Boston, Massachusetts (P.B., R.B., W.C.H.); Department of Pathology, Brigham and Women's Hospital, Boston, Massachusetts (S.H.R., K.L.L.); Department of Pathology, Boston Children's Hospital, Boston, Massachusetts (K.L.L.).
authors.forename: Pratiti
authors.initials: P
authors.lastname: Bandopadhayay
authors.affiliation: Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, Massachusetts (J.N., S.X., V.L., Y.S., P.B., R.B., T.M.R., C.D.S., R.A.S., J.J.Z.); Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts (J.N., S.X., V.L., T.M.R., J.J.Z.); Department of Medical Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, Massachusetts (S.H.R., R.B., K.L.L., W.C.H.); Broad Institute, Boston, Massachusetts (P.B., R.B., W.C.H.); Department of Pathology, Brigham and Women's Hospital, Boston, Massachusetts (S.H.R., K.L.L.); Department of Pathology, Boston Children's Hospital, Boston, Massachusetts (K.L.L.).
authors.forename: Rameen
authors.initials: R
authors.lastname: Beroukhim
authors.affiliation: Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, Massachusetts (J.N., S.X., V.L., Y.S., P.B., R.B., T.M.R., C.D.S., R.A.S., J.J.Z.); Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts (J.N., S.X., V.L., T.M.R., J.J.Z.); Department of Medical Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, Massachusetts (S.H.R., R.B., K.L.L., W.C.H.); Broad Institute, Boston, Massachusetts (P.B., R.B., W.C.H.); Department of Pathology, Brigham and Women's Hospital, Boston, Massachusetts (S.H.R., K.L.L.); Department of Pathology, Boston Children's Hospital, Boston, Massachusetts (K.L.L.).
authors.forename: Thomas M
authors.initials: TM
authors.lastname: Roberts
authors.affiliation: Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, Massachusetts (J.N., S.X., V.L., Y.S., P.B., R.B., T.M.R., C.D.S., R.A.S., J.J.Z.); Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts (J.N., S.X., V.L., T.M.R., J.J.Z.); Department of Medical Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, Massachusetts (S.H.R., R.B., K.L.L., W.C.H.); Broad Institute, Boston, Massachusetts (P.B., R.B., W.C.H.); Department of Pathology, Brigham and Women's Hospital, Boston, Massachusetts (S.H.R., K.L.L.); Department of Pathology, Boston Children's Hospital, Boston, Massachusetts (K.L.L.).
authors.forename: Charles D
authors.initials: CD
authors.lastname: Stiles
authors.affiliation: Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, Massachusetts (J.N., S.X., V.L., Y.S., P.B., R.B., T.M.R., C.D.S., R.A.S., J.J.Z.); Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts (J.N., S.X., V.L., T.M.R., J.J.Z.); Department of Medical Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, Massachusetts (S.H.R., R.B., K.L.L., W.C.H.); Broad Institute, Boston, Massachusetts (P.B., R.B., W.C.H.); Department of Pathology, Brigham and Women's Hospital, Boston, Massachusetts (S.H.R., K.L.L.); Department of Pathology, Boston Children's Hospital, Boston, Massachusetts (K.L.L.).
authors.forename: Rosalind A
authors.initials: RA
authors.lastname: Segal
authors.affiliation: Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, Massachusetts (J.N., S.X., V.L., Y.S., P.B., R.B., T.M.R., C.D.S., R.A.S., J.J.Z.); Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts (J.N., S.X., V.L., T.M.R., J.J.Z.); Department of Medical Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, Massachusetts (S.H.R., R.B., K.L.L., W.C.H.); Broad Institute, Boston, Massachusetts (P.B., R.B., W.C.H.); Department of Pathology, Brigham and Women's Hospital, Boston, Massachusetts (S.H.R., K.L.L.); Department of Pathology, Boston Children's Hospital, Boston, Massachusetts (K.L.L.).
authors.forename: Keith L
authors.initials: KL
authors.lastname: Ligon
authors.affiliation: Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, Massachusetts (J.N., S.X., V.L., Y.S., P.B., R.B., T.M.R., C.D.S., R.A.S., J.J.Z.); Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts (J.N., S.X., V.L., T.M.R., J.J.Z.); Department of Medical Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, Massachusetts (S.H.R., R.B., K.L.L., W.C.H.); Broad Institute, Boston, Massachusetts (P.B., R.B., W.C.H.); Department of Pathology, Brigham and Women's Hospital, Boston, Massachusetts (S.H.R., K.L.L.); Department of Pathology, Boston Children's Hospital, Boston, Massachusetts (K.L.L.).
authors.forename: William C
authors.initials: WC
authors.lastname: Hahn
authors.affiliation: Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, Massachusetts (J.N., S.X., V.L., Y.S., P.B., R.B., T.M.R., C.D.S., R.A.S., J.J.Z.); Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts (J.N., S.X., V.L., T.M.R., J.J.Z.); Department of Medical Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, Massachusetts (S.H.R., R.B., K.L.L., W.C.H.); Broad Institute, Boston, Massachusetts (P.B., R.B., W.C.H.); Department of Pathology, Brigham and Women's Hospital, Boston, Massachusetts (S.H.R., K.L.L.); Department of Pathology, Boston Children's Hospital, Boston, Massachusetts (K.L.L.) jean_zhao@dfci.harvard.edu.
authors.forename: Jean J
authors.initials: JJ
authors.lastname: Zhao
mesh_terms: D020823:ADP-Ribosylation Factor 1 / Q000502:physiology*; D000818:Animals; D001253:Astrocytes / Q000201:enzymology / Q000473:pathology*; D001254:Astrocytoma / Q000201:enzymology / Q000473:pathology*; D002478:Cells, Cultured; D019941:Cyclin-Dependent Kinase Inhibitor p16 / Q000502:physiology; D057166:High-Throughput Screening Assays; D006801:Humans; D008562:Membrane Glycoproteins / Q000378:metabolism*; D051379:Mice; D018345:Mice, Knockout; D015514:Oncogene Proteins, Fusion / Q000378:metabolism*; D016601:RNA-Binding Proteins / Q000378:metabolism*; D020813:Receptor, trkB / Q000378:metabolism*; D015398:Signal Transduction
chemical_list: D019941:Cyclin-Dependent Kinase Inhibitor p16; D008562:Membrane Glycoproteins; D015514:Oncogene Proteins, Fusion; C490832:QKI protein, human; D016601:RNA-Binding Proteins; D020813:Receptor, trkB; C000591259:tropomyosin-related kinase-B, human; D020823:ADP-Ribosylation Factor 1
keywords: 
  NTRK2
  ; CCL2; QKI-NTRK2; STAT3; astrocytoma