title: Quantitative Phosphoproteomics Reveals Wee1 Kinase as a Therapeutic Target in a Model of Proneural Glioblastoma.
abstract: Glioblastoma (GBM) is the most common malignant primary brain cancer. With a median survival of about a year, new approaches to treating this disease are necessary. To identify signaling molecules regulating GBM progression in a genetically engineered murine model of proneural GBM, we quantified phosphotyrosine-mediated signaling using mass spectrometry. Oncogenic signals, including phosphorylated ERK MAPK, PI3K, and PDGFR, were found to be increased in the murine tumors relative to brain. Phosphorylation of CDK1 pY15, associated with the G2 arrest checkpoint, was identified as the most differentially phosphorylated site, with a 14-fold increase in phosphorylation in the tumors. To assess the role of this checkpoint as a potential therapeutic target, syngeneic primary cell lines derived from these tumors were treated with MK-1775, an inhibitor of Wee1, the kinase responsible for CDK1 Y15 phosphorylation. MK-1775 treatment led to mitotic catastrophe, as defined by increased DNA damage and cell death by apoptosis. To assess the extensibility of targeting Wee1/CDK1 in GBM, patient-derived xenograft (PDX) cell lines were also treated with MK-1775. Although the response was more heterogeneous, on-target Wee1 inhibition led to decreased CDK1 Y15 phosphorylation and increased DNA damage and apoptosis in each line. These results were also validated in vivo, where single-agent MK-1775 demonstrated an antitumor effect on a flank PDX tumor model, increasing mouse survival by 1.74-fold. This study highlights the ability of unbiased quantitative phosphoproteomics to reveal therapeutic targets in tumor models, and the potential for Wee1 inhibition as a treatment approach in preclinical models of GBM. Mol Cancer Ther; 15(6); 1332-43. ©2016 AACR.
authors.affiliation: Department of Biological Engineering and David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, Massachusetts.
authors.forename: Rebecca S
authors.initials: RS
authors.lastname: Lescarbeau
authors.affiliation: Department of Pathology and Cell Biology and Herbert Irving Comprehensive Cancer Center, Columbia University, New York, New York.
authors.forename: Liang
authors.initials: L
authors.lastname: Lei
authors.affiliation: Department of Radiation Oncology, Mayo Clinic, Rochester, Minnesota.
authors.forename: Katrina K
authors.initials: KK
authors.lastname: Bakken
authors.affiliation: Department of Systems Biology and Department of Biochemistry and Molecular Biophysics, Columbia University, New York, New York.
authors.forename: Peter A
authors.initials: PA
authors.lastname: Sims
authors.affiliation: Department of Radiation Oncology, Mayo Clinic, Rochester, Minnesota.
authors.forename: Jann N
authors.initials: JN
authors.lastname: Sarkaria
authors.affiliation: Department of Pathology and Cell Biology and Herbert Irving Comprehensive Cancer Center, Columbia University, New York, New York.
authors.forename: Peter
authors.initials: P
authors.lastname: Canoll
authors.affiliation: Department of Biological Engineering and David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, Massachusetts. fwhite@mit.edu.
authors.forename: Forest M
authors.initials: FM
authors.lastname: White
mesh_terms: D000818:Animals; D014408:Biomarkers, Tumor / Q000378:metabolism; D001932:Brain Neoplasms / Q000188:drug therapy* / Q000378:metabolism; D016203:CDC2 Protein Kinase / Q000378:metabolism*; D018797:Cell Cycle Proteins / Q000378:metabolism*; D045744:Cell Line, Tumor; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D005909:Glioblastoma / Q000188:drug therapy* / Q000378:metabolism; D006801:Humans; D013058:Mass Spectrometry; D051379:Mice; D058990:Molecular Targeted Therapy; D009687:Nuclear Proteins / Q000378:metabolism*; D010766:Phosphorylation / Q000187:drug effects; D011505:Protein-Tyrosine Kinases / Q000378:metabolism*; D040901:Proteomics / Q000379:methods*; D011720:Pyrazoles / Q000008:administration & dosage* / Q000494:pharmacology; D011743:Pyrimidines / Q000008:administration & dosage* / Q000494:pharmacology; D011744:Pyrimidinones; D023041:Xenograft Model Antitumor Assays
chemical_list: D014408:Biomarkers, Tumor; D018797:Cell Cycle Proteins; D009687:Nuclear Proteins; D011720:Pyrazoles; D011743:Pyrimidines; D011744:Pyrimidinones; D011505:Protein-Tyrosine Kinases; C499348:Wee1 protein, mouse; D016203:CDC2 Protein Kinase; C549567:adavosertib