crizotinib and Glioma

The proto-oncogene tyrosine-protein kinase ROS1 (ROS1) is a tyrosine kinase that is closely related to anaplastic lymphoma kinase receptor (ALK). We describe a novel KLC1-ROS1 fusion identified in a case of pediatric low-grade glioma. This was detected by RNA sequencing and confirmed by reverse-transcription PCR and fluorescent in situ hybridization. Immunohistochemical staining for ROS1 was positive in the tumor cytoplasm. In vitro analysis demonstrated the oncogenic activity of this fusion, which was suppressed by the ALK/ROS1 inhibitor, crizotinib. Our case and others suggest that various ROS1 fusions might be present in a subset of pediatric gliomas, which could be targeted for therapy.

Topics: Brain Neoplasms; Child, Preschool; Crizotinib; Female; Gene Fusion; Glioma; Humans; Immunohistochemistry; In Situ Hybridization, Fluorescence; Kinesins; Microtubule-Associated Proteins; Molecular Targeted Therapy; Neoplasm Staging; Protein-Tyrosine Kinases; Proto-Oncogene Mas; Proto-Oncogene Proteins; Reverse Transcriptase Polymerase Chain Reaction

Glioblastoma (GBM) is a highly aggressive form of brain cancer with a poor prognosis and limited treatment options. The ALK and c-MET inhibitor Crizotinib has demonstrated preclinical therapeutic potential for newly diagnosed GBM, although its efficacy is limited by poor penetration of the blood brain barrier. Here, we identify Crizotinib as a novel inhibitor of nuclear factor-κB (NF-κB)-inducing kinase, which is a key regulator of GBM growth and proliferation. We further show that the conjugation of Crizotinib to a heptamethine cyanine dye, or a near-infrared dye (IR-Crizotinib), attenuated glioma cell proliferation and survival

Topics: Animals; Brain Neoplasms; Cell Line, Tumor; Crizotinib; Glioblastoma; Glioma; Humans; Mice; NF-kappa B; NF-kappaB-Inducing Kinase

Oncogenic c-ros oncogene1 (ROS1) fusion kinases have been identified in a variety of human cancers and are attractive targets for cancer therapy. The MET/ALK/ROS1 inhibitor crizotinib (Xalkori, PF-02341066) has demonstrated promising clinical activity in ROS1 fusion-positive non-small cell lung cancer. However, emerging clinical evidence has shown that patients can develop resistance by acquiring secondary point mutations in ROS1 kinase. In this study we characterized the ROS1 activity of PF-06463922, a novel, orally available, CNS-penetrant, ATP-competitive small-molecule inhibitor of ALK/ROS1. In vitro, PF-06463922 exhibited subnanomolar cellular potency against oncogenic ROS1 fusions and inhibited the crizotinib-refractory ROS1(G2032R) mutation and the ROS1(G2026M) gatekeeper mutation. Compared with crizotinib and the second-generation ALK/ROS1 inhibitors ceritinib and alectinib, PF-06463922 showed significantly improved inhibitory activity against ROS1 kinase. A crystal structure of the PF-06463922-ROS1 kinase complex revealed favorable interactions contributing to the high-affinity binding. In vivo, PF-06463922 showed marked antitumor activity in tumor models expressing FIG-ROS1, CD74-ROS1, and the CD74-ROS1(G2032R) mutation. Furthermore, PF-06463922 demonstrated antitumor activity in a genetically engineered mouse model of FIG-ROS1 glioblastoma. Taken together, our results indicate that PF-06463922 has potential for treating ROS1 fusion-positive cancers, including those requiring agents with CNS-penetrating properties, as well as for overcoming crizotinib resistance driven by ROS1 mutation.

Topics: Aminopyridines; Animals; Carcinogenesis; Cell Proliferation; Crizotinib; Crystallography, X-Ray; Disease Models, Animal; Drug Resistance, Neoplasm; Glioma; Humans; Lactams; Lactams, Macrocyclic; Mice; Models, Molecular; Mutation; Protein Kinase Inhibitors; Protein-Tyrosine Kinases; Proto-Oncogene Proteins; Pyrazoles; Pyridines; Signal Transduction

Epidermal growth factor receptor (EGFR) is highly amplified, mutated, and overexpressed in human malignant gliomas. Despite its prevalence and growth-promoting functions, therapeutic strategies to inhibit EGFR kinase activity have not been translated into profound beneficial effects in glioma clinical trials. To determine the roles of oncogenic EGFR signaling in gliomagenesis and tumor maintenance, we generated a novel glioma mouse model driven by inducible expression of a mutant EGFR (EGFR*). Using combined genetic and pharmacologic interventions, we revealed that EGFR*-driven gliomas were insensitive to EGFR tyrosine kinase inhibitors, although they could efficiently inhibit EGFR* autophosphorylation in vitro and in vivo. This is in contrast with the genetic suppression of EGFR* induction that led to significant tumor regression and prolonged animal survival. However, despite their initial response to genetic EGFR* extinction, all tumors would relapse and propagate independent of EGFR*. We further showed that EGFR*-independent tumor cells existed prior to treatment and were responsible for relapse following genetic EGFR* suppression. And, the addition of a PI3K/mTOR inhibitor could significantly delay relapse and prolong animal survival. Our findings shed mechanistic insight into EGFR drug resistance in glioma and provide a platform to test therapies targeting aberrant EGFR signaling in this setting.

Topics: Animals; Brain Neoplasms; Crizotinib; Cyclin-Dependent Kinase Inhibitor p16; Doxycycline; Drug Resistance, Neoplasm; ErbB Receptors; Erlotinib Hydrochloride; Gefitinib; Glioma; Humans; Imidazoles; Mice, Inbred C57BL; Mice, Transgenic; Molecular Targeted Therapy; Phosphorylation; Protein Processing, Post-Translational; PTEN Phosphohydrolase; Pyrazoles; Pyridines; Quinazolines; Quinolines; Tumor Cells, Cultured