azd2014 and Disease-Models--Animal

When Zika virus emerged as a public health emergency there were no drugs or vaccines approved for its prevention or treatment. We used a high-throughput screen for Zika virus protease inhibitors to identify several inhibitors of Zika virus infection. We expressed the NS2B-NS3 Zika virus protease and conducted a biochemical screen for small-molecule inhibitors. A quantitative structure-activity relationship model was employed to virtually screen ∼138,000 compounds, which increased the identification of active compounds, while decreasing screening time and resources. Candidate inhibitors were validated in several viral infection assays. Small molecules with favorable clinical profiles, especially the five-lipoxygenase-activating protein inhibitor, MK-591, inhibited the Zika virus protease and infection in neural stem cells. Members of the tetracycline family of antibiotics were more potent inhibitors of Zika virus infection than the protease, suggesting they may have multiple mechanisms of action. The most potent tetracycline, methacycline, reduced the amount of Zika virus present in the brain and the severity of Zika virus-induced motor deficits in an immunocompetent mouse model. As Food and Drug Administration-approved drugs, the tetracyclines could be quickly translated to the clinic. The compounds identified through our screening paradigm have the potential to be used as prophylactics for patients traveling to endemic regions or for the treatment of the neurological complications of Zika virus infection.

Topics: Animals; Antiviral Agents; Artificial Intelligence; Chlorocebus aethiops; Disease Models, Animal; Drug Evaluation, Preclinical; High-Throughput Screening Assays; Immunocompetence; Inhibitory Concentration 50; Methacycline; Mice, Inbred C57BL; Protease Inhibitors; Quantitative Structure-Activity Relationship; Small Molecule Libraries; Vero Cells; Zika Virus; Zika Virus Infection

Neurofibromatosis type 2 (NF2) is an inherited disorder characterized by bilateral vestibular schwannomas (VS) that arise from neoplastic Schwann cells (SCs). NF2-associated VSs are often accompanied by meningioma (MN), and the majority of NF2 patients show loss of the NF2 tumor suppressor. mTORC1 and mTORC2-specific serum/glucocorticoid-regulated kinase 1 (SGK1) are constitutively activated in MN with loss of NF2. In a recent high-throughput kinome screen in NF2-null human arachnoidal and meningioma cells, we showed activation of EPH RTKs, c-KIT, and SFK members independent of mTORC1/2 activation. Subsequently, we demonstrated in vitro and in vivo efficacy of combination therapy with the dual mTORC1/2 inhibitor AZD2014 and the multi-kinase inhibitor dasatinib. For these reasons, we investigated activated mTORC1/2 and EPH receptor-mediated signaling in sporadic and NF2-associated VS. Using primary human VS cells and a mouse allograft model of schwannoma, we evaluated the dual mTORC1/2 inhibitor AZD2014 and the tyrosine kinase inhibitor dasatinib as monotherapies and in combination. Escalating dose-response experiments on primary VS cells grown from 15 human tumors show that combination therapy with AZD2014 and dasatinib is more effective at reducing metabolic activity than either drug alone and exhibits a therapeutic effect at a physiologically reasonable concentration (~0.1 µM). In vivo, while AZD2014 and dasatinib each inhibit tumor growth alone, the effect of combination therapy exceeds that of either drug. Co-targeting the mTOR and EPH receptor pathways with these or similar compounds may constitute a novel therapeutic strategy for VS, a condition for which there is no FDA-approved pharmacotherapy.

Topics: Animals; Benzamides; Dasatinib; Disease Models, Animal; Drug Therapy, Combination; Female; Humans; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Morpholines; Neurofibromin 2; Neuroma, Acoustic; Protein Kinase Inhibitors; Pyrimidines; Receptor, EphA1; TOR Serine-Threonine Kinases

Malignant peripheral nerve sheath tumors (MPNSTs) are soft-tissue sarcomas that frequently arise in patients with neurofibromatosis type 1 (NF1). Most of these tumors are unresectable at diagnosis and minimally responsive to conventional treatment, lending urgency to the identification of new pathway dependencies and drugs with potent antitumor activities. We therefore examined a series of candidate agents for their ability to induce apoptosis in MPNST cells arising in nf1/tp53-deficient zebrafish. In this study, we found that DNA topoisomerase I-targeted drugs and mTOR kinase inhibitors were the most effective single agents in eliminating MPNST cells without prohibitive toxicity. In addition, three members of these classes of drugs, either AZD2014 or INK128 in combination with irinotecan, acted synergistically to induce apoptosis both in vitro and in vivo. In mechanistic studies, irinotecan not only induces apoptosis by eliciting a DNA damage response, but also acts synergistically with AZD2014 to potentiate the hypophosphorylation of 4E-BP1, a downstream target of mTORC1. Profound hypophosphorylation of 4E-BP1 induced by this drug combination causes an arrest of protein synthesis, which potently induces tumor cell apoptosis. Our findings provide a compelling rationale for further in vivo evaluation of the combination of DNA topoisomerase I-targeted drugs and mTOR kinase inhibitors against these aggressive nerve sheath tumors.

Topics: Adaptor Proteins, Signal Transducing; Animals; Apoptosis; Benzamides; Cell Cycle Proteins; Disease Models, Animal; Humans; Irinotecan; Morpholines; Nerve Sheath Neoplasms; Neurofibromatosis 1; Peripheral Nerves; Phosphorylation; Protein Kinase Inhibitors; Pyrimidines; Topoisomerase I Inhibitors; TOR Serine-Threonine Kinases; Xenograft Model Antitumor Assays; Zebrafish

The FGFR1 is a therapeutic target under investigation in multiple solid tumors and clinical trials of selective tyrosine kinase inhibitors (TKI) are underway. Treatment with a single TKI represents a logical step toward personalized cancer therapy, but intrinsic and acquired resistance mechanisms limit their long-term benefit. In this study, we deployed RNAi-based functional genomic screens to identify protein kinases controlling the intrinsic sensitivity of FGFR1-dependent lung cancer and head and neck squamous cell cancer (HNSCC) cells to ponatinib, a multikinase FGFR-active inhibitor. We identified and validated a synthetic lethal interaction between MTOR and ponatinib in non-small cell lung carcinoma cells. In addition, treatment with MTOR-targeting shRNAs and pharmacologic inhibitors revealed that MTOR is an essential protein kinase in other FGFR1-expressing cancer cells. The combination of FGFR inhibitors and MTOR or AKT inhibitors resulted in synergistic growth suppression in vitro. Notably, tumor xenografts generated from FGFR1-dependent lung cancer cells exhibited only modest sensitivity to monotherapy with the FGFR-specific TKI, AZD4547, but when combined with the MTOR inhibitor, AZD2014, significantly attenuated tumor growth and prolonged survival. Our findings support the existence of a signaling network wherein FGFR1-driven ERK and activated MTOR/AKT represent distinct arms required to induce full transformation. Furthermore, they suggest that clinical efficacy of treatments for FGFR1-driven lung cancers and HNSCC may be achieved by combining MTOR inhibitors and FGFR-specific TKIs.

Topics: Animals; Antineoplastic Agents; Benzamides; Carcinoma, Non-Small-Cell Lung; Cell Line, Tumor; Disease Models, Animal; Drug Resistance, Neoplasm; Drug Synergism; Gene Library; Genes, Essential; Genomics; Humans; Lung Neoplasms; Morpholines; Piperazines; Protein Binding; Protein Kinase Inhibitors; Pyrazoles; Pyrimidines; Receptor, Fibroblast Growth Factor, Type 1; RNA Interference; RNA, Small Interfering; Signal Transduction; TOR Serine-Threonine Kinases; Tumor Burden; Xenograft Model Antitumor Assays