onc201 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

Imipridones constitute a novel class of antitumor agents. Here, we report that a second-generation imipridone, ONC212, possesses highly increased antitumor activity compared to the first-generation compound ONC201. In vitro studies using human acute myeloid leukemia (AML) cell lines, primary AML, and normal bone marrow (BM) samples demonstrate that ONC212 exerts prominent apoptogenic effects in AML, but not in normal BM cells, suggesting potential clinical utility. Imipridones putatively engage G protein-coupled receptors (GPCRs) and/or trigger an integrated stress response in hematopoietic tumor cells. Comprehensive GPCR screening identified ONC212 as activator of an orphan GPCR GPR132 and Gαq signaling, which functions as a tumor suppressor. Heterozygous knock-out of GPR132 decreased the antileukemic effects of ONC212. ONC212 induced apoptogenic effects through the induction of an integrated stress response, and reduced MCL-1 expression, a known resistance factor for BCL-2 inhibition by ABT-199. Oral administration of ONC212 inhibited AML growth in vivo and improved overall survival in xenografted mice. Moreover, ONC212 abrogated the engraftment capacity of patient-derived AML cells in an NSG PDX model, suggesting potential eradication of AML initiating cells, and was highly synergistic in combination with ABT-199. Collectively, our results suggest ONC212 as a novel therapeutic agent for AML.

Topics: Animals; Antineoplastic Agents; Apoptosis; Biomarkers; Cell Cycle; Cell Cycle Proteins; Cell Line, Tumor; Cell Proliferation; Cell Survival; Disease Models, Animal; Gene Expression Regulation, Leukemic; Humans; Imidazoles; Leukemia, Myeloid, Acute; Mice; Molecular Structure; Pyridines; Pyrimidines; Receptors, G-Protein-Coupled; Stress, Physiological; Transcriptional Activation; Treatment Outcome; Xenograft Model Antitumor Assays

Despite the success of antiretroviral therapy (ART), eradication of HIV-1 from brain reservoirs remains elusive. HIV-1 brain reservoirs include perivascular macrophages that are behind the blood-brain barrier and difficult to access by ART. Macrophages express transcription factor FOXO3a and the TNF superfamily cytokine TRAIL, which are known to target HIV-1-infected macrophages for viral inhibition. ONC201 is a novel and potent FOXO3a activator capable of inducing TRAIL. It can cross the blood-brain barrier, and has shown antitumor effects in clinical trials. We hypothesized that activation of FOXO3a/TRAIL by ONC201 will inhibit HIV-1 replication in macrophages. Using primary human monocyte-derived macrophages, we demonstrated that ONC201 dose-dependently decreased replication levels of both HIV-1 laboratory strain and primary strains as determined by HIV-1 reverse transcriptase activity assay. Consistent with data on HIV-1 replication, ONC201 also reduced intracellular and extracellular p24, viral RNA, and integrated HIV-1 DNA in infected macrophages. Blocking TRAIL or knockdown of FOXO3a with siRNA reversed ONC201-mediated HIV-1 suppression, suggesting that ONC201 inhibits HIV-1 through FOXO3a and TRAIL. The anti-HIV-1 effect of ONC201 was further validated in vivo in NOD/scid-IL-2Rgcnull mice. After intracranial injection of HIV-1-infected macrophages into the basal ganglia, we treated the mice daily with ONC201 through intraperitoneal injection for six days. ONC201 significantly decreased p24 levels in both the macrophages and the brain tissues, suggesting that ONC201 suppresses HIV-1 in vivo. Therefore, ONC201 can be a promising drug candidate to combat persistent HIV-1 infection in the brain.

Topics: Animals; Anti-HIV Agents; Cell Survival; Cells, Cultured; Disease Models, Animal; Forkhead Box Protein O3; Gene Knockdown Techniques; HIV Infections; HIV-1; Humans; Imidazoles; Macrophages; Male; Mice; Mice, Inbred NOD; Mice, SCID; Pyridines; Pyrimidines; Signal Transduction; TNF-Related Apoptosis-Inducing Ligand; Virus Replication

Small molecule ONC201 is an investigational anti-tumor agent that upregulates intra-tumoral TRAIL expression and the integrated stress response pathway. A Phase I clinical trial using ONC201 therapy in advanced cancer patients has been completed and the drug has progressed into Phase II trials in several cancer types. Colorectal cancer (CRC) remains one of the leading causes of cancer worldwide and metastatic disease has a poor prognosis. Clinical trials in CRC and other tumor types have demonstrated that therapeutics targeting the vascular endothelial growth factor (VEGF) pathway, such as bevacizumab, are effective in combination with certain chemotherapeutic agents.. We investigated the potential combination of VEGF inhibitors such as bevacizumab and its murine-counterpart; along with other anti-angiogenic agents and ONC201 in both CRC xenograft and patient-derived xenograft (PDX) models. We utilized non-invasive imaging and immunohistochemistry to determine potential mechanisms of action.. Our results demonstrate significant tumor regression or complete tumor ablation in human xenografts with the combination of ONC201 with bevacizumab, and in syngeneic MC38 colorectal cancer xenografts using a murine VEGF-A inhibitor. Imaging demonstrated the impact of this combination on decreasing tumor growth and tumor metastasis. Our results indicate that ONC201 and anti-angiogenic agents act through distinct mechanisms while increasing tumor cell death and inhibiting proliferation.. With the use of both a murine VEGF inhibitor in syngeneic models, and bevacizumab in human cell line-derived xenografts, we demonstrate that ONC201 in combination with anti-angiogenic therapies such as bevacizumab represents a promising approach for further testing in the clinic for the treatment of CRC.

Topics: Angiogenesis Inhibitors; Animals; Antineoplastic Agents; Apoptosis; Bevacizumab; Cell Line, Tumor; Cell Proliferation; Cell Survival; Colorectal Neoplasms; Disease Models, Animal; Drug Synergism; Heterocyclic Compounds, 4 or More Rings; Human Umbilical Vein Endothelial Cells; Humans; Imidazoles; Mice; Models, Biological; Neovascularization, Pathologic; Pyridines; Pyrimidines; Tumor Burden; Vascular Endothelial Growth Factor A; Xenograft Model Antitumor Assays

The current study tested the anti-hepatocellular carcinoma (HCC) cell activity of TIC10, a first-in-class small-molecule tumor necrosis (TNF)-related apoptosis-inducing ligand (TRAIL) inducer. TIC10 exerted potent anti-proliferative and pro-apoptotic actions in primary and established human HCC cells. TIC10 blocked Akt-Erk activation, leading to Foxo3a nuclear translocation, as well as TRAIL and death receptor-5 (DR5) transcription in HCC cells. We propose that DNA-PKcs is a major resistance factor of TIC10 possibly via inhibiting Foxo3a nuclear translocation. DNA-PKcs inhibition, knockdown or mutation facilitated TIC10-induced Foxo3a nuclear translocation, TRAIL/DR5 expression and cell apoptosis. Reversely, exogenous DNA-PKcs over-expression inhibited above actions by TIC10. In vivo, oral administration of TIC10 significantly inhibited HepG2 tumor growth in nude mice, which was further potentiated with Nu7026 co-administration. Thus, TIC10 shows promising anti-HCC activity, alone or together with DNA-PKcs inhibitors.

Topics: Animals; Antineoplastic Agents; Apoptosis; Carcinoma, Hepatocellular; Cell Line, Tumor; Cell Proliferation; Disease Models, Animal; DNA-Activated Protein Kinase; Drug Resistance, Neoplasm; Female; Forkhead Box Protein O3; Gene Expression; Heterocyclic Compounds, 4 or More Rings; Humans; Imidazoles; Liver Neoplasms; Mice; Nuclear Proteins; Protein Transport; Pyridines; Pyrimidines; Receptors, TNF-Related Apoptosis-Inducing Ligand; TNF-Related Apoptosis-Inducing Ligand; Xenograft Model Antitumor Assays