gdc-0973 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

A pancreatic ductal adenocarcinoma (PDAC), obtained from a patient, was grown orthotopically in the pancreatic tail of nude mice to establish a patient-derived orthotopic (PDOX) model. Seven weeks after implantation, PDOX nude mice were divided into the following groups: untreated control (n = 7); gemcitabine (100 mg/kg, i.p., once a week for 2 weeks, n = 7); cobimetinib (5 mg/kg, p.o., 14 consecutive days, n = 7); trametinib (0.3 mg/kg, p.o., 14 consecutive days, n = 7); trabectedin (0.15 mg/kg, i.v., once a week for 2 weeks, n = 7); temozolomide (25 mg/kg, p.o., 14 consecutive days, n = 7); carfilzomib (2 mg/kg, i.v., twice a week for 2 weeks, n = 7); bortezomib (1 mg/kg, i.v., twice a week for 2 weeks, n = 7); MK-1775 (20 mg/kg, p.o., 14 consecutive days, n = 7); BEZ-235 (45 mg/kg, p.o., 14 consecutive days, n = 7); vorinostat (50 mg/kg, i.p., 14 consecutive days, n = 7). Only the MEK inhibitors, cobimetinib and trametinib, regressed tumor growth, and they were more significantly effective than other therapies (p < 0.0001, respectively), thereby demonstrating the precision of the PDOX models of PDAC and its potential for individualizing pancreatic-cancer therapy.

Topics: Animals; Antineoplastic Agents; Azetidines; Cell Line, Tumor; Deoxycytidine; Disease Models, Animal; Dose-Response Relationship, Drug; Drug Resistance, Neoplasm; Gemcitabine; Humans; Mice; Mitogen-Activated Protein Kinases; Pancreatic Neoplasms; Piperidines; Protein Kinase Inhibitors; Pyridones; Pyrimidinones; Xenograft Model Antitumor Assays

Previously, a BRAF-V600E-mutant melanoma obtained from the right chest wall of a patient was grown orthotopically in the right chest wall of nude mice to establish a patient-derived orthotopic xenograft (PDOX) model. Trametinib (TRA), an MEK inhibitor, caused tumor regression. In contrast, another MEK inhibitor, cobimetinib (COB) could slow but not arrest growth or cause regression of the melanoma PDOX. First-line therapy temozolomide (TEM) could slow but not arrest tumor growth or cause regression. In addition, vemurafenib (VEM) was not effective even though VEM is supposed to target the BRAF-V600E mutation. We also previously demonstrated that tumor-targeting with S. typhimurium A1-R combined with TEM was significantly more effective than either S. typhimurium A1-R alone or TEM alone on the melanoma PDOX with the BRAF-V600E mutation. The present study used this PDOX model of melanoma to test its sensitivity to VEM combined with S. typhimurium A1-R compared to VEM alone and VEM combined with COB. VEM combined with S. typhimurium A1-R was significantly more effective than VEM alone or VEM combined with COB (P = 0.0216) which is currently first line therapy for advanced melanoma with a BRAF-V600E mutation. J. Cell. Biochem. 118: 2314-2319, 2017. © 2017 Wiley Periodicals, Inc.

Topics: Aged; Animals; Azetidines; Cell Line, Tumor; Disease Models, Animal; Female; Humans; Indoles; Melanoma; Mice; Mice, Nude; Microscopy, Confocal; Microscopy, Electron, Transmission; Mutation; Piperidines; Proto-Oncogene Proteins B-raf; Pyridones; Pyrimidinones; Salmonella typhimurium; Sulfonamides; Vemurafenib; Xenograft Model Antitumor Assays

Pancreatic adenocarcinoma (PDAC) is a major unmet medical need and a deeper understanding of molecular drivers is needed to advance therapeutic options for patients. We report here that p21-activated kinase 1 (PAK1) is a central node in PDAC cells downstream of multiple growth factor signalling pathways, including hepatocyte growth factor (HGF) and MET receptor tyrosine kinase. PAK1 inhibition blocks signalling to cytoskeletal effectors and tumour cell motility driven by HGF/MET. MET antagonists, such as onartuzumab and crizotinib, are currently in clinical development. Given that even highly effective therapies have resistance mechanisms, we show that combination with PAK1 inhibition overcomes potential resistance mechanisms mediated either by activation of parallel growth factor pathways or by direct amplification of PAK1. Inhibition of PAK1 attenuated in vivo tumour growth and metastasis in a model of pancreatic adenocarcinoma. In human tissues, PAK1 is highly expressed in a proportion of PDACs (33% IHC score 2 or 3; n = 304) and its expression is significantly associated with MET positivity (p < 0.0001) and linked to a widespread metastatic pattern in patients (p = 0.067). Taken together, our results provide evidence for a functional role of MET/PAK1 signalling in pancreatic adenocarcinoma and support further characterization of therapeutic inhibitors in this indication.

Topics: Adenocarcinoma; Animals; Antibodies, Monoclonal; Antineoplastic Combined Chemotherapy Protocols; Azetidines; Cell Movement; Disease Models, Animal; Drug Resistance, Neoplasm; Humans; Immunohistochemistry; Mice; p21-Activated Kinases; Pancreatic Neoplasms; Piperidines; Proto-Oncogene Proteins c-met; Signal Transduction