lde225 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

Pancreatic ductal adenocarcinoma (PDAC) is one of the most chemotherapy- and radiotherapy-resistant tumors. The c-Met and Hedgehog (Hh) pathways have been shown previously by our group to be key regulatory pathways in the primary tumor growth and metastases formation. Targeting both the HGF/c-Met and Hh pathways has shown promising results in preclinical studies; however, the benefits were not readily translated into clinical trials with PDAC patients. In this study, utilizing mouse models of PDAC, we showed that inhibition of either HGF/c-Met or Hh pathways sensitize the PDAC tumors to gemcitabine, resulting in decreased primary tumor volume as well as significant reduction of metastatic tumor burden. However, prolonged treatment of single HGF/c-Met or Hh inhibitor leads to resistance to these single inhibitors, likely because the single c-Met treatment leads to enhanced expression of Shh, and vice versa. Targeting both the HGF/c-Met and Hh pathways simultaneously overcame the resistance to the single-inhibitor treatment and led to a more potent antitumor effect in combination with the chemotherapy treatment.

Topics: Adenocarcinoma; Animals; Benzamides; Biphenyl Compounds; Bridged Bicyclo Compounds, Heterocyclic; Carcinoma, Pancreatic Ductal; Cell Line, Tumor; Cell Proliferation; Deoxycytidine; Disease Models, Animal; Drug Resistance, Neoplasm; Gemcitabine; Gene Expression Regulation, Neoplastic; Hedgehog Proteins; Hepatocyte Growth Factor; Humans; Imidazoles; Mice; Mice, Transgenic; Neoplasm Metastasis; Proto-Oncogene Proteins c-met; Pyridines; Triazines; Tumor Microenvironment

Topics: Animals; Antineoplastic Agents; Biphenyl Compounds; Carcinoma, Basal Cell; Cell Differentiation; Cell Proliferation; Chorda Tympani Nerve; Disease Models, Animal; Dysgeusia; Hedgehog Proteins; Humans; Mice; Mice, Inbred C57BL; Mice, Knockout; Pyridines; Recovery of Function; Signal Transduction; Skin Neoplasms; Smoothened Receptor; Stem Cells; Taste; Taste Buds; Tongue

Targeting the Hedgehog (Hh) pathway represents a potential leukaemia stem cell (LSC)-directed therapy which may compliment tyrosine kinase inhibitors (TKIs) to eradicate LSC in chronic phase (CP) chronic myeloid leukaemia (CML). We set out to elucidate the role of Hh signaling in CP-CML and determine if inhibition of Hh signaling, through inhibition of smoothened (SMO), was an effective strategy to target CP-CML LSC. Assessment of Hh pathway gene and protein expression demonstrated that the Hh pathway is activated in CD34(+) CP-CML stem/progenitor cells. LDE225 (Sonidegib), a small molecule, clinically investigated SMO inhibitor, used alone and in combination with nilotinib, inhibited the Hh pathway in CD34(+) CP-CML cells, reducing the number and self-renewal capacity of CML LSC in vitro. The combination had no effect on normal haemopoietic stem cells. When combined, LDE225 + nilotinib reduced CD34(+) CP-CML cell engraftment in NSG mice and, upon administration to EGFP(+) /SCLtTA/TRE-BCR-ABL mice, the combination enhanced survival with reduced leukaemia development in secondary transplant recipients. In conclusion, the Hh pathway is deregulated in CML stem and progenitor cells. We identify Hh pathway inhibition, in combination with nilotinib, as a potentially effective therapeutic strategy to improve responses in CP-CML by targeting both stem and progenitor cells.

Topics: Animals; Antigens, CD34; Biphenyl Compounds; Disease Models, Animal; Hedgehog Proteins; Hematopoietic Stem Cells; Humans; Lentivirus; Leukemia, Myelogenous, Chronic, BCR-ABL Positive; Mice; Mice, SCID; Mice, Transgenic; Neoplastic Stem Cells; Pyridines; Pyrimidines; Signal Transduction; Small Molecule Libraries; Spleen

Melanoma is one of the most aggressive cancers and its incidence is increasing worldwide. So far there are no curable therapies especially after metastasis. Due to frequent mutations in members of the mitogen-activated protein kinase (MAPK) signaling pathway, this pathway is constitutively active in melanoma. It has been shown that the SONIC HEDGEHOG (SHH)-GLI and MAPK signaling pathway regulate cell growth in many tumors including melanoma and interact with each other in the regulation of cell proliferation and survival. Here we show that the SHH-GLI pathway is active in human melanoma cell lines as they express downstream target of this pathway GLI1. Expression of GLI1 was significantly higher in human primary melanoma tissues harboring BRAF(V600E) mutation than those with wild type BRAF. Pharmacologic inhibition of BRAF(V600E) in human melanoma cell lines resulted in decreased expression of GLI1 thus demonstrating interaction of SHH-GLI and MAPK pathways. Inhibition of SHH-GLI pathway by the novel small molecule inhibitor of smoothened NVP-LDE225 was followed by inhibition of cell growth and induction of apoptosis in human melanoma cell lines, interestingly with both BRAF(V600E) and BRAF(Wild Type) status. NVP-LDE225 was potent in reducing cell proliferation and inducing tumor growth arrest in vitro and in vivo, respectively and these effects were superior to the natural compound cyclopamine. Finally, we conclude that inhibition of SHH-GLI signaling pathway in human melanoma by the specific smoothened inhibitor NVP-LDE225 could have potential therapeutic application in human melanoma even in the absence of BRAF(V600E) mutation and warrants further investigations.

Topics: Animals; Antineoplastic Agents; Apoptosis; Biphenyl Compounds; Cell Line, Tumor; Cell Proliferation; Cell Survival; Disease Models, Animal; Female; G1 Phase Cell Cycle Checkpoints; Gene Expression Regulation, Neoplastic; Hedgehog Proteins; Humans; Indoles; Melanoma; Mice; Mutation; Proto-Oncogene Proteins B-raf; Pyridines; Receptors, G-Protein-Coupled; Signal Transduction; Smoothened Receptor; Sulfonamides; Transcription Factors; Tumor Burden; Vemurafenib; Xenograft Model Antitumor Assays; Zinc Finger Protein GLI1

This study was designed to evaluate the role of the hedgehog pathway in tumor progression of murine islet cell tumors. Blockade of aberrant hedgehog activation has recently been proposed as a therapeutic target, but effects in models of islet cell tumors with a new orally bioavailable Smoothened (Smo) antagonist LDE225 have not been examined.. To assess in vivo effects, transgenic Rip1Tag2 mice, which develop islet cell neoplasms, were treated with vehicle or LDE225 (80 mg/kg/d) from week 5 until death. The resected pancreata were evaluated macroscopically and microscopically by iummohistochemsistry. Quantitative real-time polymerase chain reaction was performed for hedgehog target genes with RNA from islet, isolated from treated and untreated Rip1Tag2 mice.. LDE225 significantly reduced tumor volume by 95% compared with untreated control mice. Hedgehog inhibition with LDE225 significantly prolonged median survival in the used transgenic mouse model (105 vs 116 days; P = 0.02). Quantitative real-time polymerase chain reaction for downstream hedgehog target genes demonstrated significant downregulation in the islet cell tumors of Rip1Tag2 mice treated with LDE225, confirming the ability to achieve effective pharmacologic levels of LDE225 within the desired tissue site, in vivo.. This is the first study to show that the orally bioavailable Smo antagonist LDE225 may provide a new option for therapy of islet cell neoplasms.

Topics: Adenoma, Islet Cell; Administration, Oral; Animals; Animals, Genetically Modified; Antineoplastic Agents; Biological Availability; Biphenyl Compounds; Disease Models, Animal; Down-Regulation; Female; Hedgehog Proteins; Male; Mice; Pancreatic Neoplasms; Pyridines; Real-Time Polymerase Chain Reaction; Receptors, G-Protein-Coupled; Smoothened Receptor