Optimization of N-piperidinyl-benzimidazolone derivatives as potent and selective inhibitors of 8-Oxo Guanine DNA Glycosylase 1

8-oxo Guanine DNA Glycosylase 1 is the initiating enzyme within base excision repair and removes oxidized guanines from damaged DNA. Since unrepaired 8-oxoG could lead to G:C→T:A transversion, base removal is of the utmost importance for cells to ensure genomic integrity. For cells with elevat-ed levels of reactive oxygen species this dependency is further increased. In the past we and others have validated OGG1 as a target for inhibitors to treat cancer and inflammation. Here, we present the optimization campaign that led to the broadly used tool compound TH5487. Based on a high-throughput screen, we performed hit to lead expansion and arrived at potent and selective substituted N-piperidinyl-benzimidazolones. Using X-ray crystallography data, we describe the surprising bind-ing mode of the most potent member of the class, TH8535. Here, the N-Piperidinyl-linker adopts a chair instead of a boat conformation which was found for weaker analogues. We further demonstrate cellular target engagement and efficacy of TH8535 against a number of cancer cell lines.

Development of a NanoBRET assay to validate dual inhibitors of Sirt2-mediated lysine deacetylation and defatty-acylation that block prostate cancer cell migration

Sirtuin2 (Sirt2) with its NAD+-dependent deacetylase and defatty-acylase activities plays a central role in the regulation of specific cellular functions. Dysregulation of Sirt2 activity has been associated with the pathogenesis of many diseases, thus making Sirt2 a promising target for pharmaceutical intervention. Herein, we present new high affinity Sirt2 selective Sirtuin-Rearranging Ligands (SirReals) that inhibit both Sirt2-dependent deacetylation and defatty-acylation in vitro and in cells. We show that dual inhibition of Sirt2 results in strongly reduced levels of the oncogene c-Myc and an inhibition of cancer cell migration. Furthermore, we describe the development of a NanoBRET-based assay for Sirt2, thereby providing a method to study cellular target engagement for Sirt2 in a straightforward and accurately quantifiable manner. Applying this assay, we could confirm cellular Sirt2 binding of our new Sirt2 inhibitors and correlate their anticancer effects with their cellular target engagement.

In Silico Taste – Toxicological Study of Chlorfenvinphos, Dichlofluanid, Fonofos, or Methacrifos Partial Degradation Products

Toxicity is important factor to human and environment and can be tested in lab and by computerized models. ProTox-II is in Silico method to assess safety of chemicals to minimize risk health threating to human and other living organisms in nature. Taste of material is another character can be calculated in Silico model like virtualtaste. Here, first attempt of using two computerized methods and hypothetical partial degradation products of four toxics materials used to control agricultural productivity was carried out to predicate taste and toxicity characters. LD50, Toxicity Class, organ and end point toxicities, Tox21-Nuclear receptor signaling and stress response pathways of Chlorfenvinphos, Dichlofluanid, Fonofos, and Methacrifos with their hypothetical degradation products were calculated. Hypothetical degradation products were a results of (C-C, C-O, C-N, C-S, C-P, P-O, P-S, or N-S) bond breakage. The hypothesized degradation chemicals showed that most of them were with sour taste and their toxicity were less class compared to the parent compound but not to non-toxic material (Class 6, LD50 more than 5000 mg/kg). Also, they were structurally toxics and could be interact with molecular cellular target resulting than parent compound if they presented in required concentration.

Chronic Administration of 13-cis-retinoic Acid Induces Depression-Like Behavior by Altering the Activity of Dentate Granule Cells

Depression is a common but serious mental disorder and can be caused by the side effects of medications. Evidence from abundant clinical case reports and experimental animal models has revealed the association between the classic anti-acne drug 13-cis-retinoic acid (13-cis-RA) and depressive symptoms. However, direct experimental evidence of this mechanism and information on appropriate therapeutic rescue strategies are lacking. Herein, our data revealed that chronic administration of 13-cis-RA to adolescent mice induced depression-like behavior but not anxiety-like behavior. We next demonstrated that chronic 13-cis-RA application increased neural activity in the dentate gyrus (DG) using c-Fos immunostaining, which may be critically involved in some aspects of depression-like behavior. Therefore, we assessed electrophysiological functions by obtaining whole-cell patch-clamp recordings of dentate granule cells (DGCs), which revealed that chronic 13-cis-RA treatment shifted the excitatory-inhibitory balance toward excitation and increased intrinsic excitability. Furthermore, a pharmacogenetic approach was performed to repeatedly silence DGCs, and this manipulation could rescue depression-like behavior in chronically 13-cis-RA-treated mice, suggesting DGCs as a potential cellular target for the direct alleviation of 13-cis-RA-induced depression.

JAK-STAT Pathway: A Novel Target to Tackle Viral Infections

Modulation of the antiviral innate immune response has been proposed as a putative cellular target for the development of novel pan-viral therapeutic strategies. The Janus kinase–signal transducer and activator of transcription (JAK-STAT) pathway is especially relevant due to its essential role in the regulation of local and systemic inflammation in response to viral infections, being, therefore, a putative therapeutic target. Here, we review the extraordinary diversity of strategies that viruses have evolved to interfere with JAK-STAT signaling, stressing the relevance of this pathway as a putative antiviral target. Moreover, due to the recent remarkable progress on the development of novel JAK inhibitors (JAKi), the current knowledge on its efficacy against distinct viral infections is also discussed. JAKi have a proven efficacy against a broad spectrum of disorders and exhibit safety profiles comparable to biologics, therefore representing good candidates for drug repurposing strategies, including viral infections.

Characterising the Biological Activity of a Trichlorovinyl Cysteine-Containing Mycothiol Analogue

<p>Cancer is a disease characterised by the uncontrolled growth of mutated cells, and is one of the leading causes of death worldwide, with over a third of people diagnosed with cancer in their lifetime. Despite extensive investment of both time and money in cancer research, poor patient outcomes and quality of life, and the evolution of treatment resistant cancers indicates that continued research, and more efficacious therapies are required. A recent investigation identified a mycothiol analogue which displayed significant toxicity in the promyelocytic leukemia cell line (HL60). Designed as a negative control, no biological activity was expected from this compound and its cellular target and mode of action are unknown. This thesis describes the synthesis of a toxic trichlorovinyl cysteine-containing analogue of mycothiol, and the attempted synthesis of a propynylated and fluorescent derivative of this. The research also details immunomodulatory investigations, which were undertaken to probe the mode of action of the lead compound, and to determine whether its precursor, N-Boc-S-trichlorovinyl cysteine, induced toxicity through the same mechanism. The lead compound demonstrated mild immunomodulatory activity in splenocytes isolated from euthanised C57BL/6 mice, and enzyme linked immunosorbent assays revealed a likely Th2 mediated response, induced by the production of IL-4. The precursor however appears to promote a strong pro-inflammatory response, by inducing IL-17a production, which is widely considered a deleterious immune response in cancer. Whilst further work is required to determine the cellular target of the lead compound, the research described demonstrates the potential for this compound as an anti-cancer agent, while the precursor appears inappropriate for further development.</p>

Characterising the Biological Activity of a Trichlorovinyl Cysteine-Containing Mycothiol Analogue

<p>Cancer is a disease characterised by the uncontrolled growth of mutated cells, and is one of the leading causes of death worldwide, with over a third of people diagnosed with cancer in their lifetime. Despite extensive investment of both time and money in cancer research, poor patient outcomes and quality of life, and the evolution of treatment resistant cancers indicates that continued research, and more efficacious therapies are required. A recent investigation identified a mycothiol analogue which displayed significant toxicity in the promyelocytic leukemia cell line (HL60). Designed as a negative control, no biological activity was expected from this compound and its cellular target and mode of action are unknown. This thesis describes the synthesis of a toxic trichlorovinyl cysteine-containing analogue of mycothiol, and the attempted synthesis of a propynylated and fluorescent derivative of this. The research also details immunomodulatory investigations, which were undertaken to probe the mode of action of the lead compound, and to determine whether its precursor, N-Boc-S-trichlorovinyl cysteine, induced toxicity through the same mechanism. The lead compound demonstrated mild immunomodulatory activity in splenocytes isolated from euthanised C57BL/6 mice, and enzyme linked immunosorbent assays revealed a likely Th2 mediated response, induced by the production of IL-4. The precursor however appears to promote a strong pro-inflammatory response, by inducing IL-17a production, which is widely considered a deleterious immune response in cancer. Whilst further work is required to determine the cellular target of the lead compound, the research described demonstrates the potential for this compound as an anti-cancer agent, while the precursor appears inappropriate for further development.</p>