LIVIVO - The Search Portal for Life Sciences

zur deutschen Oberfläche wechseln
Advanced search

Search results

Result 1 - 10 of total 54

Search options

  1. Article: White Paper: Mimetics of Class 2 Tumor Suppressor Proteins as Novel Drug Candidates for Personalized Cancer Therapy.

    Dahl, Edgar / Villwock, Sophia / Habenberger, Peter / Choidas, Axel / Rose, Michael / Klebl, Bert M

    Cancers

    2022  Volume 14, Issue 18

    Abstract: The aim of our proposed concept is to find new target structures for combating cancers with unmet medical needs. This, unfortunately, still applies to the majority of the clinically most relevant tumor entities such as, for example, liver cancer, ... ...

    Abstract The aim of our proposed concept is to find new target structures for combating cancers with unmet medical needs. This, unfortunately, still applies to the majority of the clinically most relevant tumor entities such as, for example, liver cancer, pancreatic cancer, and many others. Current target structures almost all belong to the class of oncogenic proteins caused by tumor-specific genetic alterations, such as activating mutations, gene fusions, or gene amplifications, often referred to as cancer "driver alterations" or just "drivers." However, restoring the lost function of tumor suppressor genes (TSGs) could also be a valid approach to treating cancer. TSG-derived proteins are usually considered as control systems of cells against oncogenic properties; thus, they represent the brakes in the "car-of-life." Restoring these tumor-defective brakes by gene therapy has not been successful so far, with a few exceptions. It can be assumed that most TSGs are not being inactivated by genetic alteration (class 1 TSGs) but rather by epigenetic silencing (class 2 TSGs or short "C2TSGs"). Reactivation of C2TSGs in cancer therapy is being addressed by the use of DNA demethylating agents and histone deacetylase inhibitors which act on the whole cancer cell genome. These epigenetic therapies have neither been particularly successful, probably because they are "shotgun" approaches that, although acting on C2TSGs, may also reactivate epigenetically silenced oncogenic sequences in the genome. Thus, new strategies are needed to exploit the therapeutic potential of C2TSGs, which have also been named DNA methylation cancer driver genes or "DNAme drivers" recently. Here we present a concept for a new translational and therapeutic approach that focuses on the phenotypic imitation ("mimesis") of proteins encoded by highly disease-relevant C2TSGs/DNAme drivers. Molecular knowledge on C2TSGs is used in two complementary approaches having the translational concept of defining mimetic drugs in common: First, a concept is presented how truncated and/or genetically engineered C2TSG proteins, consisting solely of domains with defined tumor suppressive function can be developed as biologicals. Second, a method is described for identifying small molecules that can mimic the effect of the C2TSG protein lost in the cancer cell. Both approaches should open up a new, previously untapped discovery space for anticancer drugs.
    Language English
    Publishing date 2022-09-09
    Publishing country Switzerland
    Document type Journal Article
    ZDB-ID 2527080-1
    ISSN 2072-6694
    ISSN 2072-6694
    DOI 10.3390/cancers14184386
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  2. Article ; Online: Pyrrolopyrimidine based CSF1R inhibitors: Attempted departure from Flatland.

    Bjørnstad, Frithjof / Havik, Simen / Aarhus, Thomas Ihle / Mahdi, Iktedar / Unger, Anke / Habenberger, Peter / Degenhart, Carsten / Eickhoff, Jan / Klebl, Bert M / Sundby, Eirik / Hoff, Bård Helge

    European journal of medicinal chemistry

    2023  Volume 265, Page(s) 116053

    Abstract: The colony-stimulating factor 1 receptor (CSF1R) is an attractive target for inflammation disorders and cancers. Based on a series of pyrrolo[2,3-d]pyrimidine containing two carbo-aromatic rings, we have searched for new CSF1R inhibitors having a higher ... ...

    Abstract The colony-stimulating factor 1 receptor (CSF1R) is an attractive target for inflammation disorders and cancers. Based on a series of pyrrolo[2,3-d]pyrimidine containing two carbo-aromatic rings, we have searched for new CSF1R inhibitors having a higher fraction of sp
    MeSH term(s) Pyrimidines/pharmacology ; Receptor Protein-Tyrosine Kinases ; Pyrroles/pharmacology ; Structure-Activity Relationship ; Protein Kinase Inhibitors/pharmacology
    Chemical Substances pyrrolopyrimidine ; Pyrimidines ; Receptor Protein-Tyrosine Kinases (EC 2.7.10.1) ; Pyrroles ; Protein Kinase Inhibitors
    Language English
    Publishing date 2023-12-17
    Publishing country France
    Document type Journal Article
    ZDB-ID 188597-2
    ISSN 1768-3254 ; 0009-4374 ; 0223-5234
    ISSN (online) 1768-3254
    ISSN 0009-4374 ; 0223-5234
    DOI 10.1016/j.ejmech.2023.116053
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  3. Article ; Online: Advances in anti-viral therapeutics.

    Klebl, Bert M

    Expert opinion on investigational drugs

    2005  Volume 14, Issue 3, Page(s) 343–348

    Abstract: Hepatitis C virus (HCV) and HIV infections are of high economical importance as they have a global impact, high mortality rates and, consequently novel treatments are urgently needed. Worldwide, 170 and 34 - 46 million people are infected with HCV and ... ...

    Abstract Hepatitis C virus (HCV) and HIV infections are of high economical importance as they have a global impact, high mortality rates and, consequently novel treatments are urgently needed. Worldwide, 170 and 34 - 46 million people are infected with HCV and HIV, respectively. HCV and HIV medications constitute the largest antiviral markets today. The efforts in fighting HCV infections are still limited to early clinical development, trying to establish proof-of-concept in man. However, in HIV, there is a better chance that some of the new drugs on new and old targets (indirect and direct antiviral targets, like CCR5 and HIV protease, respectively) will finally reach the market.
    MeSH term(s) Animals ; Antiviral Agents/chemistry ; Antiviral Agents/pharmacology ; Antiviral Agents/therapeutic use ; Drugs, Investigational/chemistry ; Drugs, Investigational/pharmacology ; Drugs, Investigational/therapeutic use ; Hepacivirus/drug effects ; Hepatitis C/drug therapy ; Hepatitis C/virology ; Humans ; London ; Technology, Pharmaceutical/trends
    Chemical Substances Antiviral Agents ; Drugs, Investigational
    Language English
    Publishing date 2005-03-15
    Publishing country England
    Document type Congress
    ZDB-ID 1182884-5
    ISSN 1744-7658 ; 0967-8298 ; 1354-3784
    ISSN (online) 1744-7658
    ISSN 0967-8298 ; 1354-3784
    DOI 10.1517/13543784.14.3.343
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  4. Article: Stacking up the armory against viruses.

    Klebl, Bert M

    Drug discovery today

    2004  Volume 9, Issue 4, Page(s) 162–164

    MeSH term(s) Animals ; Antiviral Agents/therapeutic use ; Chemistry, Pharmaceutical/trends ; Communicable Diseases, Emerging/drug therapy ; HIV Infections/drug therapy ; Hepatitis C/drug therapy ; Humans ; Severe Acute Respiratory Syndrome/drug therapy
    Chemical Substances Antiviral Agents
    Keywords covid19
    Language English
    Publishing date 2004-02-03
    Publishing country England
    Document type Letter
    ZDB-ID 1324988-5
    ISSN 1878-5832 ; 1359-6446
    ISSN (online) 1878-5832
    ISSN 1359-6446
    DOI 10.1016/S1359-6446(03)02970-2
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  5. Article: Chemical kinomics - a target gene family approach in chemical biology.

    Klebl, Bert M

    Drug discovery today. Technologies

    2004  Volume 1, Issue 1, Page(s) 25–34

    Abstract: Traditionally, protein kinases have been regarded as non-druggable targets, instead they play a central role in physiological and pathophysiological processes. This changed when STI571, an inhibitor of the Bcr-Abl kinase, known as Gleevec, reached the ... ...

    Abstract Traditionally, protein kinases have been regarded as non-druggable targets, instead they play a central role in physiological and pathophysiological processes. This changed when STI571, an inhibitor of the Bcr-Abl kinase, known as Gleevec, reached the market as the first designer drug. Ever since, kinase-directed research and development (R&D) expanded rapidly, leading to more than 45 clinically relevant kinase inhibitors. At a comparable pace the kinase-based technologies matured, cumulating in the development of sophisticated chemogenetic and chemoproteomic tools, which are referred to as chemical kinomics.:
    Language English
    Publishing date 2004-09
    Publishing country England
    Document type Journal Article
    ISSN 1740-6749
    ISSN 1740-6749
    DOI 10.1016/j.ddtec.2004.08.013
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  6. Article ; Online: Structure-Activity Relationship Studies of Trisubstituted Isoxazoles as Selective Allosteric Ligands for the Retinoic-Acid-Receptor-Related Orphan Receptor γt.

    Meijer, Femke A / Saris, Annet O W M / Doveston, Richard G / Oerlemans, Guido J M / de Vries, Rens M J M / Somsen, Bente A / Unger, Anke / Klebl, Bert / Ottmann, Christian / Cossar, Peter J / Brunsveld, Luc

    Journal of medicinal chemistry

    2021  Volume 64, Issue 13, Page(s) 9238–9258

    Abstract: The inhibition of the nuclear receptor retinoic-acid-receptor-related orphan receptor γt (RORγt) is a promising strategy in the treatment of autoimmune diseases. RORγt features an allosteric binding site within its ligand-binding domain that provides an ... ...

    Abstract The inhibition of the nuclear receptor retinoic-acid-receptor-related orphan receptor γt (RORγt) is a promising strategy in the treatment of autoimmune diseases. RORγt features an allosteric binding site within its ligand-binding domain that provides an opportunity to overcome drawbacks associated with orthosteric modulators. Recently, trisubstituted isoxazoles were identified as a novel class of allosteric RORγt inverse agonists. This chemotype offers new opportunities for optimization into selective and efficacious allosteric drug-like molecules. Here, we explore the structure-activity relationship profile of the isoxazole series utilizing a combination of structure-based design, X-ray crystallography, and biochemical assays. The initial lead isoxazole (
    MeSH term(s) Allosteric Site/drug effects ; Dose-Response Relationship, Drug ; Humans ; Isoxazoles/chemical synthesis ; Isoxazoles/chemistry ; Isoxazoles/pharmacology ; Ligands ; Models, Molecular ; Molecular Structure ; Nuclear Receptor Subfamily 1, Group F, Member 3/agonists ; Nuclear Receptor Subfamily 1, Group F, Member 3/metabolism ; Structure-Activity Relationship
    Chemical Substances Isoxazoles ; Ligands ; Nuclear Receptor Subfamily 1, Group F, Member 3
    Language English
    Publishing date 2021-05-19
    Publishing country United States
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 218133-2
    ISSN 1520-4804 ; 0022-2623
    ISSN (online) 1520-4804
    ISSN 0022-2623
    DOI 10.1021/acs.jmedchem.1c00475
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  7. Article: Blocking the Farnesyl Pocket of PDEδ Reduces Rheb-Dependent mTORC1 Activation and Survival of

    Armijo, Marisol Estrella / Escalona, Emilia / Peña, Daniela / Farias, Alejandro / Morin, Violeta / Baumann, Matthias / Klebl, Bert Matthias / Pincheira, Roxana / Castro, Ariel Fernando

    Frontiers in pharmacology

    2022  Volume 13, Page(s) 912688

    Abstract: Rheb is a small GTPase member of the Ras superfamily and an activator of mTORC1, a protein complex master regulator of cell metabolism, growth, and proliferation. Rheb/mTORC1 pathway is hyperactivated in proliferative diseases, such as Tuberous Sclerosis ...

    Abstract Rheb is a small GTPase member of the Ras superfamily and an activator of mTORC1, a protein complex master regulator of cell metabolism, growth, and proliferation. Rheb/mTORC1 pathway is hyperactivated in proliferative diseases, such as Tuberous Sclerosis Complex syndrome and cancer. Therefore, targeting Rheb-dependent signaling is a rational strategy for developing new drug therapies. Rheb activates mTORC1 in the cytosolic surface of lysosomal membranes. Rheb's farnesylation allows its anchorage on membranes, while its proper localization depends on the prenyl-binding chaperone PDEδ. Recently, the use of PDEδ inhibitors has been proposed as anticancer agents because they interrupted KRas signaling leading to antiproliferative effects in KRas-dependent pancreatic cancer cells. However, the effect of PDEδ inhibition on the Rheb/mTORC1 pathway has been poorly investigated. Here, we evaluated the impact of a new PDEδ inhibitor, called Deltasonamide 1, in
    Language English
    Publishing date 2022-06-23
    Publishing country Switzerland
    Document type Journal Article
    ZDB-ID 2587355-6
    ISSN 1663-9812
    ISSN 1663-9812
    DOI 10.3389/fphar.2022.912688
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  8. Article: An Antiherpesviral Host-Directed Strategy Based on CDK7 Covalently Binding Drugs: Target-Selective, Picomolar-Dose, Cross-Virus Reactivity.

    Yu, DongHoon / Wagner, Sabrina / Schütz, Martin / Jeon, Yeejin / Seo, Mooyoung / Kim, Jaeseung / Brückner, Nadine / Kicuntod, Jintawee / Tillmanns, Julia / Wangen, Christina / Hahn, Friedrich / Kaufer, Benedikt B / Neipel, Frank / Eickhoff, Jan / Klebl, Bert / Nam, Kiyean / Marschall, Manfred

    Pharmaceutics

    2024  Volume 16, Issue 2

    Abstract: The repertoire of currently available antiviral drugs spans therapeutic applications against a number of important human pathogens distributed worldwide. These include cases of the pandemic severe acute respiratory coronavirus type 2 (SARS-CoV-2 or COVID- ...

    Abstract The repertoire of currently available antiviral drugs spans therapeutic applications against a number of important human pathogens distributed worldwide. These include cases of the pandemic severe acute respiratory coronavirus type 2 (SARS-CoV-2 or COVID-19), human immunodeficiency virus type 1 (HIV-1 or AIDS), and the pregnancy- and posttransplant-relevant human cytomegalovirus (HCMV). In almost all cases, approved therapies are based on direct-acting antivirals (DAAs), but their benefit, particularly in long-term applications, is often limited by the induction of viral drug resistance or side effects. These issues might be addressed by the additional use of host-directed antivirals (HDAs). As a strong input from long-term experiences with cancer therapies, host protein kinases may serve as HDA targets of mechanistically new antiviral drugs. The study demonstrates such a novel antiviral strategy by targeting the major virus-supportive host kinase CDK7. Importantly, this strategy focuses on highly selective, 3D structure-derived CDK7 inhibitors carrying a warhead moiety that mediates covalent target binding. In summary, the main experimental findings of this study are as follows: (1) the in vitro verification of CDK7 inhibition and selectivity that confirms the warhead covalent-binding principle (by CDK-specific kinase assays), (2) the highly pronounced antiviral efficacies of the hit compounds (in cultured cell-based infection models) with half-maximal effective concentrations that reach down to picomolar levels, (3) a particularly strong potency of compounds against strains and reporter-expressing recombinants of HCMV (using infection assays in primary human fibroblasts), (4) additional activity against further herpesviruses such as animal CMVs and VZV, (5) unique mechanistic properties that include an immediate block of HCMV replication directed early (determined by Western blot detection of viral marker proteins), (6) a substantial drug synergism in combination with MBV (measured by a Loewe additivity fixed-dose assay), and (7) a strong sensitivity of clinically relevant HCMV mutants carrying MBV or ganciclovir resistance markers. Combined, the data highlight the huge developmental potential of this host-directed antiviral targeting concept utilizing covalently binding CDK7 inhibitors.
    Language English
    Publishing date 2024-01-23
    Publishing country Switzerland
    Document type Journal Article
    ZDB-ID 2527217-2
    ISSN 1999-4923
    ISSN 1999-4923
    DOI 10.3390/pharmaceutics16020158
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  9. Article ; Online: Cytomegalovirus cyclin-dependent kinase ortholog vCDK/pUL97 undergoes regulatory interaction with human cyclin H and CDK7 to codetermine viral replication efficiency.

    Schütz, Martin / Wangen, Christina / Sommerer, Mona / Kögler, Melanie / Eickhoff, Jan / Degenhart, Carsten / Klebl, Bert / Naing, Zin / Egilmezer, Ece / Hamilton, Stuart T / Rawlinson, William D / Sticht, Heinrich / Marschall, Manfred

    Virus research

    2023  Volume 335, Page(s) 199200

    Abstract: Human cytomegalovirus (HCMV) infection is shaped by a tightly regulated interplay between viral and cellular proteins. Distinct kinase activities, such as the viral cyclin-dependent kinase ortholog (vCDK) pUL97 and cellular CDK7 are both crucial for ... ...

    Abstract Human cytomegalovirus (HCMV) infection is shaped by a tightly regulated interplay between viral and cellular proteins. Distinct kinase activities, such as the viral cyclin-dependent kinase ortholog (vCDK) pUL97 and cellular CDK7 are both crucial for efficient viral replication. Previously, we reported that both kinases, vCDK/pUL97 and CDK7, interact with cyclin H, thereby achieving an enhanced level of kinase activity and overall functionality in viral replication. Here we provide a variety of novel results, as generated on a methodologically extended basis, and present a concept for the codetermination of viral replication efficiency through these kinase activities: (i) cyclin H expression, in various human cell types, is substantially upregulated by strains of HCMV including the clinically relevant HCMV Merlin; (ii) vCDK/pUL97 interacts with human cyclin H in both HCMV-infected and plasmid-transfected cell systems; (iii) a doxycycline-inducible shRNA-dependent knock-down (KD) of cyclin H significantly reduces pUL97 activity (qSox in vitro kinase assay); (iv) accordingly, pUL97 in vitro kinase activity is seen significantly increased upon addition of recombinant cyclin H; (v) as a point of specific importance, human CDK7 activity shows an increase by vCDK/pUL97-mediated trans-stimulation (whereas pUL97 is not stimulated by CDK7); (vi) phosphosite-specific antibodies indicate an upregulated CDK7 phosphorylation upon HCMV infection, as mediated through a pUL97-specific modulatory effect (i.e. shown by pUL97 inhibitor treatment or pUL97-deficient viral mutant); (vii) finally, an efficient KD of cyclin H in primary fibroblasts generally results in an impaired HCMV replication efficiency as measured on protein and genomic levels. These results show evidence for the codetermination of viral replication by vCDK/pUL97, cyclin H and CDK7, thus supporting the specific importance of cyclin H as a central regulatory factor, and suggesting novel targeting options for antiviral drugs.
    MeSH term(s) Humans ; Antiviral Agents ; Cyclin H ; Cyclin-Dependent Kinases/genetics ; Cytomegalovirus/genetics ; Phosphorylation
    Chemical Substances Antiviral Agents ; Cyclin H ; Cyclin-Dependent Kinases (EC 2.7.11.22) ; CCNH protein, human ; CDK7 protein, human
    Language English
    Publishing date 2023-08-19
    Publishing country Netherlands
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 605780-9
    ISSN 1872-7492 ; 0168-1702
    ISSN (online) 1872-7492
    ISSN 0168-1702
    DOI 10.1016/j.virusres.2023.199200
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  10. Article ; Online: Assessment of Covalently Binding Warhead Compounds in the Validation of the Cytomegalovirus Nuclear Egress Complex as an Antiviral Target.

    Tillmanns, Julia / Häge, Sigrun / Borst, Eva Maria / Wardin, Julia / Eickhoff, Jan / Klebl, Bert / Wagner, Sabrina / Wangen, Christina / Hahn, Friedrich / Socher, Eileen / Marschall, Manfred

    Cells

    2023  Volume 12, Issue 8

    Abstract: Herpesviral nuclear egress is a regulated process of viral capsid nucleocytoplasmic release. Due to the large capsid size, a regular transport via the nuclear pores is unfeasible, so that a multistage-regulated export pathway through the nuclear lamina ... ...

    Abstract Herpesviral nuclear egress is a regulated process of viral capsid nucleocytoplasmic release. Due to the large capsid size, a regular transport via the nuclear pores is unfeasible, so that a multistage-regulated export pathway through the nuclear lamina and both leaflets of the nuclear membrane has evolved. This process involves regulatory proteins, which support the local distortion of the nuclear envelope. For human cytomegalovirus (HCMV), the nuclear egress complex (NEC) is determined by the pUL50-pUL53 core that initiates multicomponent assembly with NEC-associated proteins and capsids. The transmembrane NEC protein pUL50 serves as a multi-interacting determinant that recruits regulatory proteins by direct and indirect contacts. The nucleoplasmic core NEC component pUL53 is strictly associated with pUL50 in a structurally defined hook-into-groove complex and is considered as the potential capsid-binding factor. Recently, we validated the concept of blocking the pUL50-pUL53 interaction by small molecules as well as cell-penetrating peptides or an overexpression of hook-like constructs, which can lead to a pronounced degree of antiviral activity. In this study, we extended this strategy by utilizing covalently binding warhead compounds, originally designed as binders of distinct cysteine residues in target proteins, such as regulatory kinases. Here, we addressed the possibility that warheads may likewise target viral NEC proteins, building on our previous crystallization-based structural analyses that revealed distinct cysteine residues in positions exposed from the hook-into-groove binding surface. To this end, the antiviral and NEC-binding properties of a selection of 21 warhead compounds were investigated. The combined findings are as follows: (i) warhead compounds exhibited a pronounced anti-HCMV potential in cell-culture-based infection models; (ii) computational analysis of NEC primary sequences and 3D structures revealed cysteine residues exposed to the hook-into-groove interaction surface; (iii) several of the active hit compounds exhibited NEC-blocking activity, as shown at the single-cell level by confocal imaging; (iv) the clinically approved warhead drug ibrutinib exerted a strong inhibitory impact on the pUL50-pUL53 core NEC interaction, as demonstrated by the NanoBiT assay system; and (v) the generation of recombinant HCMV ∆UL50-ΣUL53, allowing the assessment of viral replication under conditional expression of the viral core NEC proteins, was used for characterizing viral replication and a mechanistic evaluation of ibrutinib antiviral efficacy. Combined, the results point to a rate-limiting importance of the HCMV core NEC for viral replication and to the option of exploiting this determinant by the targeting of covalently NEC-binding warhead compounds.
    MeSH term(s) Humans ; Cytomegalovirus ; Antiviral Agents/pharmacology ; Antiviral Agents/metabolism ; Cysteine/metabolism ; Nuclear Envelope/metabolism ; Cell Nucleus/metabolism ; Viral Proteins/metabolism
    Chemical Substances Antiviral Agents ; Cysteine (K848JZ4886) ; Viral Proteins
    Language English
    Publishing date 2023-04-14
    Publishing country Switzerland
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 2661518-6
    ISSN 2073-4409 ; 2073-4409
    ISSN (online) 2073-4409
    ISSN 2073-4409
    DOI 10.3390/cells12081162
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

To top