58 results on '"Martina Gobec"'
Search Results
2. In Silico Discovery and Optimisation of a Novel Structural Class of Hsp90 C-Terminal Domain Inhibitors
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Živa Zajec, Jaka Dernovšek, Martina Gobec, and Tihomir Tomašič
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allosteric ,cancer ,heat shock ,Hsp90 ,inhibitor ,virtual screening ,Microbiology ,QR1-502 - Abstract
Hsp90 is a promising target for the development of novel agents for cancer treatment. The N-terminal Hsp90 inhibitors have several therapeutic limitations, the most important of which is the induction of heat shock response, which can be circumvented by targeting the allosteric binding site on the C-terminal domain (CTD) of Hsp90. In the absence of an Hsp90—CTD inhibitor co-crystal structure, the use of structure-based design approaches for the Hsp90 CTD is difficult and the structural diversity of Hsp90 CTD inhibitors is limited. In this study, we describe the discovery of a novel structural class of Hsp90 CTD inhibitors. A structure-based virtual screening was performed by docking a library of diverse compounds to the Hsp90β CTD binding site. Three selected virtual hits were tested in the MCF-7 breast cancer cell line, with compound TVS-23 showing antiproliferative activity with an IC50 value of 26.4 ± 1.1 µM. We report here the optimisation, synthesis and biological evaluation of TVS-23 analogues. Several analogues showed significantly enhanced antiproliferative activities in MCF-7 breast cancer and SK-N-MC Ewing sarcoma cell lines, with 7l being the most potent (IC50 = 1.4 ± 0.4 µM MCF-7; IC50 = 2.8 ± 0.4 µM SK-N-MC). The results of this study highlight the use of virtual screening to expand the structural diversity of Hsp90 CTD inhibitors and provide new starting points for further development.
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- 2022
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3. New Quinolinone O-GlcNAc Transferase Inhibitors Based on Fragment Growth
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Matjaž Weiss, Elena M. Loi, Maša Sterle, Cyril Balsollier, Tihomir Tomašič, Roland J. Pieters, Martina Gobec, and Marko Anderluh
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O-GlcNAc ,O-GlcNAc transferase ,protein glycosylation ,fragments growth ,molecular docking ,Chemistry ,QD1-999 - Abstract
O-GlcNAcylation is an important post-translational and metabolic process in cells that must be carefully regulated. O-GlcNAc transferase (OGT) is ubiquitously present in cells and is the only enzyme that catalyzes the transfer of O-GlcNAc to proteins. OGT is a promising target in various pathologies such as cancer, immune system diseases, or nervous impairment. In our previous work we identified the 2-oxo-1,2-dihydroquinoline-4-carboxamide derivatives as promising compounds by a fragment-based drug design approach. Herein, we report the extension of this first series with several new fragments. As the most potent fragment, we identified 3b with an IC50 value of 116.0 μM. If compared with the most potent inhibitor of the first series, F20 (IC50 = 117.6 μM), we can conclude that the new fragments did not improve OGT inhibition remarkably. Therefore, F20 was used as the basis for the design of a series of compounds with the elongation toward the O-GlcNAc binding pocket as the free carboxylate allows easy conjugation. Compound 6b with an IC50 value of 144.5 μM showed the most potent OGT inhibition among the elongated compounds, but it loses inhibition potency when compared to the UDP mimetic F20. We therefore assume that the binding of the compounds in the O-GlcNAc binding pocket is likely not crucial for OGT inhibition. Furthermore, evaluation of the compounds with two different assays revealed that some inhibitors most likely interfere with the commercially available UDP-Glo™ glycosyltransferase assay, leading to false positive results. This observation calls for caution, when evaluating UDP mimetic as OGT inhibitors with the UDP-Glo™ glycosyltransferase assay, as misinterpretations can occur.
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- 2021
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4. Discovery of a New Drug-like Series of OGT Inhibitors by Virtual Screening
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Elena M. Loi, Tihomir Tomašič, Cyril Balsollier, Kevin van Eekelen, Matjaž Weiss, Martina Gobec, Matthew G. Alteen, David J. Vocadlo, Roland J. Pieters, and Marko Anderluh
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O-GlcNAc transferase ,OGT inhibitors ,virtual screening ,Organic chemistry ,QD241-441 - Abstract
O-GlcNAcylation is an essential post-translational modification installed by the enzyme O-β-N-acetyl-d-glucosaminyl transferase (OGT). Modulating this enzyme would be extremely valuable to better understand its role in the development of serious human pathologies, such as diabetes and cancer. However, the limited availability of potent and selective inhibitors hinders the validation of this potential therapeutic target. To explore new chemotypes that target the active site of OGT, we performed virtual screening of a large library of commercially available compounds with drug-like properties. We purchased samples of the most promising virtual hits and used enzyme assays to identify authentic leads. Structure-activity relationships of the best identified OGT inhibitor were explored by generating a small library of derivatives. Our best hit displays a novel uridine mimetic scaffold and inhibited the recombinant enzyme with an IC50 value of 7 µM. The current hit represents an excellent starting point for designing and developing a new set of OGT inhibitors that may prove useful for exploring the biology of OGT.
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- 2022
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5. Fragment-Sized and Bidentate (Immuno)Proteasome Inhibitors Derived from Cysteine and Threonine Targeting Warheads
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Levente Kollár, Martina Gobec, Matic Proj, Lara Smrdel, Damijan Knez, Tímea Imre, Ágnes Gömöry, László Petri, Péter Ábrányi-Balogh, Dorottya Csányi, György G. Ferenczy, Stanislav Gobec, Izidor Sosič, and György M. Keserű
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immunoproteasome ,benzoxazole-2-carbonitriles ,bidentate covalent inhibitors ,fragments ,non-covalent recognition ,Cytology ,QH573-671 - Abstract
Constitutive- and immunoproteasomes are part of the ubiquitin–proteasome system (UPS), which is responsible for the protein homeostasis. Selective inhibition of the immunoproteasome offers opportunities for the treatment of numerous diseases, including inflammation, autoimmune diseases, and hematologic malignancies. Although several inhibitors have been reported, selective nonpeptidic inhibitors are sparse. Here, we describe two series of compounds that target both proteasomes. First, benzoxazole-2-carbonitriles as fragment-sized covalent immunoproteasome inhibitors are reported. Systematic substituent scans around the fragment core of benzoxazole-2-carbonitrile led to compounds with single digit micromolar inhibition of the β5i subunit. Experimental and computational reactivity studies revealed that the substituents do not affect the covalent reactivity of the carbonitrile warhead, but mainly influence the non-covalent recognition. Considering the small size of the inhibitors, this finding emphasizes the importance of the non-covalent recognition step in the covalent mechanism of action. As a follow-up series, bidentate inhibitors are disclosed, in which electrophilic heterocyclic fragments, i.e., 2-vinylthiazole, benzoxazole-2-carbonitrile, and benzimidazole-2-carbonitrile were linked to threonine-targeting (R)-boroleucine moieties. These compounds were designed to bind both the Thr1 and β5i-subunit-specific residue Cys48. However, inhibitory activities against (immuno)proteasome subunits showed that bidentate compounds inhibit the β5, β5i, β1, and β1i subunits with submicromolar to low-micromolar IC50 values. Inhibitory assays against unrelated enzymes showed that compounds from both series are selective for proteasomes. The presented nonpeptidic and covalent derivatives are suitable hit compounds for the development of either β5i-selective immunoproteasome inhibitors or compounds targeting multiple subunits of both proteasomes.
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- 2021
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6. Inhibition of O-GlcNAc Transferase Alters the Differentiation and Maturation Process of Human Monocyte Derived Dendritic Cells
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Matjaž Weiss, Marko Anderluh, and Martina Gobec
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O-GlcNAcylation ,O-GlcNAc transferase (OGT) ,monocyte derived DCs ,OSMI-1 ,immunometabolism ,Cytology ,QH573-671 - Abstract
The O-GlcNAcylation is a posttranslational modification of proteins regulated by O-GlcNAc transferase (OGT) and O-GlcNAcase. These enzymes regulate the development, proliferation and function of cells, including the immune cells. Herein, we focused on the role of O-GlcNAcylation in human monocyte derived dendritic cells (moDCs). Our study suggests that inhibition of OGT modulates AKT and MEK/ERK pathways in moDCs. Changes were also observed in the expression levels of relevant surface markers, where reduced expression of CD80 and DC-SIGN, and increased expression of CD14, CD86 and HLA-DR occurred. We also noticed decreased IL-10 and increased IL-6 production, along with diminished endocytotic capacity of the cells, indicating that inhibition of O-GlcNAcylation hampers the transition of monocytes into immature DCs. Furthermore, the inhibition of OGT altered the maturation process of immature moDCs, since a CD14medDC-SIGNlowHLA-DRmedCD80lowCD86high profile was noticed when OGT inhibitor, OSMI-1, was present. To evaluate DCs ability to influence T cell differentiation and polarization, we co-cultured these cells. Surprisingly, the observed phenotypic changes of mature moDCs generated in the presence of OSMI-1 led to an increased proliferation of allogeneic T cells, while their polarization was not affected. Taken together, we confirm that shifting the O-GlcNAcylation status due to OGT inhibition alters the differentiation and function of moDCs in in vitro conditions.
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- 2021
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7. Structure-Activity Relationships of Benzothiazole-Based Hsp90 C-Terminal-Domain Inhibitors
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Jaka Dernovšek, Živa Zajec, Martina Durcik, Lucija Peterlin Mašič, Martina Gobec, Nace Zidar, and Tihomir Tomašič
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allosteric ,Hsp90 ,benzothiazole ,cancer ,inhibitor ,cancer therapy ,Pharmacy and materia medica ,RS1-441 - Abstract
Heat shock protein 90 (Hsp90) is a chaperone responsible for the maturation of many cancer-related proteins, and is therefore an important target for the design of new anticancer agents. Several Hsp90 N-terminal domain inhibitors have been evaluated in clinical trials, but none have been approved as cancer therapies. This is partly due to induction of the heat shock response, which can be avoided using Hsp90 C-terminal-domain (CTD) inhibition. Several structural features have been shown to be useful in the design of Hsp90 CTD inhibitors, including an aromatic ring, a cationic center and the benzothiazole moiety. This study established a previously unknown link between these structural motifs. Using ligand-based design methodologies and structure-based pharmacophore models, a library of 29 benzothiazole-based Hsp90 CTD inhibitors was prepared, and their antiproliferative activities were evaluated in MCF-7 breast cancer cells. Several showed low-micromolar IC50, with the most potent being compounds 5g and 9i (IC50, 2.8 ± 0.1, 3.9 ± 0.1 μM, respectively). Based on these results, a ligand-based structure–activity relationship model was built, and molecular dynamics simulation was performed to elaborate the binding mode of compound 9i. Moreover, compound 9i showed degradation of Hsp90 client proteins and no induction of the heat shock response.
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- 2021
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8. Synthesis and Biochemical Evaluation of Warhead-Decorated Psoralens as (Immuno)Proteasome Inhibitors
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Eva Shannon Schiffrer, Matic Proj, Martina Gobec, Luka Rejc, Andrej Šterman, Janez Mravljak, Stanislav Gobec, and Izidor Sosič
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immunoproteasome ,psoralen core ,non-peptidic ,electrophilic compounds ,warhead scan ,Organic chemistry ,QD241-441 - Abstract
The immunoproteasome is a multicatalytic protease that is predominantly expressed in cells of hematopoietic origin. Its elevated expression has been associated with autoimmune diseases, various types of cancer, and inflammatory diseases. Selective inhibition of its catalytic activities is therefore a viable approach for the treatment of these diseases. However, the development of immunoproteasome-selective inhibitors with non-peptidic scaffolds remains a challenging task. We previously reported 7H-furo[3,2-g]chromen-7-one (psoralen)-based compounds with an oxathiazolone warhead as selective inhibitors of the chymotrypsin-like (β5i) subunit of immunoproteasome. Here, we describe the influence of the electrophilic warhead variations at position 3 of the psoralen core on the inhibitory potencies. Despite mapping the chemical space with different warheads, all compounds showed decreased inhibition of the β5i subunit of immunoproteasome in comparison to the parent oxathiazolone-based compound. Although suboptimal, these results provide crucial information about structure–activity relationships that will serve as guidance for the further design of (immuno)proteasome inhibitors.
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- 2021
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9. Intracellular Hydrolysis of Small-Molecule O-Linked N-Acetylglucosamine Transferase Inhibitors Differs among Cells and Is Not Required for Its Inhibition
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Elena Maria Loi, Matjaž Weiss, Stane Pajk, Martina Gobec, Tihomir Tomašič, Roland J. Pieters, and Marko Anderluh
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ester hydrolysis ,inhibitor ,O-GlcNAc transferase ,OGT inhibitor ,Organic chemistry ,QD241-441 - Abstract
O-GlcNAcylation is an essential post-translational modification that occurs on nuclear and cytoplasmic proteins, regulating their function in response to cellular stress and altered nutrient availability. O-GlcNAc transferase (OGT) is the enzyme that catalyzes this reaction and represents a potential therapeutic target, whose biological role is still not fully understood. To support this research field, a series of cell-permeable, low-nanomolar OGT inhibitors were recently reported. In this study, we resynthesized the most potent OGT inhibitor of the library, OSMI-4, and we used it to investigate OGT inhibition in different human cell lines. The compound features an ethyl ester moiety that is supposed to be cleaved by carboxylesterases to generate its active metabolite. Our LC-HRMS analysis of the cell lysates shows that this is not always the case and that, even in the cell lines where hydrolysis does not occur, OGT activity is inhibited.
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- 2020
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10. Glycosaminoglycans as Tools to Decipher the Platelet Tumor Cell Interaction: A Focus on P-Selectin
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Svenja Schwarz, Lukas Maria Gockel, Annamaria Naggi, Uri Barash, Martina Gobec, Gerd Bendas, and Martin Schlesinger
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ro-heparin ,2-o-desulfated heparin ,hexasaccharide heparin fragment ,decasaccharide heparin fragment ,unfractionated heparin ,low molecular weight heparin ,platelets ,p-selectin ,platelet aggregation ,platelet secretion ,tumor metastasis ,Organic chemistry ,QD241-441 - Abstract
Tumor cell−platelet interactions are regarded as an initial crucial step in hematogenous metastasis. Platelets protect tumor cells from immune surveillance in the blood, mediate vascular arrest, facilitate tumor extravasation, growth, and finally angiogenesis in the metastatic foci. Tumor cells aggregate platelets in the bloodstream by activation of the plasmatic coagulation cascade and by direct contact formation. Antimetastatic activities of unfractionated or low molecular weight heparin (UFH/LMWH) can undoubtedly be related to attenuated platelet activation, but molecular mechanisms and contribution of contact formation vs. coagulation remain to be elucidated. Using a set of non-anticoagulant heparin derivatives varying in size or degree of sulfation as compared with UFH, we provide insight into the relevance of contact formation for platelet activation. Light transmission aggregometry and ATP release assays confirmed that only those heparin derivatives with P-selectin blocking capacities were able to attenuate breast cancer cell-induced platelet activation, while pentasaccharide fondaparinux was without effects. Furthermore, a role of P-selectin in platelet activation and signaling could be confirmed by proteome profiler arrays detecting platelet kinases. In this study, we demonstrate that heparin blocks tumor cell-induced coagulation. Moreover, we identify platelet P-selectin, which obviously acts as molecular switch and controls aggregation and secretion of procoagulant platelets.
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- 2020
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11. Discovery of Novel Small-Molecule Compounds with Selective Cytotoxicity for Burkitt’s Lymphoma Cells Using 3D Ligand-Based Virtual Screening
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Martina Gobec, Izidor Sosič, Boris Brus, Aleš Obreza, Stanislav Gobec, and Irena Mlinarič-Raščan
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Burkitt’s lymphoma ,ligand-based ,similarity search ,selectivity ,Organic chemistry ,QD241-441 - Abstract
We describe a ligand-based approach towards compounds with more specific targeting for Burkitt’s lymphoma. Using three-dimensional ligand-based similarity searches and a previously described hit compound, we have identified six compounds that are chemically different but with similar spatial conformations. Biological evaluation revealed that one compound has better growth inhibition and improved selectivity towards Burkitt’s lymphoma cells than the query compound. However, initial mechanism-of-action studies show a different target profile in comparison with the previous hit compound, which does not involve the inhibition of the proteasome or the NFκB pathway. The data from this study provide a solid basis for further efforts in the search for selective agents against Burkitt’s lymphoma.
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- 2014
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12. Discovery of Immunoproteasome Inhibitors Using Large-Scale Covalent Virtual Screening
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Andrea Scarpino, Dávid Bajusz, Matic Proj, Martina Gobec, Izidor Sosič, Stanislav Gobec, György G. Ferenczy, and György M. Keserű
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immunoproteasome ,covalent inhibitor ,virtual screening ,β5i selective inhibitor ,Organic chemistry ,QD241-441 - Abstract
Large-scale virtual screening of boronic acid derivatives was performed to identify nonpeptidic covalent inhibitors of the β5i subunit of the immunoproteasome. A hierarchical virtual screening cascade including noncovalent and covalent docking steps was applied to a virtual library of over 104,000 compounds. Then, 32 virtual hits were selected, out of which five were experimentally confirmed. Biophysical and biochemical tests showed micromolar binding affinity and time-dependent inhibitory potency for two compounds. These results validate the computational protocol that allows the screening of large compound collections. One of the lead-like boronic acid derivatives identified as a covalent immunoproteasome inhibitor is a suitable starting point for chemical optimization.
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- 2019
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13. Selective cytotoxicity of amidinopiperidine based compounds towards Burkitt's lymphoma cells involves proteasome inhibition.
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Martina Gobec, Ales Obreza, Matevz Prijatelj, Boris Brus, Stanislav Gobec, and Irena Mlinaric-Rascan
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Medicine ,Science - Abstract
Serine proteases have proven to be promising pharmacological targets in contemporary drug discovery for cancer treatment. Since azaphenylalanine-based compounds manifest cytotoxic activity, we have selected serine protease inhibitors designed and synthesized in-house with large hydrophobic naphthalene moiety for screening. The cytotoxic potential of screened molecules was correlated to modifications of R(1) residues. The most cytotoxic were compounds with greater basicity; amidinopiperidines, piperidines and benzamidines. Amidinopiperidine-based compounds exert cytotoxicity in low µM range, with IC(50) 18 µM and 22 µM for inhibitors 15 and 16 respectively. These compounds exhibited selective cytotoxicity towards the Burkitt's lymphoma cells Ramos and Daudi, and proved nontoxic to PMBC, Jurkat and U937. They induce caspase-dependent apoptotic cell death, as demonstrated by the use of a pan-caspase inihibitor, zVADfmk, which was able to rescue Ramos cells from compound(s)-induced apoptosis. We confirm a disruption of the pro-survival pathway in Burkitt's lymphoma through NFκB inhibition. The accumulation of phosphorylated precursor (p105) and inhibitory (IκB) molecules with no subsequent release of active NFκB implicated the involvement of proteasome. Indeed, we show that the amidinopiperidine-based compounds inhibit all three proteolytical activities of the human 20S proteasome, with the most prominent effect being on the trypsin-like activity. Consistently, treatment of Ramos cells with these compounds led to an increase in ubiquitinated proteins. The amidinopiperidine-based serine protease inhibitors presented are, as selective inducers of apoptosis in Burkitt's lymphoma cells, promising leads for the development of novel chemotherapeutics.
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- 2012
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14. Nanofibers with genotyped Bacillus strains exhibiting antibacterial and immunomodulatory activity
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Nina Katarina Grilc, Anže Zidar, Petra Kocbek, Tomaž Rijavec, Teja Colja, Aleš Lapanje, Matjaž Jeras, Martina Gobec, Irena Mlinarič-Raščan, Mirjana Gašperlin, Julijana Kristl, and Špela Zupančič
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Pharmaceutical Science - Published
- 2023
15. Optimisation of pyrazolo[1,5-a]pyrimidin-7(4H)-one derivatives as novel Hsp90 C-terminal domain inhibitors against Ewing sarcoma
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Živa Zajec, Jaka Dernovšek, Martin Distel, Martina Gobec, and Tihomir Tomašič
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Ewingov sarkom ,inhibitorji ,osteosarkom ,Organic Chemistry ,Hsp90 ,Biochemistry ,udc:615.2:616-006.34 ,molecular modelling ,molekularno modeliranje ,inhibitor ,Drug Discovery ,rak ,cancer ,maligni tumor kosti ,Molecular Biology ,Ewing sarcoma ,medicina - Abstract
Ewing sarcoma is the second most prevalent paediatric malignant bone tumour. In most cases, it is driven by the fusion oncoprotein EWS::FLI1, which acts as an aberrant transcription factor and dysregulates gene expression. EWS::FLI1 and a large number of downstream dysregulated proteins are Hsp90 client proteins, making Hsp90 an attractive target for the treatment of Ewing sarcoma. In this article, we report a new structural class of allosteric Hsp90 C-terminal domain (CTD) inhibitors based on the virtual screening hit TVS24, which showed antiproliferative activity in the SK-N-MC Ewing sarcoma cell line with an IC$_{50}$ value of 15.9 ± 0.7 µM. The optimised compounds showed enhanced anticancer activity in the SK-N-MC cell line. Exposure of Ewing sarcoma cells to the most potent analogue 11c resulted in depletion of critical Hsp90 client proteins involved in cancer pathways such as EWS::FLI1, CDK4, RAF-1 and IGF1R, without inducing a heat shock response. The results of this study highlight Hsp90 CTD inhibitors as promising new agents for the treatment of Ewing sarcoma.
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- 2022
16. Halogenated ingredients of household and personal care products as emerging endocrine disruptors
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Veronika Klančič, Martina Gobec, and Žiga Jakopin
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Environmental Engineering ,Health, Toxicology and Mutagenesis ,hormonski motilci ,Parabens ,Cosmetics ,Endocrine Disruptors ,parabens ,UV filters ,halogenirani produkti transformacije ,endokrine motnje ,Environmental Chemistry ,parabeni ,UV filtri ,bisfenoli ,udc:612.43:620.266.1 ,alkilfenol etoksilati ,Public Health, Environmental and Occupational Health ,Water ,General Medicine ,General Chemistry ,endocrine disruption ,Pollution ,alkylphenol ethoxylates ,bisphenols ,Plastics ,halogenated transformation products - Abstract
The everyday use of household and personal care products (HPCPs) generates an enormous amount of chemicals, of which several groups warrant additional attention, including: (i) parabens, which are widely used as preservatives; (ii) bisphenols, which are used in the manufacture of plastics; (iii) UV filters, which are essential components of many cosmetic products; and (iv) alkylphenol ethoxylates, which are used extensively as non-ionic surfactants. These chemicals are released continuously into the environment, thus contaminating soil, water, plants and animals. Wastewater treatment and water disinfection procedures can convert these chemicals into halogenated transformation products, which end up in the environment and pose a potential threat to humans and wildlife. Indeed, while certain parent HPCP ingredients have been confirmed as endocrine disruptors, less is known about the endocrine activities of their halogenated derivatives. The aim of this review is first to examine the sources and occurrence of halogenated transformation products in the environment, and second to compare their endocrine-disrupting properties to those of their parent compounds (i.e., parabens, bisphenols, UV filters, alkylphenol ethoxylates). Albeit previous reports have focused individually on selected classes of such substances, none have considered the problem of their halogenated transformation products. This review therefore summarizes the available research on these halogenated compounds, highlights the potential exposure pathways, and underlines the existing knowledge gaps within their toxicological profiles.
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- 2022
17. Virtual Screening and Biochemical Testing of Borocycles as Immunoproteasome Inhibitors
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Izidor Sosič, György Gábor Frenczy, Martina Gobec, Matic Proj, Levente Kollár, Stanislav Gobec, and György M. Keserű
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Ring size ,Virtual screening ,chemistry.chemical_compound ,Biochemistry ,Proteasome ,chemistry ,Docking (molecular) ,General Chemical Engineering ,Protein subunit ,Biochemical testing ,Ring (chemistry) ,Boronic acid - Abstract
Inhibition of the immunoproteasome (iCP) offers new opportunities in the treatment of cancer, autoimmune disorders and neurodegenerative diseases. Inspired by the success of boronic acids as proteasome inhibitors we have complied a virtual library of commercially available 5- and 6-membered borocycles and performed a structure based virtual screening against the chymotrypsin-like (β5i) subunit of the iCP. The top scored docking poses were visually inspected to select compounds for experimental testing. Six compounds with 5-membered ring and another six compounds with 6-membered ring were subjected to biochemical tests. All compounds exhibited detectable inhibitory activity at 100 µM concentration and these are the first reported cyclic boronic acid inhibitors of the iCP. Structural variations including the ring size and the substitution of the borocyles and the substitution pattern of the attached aromatic ring resulted in no major variation of the inhibitory activity. We propose that the evaluation of larger cycling boronic acid libraries is needed to fully elucidate the potential of these structures.
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- 2021
18. Targeting the deubiquitinase USP7 for degradation with PROTACs
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Arunima Murgai, Izidor Sosič, Martina Gobec, Patricia Lemnitzer, Matic Proj, Sophie Wittenburg, Rabea Voget, Michael Gütschow, Jan Krönke, and Christian Steinebach
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deubikvitinacijski encimi, terapevtski pristop ,Metals and Alloys ,Apoptosis ,General Chemistry ,udc:615 ,Catalysis ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Ubiquitin-Specific Peptidase 7 ,Rak (medicina) ,Neoplasms ,Materials Chemistry ,Ceramics and Composites ,Humans ,Intercellular Signaling Peptides and Proteins ,Terapevtska uporaba ,Farmakologija - Abstract
Targeting deubiquitinating enzymes (DUBs) has emerged as a promising therapeutic approach in several human cancers and other diseases. DUB inhibitors are exciting pharmacological tools but often exhibit limited cellular potency. Here we report PROTACs based on an ubiquitin-specific protease 7 (USP7) inhibitor scaffold to degrade USP7. By investigating several linker and E3 ligand types, including novel cereblon recruiters, we discovered a highly selective USP7 degrader tool compound that induced apoptosis of USP7-dependent cancer cells. This work represents one of the first DUB degraders and unlocks a new drug target class for protein degradation. Nasl. z nasl. zaslona. Opis vira z dne 13. 7. 2022. Bibliografija: str. 8861. ARRS, projekt ARRS, program DFG, projekt DFG, projekt Costa action Cost action
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- 2022
19. Environmental contamination status with common ingredients of household and personal care products
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Veronika Klančič, Martina Gobec, and Žiga Jakopin
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The continuous use of household and personal care products (HPCPs) produces an immense amount of chemicals, such as parabens, bisphenols, UV filters, and alkylphenol ethoxylates, which are of great concern due to their well-known endocrine-disrupting properties. These chemicals easily enter the environment through man-made activities, thus contaminating the biota, including soil, water, plants and animals. Thus, on top of the direct exposure on account of their presence in HPCPs, humans are also susceptible to secondary indirect exposure attributed to the ubiquitous environmental contamination. The aim of this review is therefore to examine the sources and occurrence of these noteworthy contaminants (i.e., parabens, bisphenols, UV filters, alkylphenol ethoxylates), to summarize the available research on their environmental presence and to highlight the potential exposure pathways.
- Published
- 2022
20. Environmental contamination status with common ingredients of household and personal care products exhibiting endocrine-disrupting potential
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Veronika Klančič, Martina Gobec, and Žiga Jakopin
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Benzophenones ,Soil ,Phenols ,Health, Toxicology and Mutagenesis ,Environmental Chemistry ,Humans ,Parabens ,Water ,General Medicine ,Cosmetics ,Benzhydryl Compounds ,Endocrine Disruptors ,Pollution - Abstract
The continuous use of household and personal care products (HPCPs) produces an immense amount of chemicals, such as parabens, bisphenols, benzophenones and alkylphenol ethoxylates, which are of great concern due to their well-known endocrine-disrupting properties. These chemicals easily enter the environment through man-made activities, thus contaminating the biota, including soil, water, plants and animals. Thus, on top of the direct exposure on account of their presence in HPCPs, humans are also susceptible to secondary indirect exposure attributed to the ubiquitous environmental contamination. The aim of this review was therefore to examine the sources and occurrence of these noteworthy contaminants (i.e. parabens, bisphenols, benzophenones, alkylphenol ethoxylates), to summarise the available research on their environmental presence and to highlight their bioaccumulation potential. The most notable environmental contaminants appear to be MeP and PrP among parabens, BPA and BPS among bisphenols, BP-3 among benzophenones and NP among alkylphenols. Their maximum detected concentrations in the environment are mostly in the range of ng/L, while in human tissues, their maximum concentrations achieved μg/L due to bioaccumulation, with BP-3 and nonylphenol showing the highest potential to bioaccumulate. Finally, of another great concern is the fact that even the unapproved parabens and benzophenones have been detected in the environment.
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- 2022
21. In vitro investigation of immunomodulatory activities of selected UV-filters
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Veronika Weiss, Martina Gobec, and Žiga Jakopin
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General Medicine ,Toxicology ,Food Science - Published
- 2023
22. Assessment of Tractable Cysteines for Covalent Targeting by Screening Covalent Fragments
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András Perczel, Luca Giacinto Iacovino, Stanislav Gobec, Imre Tímea, Simona Golic Grdadolnik, Iza Ogris, Niklas Jänsch, Franz-Josef Meyer-Almes, László Petri, Damijan Knez, Martina Hrast, Izidor Sosič, György M. Keserű, Martina Gobec, Claudia Binda, Charlotte Desczyk, Gyula Pálfy, Péter Ábrányi-Balogh, Kinga Nyíri, and Beáta G. Vértessy
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Proteome ,Chemical biology ,010402 general chemistry ,01 natural sciences ,Biochemistry ,Nucleophile ,Drug Discovery ,Humans ,Reactivity (chemistry) ,Cysteine ,Enzyme Inhibitors ,Molecular Biology ,chemistry.chemical_classification ,Alkyl and Aryl Transferases ,010405 organic chemistry ,Drug discovery ,Chemistry ,Organic Chemistry ,Combinatorial chemistry ,High-Throughput Screening Assays ,0104 chemical sciences ,Amino acid ,Covalent bond ,Electrophile ,Molecular Medicine - Abstract
Targeted covalent inhibition and the use of irreversible chemical probes are important strategies in chemical biology and drug discovery. To date, the availability and reactivity of cysteine residues amenable for covalent targeting have been evaluated by proteomic and computational tools. Herein, we present a toolbox of fragments containing a 3,5-bis(trifluoromethyl)phenyl core that was equipped with chemically diverse electrophilic warheads showing a range of reactivities. We characterized the library members for their reactivity, aqueous stability and specificity for nucleophilic amino acids. By screening this library against a set of enzymes amenable for covalent inhibition, we showed that this approach experimentally characterized the accessibility and reactivity of targeted cysteines. Interesting covalent fragment hits were obtained for all investigated cysteine-containing enzymes.
- Published
- 2020
23. Expanding the PROTAC Toolbox: Targeted Degradation of the Deubiquitinase USP7 in Cancer
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Arunima Murgai, Izidor Sosič, Martina Gobec, Patricia Lemnitzer, Matic Proj, Sophie Wittenburg, Michael Gütschow, Jan Krönke, and Christian Steinebach
- Abstract
Targeting deubiquitinating enzymes (DUBs) has emerged as a promising therapeutic approach in several human cancers and other diseases. DUB inhibitors are exciting pharmacological tools but often exhibit limited cellular potency. Here we report PROTACs based on an ubiquitin-specific protease 7 (USP7) inhibitor scaffold to degrade USP7. The hit compound CST967 caused highly selective degradation of USP7 and inhibited proliferation of USP7-dependent cancer cells. We present the first DUB degrader, which will be a useful tool to deepen our understanding of USP7.
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- 2022
24. Inhibition of O-GlcNAc Transferase Alters the Differentiation and Maturation Process of Human Monocyte Derived Dendritic Cells
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Marko Anderluh, Martina Gobec, and Matjaž Weiss
- Subjects
MAPK/ERK pathway ,QH301-705.5 ,T-Lymphocytes ,CD14 ,immunometabolism ,Farmacevtska kemija ,N-Acetylglucosaminyltransferases ,DC ,Monocytes ,Article ,imunometabolizem ,O-GlcNAcylation ,O-GlcNAc transferase (OGT) ,Immune system ,udc:615.4:54 ,Humans ,Biology (General) ,Enzyme Inhibitors ,udc:615.4 ,Protein kinase B ,Cell Proliferation ,CD86 ,monocyte derived DCs ,OSMI-1 ,Interleukin-6 ,Chemistry ,pridobljeni iz monocitov ,TOR Serine-Threonine Kinases ,Cell Differentiation ,Dendritic Cells ,General Medicine ,Endocytosis ,In vitro ,pharmaceutical chemistry ,Interleukin-10 ,Cell biology ,O-GlcNAcilacija ,T cell differentiation ,farmacevtska kemija ,O-GlcNAc transferaza (OGT) ,O-GlcNAcylation, O-GlcNAc transferase (OGT), monocyte derived DCs, OSMI-1, immunometabolism ,Proto-Oncogene Proteins c-akt ,CD80 ,Signal Transduction - Abstract
The O-GlcNAcylation is a posttranslational modification of proteins regulated by O-GlcNAc transferase (OGT) and O-GlcNAcase. These enzymes regulate the development, proliferation and function of cells, including the immune cells. Herein, we focused on the role of O-GlcNAcylation in human monocyte derived dendritic cells (moDCs). Our study suggests that inhibition of OGT modulates AKT and MEK/ERK pathways in moDCs. Changes were also observed in the expression levels of relevant surface markers, where reduced expression of CD80 and DC-SIGN, and increased expression of CD14, CD86 and HLA-DR occurred. We also noticed decreased IL-10 and increased IL-6 production, along with diminished endocytotic capacity of the cells, indicating that inhibition of O-GlcNAcylation hampers the transition of monocytes into immature DCs. Furthermore, the inhibition of OGT altered the maturation process of immature moDCs, since a CD14medDC-SIGNlowHLA-DRmedCD80lowCD86high profile was noticed when OGT inhibitor, OSMI-1, was present. To evaluate DCs ability to influence T cell differentiation and polarization, we co-cultured these cells. Surprisingly, the observed phenotypic changes of mature moDCs generated in the presence of OSMI-1 led to an increased proliferation of allogeneic T cells, while their polarization was not affected. Taken together, we confirm that shifting the O-GlcNAcylation status due to OGT inhibition alters the differentiation and function of moDCs in in vitro conditions. Nasl. z nasl. zaslona. Opis vira z dne 26. 11. 2021. Št. članka: 3312. Bibliografija: str. 14-16. Abstract. ARRS Slovenian Research Agency Young Researcher programme
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- 2021
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25. Structure-Activity Relationships of Benzothiazole-Based Hsp90 C-Terminal-Domain Inhibitors
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Lucija Peterlin Mašič, Tihomir Tomašič, Nace Zidar, Živa Zajec, Martina Durcik, Martina Gobec, and Jaka Dernovšek
- Subjects
alosterija ,Stereochemistry ,Allosteric regulation ,Pharmaceutical Science ,Hsp90 ,benzotiazol ,Article ,allosteric ,chemistry.chemical_compound ,Pharmacy and materia medica ,Heat shock protein ,rak ,cancer ,Heat shock ,udc:616-006-085 ,allostery ,zaviralci ,biology ,Chemistry ,zdravljenje ,benzothiazole ,Ligand (biochemistry) ,inhibitor ,RS1-441 ,Benzothiazole ,Chaperone (protein) ,biology.protein ,cancer therapy ,Pharmacophore - Abstract
Heat shock protein 90 (Hsp90) is a chaperone responsible for the maturation of many cancer-related proteins, and is therefore an important target for the design of new anticancer agents. Several Hsp90 N-terminal domain inhibitors have been evaluated in clinical trials, but none have been approved as cancer therapies. This is partly due to induction of the heat shock response, which can be avoided using Hsp90 C-terminal-domain (CTD) inhibition. Several structural features have been shown to be useful in the design of Hsp90 CTD inhibitors, including an aromatic ring, a cationic center and the benzothiazole moiety. This study established a previously unknown link between these structural motifs. Using ligand-based design methodologies and structure-based pharmacophore models, a library of 29 benzothiazole-based Hsp90 CTD inhibitors was prepared, and their antiproliferative activities were evaluated in MCF-7 breast cancer cells. Several showed low-micromolar IC50, with the most potent being compounds 5g and 9i (IC50, 2.8 ± 0.1, 3.9 ± 0.1 μM, respectively). Based on these results, a ligand-based structure–activity relationship model was built, and molecular dynamics simulation was performed to elaborate the binding mode of compound 9i. Moreover, compound 9i showed degradation of Hsp90 client proteins and no induction of the heat shock response.
- Published
- 2021
26. Another structural correction for 1-oxo-1H-phenalene-2,3-dicarbonitriles: Synthesis of a potent BCL-2 inhibiting 7-phenoxy derivative
- Author
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Gerd Bendas, Izidor Sosič, Christian Steinebach, Martina Gobec, Martin Schlesinger, and Michael Gütschow
- Subjects
Magnetic Resonance Spectroscopy ,010405 organic chemistry ,Chemistry ,Pharmaceutical Science ,Biological activity ,Antineoplastic Agents ,01 natural sciences ,Combinatorial chemistry ,0104 chemical sciences ,010404 medicinal & biomolecular chemistry ,Metabolic pathway ,chemistry.chemical_compound ,Structure-Activity Relationship ,Phenalene ,Derivative (finance) ,Proto-Oncogene Proteins c-bcl-2 ,Cell Line, Tumor ,Neoplasms ,Drug Discovery ,Nitriles ,Structural isomer ,Humans ,Reactivity (chemistry) ,Molecular probe ,Cytotoxicity - Abstract
Aromatic scaffolds are an important part of biologically active compounds and molecular probes used to study biochemical pathways and the involved targeted proteins of interest. 1-Oxo-1H-phenalene-2,3-dicarbonitrile-based compounds have been described as inhibitors of the BCL-2 family of proteins, and this core structure represents numerous possibilities for modifications that could lead to improved inhibitory potencies. Many studies demonstrated intriguing characteristics of these compounds in terms of reactivity and, interestingly, some contradictory literature reports appeared about reaction outcomes to synthesize them. Here, we initially provide a condensed overview of transformations performed on the phenalene scaffold, followed by the resynthesis of a 6-phenoxy-substituted derivative. We show that the initial determination of this particular structure was wrong and provide two-dimensional nuclear magnetic resonance (NMR) evidence to assign the structure properly. When preparing new derivatives using the same synthetic route, we observed 6- and 7-substituted regioisomers. After confirming their structures by NMR experiments, the ability of these compounds to inhibit BCL-2 was evaluated. The most potent 1-oxo-1H-phenalene-2,3-dicarbonitrile derivatives inhibited BCL-2 in the nanomolar range and showed double-digit micromolar cytotoxicity against four different cancer cell lines.
- Published
- 2021
27. New Quinolinone O-GlcNAc Transferase Inhibitors Based on Fragment Growth
- Author
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Marko Anderluh, Cyril Balsollier, Elena M. Loi, Martina Gobec, Tihomir Tomašič, Roland J. Pieters, Matjaž Weiss, Maša Sterle, Afd Chemical Biology and Drug Discovery, and Chemical Biology and Drug Discovery
- Subjects
glikozirani proteini, fragmentna rast, molekularno sidranje, O-GlcNAc transferaza ,molekularno sidranje ,Chemistry(all) ,Binding pocket ,udc:616-097 ,Farmacevtska kemija ,Imunski sistem ,010402 general chemistry ,O-GlcNAc transferase ,01 natural sciences ,fragmentna rast ,lcsh:Chemistry ,03 medical and health sciences ,Immune system ,protein glycosylation ,Glycosyltransferase ,Potency ,Transferase ,IC50 ,Original Research ,030304 developmental biology ,O-GlcNAc, O-GlcNAc transferase, protein glycosylation, fragments growth, molecular docking ,chemistry.chemical_classification ,O-GlcNAc transferaza ,0303 health sciences ,udc:615.4:54:616-097 ,biology ,Chemistry ,General Chemistry ,molecular docking ,fragments growth ,0104 chemical sciences ,Enzyme ,lcsh:QD1-999 ,Biochemistry ,glikozirani proteini ,biology.protein ,O-GlcNAc ,OGT ,GlcNAcylation ,O-GlcNAc Transferase ,OGT inhibitor ,Assay - Abstract
O-GlcNAcylation is an important posttranslational and metabolic process in cells that must be carefully regulated. O-GlcNAc transferase (OGT) is ubiquitously present in cells and is the only enzyme that catalyzes the transfer of O-GlcNAc to proteins. OGT is a promising target in various pathologies such as cancer, immune system diseases, or nervous impairment. In our previous, work we identified the 2-oxo-1,2-dihydroquinoline-4-carboxamide derivatives as promising compounds by a fragment-based drug design approach. Herein, we report the extension of this first series with several new fragments. As the most potent fragment, we identified 3b with an IC50 value of 116.0 [micro]M. If compared with the most potent inhibitor of the first series, F20 (IC50 = 117.6 [micro]M), we can conclude that the new fragments did not improve OGT inhibition remarkably. Therefore, F20 was used as the basis for the design of a series of compounds with the elongation towards the O-GlcNAc binding pocket as the free carboxylate allows easy conjugation. Compound 6b with an IC50 value of 144.5 [micro]M showed the most potent OGT inhibition among the elongated compounds, but it loses inhibition potency when compared to the UDP mimetic F20. We therefore assume that the binding of the compounds in the O-GlcNAc binding pocket is likely not crucial for OGT inhibition. Furthermore, evaluation of the compounds with two different assays revealed that some inhibitors most likely interfere with the commercially available UDP-Glo glycosyltransferase assay, leading to false positive results. This observation calls for caution, when evaluating UDP mimetic as OGT inhibitors with the UDP-Glo glycosyltransferase assay, as misinterpretations can occur. Nasl. z nasl. zaslona. Opis vira z dne 18. 3. 2021. This research was funded by the Slovenian Research Agency, grant number P1-0208 and from the European Union's Horizon2020 programme under the Marie Skłodowska-Curie Grant Agreement No. 765581 (project PhD4GlycoDrug; www.phd4glycodrug.eu). MW acknowledged Young researcher postgraduate research funding granted by the Slovenian Research Agency No. 50503. Št. članka: 666122. Bibliografija: str. 7-8. Abstract. ARRS, Farmacevtska kemija: načrtovanje, sinteza in vrednotenje učinkovin European Union’s Horizon2020 programme under the Marie Skłodowska-Curie, PhD4GlycoDrug; www.phd4glycodrug.eu
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- 2021
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28. Synthesis and Biochemical Evaluation of Warhead-Decorated Psoralens as (Immuno)Proteasome Inhibitors
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Martina Gobec, Matic Proj, Eva Shannon Schiffrer, Stanislav Gobec, Luka Rejc, Janez Mravljak, Izidor Sosič, and Andrej Šterman
- Subjects
Models, Molecular ,Proteasome Endopeptidase Complex ,Magnetic Resonance Spectroscopy ,electrophilic compounds ,Protein subunit ,medicine.medical_treatment ,non-peptidic ,Pharmaceutical Science ,01 natural sciences ,Article ,Analytical Chemistry ,lcsh:QD241-441 ,03 medical and health sciences ,chemistry.chemical_compound ,immunoproteasome ,lcsh:Organic chemistry ,Furocoumarins ,Drug Discovery ,medicine ,Physical and Theoretical Chemistry ,Psoralen ,warhead scan ,030304 developmental biology ,0303 health sciences ,Protease ,zaviralci ,udc:615.4:54:616-097 ,010405 organic chemistry ,imunopreoteasom ,Organic Chemistry ,Cancer ,medicine.disease ,avtoimunske bolezni ,Chemical space ,0104 chemical sciences ,Haematopoiesis ,Warhead ,Biochemistry ,chemistry ,Proteasome ,Chemistry (miscellaneous) ,farmacevtska kemija ,Molecular Medicine ,psoralen core ,psoralen ,Peptides ,Proteasome Inhibitors - Abstract
The immunoproteasome is a multicatalytic protease that is predominantly expressed in cells of hematopoietic origin. Its elevated expression has been associated with autoimmune diseases, various types of cancer, and inflammatory diseases. Selective inhibition of its catalytic activities is therefore a viable approach for the treatment of these diseases. However, the development of immunoproteasome-selective inhibitors with non-peptidic scaffolds remains a challenging task. We previously reported 7H-furo[3,2-g]chromen-7-one (psoralen)-based compounds with an oxathiazolone warhead as selective inhibitors of the chymotrypsin-like (&beta, 5i) subunit of immunoproteasome. Here, we describe the influence of the electrophilic warhead variations at position 3 of the psoralen core on the inhibitory potencies. Despite mapping the chemical space with different warheads, all compounds showed decreased inhibition of the &beta, 5i subunit of immunoproteasome in comparison to the parent oxathiazolone-based compound. Although suboptimal, these results provide crucial information about structure&ndash, activity relationships that will serve as guidance for the further design of (immuno)proteasome inhibitors.
- Published
- 2021
29. Glycosaminoglycans as Tools to Decipher the Platelet Tumor Cell Interaction: A Focus on P-Selectin
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Annamaria Naggi, Gerd Bendas, Martin Schlesinger, Martina Gobec, Svenja Schwarz, Uri Barash, and Lukas Maria Gockel
- Subjects
P-selectin ,Platelet Aggregation ,Angiogenesis ,Pharmaceutical Science ,Cell Communication ,Analytical Chemistry ,0302 clinical medicine ,Neoplasms ,Drug Discovery ,Platelet ,hexasaccharide heparin fragment ,Glycosaminoglycans ,0303 health sciences ,Chemistry ,low molecular weight heparin ,Heparin ,unfractionated heparin ,Extravasation ,2-O-desulfated heparin ,P-Selectin ,Coagulation ,Chemistry (miscellaneous) ,030220 oncology & carcinogenesis ,platelets ,Molecular Medicine ,medicine.drug ,Signal Transduction ,Blood Platelets ,medicine.drug_class ,platelet secretion ,Low molecular weight heparin ,Breast Neoplasms ,Cytoplasmic Granules ,RO-heparin ,Article ,lcsh:QD241-441 ,03 medical and health sciences ,lcsh:Organic chemistry ,decasaccharide heparin fragment ,Cell Line, Tumor ,medicine ,Humans ,Platelet activation ,Physical and Theoretical Chemistry ,Cell Shape ,030304 developmental biology ,tumor metastasis ,Organic Chemistry ,Platelet Activation ,2-o-desulfated heparin ,Cancer research - Abstract
Tumor cell&ndash, platelet interactions are regarded as an initial crucial step in hematogenous metastasis. Platelets protect tumor cells from immune surveillance in the blood, mediate vascular arrest, facilitate tumor extravasation, growth, and finally angiogenesis in the metastatic foci. Tumor cells aggregate platelets in the bloodstream by activation of the plasmatic coagulation cascade and by direct contact formation. Antimetastatic activities of unfractionated or low molecular weight heparin (UFH/LMWH) can undoubtedly be related to attenuated platelet activation, but molecular mechanisms and contribution of contact formation vs. coagulation remain to be elucidated. Using a set of non-anticoagulant heparin derivatives varying in size or degree of sulfation as compared with UFH, we provide insight into the relevance of contact formation for platelet activation. Light transmission aggregometry and ATP release assays confirmed that only those heparin derivatives with P-selectin blocking capacities were able to attenuate breast cancer cell-induced platelet activation, while pentasaccharide fondaparinux was without effects. Furthermore, a role of P-selectin in platelet activation and signaling could be confirmed by proteome profiler arrays detecting platelet kinases. In this study, we demonstrate that heparin blocks tumor cell-induced coagulation. Moreover, we identify platelet P-selectin, which obviously acts as molecular switch and controls aggregation and secretion of procoagulant platelets.
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- 2020
30. A focused structure-activity relationship study of psoralen-based immunoproteasome inhibitors
- Author
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Andrej Šterman, Martina Gobec, Eva Shannon Schiffrer, Izidor Sosič, Irena Mlinarič Raščan, Janez Mravljak, and Stanislav Gobec
- Subjects
medicine.medical_treatment ,Protein subunit ,Avtoimunske bolezni ,Pharmaceutical Science ,Farmacevtska kemija ,01 natural sciences ,Biochemistry ,Peripheral blood mononuclear cell ,chemistry.chemical_compound ,Drug Discovery ,medicine ,Structure–activity relationship ,Psoralen ,Pharmacology ,Protease ,010405 organic chemistry ,Organic Chemistry ,0104 chemical sciences ,Chemistry ,010404 medicinal & biomolecular chemistry ,Haematopoiesis ,udc:543.2/.9 ,chemistry ,Proteasome ,Molecular Medicine ,Cytokine secretion ,imunoproteasom - Abstract
The immunoproteasome is a multicatalytic protease that is predominantly expressed in cells of hematopoietic origin. Its elevated expression has been associated with autoimmune diseases, various types of cancer, and inflammatory diseases. The development of immunoproteasome-selective inhibitors with non-peptidic scaffolds remains a challenging task. Here, we describe a focused series of psoralen-based inhibitors of the beta5i subunit of the immunoproteasome with different substituents placed at position 4'. The most promising compound was further modified at position 3 of the psoralen ring. Despite a small decrease in the inhibitory potency in comparison with parent compound, we were able to improve the selectivity against other subunits of both the immunoproteasome and the constitutive proteasome. The most potent compounds discriminated between the both proteasome types in cell lysates and also showed a decrease in cytokine secretion in peripheral blood mononuclear cells. Abstract. Bibliografija: str. 1965. ARRS ARRS
- Published
- 2019
31. Structural features and functional activities of benzimidazoles as NOD2 antagonists
- Author
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Dunja Urbančič, Samo Guzelj, Irena Mlinarič-Raščan, Martina Gobec, Žiga Jakopin, and Emanuela Corsini
- Subjects
Anti-Inflammatory Agents ,Nod2 Signaling Adaptor Protein ,udc:616-097 ,Farmacevtska kemija ,Computational biology ,NOD2 antagonist, NOD1 antagonist, NF-kB activationImmunomodulation, Interleukin-8Tumor, necrosis factor-[alpha] ,01 natural sciences ,03 medical and health sciences ,Structure-Activity Relationship ,NOD2 ,Nod1 Signaling Adaptor Protein ,Drug Discovery ,NOD1 ,Humans ,Structural class ,030304 developmental biology ,Pharmacology ,0303 health sciences ,Innate immune system ,Citokini ,Molecular Structure ,010405 organic chemistry ,Chemistry ,Organic Chemistry ,Antagonist ,Pattern recognition receptor ,General Medicine ,digestive system diseases ,0104 chemical sciences ,Receptorji (medicina) ,HEK293 Cells ,Drug Design ,Functional activity ,Benzimidazoles ,Antagonism ,Imunski odziv - Abstract
NOD1 and NOD2 are pattern recognition receptors that have important roles in innate immune responses. Although their overactivation has been linked to a number of diseases, NOD2 in particular remains a virtually unexploited target in this respect, with only one structural class of antagonist reported. To gain insight into the structure-activity relationships of NOD2 antagonists, a series of novel analogs was designed and synthesized, and then screened for antagonist activity versus NOD2, and counter-screened versus NOD1. Compounds 32 and 38 were identified as potent and moderately selective NOD2 antagonists, and 33 and 42 as dual NOD1/NOD2 antagonists, with balanced activities against both targets in the low micromolar range. These data enable in-depth exploration of their structure-activity relationships and provide deeper understanding of the structural features required for NOD2 antagonism. Članek: št. 112089. Bibliografija: str. 14-15. Abstract. ARRS COST action CA15135 “Multi-target para- digm for innovative ligand identification in the drug discovery proces
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- 2019
32. Discovery of Nanomolar Desmuramylpeptide Agonists of the Innate Immune Receptor Nucleotide-Binding Oligomerization Domain-Containing Protein 2 (NOD2) Possessing Immunostimulatory Properties
- Author
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Tihomir Tomašič, Žiga Jakopin, Adela Štimac, Jurij Trontelj, Ruža Frkanec, Irena Mlinarič-Raščan, Marko Anderluh, and Martina Gobec
- Subjects
Lipopolysaccharides ,Models, Molecular ,0301 basic medicine ,Agonist ,medicine.drug_class ,Molecular Conformation ,Nod2 Signaling Adaptor Protein ,Antineoplastic Agents ,01 natural sciences ,Monocytes ,Mice ,Structure-Activity Relationship ,03 medical and health sciences ,chemistry.chemical_compound ,Adjuvants, Immunologic ,Cell Line, Tumor ,NOD2 ,Drug Discovery ,medicine ,Animals ,Humans ,Structure–activity relationship ,Receptor ,Innate immune system ,010405 organic chemistry ,Chemistry ,Drug discovery ,Immunity, Innate ,digestive system diseases ,0104 chemical sciences ,030104 developmental biology ,Biochemistry ,Drug Design ,Immunoglobulin G ,Muramyl dipeptide, immunomodulator, desmuramylpeptide, NOD2 agonist, immunostimulant, adjuvant ,Cytokines ,Molecular Medicine ,Female ,Peptidoglycan ,Acetylmuramyl-Alanyl-Isoglutamine ,Muramyl dipeptide - Abstract
Muramyl dipeptide (MDP), a fragment of bacterial peptidoglycan, has long been known as the smallest fragment possessing adjuvant activity, on the basis of its agonistic action on the nucleotide-binding oligomerization domain- containing protein 2 (NOD2). There is a pressing need for novel adjuvants and NOD2 agonists provide an untapped source of potential candidates. Here, we report the design, synthesis and characterization of a series of novel acyl tripeptides. A pivotal structural element for molecular recognition by NOD2 has been identified, culminating in the discovery of compound 9, the most potent desmuramylpeptide NOD2 agonist to date. Compound 9 augmented pro- inflammatory cytokine release from human peripheral blood mononuclear cells in synergy with lipopolysaccharide. Furthermore, it was able to induce ovalbumin- specific IgG titers in a mouse model of adjuvancy. These findings provide deeper insights into the structural requirements of desmuramylpeptides for NOD2-activation and highlight the potential use of NOD2 agonists as adjuvants for vaccines.
- Published
- 2018
33. Discovery of selective fragment-sized immunoproteasome inhibitors
- Author
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Martina Gobec, Izidor Sosič, György G. Ferenczy, Stanislav Gobec, Matic Proj, Levente Kollár, Tímea Imre, György M. Keserű, László Petri, Damijan Knez, Bence Szilágyi, Péter Ábrányi-Balogh, and Dávid Bajusz
- Subjects
Gene isoform ,Proteasome Endopeptidase Complex ,Protein subunit ,Drug Evaluation, Preclinical ,Protein Homeostasis ,01 natural sciences ,Inhibitory Concentration 50 ,Structure-Activity Relationship ,03 medical and health sciences ,Drug Discovery ,Humans ,Oxazoles ,030304 developmental biology ,Pharmacology ,0303 health sciences ,biology ,010405 organic chemistry ,Chemistry ,Organic Chemistry ,Disulfide bond ,Thiones ,Active site ,General Medicine ,0104 chemical sciences ,Protein Subunits ,Thiazoles ,Biochemistry ,Proteasome ,Covalent bond ,biology.protein ,Proteasome Inhibitors - Abstract
Proteasomes contribute to maintaining protein homeostasis and their inhibition is beneficial in certain types of cancer and in autoimmune diseases. However, the inhibition of the proteasomes in healthy cells leads to unwanted side-effects and significant effort has been made to identify inhibitors specific for the immunoproteasome, especially to treat diseases which manifest increased levels and activity of this proteasome isoform. Here, we report our efforts to discover fragment-sized inhibitors of the human immunoproteasome. The screening of an in-house library of structurally diverse fragments resulted in the identification of benzo[d]oxazole-2(3H)-thiones, benzo[d]thiazole-2(3H)-thiones, benzo[d]imidazole-2(3H)-thiones, and 1-methylbenzo[d]imidazole-2(3H)-thiones (with a general term benzoXazole-2(3H)-thiones) as inhibitors of the chymotrypsin-like (β5i) subunit of the immunoproteasome. A subsequent structure-activity relationship study provided us with an insight regarding growing vectors. Binding to the β5i subunit was shown and selectivity against the β5 subunit of the constitutive proteasome was determined. Thorough characterization of these compounds suggested that they inhibit the immunoproteasome by forming a disulfide bond with the Cys48 available specifically in the β5i active site. To obtain fragments with biologically more tractable covalent interactions, we performed a warhead scan, which yielded benzoXazole-2-carbonitriles as promising starting points for the development of selective immunoproteasome inhibitors with non-peptidic scaffolds.
- Published
- 2021
34. Pyridylethanol(phenylethyl)amines are non-azole, highly selective Candida albicans sterol 14α-demethylase inhibitors
- Author
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Urska Zelenko, Martina Gobec, Damjana Rozman, Simona Golic Grdadolnik, Iza Ogris, Darko Kocjan, Marija Ivanov, Izidor Sosič, Marina Soković, and Cene Skubic
- Subjects
Antifungal Agents ,Antifungal drugs ,Microbial Sensitivity Tests ,01 natural sciences ,Biochemistry ,Sterol 14-Demethylase ,Structure-Activity Relationship ,Candida albicans ,Drug Discovery ,Humans ,Potency ,Enzyme Inhibitors ,Molecular Biology ,chemistry.chemical_classification ,Dose-Response Relationship, Drug ,Molecular Structure ,biology ,010405 organic chemistry ,Chemistry ,Organic Chemistry ,Binding properties ,biology.organism_classification ,Highly selective ,Sterol ,0104 chemical sciences ,010404 medicinal & biomolecular chemistry ,biology.protein ,Azole ,Demethylase - Abstract
Sterol 14α-demethylase (CYP51) is the main drug target for the treatment of fungal infections. The worldwide increase in the incidence of opportunistic fungal infections and the emerging resistance to available azole-based antifungal drugs, raise the need to develop structurally distinct and selective fungal CYP51 inhibitors. In this work we have, for the first time, investigated the binding of pyridylethanol(phenylethyl)amines to any fungal CYP51. The comparison of the binding to Candida albicans and human CYP51 studied by spectroscopic and modeling methods revealed moieties decisive for selectivity and potency and resulted in the development of highly selective derivatives with significantly increased inhibitory potency. The structure-based insight into the selectivity requirements of this new chemical class of fungal CYP51 inhibitors, their unique binding properties and the low molecular weight of lead derivatives offer novel directions for the targeted development of antifungal clinical candidates.
- Published
- 2021
35. EP4 receptor agonist L-902688 augments cytotoxic activities of ibrutinib, idelalisib, and venetoclax against chronic lymphocytic leukemia cells
- Author
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Tijana Markovič, Sanja Nabergoj, Martina Gobec, Irena Mlinarič-Raščan, Žiga Jakopin, Helena Podgornik, and Damjan Avsec
- Subjects
0301 basic medicine ,receptor ,Chronic lymphocytic leukemia ,Tetrazoles ,Apoptosis ,Biochemistry ,synergistic cytotoxic activity ,celice kronične limfocitne levkemije ,Jurkat Cells ,chemistry.chemical_compound ,0302 clinical medicine ,Piperidines ,hemic and lymphatic diseases ,Antineoplastic Combined Chemotherapy Protocols ,Citotoksičnost ,Cytotoxic T cell ,citotoksičnost ,Sulfonamides ,prostaglandin E4 receptor ,kronična limfocitna levkemija ,Drug Synergism ,U937 Cells ,Pyrrolidinones ,030220 oncology & carcinogenesis ,Ibrutinib ,Refractory Chronic Lymphocytic Leukemia ,Idelalisib ,Adult ,Agonist ,medicine.drug_class ,L-902688 ,EP4 Receptor ,Antineoplastic Agents ,receptorji ,prostaglandin E4, receptorji, sinergistična citotoksična aktivnost, celice kronične limfocitne levkemije ,03 medical and health sciences ,medicine ,Humans ,NF-κB inhibition ,Quinazolinones ,udc:616.1 ,Pharmacology ,Dose-Response Relationship, Drug ,Venetoclax ,business.industry ,Adenine ,prostaglandin E4 ,sinergistična citotoksična aktivnost ,Bridged Bicyclo Compounds, Heterocyclic ,medicine.disease ,Leukemia, Lymphocytic, Chronic, B-Cell ,030104 developmental biology ,chemistry ,Purines ,Kronična limfocitna levkemija ,chronic lymphocytic leukemia, L-902688, NF-{kappa]B inhibition, prostaglandin E4, receptor, synergistic cytotoxic activity ,Leukocytes, Mononuclear ,udc:616.155.392+577.27 ,Cancer research ,chronic lymphocytic leukemia ,business ,Receptors, Prostaglandin E, EP4 Subtype - Abstract
Treatment of patients with relapsed or refractory chronic lymphocytic leukemia (CLL) has significantly improved more recently with the approval of several new agents, including ibrutinib, idelalisib, and venetoclax. Despite the outstanding efficacies observed with these agents, these treatments are sometimes discontinued due to toxicity, unresponsiveness, transformation of the disease and/or resistance. Constitutive NF-[kappa]B activation that protects CLL cells from apoptotic stimuli represents one of molecular mechanisms that underlie the emergence of drug resistance. As prostaglandin E (EP)4 receptor agonists have been shown to successfully inhibit the NF-[kappa]B pathway in B-cell lymphoma cells, we investigated the potential of the highly specific EP4 receptor agonist L-902688 for the potential treatment of patients with CLL. We show here that low micromolar concentrations of L-902688 can indeed induce selective cytotoxicity towards several B-cell malignancies, including CLL. Moreover, L-902688-mediated activation of the EP4 receptor in patient derived CLL cells resulted in inhibition of the NF-[kappa]B pathway, cell proliferation, and induction of apoptosis. Most importantly, we show for the first time that in combination with ibrutinib, idelalisib, or venetoclax, L-902688 induces synergistic cytotoxic activity against patient derived CLL cells. To conclude, the modulation of NF-[kappa]B activity by EP4 receptor agonists represents an innovative approach to improve the treatment of patients with CLL. In particular, EP4 receptor agonists appear to represent promising adjuncts to the already existing therapies for patients with CLL due to these promising synergistic activities. Članek št.: 114352. Bibliografija: str. 12-14. Abstract. ARRS ARRS European Regional Development Plan, EATRIS-TRI.SI
- Published
- 2021
36. Nonpeptidic Selective Inhibitors of the Chymotrypsin-Like (β5 i) Subunit of the Immunoproteasome
- Author
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Izidor Sosič, Irena Mlinarič-Raščan, Samo Lešnik, Damijan Knez, Aleš Obreza, Mitja Ogrizek, Dušanka Janežič, Dušan Žigon, Boris Brus, Martina Gobec, Janez Konc, Stanislav Gobec, and Matej Živec
- Subjects
0301 basic medicine ,Proteasome Endopeptidase Complex ,Cell Survival ,Protein subunit ,Peptide ,010402 general chemistry ,01 natural sciences ,Catalysis ,Cell Line ,Inhibitory Concentration 50 ,Structure-Activity Relationship ,03 medical and health sciences ,Humans ,Structure–activity relationship ,Cytotoxicity ,chemistry.chemical_classification ,Oligopeptide ,Chemistry ,010405 organic chemistry ,General Chemistry ,General Medicine ,Small molecule ,0104 chemical sciences ,3. Good health ,Molecular Docking Simulation ,Kinetics ,Protein Subunits ,030104 developmental biology ,Biochemistry ,Proteasome ,Cell culture ,Oligopeptides ,Proteasome Inhibitors ,HeLa Cells - Abstract
Elevated expression of the immunoproteasome has been associated with autoimmune diseases, inflammatory diseases, and various types of cancer. Selective inhibitors of the immunoproteasome are not only scarce, but also almost entirely restricted to peptide-based compounds. Herein, we describe nonpeptidic reversible inhibitors that selectively block the chymotrypsin-like (β5i) subunit of the human immunoproteasome in the low micromolar range. The most potent of the reversibly acting compounds were then converted into covalent, irreversible, nonpeptidic inhibitors that retained selectivity for the β5i subunit. In addition, these inhibitors discriminate between the immunoproteasome and the constitutive proteasome in cell-based assays. Along with their lack of cytotoxicity, these data point to these nonpeptidic compounds being suitable for further investigation as β5i-selective probes for possible application in noncancer diseases related to the immunoproteasome.
- Published
- 2016
37. Affinity Separation Techniques
- Author
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Martina Gobec, Jasna Omersel, and Borut Božič
- Subjects
Chromatography ,Chemistry ,Separation (statistics) - Published
- 2018
38. Novel N-amidinopiperidine-based proteasome inhibitor preserves dendritic cell functionality and rescues their Th1-polarizing capacity in Ramos-conditioned tumor environment
- Author
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Irena Mlinarič-Raščan, Martina Gobec, Urban Švajger, and Aleš Obreza
- Subjects
Proteasome Endopeptidase Complex ,Cancer Research ,Blotting, Western ,Immunology ,Amidines ,Antineoplastic Agents ,Apoptosis ,Context (language use) ,Biology ,Lymphocyte Activation ,Immune system ,Piperidines ,Tumor Microenvironment ,medicine ,Humans ,Immunology and Allergy ,Cells, Cultured ,Cell Proliferation ,Tumor microenvironment ,Cell Differentiation ,Dendritic Cells ,Dendritic cell ,Th1 Cells ,Flow Cytometry ,Burkitt Lymphoma ,Cell biology ,Oncology ,Proteasome ,Proteasome inhibitor ,Cytokines ,Cytokine secretion ,Proteasome Inhibitors ,medicine.drug - Abstract
The tumor microenvironment represents a burden that hampers the proper activation of immune cells, including the dendritic cells (DCs). It is, therefore, desired that the important characteristics of a given anticancer drug candidate be seen as consisting not solely of its antitumor properties, but that it also lacks potential side effects that could additionally constrain the development and function of immune cells associated with tumor immunity. We have previously identified compounds with a N-amidinopiperidine scaffold that selectively induce apoptosis in Burkitt's lymphoma cells through proteasome inhibition. Here, we demonstrate that SPI-15 affected neither the viability of DCs nor their differentiation. In addition, the compound had no significant effect on their cytokine secretion or allostimulatory capacity. Moreover, DC functionality in the context of tumor microenvironment was also unaffected, as demonstrated by experiments performed on DCs differentiated in Ramos-conditioned media in the presence or absence of SPI-15. The cytokine profile and functional assays revealed that SPI-15 rescues DC differentiation from the immunosuppressive environment produced by Ramos cells; this was seen by their reacquired ability to induce IFN-γ-secretion from naïve CD4(+)CD45RA(+) T cells and the consequently induced Th1-effector differentiation. Herein, we present novel characteristics of an N-amidinopiperidine-based protease inhibitor whose anticancer properties are not associated with the immunosuppression of DCs. We propose future studies toward the design of structurally similar compounds with the aim of developing potent anticancer drugs with minimal negative effects on crucial factors involved in tumor immunity.
- Published
- 2014
39. Structural characterization and biological evaluation of a clioquinol–ruthenium complex with copper-independent antileukaemic activity
- Author
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Jakob Kljun, Iztok Turel, Irena Mlinarič-Raščan, Matija Uršič, Izidor Sosič, Stanislav Gobec, and Martina Gobec
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Proteasome Endopeptidase Complex ,Programmed cell death ,Stereochemistry ,Base pair ,chemistry.chemical_element ,Antineoplastic Agents ,Apoptosis ,Ruthenium ,Inorganic Chemistry ,Inhibitory Concentration 50 ,Jurkat Cells ,chemistry.chemical_compound ,Cell Line, Tumor ,medicine ,Humans ,Dimethyl Sulfoxide ,Cell Proliferation ,Leukemia ,Dose-Response Relationship, Drug ,Clioquinol ,Cell Cycle ,NF-kappa B ,Oxyquinoline ,Hedgehog signaling pathway ,Mechanism of action ,chemistry ,Drug Design ,MCF-7 Cells ,Biophysics ,Drug Screening Assays, Antitumor ,medicine.symptom ,Copper ,Derivative (chemistry) ,medicine.drug - Abstract
In this study, we present the synthesis, biological characterization, and first crystal structure of an organometallic-clioquinol complex. Combining ruthenium with the established apoptotic agent and 8-hydroxyquinoline derivative, clioquinol, resulted in a complex that induces caspase-dependent cell death in leukaemia cells. This activity is copper independent and is improved compared to the parent compound, clioquinol. The study of the mode of action reveals that this clioquinol-ruthenium complex does not intercalate between DNA base pairs. Additionally, this clioquinol-ruthenium complex shows proteasome-independent inhibition of the NFκB signalling pathway, with no effects on cell-cycle distribution. These data suggest a mechanism of action that involves a target profile that is different from that for clioquinol alone.
- Published
- 2014
40. Synthesis of conformationally constrained γ-d-glutamyl-meso-diaminopimelic acid derivatives as ligands of nucleotide-binding oligomerization domain protein 1 (Nod1)
- Author
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Žiga Jakopin, Jaka Kodela, Toni Hazdovac, Martina Gobec, Irena Mlinarič-Raščan, and Marija Sollner Dolenc
- Subjects
Chemokine ,Stereochemistry ,Protein domain ,Molecular Conformation ,Diaminopimelic Acid ,Ligands ,Structure-Activity Relationship ,Nod1 Signaling Adaptor Protein ,Drug Discovery ,NOD1 ,Humans ,Receptor ,Cells, Cultured ,Pharmacology ,Innate immune system ,Dose-Response Relationship, Drug ,biology ,Chemistry ,Organic Chemistry ,NF-kappa B ,Pattern recognition receptor ,General Medicine ,In vitro ,body regions ,Biochemistry ,Leukocytes, Mononuclear ,TLR4 ,biology.protein ,Cytokines - Abstract
Nod1, an important member of the pattern recognition receptor family, remains a virtually unexploited target. Harnessing its innate immune stimulatory properties still remains an unfulfilled goal of medicinal chemistry. Nucleotide-binding oligomerization domain protein 1 (Nod1) agonists have been shown to boost the inflammatory responses against pathogenic microbes and could thus constitute a new class of broad spectrum antimicrobial agents. To gain additional insight into the structure/activity relationships of Nod1 agonistic compounds, a series of novel, conformationally constrained γ-D-glutamyl-meso-diaminopimelic acid (iE-DAP) analogs have been designed and synthesized. Ramos-Blue cells expressing Nod1 were used to screen and validate our compounds for their Nod1-agonist activity. Their immunomodulatory properties were subsequently determined in vitro, by evaluating their capacity to induce pro-inflammatory cytokine and chemokine production from human peripheral blood mononuclear cells (PBMC), by themselves and in synergy with lipopolysaccharide (LPS), a Toll-like receptor 4 (TLR4) ligand. The synthesized iE-DAP analogs were shown to possess immuno-enhancing properties as a result of their potent and specific Nod1-agonistic effect. The activity of the compound exhibiting the greatest capacity to induce pro-inflammatory cytokine release from PBMC surpassed that of lauroyl-γ-D-glutamyl-meso-diaminopimelic acid (C12-iE-DAP).
- Published
- 2013
41. Identification of indole scaffold-based dual inhibitors of NOD1 and NOD2
- Author
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Martina Gobec, Aleksandra Pekošak, Irena Mlinarič-Raščan, Žiga Jakopin, Dunja Urbančič, Marko Anderluh, Kaja Keček Plešec, and Tihomir Tomašič
- Subjects
0301 basic medicine ,Scaffold ,Indoles ,Clinical Biochemistry ,Nod2 Signaling Adaptor Protein ,Pharmaceutical Science ,Context (language use) ,Biochemistry ,03 medical and health sciences ,Structure-Activity Relationship ,NOD2 ,Nod1 Signaling Adaptor Protein ,Drug Discovery ,NOD1 ,Humans ,Molecular Biology ,Cells, Cultured ,Cell Proliferation ,Indole test ,Innate immune system ,Dose-Response Relationship, Drug ,Molecular Structure ,Chemistry ,Organic Chemistry ,Pattern recognition receptor ,NF-kappa B ,digestive system diseases ,body regions ,030104 developmental biology ,Drug Design ,Molecular Medicine ,Identification (biology) - Abstract
NOD1 and NOD2 are important members of the pattern recognition receptor family and play a crucial role within the context of innate immunity. However, overactivation of NODs, especially of NOD1, has also been implicated in a number of diseases. Surprisingly, NOD1 remains a virtually unexploited target in this respect. To gain additional insight into the structure-activity relationships of NOD1 inhibitors, a series of novel analogs has been designed and synthesized and then screened for their NOD1-inhibitory activity. Selected compounds were also investigated for their NOD2-inhibitory activity. Two compounds 4 and 15, were identified as potent mixed inhibitors of NOD1 and NOD2, displaying a balanced inhibitory activity on both targets in the low micromolar range. The results obtained have enabled a deeper understanding of the structural requirements for NOD1 and NOD2 inhibition.
- Published
- 2016
42. Development of an in-vivo active reversible butyrylcholinesterase inhibitor
- Author
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Roman Šink, Adrian Podkowa, Barbara Malawska, Irena Mlinarič Raščan, Marko Živin, Martina Gobec, Nicolas Coquelle, Jacques-Philippe Colletier, Kinga Sałat, Barbara Filipek, Anja Pišlar, Larisa Tratnjek, Anna Więckowska, Jure Stojan, Martina Perše, Damijan Knez, Urban Košak, Florian Nachon, Janko Kos, Boris Brus, Simon Žakelj, Jurij Trontelj, Stanislav Gobec, Jasna Šlenc, Xavier Brazzolotto, Faculty of Pharmacy, University of Ljubljana, Institute of Pathological Physiology, Faculty of Medicine, Institute of Pathology, Faculty of Medicine, Uniwersytet Jagielloński w Krakowie = Jagiellonian University (UJ), Institut de Recherche Biomédicale des Armées (IRBA), Institute of Biochemistry, Faculty of Medicine, Institut de biologie structurale (IBS - UMR 5075 ), Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), Institut de Recherche Biomédicale des Armées [Brétigny-sur-Orge] (IRBA), Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)
- Subjects
0301 basic medicine ,Male ,medicine.medical_specialty ,Protein Conformation ,Drug Evaluation, Preclinical ,Blood–brain barrier ,Neuroprotection ,Article ,03 medical and health sciences ,chemistry.chemical_compound ,Mice ,0302 clinical medicine ,Alzheimer Disease ,Internal medicine ,Catalytic Domain ,medicine ,Animals ,Humans ,Learning ,Rats, Wistar ,Butyrylcholinesterase ,Chromatography, High Pressure Liquid ,Cholinesterase ,Mice, Knockout ,Basal forebrain ,Multidisciplinary ,biology ,[SDV.BBM.BS]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Structural Biology [q-bio.BM] ,Chemistry ,Brain ,medicine.disease ,Acetylcholinesterase ,3. Good health ,Rats ,Mice, Inbred C57BL ,030104 developmental biology ,Endocrinology ,medicine.anatomical_structure ,Blood-Brain Barrier ,Drug Design ,biology.protein ,Disease Progression ,Cholinergic ,Female ,Cholinesterase Inhibitors ,Alzheimer's disease ,030217 neurology & neurosurgery - Abstract
Alzheimer’s disease (AD) is characterized by severe basal forebrain cholinergic deficit, which results in progressive and chronic deterioration of memory and cognitive functions. Similar to acetylcholinesterase, butyrylcholinesterase (BChE) contributes to the termination of cholinergic neurotransmission. Its enzymatic activity increases with the disease progression, thus classifying BChE as a viable therapeutic target in advanced AD. Potent, selective and reversible human BChE inhibitors were developed. The solved crystal structure of human BChE in complex with the most potent inhibitor reveals its binding mode and provides the molecular basis of its low nanomolar potency. Additionally, this compound is noncytotoxic and has neuroprotective properties. Furthermore, this inhibitor moderately crosses the blood-brain barrier and improves memory, cognitive functions and learning abilities of mice in a model of the cholinergic deficit that characterizes AD, without producing acute cholinergic adverse effects. Our study provides an advanced lead compound for developing drugs for alleviating symptoms caused by cholinergic hypofunction in advanced AD.
- Published
- 2016
43. Immunomodulatory Properties of Novel Nucleotide Oligomerization Domain 2 (Nod2) Agonistic Desmuramyldipeptides
- Author
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Žiga Jakopin, Marija Sollner Dolenc, Irena Mlinarič-Raščan, and Martina Gobec
- Subjects
Time Factors ,medicine.medical_treatment ,Nod2 Signaling Adaptor Protein ,Peripheral blood mononuclear cell ,Proinflammatory cytokine ,chemistry.chemical_compound ,NOD2 ,Drug Discovery ,medicine ,Humans ,Immunologic Factors ,Dose-Response Relationship, Drug ,HEK 293 cells ,Dipeptides ,digestive system diseases ,In vitro ,HEK293 Cells ,chemistry ,Biochemistry ,Drug Design ,Leukocytes, Mononuclear ,Phorbol ,Cytokines ,Molecular Medicine ,Peptidoglycan ,Acetylmuramyl-Alanyl-Isoglutamine ,Hydrophobic and Hydrophilic Interactions ,Adjuvant - Abstract
There is a pressing need for the development of novel adjuvants for human use. The minimal bioactive structure of bacterial peptidoglycan (PGN), muramyldipeptide (MDP), and its derivative murabutide (MB) have long been known for their adjuvant activities. For this reason, a series of novel desmuramyldipeptides have been designed and synthesized as part of our search for therapeutically useful MDP analogues. Since nucleotide oligomerization domain 2 (Nod2) is a putative receptor for MDP, we used engineered HEK293 cells overexpressing Nod2 to screen and validate our compounds for their Nod2-agonist activity. Their immunomodulatory properties were subsequently assessed in vitro by evaluating their effect on proinflammatory cytokine production of phorbol 12-myristate 13-acetate (PMA)/ionomycin-stimulated human peripheral blood mononuclear cells (PBMCs). Herein, we present novel desmuramyldipeptides, the most active of them possessing immunoenhancing properties as a result of their potent Nod2-agonistic effect.
- Published
- 2012
44. Structural requirements of acylated Gly-l-Ala-d-Glu analogs for activation of the innate immune receptor NOD2
- Author
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Irena Mlinarič-Raščan, Žiga Jakopin, Martina Gobec, and Marija Sollner Dolenc
- Subjects
0301 basic medicine ,Agonist ,Indoles ,Stereochemistry ,medicine.drug_class ,Nod2 Signaling Adaptor Protein ,01 natural sciences ,Immunoadjuvant ,Cell Line ,03 medical and health sciences ,chemistry.chemical_compound ,Molecular recognition ,NOD2 ,Drug Discovery ,medicine ,Moiety ,Humans ,Pharmacology ,Oligopeptide ,010405 organic chemistry ,Organic Chemistry ,General Medicine ,digestive system diseases ,Immunity, Innate ,0104 chemical sciences ,030104 developmental biology ,chemistry ,Biochemistry ,Drug Design ,Peptidoglycan ,Oligopeptides ,Muramyl dipeptide - Abstract
The fragment of bacterial peptidoglycan muramyl dipeptide (MDP) has long been known for its adjuvant activity, however the underlying mechanism of this action has only recently been elucidated. It is ascribed to its agonist action on the nucleotide-binding oligomerization domain-containing protein 2 (NOD2). In spite of the pressing need for novel adjuvants for human use, this discovery is hampered, by not knowing the structural requirements underlying the immunostimulatory activity. We have investigated how minor modifications of hit compound acyl Gly-L-Ala-D-Glu derivative I modulate the molecular recognition by NOD2. A series of novel desmuramyldipeptides has been designed and synthesized leading to the identification of compound 16, in which the sugar moiety is replaced by a 6-phenylindole moiety, that exhibits the strongest NOD2 activation to date sans the carbohydrate moiety. The results have enabled a deeper understanding of the structural requirements of desmuramylpeptides for NOD2 activation.
- Published
- 2015
45. Structure-Activity Relationships of Novel Tryptamine-Based Inhibitors of Bacterial Transglycosylase
- Author
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Irena Mlinarič Raščan, Martina Gobec, Eefjan Breukink, Mohammed Terrak, Adeline Derouaux, Izidor Sosič, Marko Anderluh, Matej Sova, Stanislav Gobec, and Ana Maria Amoroso
- Subjects
Tryptamine ,Glycan ,Staphylococcus aureus ,Penicillin binding proteins ,Enterococcus faecium ,Plasma protein binding ,Microbial Sensitivity Tests ,chemistry.chemical_compound ,Structure-Activity Relationship ,Drug Discovery ,Escherichia coli ,Structure–activity relationship ,Humans ,Penicillin-Binding Proteins ,Peptidoglycan glycosyltransferase ,biology ,Lipid II ,Escherichia coli Proteins ,Serine-Type D-Ala-D-Ala Carboxypeptidase ,Tryptamines ,Uridine Diphosphate N-Acetylmuramic Acid ,Anti-Bacterial Agents ,HEK293 Cells ,chemistry ,Biochemistry ,biology.protein ,Molecular Medicine ,Methicillin Resistance ,Peptidoglycan ,Peptidoglycan Glycosyltransferase ,Protein Binding - Abstract
Penicillin-binding proteins represent well-established, validated, and still very promising targets for the design and development of new antibacterial agents. The transglycosylase domain of penicillin-binding proteins is especially important, as it catalyzes polymerization of glycan chains, using the peptidoglycan precursor lipid II as a substrate. On the basis of the previous discovery of a noncovalent small-molecule inhibitor of transglycosylase activity, we systematically explored the structure-activity relationships of these tryptamine-based inhibitors. The main aim was to reduce the nonspecific cytotoxic properties of the initial hit compound and concurrently to retain the mode of its inhibition. A focused library of tryptamine-based compounds was synthesized, characterized, and evaluated biochemically. The results presented here show the successful reduction of the nonspecific cytotoxicity, and the retention of the inhibition of transglycosylase enzymatic activity, as well as the ability of these compounds to bind to lipid II and to have antibacterial actions.
- Published
- 2015
46. Discovery of Novel Small-Molecule Compounds with Selective Cytotoxicity for Burkitt’s Lymphoma Cells Using 3D Ligand-Based Virtual Screening
- Author
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Izidor Sosič, Irena Mlinarič-Raščan, Boris Brus, Aleš Obreza, Stanislav Gobec, and Martina Gobec
- Subjects
Proteasome Endopeptidase Complex ,Burkitt’s lymphoma ,Pharmaceutical Science ,Burkittʼs lymphoma ,Ligands ,Article ,Analytical Chemistry ,lcsh:QD241-441 ,Small Molecule Libraries ,chemistry.chemical_compound ,lcsh:Organic chemistry ,immune system diseases ,Cell Line, Tumor ,hemic and lymphatic diseases ,Drug Discovery ,medicine ,Humans ,Physical and Theoretical Chemistry ,udc:616-006.44 ,Virtual screening ,Ligand ,ligand-based ,Organic Chemistry ,NF-kappa B ,selectivity ,similarity search ,medicine.disease ,Burkitt Lymphoma ,Combinatorial chemistry ,Small molecule ,Lymphoma ,Biochemistry ,chemistry ,Chemistry (miscellaneous) ,Cell culture ,Molecular Medicine ,Growth inhibition ,Burkitt's lymphoma - Abstract
We describe a ligand-based approach towards compounds with more specific targeting for Burkitt’s lymphoma. Using three-dimensional ligand-based similarity searches and a previously described hit compound, we have identified six compounds that are chemically different but with similar spatial conformations. Biological evaluation revealed that one compound has better growth inhibition and improved selectivity towards Burkitt’s lymphoma cells than the query compound. However, initial mechanism-of-action studies show a different target profile in comparison with the previous hit compound, which does not involve the inhibition of the proteasome or the NFκB pathway. The data from this study provide a solid basis for further efforts in the search for selective agents against Burkitt’s lymphoma.
- Published
- 2014
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47. Characterization of human lymphoblastoid cell lines as a novel in vitro test system to predict the immunotoxicity of xenobiotics
- Author
-
Tijana Markovič, Irena Mlinarič-Raščan, Martina Gobec, and David Gurwitz
- Subjects
medicine.medical_treatment ,Biology ,Pharmacology ,Toxicology ,Peripheral blood mononuclear cell ,Urethane ,Cell Line ,Xenobiotics ,chemistry.chemical_compound ,Verapamil Hydrochloride ,Inhibitory Concentration 50 ,Interferon-gamma ,Furosemide ,Toxicity Tests ,medicine ,Benzo(a)pyrene ,Animals ,Humans ,Mannitol ,Lymphocytes ,Interleukin-6 ,Tumor Necrosis Factor-alpha ,General Medicine ,In vitro ,Interleukin-10 ,Cytokine ,chemistry ,Verapamil ,Toxicity ,Ionomycin ,Cyclosporine ,Leukocytes, Mononuclear ,Interleukin-2 ,Tumor necrosis factor alpha ,Interleukin-4 ,Trialkyltin Compounds ,Xenobiotic - Abstract
Evaluating immunomodulatory effects of xenobiotics is an important component of the toxicity studies. Herein we report on the establishment of a novel invitro test system for the immunotoxicity screening of xenobiotics based on human lymphoblastoid cell lines (LCLs). Four immunotoxic compounds; tributyltin chloride, cyclosporine A, benzo(a)pyrene and verapamil hydrochloride, as well as three immune-inert compounds; urethane, furosemide and mannitol were selected for characterization. The treatment of LCLs with immunosuppressive compounds resulted in reduced viability. The IC50 values determined in human LCLs were in agreement with the data obtained for human peripheral mononuclear cells. Since cytokine production reflects lymphocytes responses to external stimuli, we evaluated the functional responses of LCLs by monitoring their pro-inflammatory and immunoregulatory cytokine production. Our findings prove that LCLs allowed for reliable differentiation between immunomodulatory and immune-inert compounds. Hence, pre-treatment with immunomodulatory compounds led to a decrease in the production of pro-inflammatory TNFα, IL-6 and immunoregulatory IL-2, IL-4, IL-10 and IFNγ cytokines, when compared to untreated ionomycin/PMA stimulated cells. Moreover, testing a panel of ten LCLs derived from unrelated healthy individuals reflects inter-individual variability in response to immunomodulatory xenobiotics. In conclusion, LCLs provide a novel alternative method for the testing of the immunotoxic effects of xenobiotics.
- Published
- 2014
48. Screening of bisphenol A, triclosan and paraben analogues as modulators of the glucocorticoid and androgen receptor activities
- Author
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Katra Kolšek, Marija Sollner Dolenc, Martina Gobec, and Irena Mlinarič Raščan
- Subjects
medicine.drug_class ,Antiandrogens ,Drug Evaluation, Preclinical ,Parabens ,Pharmacology ,Toxicology ,chemistry.chemical_compound ,Structure-Activity Relationship ,Glucocorticoid receptor ,Receptors, Glucocorticoid ,Phenols ,medicine ,Humans ,Benzhydryl Compounds ,Chemistry ,Antiglucocorticoid ,General Medicine ,Androgen ,Triclosan ,Paraben ,Androgen receptor ,Docking (molecular) ,Receptors, Androgen ,hormones, hormone substitutes, and hormone antagonists ,Glucocorticoid ,medicine.drug - Abstract
A homeostasis of the glucocorticoid and androgen endocrine system is essential to human health. Their disturbance can lead to various diseases, for example cardiovascular, inflammatory and autoimmune diseases, infertility, cancer. Fifteen widely used industrial chemicals that disrupt endocrine activity were selected for evaluation of potential (anti)glucocorticoid and (anti)androgenic activities. The human breast carcinoma MDA-kb2 cell line was utilized for reporter gene assays, since it expresses both the androgen and the glucocorticoid-responsive reporter. Two new antiandrogens, 4,4′-sulfonylbis(2-methylphenol) (dBPS) and 4,4′-thiodiphenol (THIO), and two new antiglucocorticoids, bisphenol Z and its analog bis[4-(2-hydroxyethoxy)phenyl] sulfone (BHEPS) were identified. Moreover, four new glucocorticoid agonists (methyl paraben, ethyl paraben, propyl paraben and bisphenol F) were found. To elucidate the structure–activity relationship of bisphenols, we performed molecular docking experiments with androgen and glucocorticoid receptor. These docking experiments had shown that bulky structures such as BHEPS and bisphenol Z act as antiglucocorticoid, because they are positioned toward helix H12 in the antagonist conformation and could therefore be responsible for H12 conformational change and the switch between agonistic and antagonistic conformation of receptor. On the other hand smaller structures cannot interact with H12. The results of in vitro screening of fifteen industrial chemicals as modulators of the glucocorticoid and androgen receptor activities demand additional in vivo testing of these chemicals for formulating any relevant hazard identification to human health.
- Published
- 2014
49. Chemo-sensitizing effects of EP4 receptor-induced inactivation of nuclear factor-κB
- Author
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Tijana Markovič, Jozo Delic, Martina Gobec, Irena Mlinarič-Raščan, and Matevž Prijatelj
- Subjects
Agonist ,Lymphoma, B-Cell ,medicine.drug_class ,EP4 Receptor ,bcl-X Protein ,Antineoplastic Agents ,Apoptosis ,Biology ,Bortezomib ,chemistry.chemical_compound ,Jurkat Cells ,Downregulation and upregulation ,Cell Line, Tumor ,medicine ,Leukemia, B-Cell ,Humans ,Alprostadil ,Pharmacology ,NF-kappa B ,NF-κB ,U937 Cells ,Boronic Acids ,Burkitt Lymphoma ,Interleukin 10 ,chemistry ,Doxorubicin ,Interleukin-21 receptor ,Caspases ,Pyrazines ,Cancer research ,lipids (amino acids, peptides, and proteins) ,Signal transduction ,Receptors, Prostaglandin E, EP4 Subtype ,medicine.drug ,Signal Transduction - Abstract
The EP4 receptor conveys growth-inhibitory effects in mature and immature B cells via NF-κB. Herein, the EP4 receptor was evaluated as a potential therapeutic target for leukemia and lymphoma, whose survival depends on the constitutive activity of NF-κB. Utilizing a pharmacological approach, we proved that the EP4 receptor induces caspase-mediated apoptosis in malignantly transformed B cells, with the most prominent effect being on Burkitt׳s lymphoma cells. Since the increased activation of NF-κB underlies multi-drug resistance phenomena, we modulated this signaling pathway via EP4 receptor triggering. Pge1-OH, a specific EP4 receptor agonist, led to decreased NF-κB activity and a consequent decrease in levels of the antiapoptotic gene Bcl-xL in Ramos cells, resulting in an elevated sensitivity of cells towards bortezomib- and doxorubicin-induced chemotherapeutic effects. Our study identifies the as yet unrecognized potential of EP4 receptor agonists as chemo-sensitizing agents in B-cell lymphoma. The specific downregulation of NF-κB-dependent pathways in B-cell malignancies opens new possibilities for treatment and current therapy optimization using specific EP4 receptor agonists.
- Published
- 2014
50. Antimicrobial activity and cytotoxicity of some 2-amino-5-alkylidene-thiazol-4-ones
- Author
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Andrija Smelcerovic, Martina Gobec, Aleksandra Ɖorđević, Marko Jukič, Marko Anderluh, and Jelena Lazarević
- Subjects
Models, Molecular ,Stereochemistry ,Molecular Conformation ,Bacillus subtilis ,Microbial Sensitivity Tests ,Biology ,medicine.disease_cause ,Catalysis ,Inorganic Chemistry ,Minimum inhibitory concentration ,Anti-Infective Agents ,Drug Discovery ,medicine ,Humans ,Viability assay ,Physical and Theoretical Chemistry ,Molecular Biology ,Escherichia coli ,Organic Chemistry ,General Medicine ,biology.organism_classification ,Antimicrobial ,Thiazoles ,HEK293 Cells ,Pharmacophore ,Antibacterial activity ,Information Systems ,Discovery Studio - Abstract
We report a small, focused library of 30 diverse 2-amino-5-alkylidene-thiazol-4-ones that was assayed in a whole-cell antibacterial screen against a panel of several bacterial strains and a yeast. Most of the compounds exhibited modest to significant antibacterial activity against Pseudomonas aeruginosa, Bacillus subtilis and Staphylococcus aureus, and no activity against Salmonella typhimurium and Escherichia coli. The antibacterial activity depends markedly upon substituents on the thiazol-4-one core, and the most potent compound assayed ( $$(Z)$$ -4-((2-(4-methylpiperidin-1-yl)-4-oxothiazol-5(4H)-ylidene)methyl)benzonitrile) reached a minimal inhibitory concentration (MIC) value of $$10\,\upmu \hbox {g/mL}$$ on P. aeruginosa strain. An important feature of the tested compounds is their low influence on cell viability, as determined in a HEK-293 metabolic activity assay. In light of the encouraging in vitro antimicrobial assay results against several bacterial strains, we have generated a pharmacophore model using the Discovery studio 3.0 package (Accelrys Inc., San Diego, USA), which exposed the spatial arrangement of key molecular properties responsible for our observed MIC results. Considering the absence of a defined target and the limitation of the described approach to pool different scaffolds, the calculated pharmacophore model could be used for library enrichment to identify compounds with a thiazolidinone scaffold with improved antimicrobial potency and physico-chemical properties.
- Published
- 2013
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