Groningen Research Institute of Pharmacy

Groningen, Netherlands

Groningen Research Institute of Pharmacy

Groningen, Netherlands
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Panarella A.,University College Dublin | Panarella A.,Telethon Institute of Genetics and Medicine | Bexiga M.G.,University College Dublin | Bexiga M.G.,University of Coimbra | And 7 more authors.
Scientific Reports | Year: 2016

Synthetic nanoparticles are promising tools for imaging and drug delivery; however the molecular details of cellular internalization and trafficking await full characterization. Current knowledge suggests that following endocytosis most nanoparticles pass from endosomes to lysosomes. In order to design effective drug delivery strategies that can use the endocytic pathway, or by-pass lysosomal accumulation, a comprehensive understanding of nanoparticle uptake and trafficking mechanisms is therefore fundamental. Here we describe and apply an RNA interference-based high-content screening microscopy strategy to assess the intracellular trafficking of fluorescently-labeled polystyrene nanoparticles in HeLa cells. We screened a total of 408 genes involved in cytoskeleton and membrane function, revealing roles for myosin VI, Rab33b and OATL1 in this process. This work provides the first systematic large-scale quantitative assessment of the proteins responsible for nanoparticle trafficking in cells, paving the way for subsequent genome-wide studies.

Baggelaar M.P.,University of Groningen | Huang Y.,University of Groningen | Feringa B.L.,University of Groningen | Dekker F.J.,Groningen Research Institute of Pharmacy | Minnaard A.J.,University of Groningen
Bioorganic and Medicinal Chemistry | Year: 2013

A catalytic asymmetric synthesis of (S)-(-)-zearalenone is reported using asymmetric allylic alkylation for the introduction of the stereocenter. (S)-(-)-Zearalenone turned out to be a novel lipoxygenase inhibitor. © 2013 Elsevier Ltd. All rights reserved.

Eelderink-Chen Z.,Chromatin | Olmedo M.,Institute of Medical Psychology | Bosman J.,Groningen Research Institute of Pharmacy | Merrow M.,Institute of Medical Psychology
Methods in Enzymology | Year: 2015

Three properties are most often attributed to the circadian clock: a ca. 24-h free-running rhythm, temperature compensation of the circadian rhythm, and its entrainment to zeitgeber cycles. Relatively few experiments, however, are performed under entrainment conditions. Rather, most chronobiology protocols concern constant conditions. We have turned this paradigm around and used entrainment to study the circadian clock in organisms where a free-running rhythm is weak or lacking. We describe two examples therein: Caenorhabditis elegans and Saccharomyces cerevisiae. By probing the system with zeitgeber cycles that have various structures and amplitudes, we can demonstrate the establishment of systematic entrained phase angles in these organisms. We conclude that entrainment can be utilized to discover hitherto unknown circadian clocks and we discuss the implications of using entrainment more broadly, even in model systems that show robust free-running rhythms. © 2015 Elsevier Inc. All rights reserved.

Baas B.-J.,Groningen Research Institute of Pharmacy | Poddar H.,Groningen Research Institute of Pharmacy | Geertsema E.M.,Groningen Research Institute of Pharmacy | Rozeboom H.J.,University of Groningen | And 4 more authors.
Biochemistry | Year: 2015

The vast majority of characterized oxygenases use bound cofactors to activate molecular oxygen to carry out oxidation chemistry. Here, we show that an enzyme of unknown activity, RhCC from Rhodococcus jostii RHA1, functions as an oxygenase, using 4-hydroxyphenylenolpyruvate as a substrate. This unique and complex reaction yields 3-hydroxy-3-(4-hydroxyphenyl)-pyruvate, 4-hydroxybenzaldehyde, and oxalic acid as major products. Incubations with H2 18O, 18O2, and a substrate analogue suggest that this enzymatic oxygenation reaction likely involves a peroxide anion intermediate. Analysis of sequence similarity and the crystal structure of RhCC (solved at 1.78 Å resolution) reveal that this enzyme belongs to the tautomerase superfamily. Members of this superfamily typically catalyze tautomerization, dehalogenation, or decarboxylation reactions rather than oxygenation reactions. The structure shows the absence of cofactors, establishing RhCC as a rare example of a redox-metal- and coenzyme-free oxygenase. This sets the stage to study the mechanistic details of cofactor-independent oxygen activation in the unusual context of the tautomerase superfamily. © 2015 American Chemical Society.

Kusio-Kobialka M.,Nencki Institute of Experimental Biology | Wolanin K.,Nencki Institute of Experimental Biology | Podszywalow-Bartnicka P.,Nencki Institute of Experimental Biology | Sikora E.,Nencki Institute of Experimental Biology | And 6 more authors.
Apoptosis | Year: 2012

Chronic myeloid leukemia (CML) is a disorder of hematopoietic stem cells caused by the expression of BCR-ABL. Loss of p53 has not been implicated as important for the development of CML. Mutations in p53 protein are infrequent, however they correlate with the disease progression. The absence of p53 mutations does not exclude the possibility that other dysfunctions play an important role in CML pathology. Acetylation represents a very potent posttranslational mechanism regulating p53 stability, transcriptional activity and localization. In this study we have investigated whether the expression of BCR-ABL could influence the acetylation of p53, specifically at lysine 317/320 (K317/K320), which has been shown to regulate nuclear export and transcription-independent apoptotic activity of p53. We found that BCR-ABL expression increases K317 acetylation of p53 and is able to prevent a drop in acetylation observed upon DNA damage, followed by translocation of p53 to the cytoplasm and by Bax activation. We have shown that this site plays a crucial role in the regulation of p53 localization and p53-dependent, Bax-mediated apoptosis. Our study presents a novel BCR-ABL-dependent mechanism protecting from DNA-damage-induced cell death. It can, in addition to already known mechanisms, explain the resistance to p53-dependent apoptosis observed in CML cells expressing wt p53. We propose that the acetyltransferases regulating the p53 acetylation could be an interesting and potent target for therapeutic intervention. © 2012 Springer Science+Business Media, LLC.

Kiuchi T.,King's College London | Kiuchi T.,Tohoku University | Ortiz-Zapater E.,King's College London | Monypenny J.,King's College London | And 33 more authors.
Science Signaling | Year: 2014

The epidermal growth factor receptor (EGFR) is a member of the ErbB family that can promote the migration and proliferation of breast cancer cells. Therapies that target EGFR can promote the dimerization of EGFR with other ErbB receptors, which is associated with the development of drug resistance. Understanding how interactions among ErbB receptors alter EGFR biology could provide avenues for improving cancer therapy. We found that EGFR interacted directly with the CYT1 and CYT2 variants of ErbB4 and the membrane-anchored intracellular domain (mICD). The CYT2 variant, but not the CYT1 variant, protected EGFR from ligand-induced degradation by competing with EGFR for binding to a complex containing the E3 ubiquitin ligase c-Cbl and the adaptor Grb2. Cultured breast cancer cells overexpressing both EGFR and ErbB4 CYT2 mICD exhibited increased migration. With molecular modeling, we identified residues involved in stabilizing the EGFR dimer. Mutation of these residues in the dimer interface destabilized the complex in cells and abrogated growth factor-stimulated cell migration. An exon array analysis of 155 breast tumors revealed that the relative mRNA abundance of the ErbB4 CYT2 variant was increased in ER+ HER2- breast cancer patients, suggesting that our findings could be clinically relevant. We propose a mechanism whereby competition for binding to c-Cbl in an ErbB signaling heterodimer promotes migration in response to a growth factor gradient.

Dekker F.J.,Groningen Research Institute of Pharmacy | Hedberg C.,Max Planck Institute of Molecular Physiology
Bioorganic and Medicinal Chemistry | Year: 2011

The H- and N-Ras GTPases are prominent examples of proteins, whose localizations and signalling capacities are regulated by reversible palmitoylations and depalmitoylations. Recently, the novel small molecule inhibitor palmostatin B has been described to inhibit Ras depalmitoylation and to revert the phenotype of oncogenic HRasG12V transformed cells. This demonstrates that palmostatin B is a tool to investigate the biochemical effects of the inhibition of cellular Ras depalmitoylation on Ras signalling, which is relevant for oncology. Furthermore, it is to be expected that many proteins, of which the signalling capacities depend on reversible palmitoylation, will be discovered in the near future. This stresses the urgent need for further development of small molecule inhibitors of palmitoylation and depalmitoylation in order to study their functions in cellular signalling. © 2011 Elsevier Ltd. All rights reserved.

Wisastra R.,Groningen Research Institute of Pharmacy | Ghizzoni M.,Groningen Research Institute of Pharmacy | Boltjes A.,Groningen Research Institute of Pharmacy | Haisma H.J.,Groningen Research Institute of Pharmacy | Dekker F.J.,Groningen Research Institute of Pharmacy
Bioorganic and Medicinal Chemistry | Year: 2012

Lipoxygenases catalyze the oxidation of unsaturated fatty acids, such as linoleic acid, which play a crucial role in inflammatory responses. Selective inhibitors may provide a new therapeutic approach for inflammatory diseases. In this study, we describe the identification of a novel soybean lipoxygenase-1 (SLO-1) inhibitor and a potato 5-lipoxygenase (5-LOX) activator from a screening of a focused compound collection around the natural product anacardic acid. The natural product anacardic acid inhibits SLO-1 with an IC50 of 52 μM, whereas the inhibitory potency of the novel mixed type inhibitor 23 is fivefold enhanced. In addition, another derivative (21) caused non-essential activation of potato 5-LOX. This suggests the presence of an allosteric binding site that regulates the lipoxygenase activity. © 2012 Elsevier Ltd. All rights reserved.

Kusio-Kobialka M.,Nencki Institute of Experimental Biology | Dudka-Ruszkowska W.,Nencki Institute of Experimental Biology | Ghizzoni M.,Groningen Research Institute of Pharmacy | Dekker F.J.,Groningen Research Institute of Pharmacy | Piwocka K.,Nencki Institute of Experimental Biology
Anti-Cancer Agents in Medicinal Chemistry | Year: 2013

Acetylation of histones and nonhistone proteins is a posttranslational modification which plays a major role in the regulation of intracellular processes involved in tumorigenesis. It was shown that different acetylation of proteins correlates with development of leukemia. It is proposed that histone acetyltransferases (HATs) are important novel drug targets for leukemia treatment, however data are still not consistent. Our previous data showed that a derivative of anacardic acid - small molecule MG153, which has been designed and synthesized to optimize the HAT inhibitory potency of anacardic acid, is a potent inhibitor of p300/CBP associated factor (PCAF) acetyltransferase. Here we ask whether inhibition of PCAF acetyltransferase with MG153 will show proapoptotic effects in cells expressing BCR-ABL, which show increased PCAF expression and are resistant to apoptosis. We found that inhibition of PCAF decreases proliferation and induces apoptosis, which correlates with loss of the mitochondrial membrane potential and DNA fragmentation. Importantly, cells expressing BCR-ABL are more sensitive to PCAF inhibition compared to parental cells without BCRABL. Moreover, inhibition of PCAF in BCR-ABL-expressing cells breaks their resistance to DNA damage-induced cell death. These findings provide direct evidence that targeting the PCAF alone or in combination with DNA-damaging drugs shows cytotoxic effects and should be considered as a prospective therapeutic strategy in chronic myeloid leukemia cells. Moreover, we propose that anacardic acid derivative MG153 is a valuable agent and further studies validating its therapeutic relevance should be performed. © 2013 Bentham Science Publishers.

Ghizzoni M.,Groningen Research Institute of Pharmacy | Boltjes A.,Groningen Research Institute of Pharmacy | Graaf C.D.,VU University Amsterdam | Haisma H.J.,Groningen Research Institute of Pharmacy | Dekker F.J.,Groningen Research Institute of Pharmacy
Bioorganic and Medicinal Chemistry | Year: 2010

Several lines of evidence indicate that histone acetyltransferases (HATs) are novel drug targets for treatment of diseases like, for example, cancer and inflammation. The natural product anacardic acid is a starting point for development of small molecule inhibitors of the histone acetyltransferase (HAT) p300/CBP associated factor (PCAF). In order to optimize the inhibitory potency, a binding model for PCAF inhibition by anacardic acid was proposed and new anacardic acid derivatives were designed. Ten new derivatives were synthesized using a novel synthetic route. One compound showed a twofold improved inhibitory potency for the PCAF HAT activity and a twofold improved inhibition of histone acetylation in HEP G2 cells. © 2010 Elsevier Ltd. All rights reserved.

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