Synthesis of hybrid anticancer agents based on kinase and histone deacetylase inhibitors

Fragments based on the VEGFR2i Semaxanib (SU5416, (vascular endothelial growth factor receptor-2 inhibitor) and the HDACi (histone deacetylase inhibitor) SAHA (suberanilohydroxamic acid) have been merged to form a range of low molecular weight dual action hybrids. Vindication of this approach is provided by SAR, docking studies, in vitro cancer cell line and biochemical enzyme inhibition data as well as in vivo Xenopus data for the lead molecule (Z)-N1-(3-((1H-pyrrol-2-yl)methylene)-2-oxoindolin-5-yl)- N8-hydroxyoctanediamide 6

Chytrid fungus infections in laboratory and introduced <i>Xenopus laevis </i>populations:assessing the risks for U.K. native amphibians

The chytrid fungus Batrachochytrium dendrobatidis (Bd) is notorious amongst current conservation biology challenges, responsible for mass mortality and extinction of amphibian species. World trade in amphibians is implicated in global dissemination. Exports of South African Xenopus laevis have led to establishment of this invasive species on four continents. Bd naturally infects this host in Africa and now occurs in several introduced populations. However, no previous studies have investigated transfer of infection into co-occurring native amphibian faunas. A survey of 27 U.K. institutions maintaining X. laevis for research showed that most laboratories have low-level infection, a risk for native species if animals are released into the wild. RT-PCR assays showed Bd in two introduced U.K. populations of X. laevis, in Wales and Lincolnshire. Laboratory and field studies demonstrated that infection levels increase with stress, especially low temperature. In the U.K., native amphibians may be exposed to intense transmission in spring when they enter ponds to spawn alongside X. laevis that have cold-elevated Bd infections. Exposure to cross-infection has probably been recurrent since the introduction of X. laevis, &gt;20years in Lincolnshire and 50years in Wales. These sites provide an important test for assessing the impact of X. laevis on Bd spread. However, RT-PCR assays on 174 native amphibians (Bufo, Rana, Lissotriton and Triturus spp.), sympatric with the Bd-infected introduced populations, showed no foci of self-sustaining Bd transmission associated with X. laevis. The abundance of these native amphibians suggested no significant negative population-level effect after the decades of co-occurrence

Pojamide: An HDAC3-selective ferrocene analogue with remarkably enhanced redox-triggered ferrocenium activity in cells.

A ferrocene containing ortho-aminoanilide, N1-(2-aminophenyl)-N8-ferrocenyloctanediamide, 2b (Pojamide) displayed nanomolar potency vs. HDAC3. Compared to RGFP966, a potent and selective HDAC3 inhibitor, Pojamide displayed superior activity in HCT116 colorectal cancer cell invasion assays; however, TCH106 and Romidepsin, potent HDAC1 inhibitors, outperformed Pojamide in cellular proliferation and colony formation assays. Together, these data suggest that HDAC 1 & 3 inhibition is desirable to achieve maximum anti-cancer benefits. Additionally, we explored Pojamide-induced redox-pharmacology. Indeed, treating HCT116 cells with Pojamide, SNP (sodium nitroprusside) and glutathione (GSH) led to greatly enhanced cytotoxicity and DNA damage attributed to activation to an Fe(III) species

Regulation of CHK1 inhibitor resistance by a c-Rel and USP1 dependent pathway

Previously, we discovered that deletion of c-Rel in the Em-Myc mouse model of lymphoma results in earlier onset of disease, a finding that contrasted with the expected function of this NF-κB subunit in B-cell malignancies. Here we report that Em-Myc/cRel−/− cells have an unexpected and major defect in the CHK1 pathway. Total and phospho proteomic analysis revealed that Em-Myc/cRel−/− lymphomas highly resemble wild-type (WT) Em-Myc lymphomas treated with an acute dose of the CHK1 inhibitor (CHK1i) CCT244747. Further analysis demonstrated that this is a consequence of Em-Myc/cRel−/ − lymphomas having lost expression of CHK1 protein itself, an effect that also results in resistance to CCT244747 treatment in vivo. Similar down-regulation of CHK1 protein levels was also seen in CHK1i resistant U2OS osteosarcoma and Huh7 hepatocellular carcinoma cells. Further investigation revealed that the deubiquitinase USP1 regulates CHK1 proteolytic degradation and that its down-regulation in our model systems is responsible, at least in part, for these effects. We demonstrate that treating WT Em-Myc lymphoma cells with the USP1 inhibitor ML323 was highly effective at reducing tumour burden in vivo. Targeting USP1 activity may thus be an alternative therapeutic strategy in MYC-driven tumours

A de novo paradigm for male infertility

Funding Information: (DFG, CRU326) to C.F. and F.T. This project was also supported in part by funding from the Australian National Health and Medical Research Council (APP1120356) to M.K.O.B., by grants from the National Institutes of Health of the United States of America (R01HD078641 to D.F.C. and K.I.A., P50HD096723 to D.F.C.) and from the Biotechnology and Biological Sciences Research Council (BB/S008039/1) to D.J.E. Funding Information: We are grateful for the participation of all patients and their parents in this study. We thank Laurens van de Wiel (Radboudumc), Sebastian Judd-Mole (Monash University), Arron Scott and Bryan Hepworth (Newcastle University) for technical support, and Margot J Wyrwoll (University of Münster) for help with handling MERGE samples and data. This project was funded by The Netherlands Organization for Scientific Research (918-15-667) to J.A.V. as well as an Investigator Award in Science from the Wellcome Trust (209451) to J.A.V. a grant from the Catherine van Tussenbroek Foundation to M.S.O. a grant from MERCK to R.S. a UUKi Rutherford Fund Fellowship awarded to B.J.H. and the German Research Foundation Clinical Research Unit “Male Germ Cells” Publisher Copyright: © 2022, The Author(s).De novo mutations are known to play a prominent role in sporadic disorders with reduced fitness. We hypothesize that de novo mutations play an important role in severe male infertility and explain a portion of the genetic causes of this understudied disorder. To test this hypothesis, we utilize trio-based exome sequencing in a cohort of 185 infertile males and their unaffected parents. Following a systematic analysis, 29 of 145 rare (MAF < 0.1%) protein-altering de novo mutations are classified as possibly causative of the male infertility phenotype. We observed a significant enrichment of loss-of-function de novo mutations in loss-of-function-intolerant genes (p-value = 1.00 × 10−5) in infertile men compared to controls. Additionally, we detected a significant increase in predicted pathogenic de novo missense mutations affecting missense-intolerant genes (p-value = 5.01 × 10−4) in contrast to predicted benign de novo mutations. One gene we identify, RBM5, is an essential regulator of male germ cell pre-mRNA splicing and has been previously implicated in male infertility in mice. In a follow-up study, 6 rare pathogenic missense mutations affecting this gene are observed in a cohort of 2,506 infertile patients, whilst we find no such mutations in a cohort of 5,784 fertile men (p-value = 0.03). Our results provide evidence for the role of de novo mutations in severe male infertility and point to new candidate genes affecting fertility.publishersversionpublishe

Regulation of CHK1 inhibitor resistance by a c-Rel and USP1 dependent pathway

AbstractWe previously discovered that deletion of c-Rel in the Eμ-Myc mouse model of lymphoma results in earlier onset of disease, a finding that contrasted with the expected function of this NF-κB subunit in B-cell malignancies. Here we report that c-rel -/- Eµ-Myc cells have an unexpected and major defect in the CHK1 pathway, with almost undetectable levels of CHK1 and CLSPN protein leading to therapeutic resistance to the highly specific CHK1 inhibitor (CHK1i) CCT244747. Similar downregulation of CHK1 levels was also seen in CCT244747 resistant U20S osteosarcoma cells. Further investigation revealed that downregulation of the deubiquitinase USP1 is responsible, at least in part, for these effects. Importantly, we demonstrate that c-rel -/- Eµ-Myc lymphoma cells survive though upregulation of compensatory PI3K/AKT pathway activity. Moreover, targeting this pathway with Pictilisib (GDC-0941) effectively killed c-rel -/- Eµ-Myc in vivo, while having no effect on wild type Eμ-Myc cells. This data reveals an NF-κB regulated pathway controlling CHK1 activity in cancer cells and identifies a potential mechanism for both acquiring and overcoming CHK1i resistance in cancer patients.</jats:p

A de novo paradigm for male infertility

Genetics of Male Infertility Initiative (GEMINI) consortium: Donald F. Conrad, Liina Nagirnaja, Kenneth I. Aston, Douglas T. Carrell, James M. Hotaling, Timothy G. Jenkins, Rob McLachlan, Moira K. O’Bryan, Peter N. Schlegel, Michael L. Eisenberg, Jay I. Sandlow, Emily S. Jungheim, Kenan R. Omurtag, Alexandra M. Lopes, Susana Seixas, Filipa Carvalho, Susana Fernandes, Alberto Barros, João Gonçalves, Iris Caetano, Graça Pinto, Sónia Correia, Maris Laan, Margus Punab, Ewa Rajpert-De Meyts, Niels Jørgensen, Kristian Almstrup, Csilla G. Krausz & Keith A. Jarvi.De novo mutations are known to play a prominent role in sporadic disorders with reduced fitness. We hypothesize that de novo mutations play an important role in severe male infertility and explain a portion of the genetic causes of this understudied disorder. To test this hypothesis, we utilize trio-based exome sequencing in a cohort of 185 infertile males and their unaffected parents. Following a systematic analysis, 29 of 145 rare (MAF < 0.1%) protein-altering de novo mutations are classified as possibly causative of the male infertility phenotype. We observed a significant enrichment of loss-of-function de novo mutations in loss-of-function-intolerant genes (p-value = 1.00 × 10−5) in infertile men compared to controls. Additionally, we detected a significant increase in predicted pathogenic de novo missense mutations affecting missense-intolerant genes (p-value = 5.01 × 10−4) in contrast to predicted benign de novo mutations. One gene we identify, RBM5, is an essential regulator of male germ cell pre-mRNA splicing and has been previously implicated in male infertility in mice. In a follow-up study, 6 rare pathogenic missense mutations affecting this gene are observed in a cohort of 2,506 infertile patients, whilst we find no such mutations in a cohort of 5,784 fertile men (p-value = 0.03). Our results provide evidence for the role of de novo mutations in severe male infertility and point to new candidate genes affecting fertility.This project was funded by The Netherlands Organization for Scientific Research (918-15-667) to J.A.V. as well as an Investigator Award in Science from the Wellcome Trust (209451) to J.A.V. a grant from the Catherine van Tussenbroek Foundation to M.S.O. a grant from MERCK to R.S. a UUKi Rutherford Fund Fellowship awarded to B.J.H. and the German Research Foundation Clinical Research Unit “Male Germ Cells” (DFG, CRU326) to C.F. and F.T. This project was also supported in part by funding from the Australian National Health and Medical Research Council (APP1120356) to M.K.O.B., by grants from the National Institutes of Health of the United States of America (R01HD078641 to D.F.C. and K.I.A., P50HD096723 to D.F.C.) and from the Biotechnology and Biological Sciences Research Council (BB/S008039/1) to D.J.E.info:eu-repo/semantics/publishedVersio

‘It doesn’t reveal itself’: erosion and collapse of the image in contemporary visual practice

The article explores the extent to which ‘pictorial art’ resists legibility, transparency and coherence. The analysis of three artistic case studies, Idris Khan, Maria Chevska and Jane and Louise Wilson, serves to investigate established hierarchies in our perception of visual referents. In the discussion, the article inquires the means of erosion, veiling and dissemblance as ways to critique assumption of the homogeneity of the image. All artists cast a view of the external world by diverting it, defacing it and distancing themselves from the external environment. However, the distancing is never disconnected from the everyday and never succumbs to abstraction. The article argues that the crisis of the image offers a productive framework that allows artists to draw attention to the absence of logical structure and the instability of the visual sign