28 research outputs found
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Modulation of tumour angiogenesis by targeting p38 MAPK signalling in tumour-associated macrophages
Cellular crosstalk between cancer cells and tumour-associated macrophages (TAMs) plays an important role in tumour growth and metastasis by promoting tumour angiogenesis.
Western blot analyses of cell lysates from in vitro studies revealed that RAW macrophages co-cultured with Murine Lewis lung carcinoma (LLC) cells display elevated levels of p38 MAPK (p38) activation. To further investigate this signalling pathway we used the p38 inhibitor BIRB796. Exposure of cancer cells to macrophage-conditioned medium pre-incubated with BIRB796 showed a clear dose-dependent increase in apoptosis. By preparing liposomal formulations of BIRB796 (Lip-BIRB796) we can spare normal cells from the drug’s cytotoxic effects and specifically target p38 signalling in phagocytic macrophages. In vitro cytotoxicity studies revealed an increased chemosensitivity to doxorubicin treatment when macrophage/cancer cell co-cultures were treated with Lip-BIRB796 prior to doxorubicin exposure. Furthermore, in vivo CAM assays were able to demonstrate both a marked increase in angiogenesis in CAMs inoculated with RAW and LLC cell co-cultures as compared to the respective monocultures and a significant decrease where these co-cultures were treated with Lip-BIRB796.
To conclude, our results suggest that p38 is a promising target in TAMs for cancer adjuvant therapy
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Targeting Extracellular Domains D4 and D7 of Vascular Endothelial Growth Factor Receptor 2 Reveals Allosteric Receptor Regulatory Sites
Vascular endothelial growth factors (VEGFs) activate three receptor tyrosine kinases, VEGFR-1, -2, and -3, which regulate angiogenic and lymphangiogenic signaling. VEGFR-2 is the most prominent receptor in angiogenic signaling by VEGF ligands. The extracellular part of VEGF receptors consists of seven immunoglobulin homology domains (Ig domains). Earlier studies showed that domains 2 and 3 (D23) mediate ligand binding, while structural analysis of dimeric ligand/receptor complexes by electron microscopy and small-angle solution scattering revealed additional homotypic contacts in membrane-proximal Ig domains D4 and D7. Here we show that D4 and D7 are indispensable for receptor signaling. To confirm the essential role of these domains in signaling, we isolated VEGFR-2-inhibitory “designed ankyrin repeat proteins” (DARPins) that interact with D23, D4, or D7. DARPins that interact with D23 inhibited ligand binding, receptor dimerization, and receptor kinase activation, while DARPins specific for D4 or D7 did not prevent ligand binding or receptor dimerization but effectively blocked receptor signaling and functional output. These data show that D4 and D7 allosterically regulate VEGFR-2 activity. We propose that these extracellular-domain-specific DARPins represent a novel generation of receptor-inhibitory drugs for in vivo applications such as targeting of VEGFRs in medical diagnostics and for treating vascular pathologies
Preparation for a first-in-man lentivirus trial in patients with cystic fibrosis
We have recently shown that non-viral gene therapy can stabilise the decline of lung function in patients with cystic fibrosis (CF). However, the effect was modest, and more potent gene transfer agents are still required. Fuson protein (F)/Hemagglutinin/Neuraminidase protein (HN)-pseudotyped lentiviral vectors are more efficient for lung gene transfer than non-viral vectors in preclinical models. In preparation for a first-in-man CF trial using the lentiviral vector, we have undertaken key translational preclinical studies. Regulatory-compliant vectors carrying a range of promoter/enhancer elements were assessed in mice and human air-liquid interface (ALI) cultures to select the lead candidate; cystic fibrosis transmembrane conductance receptor (CFTR) expression and function were assessed in CF models using this lead candidate vector. Toxicity was assessed and 'benchmarked' against the leading non-viral formulation recently used in a Phase IIb clinical trial. Integration site profiles were mapped and transduction efficiency determined to inform clinical trial dose-ranging. The impact of pre-existing and acquired immunity against the vector and vector stability in several clinically relevant delivery devices was assessed. A hybrid promoter hybrid cytosine guanine dinucleotide (CpG)- free CMV enhancer/elongation factor 1 alpha promoter (hCEF) consisting of the elongation factor 1α promoter and the cytomegalovirus enhancer was most efficacious in both murine lungs and human ALI cultures (both at least 2-log orders above background). The efficacy (at least 14% of airway cells transduced), toxicity and integration site profile supports further progression towards clinical trial and pre-existing and acquired immune responses do not interfere with vector efficacy. The lead rSIV.F/HN candidate expresses functional CFTR and the vector retains 90-100% transduction efficiency in clinically relevant delivery devices. The data support the progression of the F/HN-pseudotyped lentiviral vector into a first-in-man CF trial in 2017
Finishing the euchromatic sequence of the human genome
The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead
Epigenetics of ovarian cancer : from the lab to the clinic
Ovarian cancer remains the most lethal gynaecological cancer. Various molecular changes have been identified and have shown promise for their diagnostic, prognostic and curative capacity but still need further validation. Among different mechanisms, the present article reviews the importance of epigenetic changes in ovarian cancer
Practice makes perfect? Skillful performances in veterinary work
Is vetting a craft that must be learned owing to the limitations of scientific discipline, or simply a question of practice makes perfect? This question arose from our empirical research on veterinary surgeons (vets), who we found were often struggling with the divergence between the precise and unambiguous knowledge underlying the training and the unpredictability and imprecision of their everyday practices. These are comparatively underexplored issues insofar as the literature on vets tends to be descriptive and statistical, focusing primarily on clinical matters and associated human-animal interactions. Our cliché title has a question mark because while many vets remain embedded in the disciplined ‘certainties’ and causal regularities within their training, in practice this ordered world is rarely realized, and they are faced with indeterminacy where the ‘perfect’ solution eludes them. Vets often turn these unrealistic ideals of expertise back in on themselves, thus generating doubt and insecurity for any failure in their practices. In analysing vets’ experiences, we pay attention to the anatomical models of science, where linear causal analysis is expected to provide orderly and predictable outcomes or ‘right’ answers to problems, as well as notions of expertise that turn out to be illusory
Emergence of a Dhfr Mutation Conferring High-Level Drug Resistance in Plasmodium Falciparum Populations from Southwest Uganda
The S108N, C59R, and N51I mutations in the Plasmodium falciparum gene that encodes dihydrofolate reductase, dhfr, confer resistance to pyrimethamine and are common in Africa. However, the I164L mutation, which confers high-level resistance, is rarely seen. We found a 14% prevalence of the I164L mutation among a sample of 51 patients with malaria in Kabale District in southwest Uganda in 2005 and a 4% prevalence among 72 patients with malaria in the neighboring district of Rukungiri during the same year. Surveillance at 6 sites across Uganda during 2002-2004 reported a single case of infection involving an I164L mutant, also in the southwest, suggesting that this is a regional hot spot. The spatial clustering and increasing prevalence of the I164L mutation is indicative of local transmission of the mutant. Targeted surveillance is needed to confirm the extent of the spread of the I164L mutation and to monitor the impact of I164L on the efficacy of antifolates for intermittent preventive treatment of pregnant women and/or infants with falciparum malaria
Recommendations for competing sexual-asexually typified generic names in Sordariomycetes (except Diaporthales, Hypocreales, and Magnaporthales)
With the advance to one scientific name for each fungal species, the generic names in the class Sordariomycetes typified by sexual and asexual morphs are evaluated based on their type species to determine if they compete with each other for use or protection. Recommendations are made for which of the competing generic names should be used based on criteria such as priority, number of potential names changes, and frequency of use. Some recommendations for well-known genera include Arthrinium over Apiospora, Colletotrichum over Glomerella, Menispora over Zignoëlla, Microdochium over Monographella, Nigrospora over Khuskia, and Plectosphaerella over Plectosporium. All competing generic names are listed in a table of recommended names along with the required action. If priority is not accorded to sexually typified generic names after 2017, only four names would require formal protection: Chaetosphaerella over Oedemium, Diatrype over Libertella, Microdochium over Monographella, and Phaeoacremonium over Romellia and Togninia. Concerning species in the recommended genera, one replacement name (Xylaria benjaminii nom. nov.) is introduced, and the following new combinations are made: Arthrinium sinense, Chloridium caesium, C. chloroconium, C. gonytrichii, Corollospora marina, C. parvula, C. ramulosa, Juncigena fruticosae, Melanospora simplex, Seimatosporium massarina, Sporoschisma daemonoropis, S. taitense, Torpedospora mangrovei, Xylaria penicilliopsis, and X. termiticola combs. nov.Fil: Réblová, Martina. Institute of Botany of the Academy of Sciences of the Czech Republic. Department of Taxonomy; República ChecaFil: Miller, Andrew N.. University of Illinois; Estados UnidosFil: Rossman, Amy Y.. State University of Oregon; Estados UnidosFil: Seifert, Keith A.. Ottawa Research and Development Centre. Biodiversity (Mycology and Microbiology); CanadáFil: Crous, Pedro W.. CBS-KNAW Fungal Biodiversity Institute; Países BajosFil: Hawksworth, David L.. Universidad Complutense de Madrid; España. Natural History Museum; Reino Unido. Royal Botanic Gardens; Reino UnidoFil: Abdel Wahab, Mohamed A.. Sohag University. Faculty of Science. Department of Botany and Microbiology; EgiptoFil: Cannon, Paul F.. Royal Botanic Gardens; Reino UnidoFil: Daranagama, Dinushani A.. Mae Fah Luang University. Center of Excellence in Fungal Research; TailandiaFil: De Beer, Z. Wilhelm. University of Pretoria. Department of Microbiology and Plant Pathology; SudáfricaFil: Huang, Shi Ke. Mae Fah Luang University. Center of Excellence in Fungal Research; TailandiaFil: Hyde, Kevin D.. Mae Fah Luang University. Center of Excellence in Fungal Research; TailandiaFil: Jayawardena, Ruvvishika. Mae Fah Luang University. Center of Excellence in Fungal Research; TailandiaFil: Jaklitsch, Walter. BOKU-University of Natural Resources and Life Sciences. Department of Forest and Soil Sciences; Austria. Universidad de Viena; AustriaFil: Gareth Jones, E. B.. King Saud University. College of Science. Department of Botany and Microbiology; Arabia SauditaFil: Ju, Yu Ming. Academia Sinica. Institute of Plant and Microbial Biology; ChinaFil: Judith, Caroline. Goethe Universitat Frankfurt; AlemaniaFil: Maharachchikumbura, Sajeewa S. N.. Sultan Qaboos University. College of Agricultural and Marine Sciences. Department of Crop Sciences; OmánFil: Pang, Ka Lai. National Taiwan Ocean University. Institute of Marine Biology and Centre of Excellence for the Oceans; ChinaFil: Petrini, Liliane E.. Società Micologica di Lugano; SuizaFil: Raja, Huzefa A.. University of North Carolina; Estados UnidosFil: Romero, Andrea Irene. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Micología y Botánica. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Micología y Botánica; ArgentinaFil: Shearer, Carol. University of Illinois; Estados UnidosFil: Senanayake, Indunil C.. Mae Fah Luang University. Center of Excellence in Fungal Research; TailandiaFil: Voglmayr, Hermann. Universidad de Viena; AustriaFil: Weir, Bevan S.. Manaaki Whenua Landcare Research; Nueva ZelandaFil: Wijayawarden, Nalin N.. Mae Fah Luang University. Center of Excellence in Fungal Research; Tailandi