20 research outputs found

    A cancer drug atlas enables synergistic targeting of independent drug vulnerabilities.

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    Personalized cancer treatments using combinations of drugs with a synergistic effect is attractive but proves to be highly challenging. Here we present an approach to uncover the efficacy of drug combinations based on the analysis of mono-drug effects. For this we used dose-response data from pharmacogenomic encyclopedias and represent these as a drug atlas. The drug atlas represents the relations between drug effects and allows to identify independent processes for which the tumor might be particularly vulnerable when attacked by two drugs. Our approach enables the prediction of combination-therapy which can be linked to tumor-driving mutations. By using this strategy, we can uncover potential effective drug combinations on a pan-cancer scale. Predicted synergies are provided and have been validated in glioblastoma, breast cancer, melanoma and leukemia mouse-models, resulting in therapeutic synergy in 75% of the tested models. This indicates that we can accurately predict effective drug combinations with translational value

    Rapid Low-Cost Microarray-Based Genotyping for Genetic Screening in Primary Immunodeficiency

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    Background: Genetic tests for primary immunodeficiency disorders (PIDs) are expensive, time-consuming, and not easily accessible in developing countries. Therefore, we studied the feasibility of a customized single nucleotide variant (SNV) microarray that we developed to detect disease-causing variants and copy number variation (CNV) in patients with PIDs for only 40 Euros. Methods: Probes were custom-designed to genotype 9,415 variants of 277 PID-related genes, and were added to the genome-wide Illumina Global Screening Array (GSA). Data analysis of GSA was performed using Illumina GenomeStudio 2.0, Biodiscovery Nexus 10.0, and R-3.4.4 software. Validation of genotype calling was performed by comparing the GSA with whole-genome sequencing (WGS) data of 56 non-PID controls. DNA samples of 95 clinically diagnosed PID patients, of which 60 patients (63%) had a genetically established diagnosis (by Next-Generation Sequencing (NGS) PID panels or Sanger sequencing), w

    Guide-free Cas9 from pathogenic Campylobacter jejuni bacteria causes severe damage to DNA

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    CRISPR-Cas9 systems are enriched in human pathogenic bacteria and have been linked to cytotoxicity by an unknown mechanism. Here, we show that upon infection of human cells, Campylobacter jejuni secretes its Cas9 (CjeCas9) nuclease into their cytoplasm. Next, a native nuclear localization signal enables CjeCas9 nuclear entry, where it catalyzes metal-dependent nonspecific DNA cleavage leading to cell death. Compared to CjeCas9, native Cas9 of Streptococcus pyogenes (SpyCas9) is more suitable for guide-dependent editing. However, in human cells, native SpyCas9 may still cause some DNA damage, most likely because of its ssDNA cleavage activity. This side effect can be completely prevented by saturation of SpyCas9 with an appropriate guide RNA, which is only partially effective for CjeCas9. We conclude that CjeCas9 plays an active role in attacking human cells rather than in viral defense. Moreover, these unique catalytic features may therefore make CjeCas9 less suitable for genome editing applications

    Synthetic oligopeptides related to the β-subunit of human chorionic gonadotropin attenuate inflammation and liver damage after (Trauma) hemorrhagic shock and resuscitation

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    Severe hemorrhagic shock (HS) followed by resuscitation induces a massive inflammatory response, which may culminate into systemic inflammatory response syndrome, multiple organ dysfunction syndrome, and, finally, death. Treatments that effectively prevent this inflammation are limited so far. In a previous study, we demonstrated that synthetic oligopeptides related to the primary structure of human chorionic gonadotropin (HCG) can inhibit the inflammatory response and mortality that follow high-dose LPS-induced inflammation. Considering this powerful antiinflammatory effect, we investigated whether administration of similar synthetic HCG-related oligopeptides (LQGV, AQGV, LAGV) during HS were able to attenuate the inflammatory response associated with this condition. Hemorrhagic shock was induced in rats for 60 min by blood withdrawal until a MAP of 40 mmHg was reached. Rats received a single injection with one of the hCG-related oligopeptides (LQGV, AQGV or LAGV) or 0.9% NaCI solution as control 30 min after induction of HS. Treatment with LQGV, AQGV, or LAGV prevented systemic release of TNF-a and IL-6 and was associated with reduced TNF-a, IL-6, and E-selectin mRNA transcript levels in the liver. LQGV treatment prevented neutrophil infiltration into the liver and was associated with reduced liver damage. Our data suggest that HCG-related oligopeptides, in particular LQGV, have therapeutic potential by attenuating the life-threatening inflammation and organ damage that is associated with (trauma) HS and resuscitation

    The allosteric AKT inhibitor MK2206 shows a synergistic interaction with chemotherapy and radiotherapy in glioblastoma spheroid cultures

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    Glioblastoma multiforme (GBM) is the most common, invasive and deadly primary type of malignant brain tumor. The Phosphatidylinositol-3-Kinase/AKT (PI3K/AKT) pathway is highly active in GBM and has been associated with increased survival and resistance to therapy. The aim of this study is to investigate the effects of AKT inhibition in combination with the current standard of care which consists of irradiation and temozolomide (TMZ) on human malignant glioma cells growing adherent and as multicellular spheroids in vitro. The effects of the allosteric inhibitor MK2206 combined with irradiation and TMZ were assessed on glioma cells growing adherent and as multicellular 3D spheroids. The interaction was studied on proliferation, clonogenic cell survival, cell invasion, -migration and on expression of key proteins in the PI3K-AKT pathway by western blot. A differential effect was found at low- (1 μM) and high dose (10 μM) MK2206. At 1 μM, the inhibitor reduced phosphorylation of Thr308 and Ser473 residues of AKT in both adherent cells and spheroids. Low dose MK2206 delayed spheroid growth and sensitized spheroids to both irradiation and TMZ in a synergistic way (Combination index 5 μM). The data show that a 3D spheroid model show different sensitivity to irradiation when combined with AKT inhibition. Thereby we show that MK2206 has potential synergistic efficacy to the current standard of care for glioma patient

    Additional file 1: Figure S1. of The allosteric AKT inhibitor MK2206 shows a synergistic interaction with chemotherapy and radiotherapy in glioblastoma spheroid cultures

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    A) Number of cells invaded through matrigel after 16 h in the presence of 4 Gy combined with 1 μM (Left) or 10 μM (Right) MK2206. Error bars represent SD over 3 replicates, * = p < 0.05. B) U87 cells untreated. Migration of U87 cells into wound up to 8 h (Left). Migration of U87 cells out of attached spheroids up to 4 days after spheroid plating (Right). (PDF 356 kb

    Antibodies Against Angiotensin II Receptor Type 1 and Endothelin A Receptor Are Associated With an Unfavorable COVID19 Disease Course

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    Background: Lung histopathology demonstrates vasculopathy in a subset of deceased COVID19 patients, which resembles histopathology observed in antibody-mediated lung transplant rejection. Autoantibodies against angiotensin II type 1 receptor (AT1R) and Endothelin receptor Type A (ETAR) have been demonstrated in antibody-mediated rejection and may also be associated with severe COVID19 infection. Objective To assess AT1R and ETAR auto-antibodies in COVID19 patients and controls, and explore their association with disease course. Methods: 65 hospitalized patients with COVID19 infection were included. Clinical and laboratory findings were retrospectively assessed. Patients with unfavorable disease course, admitted at the intensive care unit and/or deceased during hospital admission (n=33) were compared to admitted COVID19 patients with favorable disease course (n=32). The presence of antinuclear antibodies (ANA) and auto-antibodies against AT1R or ETAR in peripheral blood were compared between COVID19 with unfavorable and favorable disease course and age matched controls (n=20). Results: The presence of ANA was not significantly different between COVID19 patients with unfavorable (n=7/33; 21%) and favorable disease course (n=6/32; 19%) (p= 0.804) and controls (n=3/20; 15%). Auto-antibodies against AT1R were significantly increased in unfavorable disease course (median 14.59 U/mL, IQR 11.28 – 19.89) compared to favorable disease course (median 10.67 U/mL, IQR 8.55 – 13.0, p< 0.01). ETAR antibody titers were also significantly increased in unfavorable disease course (median 7.21, IQR 5.0 – 10.45) as compared to favorable disease course (median 4.0, IQR 3.0 – 6.0, p <0.05). Conclusion: Auto-antibodies against AT1R and ETAR are significantly increased in COVID19 patients with an unfavorable disease course

    Identification of MEK162 as a Radiosensitizer for the Treatment of Glioblastoma

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    Glioblastoma (GBM) is a highly aggressive and lethal brain cancer type. PI3K and MAPK inhibitors have been studied pre-clinically in GBM as monotherapy, but not in combination with radiotherapy, which is a key component of the current standard treatment of GBM. In our study, GBM cell lines and patient representative primary cultures were grown as multicellular spheroids. Spheroids were treated with a panel of small-molecule drugs including MK2206, RAD001, BEZ235, MLN0128, and MEK162, alone and in combination with irradiation. Following treatment, spheroid growth parameters (growth rate, volume reduction, and time to regrow), cell-cycle distribution and expression of key target proteins were evaluated. In vivo, the effect of irradiation (3 x 2 Gy) without or with MEK162 (50 mg/kg) was studied in orthotopic GBM8 brain tumor xenografts with endpoints tumor growth and animal survival. The MAPK-targeting agent MEK162 was found to enhance the effect of irradiation as demonstrated by growth inhibition of spheroids. MEK162 downregulated and dephosphorylated the cell-cycle checkpoint proteins CDK1/CDK2/WEE1 and DNA damage response proteins p-ATM/p-CHK2. When combined with radiation, this led to a prolonged DNA damage signal. In vivo data on tumor-bearing animals demonstrated a significantly reduced growth rate, increased growth delay, and prolonged survival time. In addition, RNA expression of responsive cell cultures correlated to mesenchymal stratification of patient expression data. In conclusion, the MAPK inhibitor MEK162 was identified as a radiosensitizer in GBM spheroids in vitro and in orthotopic GBM xenografts in vivo. The data are supportive for implementation of this targeted agent in an early-phase clinical study in GBM patients. (C) 2017 AAC
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