Project description:The bryophyte was collected and dried. Aqueous extract was prepared and different concentration of the extracts were treat against Ascardia galli, chicken nematode and Trichostrongylus, sheep nematode. Control was maintained for both. The control and treated samples were further processed to study the gene expression by isolating and sequencing mRNA using Illumina next-gen sequencing.
Project description:The aim of this study was to investigate the response in gene expression before and after exposure to the Benzimidazoles drug flubendazole in adult female Ascaridia galli worms. The nematode Ascaridia galli (order Ascaridida) is an economically important intestinal parasite responsible for increased food consumption, reduced performance, and mortality in commercial poultry production. Parasite control relies on repeated use of dewormers (anthelmintics). Benzimidazoles are currently the only anthelmintic registered against A. galli in the EU and there is an obvious risk that overuse of one drug class may lead to resistance. The worms were collected from a commercial laying hen farms before and on day three during a treatment period of 7 days with flubendazole.
Project description:Anthelmintic resistance is a threat to global food security. In order to alleviate the selection pressure for resistance and maintain drug efficacy, management strategies increasingly aim to preserve a proportion of the parasite population in 'refugia', unexposed to treatment. While persuasive in its logic, and widely advocated as best practice, evidence for the ability of refugia-based approaches to slow the development of drug resistance in parasitic helminths is currently limited. Moreover, the conditions needed for refugia to work, or how transferable those are between parasite-host systems, are not known. This review, born of an international workshop, seeks to deconstruct the concept of refugia and examine its assumptions and applicability in different situations. We conclude that factors potentially important to refugia, such as the fitness cost of drug resistance, the degree of mixing between parasite sub-populations selected through treatment or not, and the impact of parasite life-history, genetics and environment on the population dynamics of resistance, vary widely between systems. The success of attempts to generate refugia to limit anthelmintic drug resistance are therefore likely to be highly dependent on the system in hand. Additional research is needed on the concept of refugia and the underlying principles for its application across systems, as well as empirical studies within systems that prove and optimise its usefulness.
| S-EPMC6531808 | biostudies-literature
Project description:Evaluation of resistance mechanism of barnyardgrass [Echinochloa crus-galli (L.) P. Beauv.] to cyhalofop-butyl
Project description:Bromodomain and Extra Terminal protein (BET) inhibitors are first-in-class targeted therapies that deliver a new therapeutic paradigm by directly targeting epigenetic readers1,2. Early clinical trials have shown significant promise especially in acute myeloid leukaemia (AML)3; therefore the evaluation of resistance mechanisms, an inevitable consequence of cancer therapies, is of utmost importance to optimise the clinical efficacy of these drugs. Using primary murine stem and progenitor cells immortalised with MLL-AF9, we have used an innovative approach to generate 20 cell lines derived from single cell clones demonstrating stable resistance, in vitro and in vivo, to the prototypical BET inhibitor, I-BET. Resistance to I-BET confers cross-resistance to chemically distinct BET inhibitors such as JQ1, as well as resistance to genetic knockdown of BET proteins. Resistance is not mediated through increased drug efflux or metabolism but is demonstrated to emerge from leukaemia stem cells (LSC). Resistant clones display a leukaemic granulocyte-macrophage progenitor (L-GMP) phenotype (Lin-, Sca-, cKit+, CD34+, Fc³RII/RIII+) and functionally exhibit increased clonogenic capacity in vitro and markedly shorter leukaemia latency in vivo. Chromatin bound BRD4 is globally reduced in resistant cells, however expression of key target genes such as MYC remains unaltered, highlighting the existence of alternative mechanisms to regulate transcription. We demonstrate that resistance to BET inhibitors is in part a consequence of increased Wnt/²-catenin signaling. Negative regulation of this pathway results in differentiation of resistant cells into mature leukaemic blasts, inhibition of MYC expression and restoration of sensitivity to I-BET in vitro and in vivo. Finally, we show that the sensitivity of primary human AML cells to I-BET correlates with the baseline expression of Wnt/²-catenin target genes. Together these findings provide novel insights into the biology of AML, highlight the potential therapeutic limitations of BET inhibitors and identify strategies that may overcome resistance and enhance the clinical utility of these unique targeted therapies. Comparison of iBET resistant and sensitive cell lines
Project description:This study is designed to evaluate the mechanism(s) of resistance to the anti-epidermal growth factor receptor (EGFR) antibody panitumumab given in combination with irinotecan in metastatic colorectal carcinoma (mCRC) patients with wild-type Kirsten rat sarcoma-2 virus oncogene (KRAS) tumor status at the time of initial diagnosis.
Project description:We have undertaken a detailed analysis of the biotransformation of five of the most therapeutically important benzimidazole anthelmintics - albendazole (ABZ), mebendazole (MBZ), thiabendazole (TBZ), oxfendazole (OxBZ) and fenbendazole (FBZ) - in Caenorhabditis elegans. As a step to identifying nematode enzymes potentially responsible for benzimidazole biotransformation, we characterised the transcriptomic response to each of the benzimidazole drugs using the C. elegans strain CB3474 ben-1(e1880)III in order to minimize general phenotypic and stress responses to the drug. In the case of albendazole (ABZ), mebendazole (MBZ), thiabendazole (TBZ), and oxfendazole (OxBZ) - the shared transcriptomic response was dominated by the up- regulation classical xenobiotic response genes.
Project description:Like other pathogens, parasitic helminths can rapidly evolve resistance to drug treatment. Understanding the genetic basis of anthelmintic drug resistance in parasitic nematodes is key to tracking its spread and improving the efficacy and sustainability of parasite control. Here, we use an in vivo genetic cross between drug-susceptible and multi-drug-resistant strains of Haemonchus contortus in a natural host-parasite system to simultaneously map resistance loci for the three major classes of anthelmintics. This approach identifies new alleles for resistance to benzimidazoles and levamisole and implicates the transcription factor cky-1 in ivermectin resistance. This gene is within a locus under selection in ivermectin-resistant populations worldwide; expression analyses and functional validation using knockdown experiments support that cky-1 is associated with ivermectin survival. Our work demonstrates the feasibility of high-resolution forward genetics in a parasitic nematode and identifies variants for the development of molecular diagnostics to combat drug resistance in the field.
Project description:PARP inhibitor and platinum based drugs such as cisplatin are promising therapies for triple negative breast cancer and exploit the deficiencies in BRCA1 or BRCA2, or homologous recombination repair defects. However, PARP inhibitor resistance is proven to be a major clinical problem. Acquired PARP inhibitor resistance has been linked with co-resistance to platinum-based drugs. To determine how acquired olaparib resistance affects cisplatin response and whether this is influenced by their BRCA1 status, we performed RNAseq transcriptome analysis of isogenic triple negative breast cancer models of olaparib resistance with normal and mutant BRCA1.