Inhibition of host NOX1 blocks tumor growth and enhances checkpoint inhibitor-based immunotherapy

NADPH oxidases catalyze the production of reactive oxygen species and are involved in physio/pathological processes. NOX1 is highly expressed in colon cancer and promotes tumor growth. To investigate the efficacy of NOX1 inhibition as an anticancer strategy, tumors were grown in immunocompetent, immunodeficient, or NOX1-deficient mice and treated with the novel NOX1-selective inhibitor GKT771. GKT771 reduced tumor growth, lymph/angiogenesis, recruited proinflammatory macrophages, and natural killer T lymphocytes to the tumor microenvironment. GKT771 treatment was ineffective in immunodeficient mice bearing tumors regardless of their NOX-expressing status. Genetic ablation of host NOX1 also suppressed tumor growth. Combined treatment with the checkpoint inhibitor anti-PD1 antibody had a greater inhibitory effect on colon carcinoma growth than each compound alone. In conclusion, GKT771 suppressed tumor growth by inhibiting angiogenesis and enhancing the recruitment of immune cells. The antitumor activity of GKT771 requires an intact immune system and enhances anti-PD1 antibody activity. Based on these results, we propose blocking of NOX1 by GKT771 as a potential novel therapeutic strategy to treat colorectal cancer, particularly in combination with checkpoint inhibition

siRNA screen identifies QPCT as a druggable target for Huntington's disease.

Huntington's disease (HD) is a currently incurable neurodegenerative condition caused by an abnormally expanded polyglutamine tract in huntingtin (HTT). We identified new modifiers of mutant HTT toxicity by performing a large-scale 'druggable genome' siRNA screen in human cultured cells, followed by hit validation in Drosophila. We focused on glutaminyl cyclase (QPCT), which had one of the strongest effects on mutant HTT-induced toxicity and aggregation in the cell-based siRNA screen and also rescued these phenotypes in Drosophila. We found that QPCT inhibition induced the levels of the molecular chaperone αB-crystallin and reduced the aggregation of diverse proteins. We generated new QPCT inhibitors using in silico methods followed by in vitro screening, which rescued the HD-related phenotypes in cell, Drosophila and zebrafish HD models. Our data reveal a new HD druggable target affecting mutant HTT aggregation and provide proof of principle for a discovery pipeline from druggable genome screen to drug development

NOX4 inhibition potentiates immunotherapy by overcoming cancer-associated fibroblast-mediated CD8 T-cell exclusion from tumours

Determining mechanisms of resistance to PD-1/PD-L1 immune checkpoint immunotherapy is key to developing new treatment strategies. Cancer-associated fibroblasts (CAF) have many tumor-promoting functions and promote immune evasion through multiple mechanisms, but as yet, there are no CAF-specific inhibitors clinically available. Here we generated CAF-rich murine tumor models (TC1, MC38, 4T1) to investigate how CAF influence the immune microenvironment and affect response to different immunotherapy modalities (anti-cancer vaccination; TC1, [HPV E7 DNA vaccine];PD-1, MC38) and found that CAFs broadly suppressed response by specifically excluding CD8+ T-cells from tumors (not CD4+ T-cells or macrophages); CD8+ T-cell exclusion was similarly present in CAF-rich human tumors. RNA sequencing of CD8+ T-cells from CAF-rich murine tumors and immunochemistry analysis of human tumors identified significant upregulation of CTLA-4 in the absence of other exhaustion markers; inhibiting CTLA-4 with a non-depleting antibody overcame the CD8+ T-cell exclusion effect without affecting T-regs. We then examined the potential for CAF targeting, focusing on the ROS-producing enzyme NOX4, which is upregulated by CAF in many human cancers, and compared this to TGF-062;1 inhibition, a key regulator of the CAF phenotype. siRNA knockdown or pharmacological inhibition (GKT137831 [Setanaxib]) of NOX4 'normalized' CAF to a quiescent phenotype and promoted intratumoral CD8+T-cell infiltration, overcoming the exclusion effect; TGF-062;1 inhibition could prevent, but not reverse, CAF differentiation. Finally, NOX4 inhibition restored immunotherapy response in CAF-rich tumors. These findings demonstrate that CAF-mediated immunotherapy resistance can be effectively overcome through NOX4 inhibition, and could improve outcome in a broad range of cancers

Targeting Vascular NADPH Oxidase 1 Blocks Tumor Angiogenesis through a PPARα Mediated Mechanism

Reactive oxygen species, ROS, are regulators of endothelial cell migration, proliferation and survival, events critically involved in angiogenesis. Different isoforms of ROS-generating NOX enzymes are expressed in the vasculature and provide distinct signaling cues through differential localization and activation. We show that mice deficient in NOX1, but not NOX2 or NOX4, have impaired angiogenesis. NOX1 expression and activity is increased in primary mouse and human endothelial cells upon angiogenic stimulation. NOX1 silencing decreases endothelial cell migration and tube-like structure formation, through the inhibition of PPARα, a regulator of NF-κB. Administration of a novel NOX-specific inhibitor reduced angiogenesis and tumor growth in vivo in a PPARα dependent manner. In conclusion, vascular NOX1 is a critical mediator of angiogenesis and an attractive target for anti-angiogenic therapies

Presence of functional oxytocin receptors in cultured human myoblasts

In the present report, we provide for the first time evidence that functional oxytocin receptors (OTRs) are present in human myoblasts obtained from clonal cultures of postnatal satellite cells. First, binding studies performed with a non selective vasopressin (AVP) and oxytocin (OT) radioligand indicated the presence of a single class of binding sites. Second, OTR mRNA was detected by RT-PCR analysis whereas transcripts for AVP V(1a), V(1b) or V(2) receptors (V(1a)R, V(1b)R and V(2)R respectively) were not detected. Third, the presence of functional OTRs was evidenced by showing that agonist substances having a high affinity for the human OTR, namely OT, AVP and [Thr(4)Gly(7)]OT, increased the rate of myoblasts fusion and myotubes formation in the cultures, whereas F180, a V(1a)R selective agonist, and dDAVP, a V(2)R agonist had no significant effect on the fusion process. In addition, we show by RT-PCR and immunocytochemistry that the OT gene is expressed in cultured myoblasts. Taken together, our data suggest that OT may act as a paracrine/autocrine agent that stimulates the fusion of human myoblasts in vitro. In vivo, OT may be involved in the differentiation of human skeletal muscle during postnatal growth, and possibly its regeneration following injury

Que sont les solutions fondées sur la nature pour la gestion du risque inondation ? Appropriations d’un concept international en France et aux États-unis

International audienceNature-based Solutions (NbS) have been defined and promoted at the international level, and their implementation in different institutional contexts remains little studied. In this article, we propose to analyze the appropriation of the concept across multiple scales in France and the United States. Through social science research anchored in an international research project, we study the definition and implementation of NBS for flood management policies in both countries, at national/federal and local scales. Our preliminary results show that in France, the concept seems to be very much linked to the definition of the International Union for Conservation of Nature (IUCN) and is mainly supported by biodiversity stakeholders. However, the concept still seems to be little used by flood management stakeholders. On the other hand, in the United States, the concept is being developed by The Nature Conservancy (TNC). The concept seems to be more mobilized by public policies related to flood management. Its appropriation nevertheless distances it from the ambition of preserving biodiversity to embrace the preservation of the environment, a term understood differently by actors and organizations.Les « solutions fondées sur la nature » (SFN) ont été définies et promues à l’échelle internationale, et leur déploiement dans différents contextes institutionnels demeure encore peu étudié. Nous proposons dans cet article d’étudier la déclinaison de ce concept à différentes échelles, en France et aux États-Unis. Grâce à une recherche ancrée en sciences sociales dans le cadre d’un projet international, nous étudions la définition et la mise en oeuvre de SFN pour les politiques de gestion des inondations dans les deux pays, aux échelles nationale/fédérale, et locales. Nos résultats préliminaires montrent qu’en France, le concept semble très lié à la définition de l’Union internationale pour la conservation de la nature (UICN) et est surtout soutenu par les acteurs du monde de la conservation de la nature. Au contraire, le concept semble encore peu approprié par les acteurs de la gestion des inondations. En revanche, aux États-Unis, c’est l’organisation The Nature Conservancy (TNC) qui promeut le concept. Le concept semble davantage mobilisé par les politiques publiques liées à la gestion des inondations. Son appropriation semble néanmoins l’éloigner de l’ambition de préservation de la biodiversité

Les Solutions fondées sur la Nature (SfN) pour la gestion des risques liés à l’eau : quelle institutionnalisation du concept en France ?

RÉSUMÉCirculant dans les arènes internationales, le concept de Solutions fondées sur la Nature (SfN) est apparu au cours de la dernière décennie dans les politiques environnementales et des risques liés à l’eau. Les SfN doivent permettre de répondre à des défis sociétaux tout en préservant ou favorisant la biodiversité. Nous proposons ici de suivre l’institutionnalisation du concept en France en nous appuyant sur des méthodes de sciences humaines et sociales. Au niveau national, nous identifions une institutionnalisation assez forte du concept dans les politiques publiques à travers différents vecteurs d’intégration. Les cas d’étude montrent des modalités d’appropriation du concept variables à l’échelle locale, oscillant entre une absence de mobilisation du concept malgré des pratiques qui semblent similaires à la définition de l’UICN, à un usage du concept stratégique dans certains contextes. Afin d’expliquer cette différence d’appropriation, nous avançons deux hypothèses. La première concerne l’« innovation conceptuelle » que représente les SfN, qui semble adaptée aux modes de fonctionnement des politiques publiques à l’échelle nationale, mais qui trouve certaines limites dans sa déclinaison à l’échelle locale. La seconde concerne les instruments d’action publique mobilisés pour promouvoir le concept, qui ne semblent pas permettre d’aboutir à un processus d’intéressement des acteurs locaux

NADPH oxidases as drug targets and biomarkers in neurodegenerative diseases: what is the evidence?

Neurodegenerative disease are frequently characterized by microglia activation and/or leukocyte infiltration in the parenchyma of the central nervous system and at the molecular level by increased oxidative modifications of proteins, lipids and nucleic acids. NADPH oxidases (NOX) emerged as a novel promising class of pharmacological targets for the treatment of neurodegeneration due to their role in oxidant generation and presumably in regulating microglia activation. The unique function of NOX is the generation of superoxide anion (O2•-) and hydrogen peroxide (H2O2). However in the context of neuroinflammation, they present paradoxical features since O2•-/H2O2 generated by NOX and/or secondary reactive oxygen species (ROS) derived from O2•-/H2O2 can either lead to neuronal oxidative damage or resolution of inflammation. The role of NOX enzymes has been investigated in many models of neurodegenerative diseases by using either genetic or pharmacological approaches. In the present review we provide a critical assessment of recent findings related to the role of NOX in the CNS as well as how the field has advanced over the last 5 years. In particular, we focus on the data derived from the work of a consortium (Neurinox) funded by the European Commission's Programme 7 (FP7). We discuss the evidence gathered from animal models and human samples linking NOX expression/activity with neuroinflammation in neurodegenerative diseases, such as amyotrophic lateral sclerosis (ALS) and Creutzfeldt-Jakob disease as well as autoimmune demyelinating diseases like multiple sclerosis (MS) and chronic inflammatory demyelinating polyneuropathy (CIDP). We address the possibility to use measurement of the activity of the NOX2 isoform in blood samples as biomarker of disease severity and treatment efficacy in neurodegenerative disease. Finally we clarify key controversial aspects in the field of NOX, such as NOX cellular expression in the brain, measurement of NOX activity, impact of genetic deletion of NOX in animal models of neurodegeneration and specificity of NOX inhibitors