Molecular characterization of membrane steroid receptors in hormone-sensitive cancers

Cancer is one of the most common causes of death worldwide, and its development is a re-sult of the complex interaction of genetic factors, environmental cues, and aging. Hormone-sensitive cancers depend on the action of one or more hormones for their development and progression. Sex steroids and corticosteroids can regulate different physiological functions, including metabolism, growth, and proliferation, through their interaction with specific nuclear receptors, that can tran-scriptionally regulate target genes via their genomic actions. Therefore, interference with hormones’ activities, e.g., deregulation of their production and downstream pathways or the exposition to exogenous hormone-active substances such as endocrine-disrupting chemicals (EDCs), can affect the regulation of their correlated pathways and trigger the neoplastic transformation. Although nuclear receptors account for most hormone-related biologic effects and their slow genomic responses are well-studied, less-known membrane receptors are emerging for their ability to mediate steroid hormones effects through the activation of rapid non-genomic responses also involved in the development of hormone-sensitive cancers. This review aims to collect pre-clinical and clinical data on these extranuclear receptors not only to draw attention to their emerging role in cancer development and progression but also to highlight their dual role as tumor microenvironment players and potential candidate drug targets

P072 The involvement of extracellular Nicotinamide Phosphoribosyltransferase (eNAMPT) and Nicotinate Phosphoribosyltransferase (eNAPRT) in inflammatory bowel disease

Abstract Background Nicotinamide phosphoribosyltrasferase (NAMPT) is a pleiotropic enzyme which catalyses the first and rate-limiting step in the biosynthesis of NAD. It is present in two different forms: an intracellular form, called iNAMPT, (Chiarugi et al., 2012), and an extracellular form, eNAMPT. eNAMPT is considered an important factor for granulocyte-colony stimulating factor-(G-CSF)-induced myeloid differentiation, with paracrine and autocrine effects on different cell types (i.e. immune and cancer cells), binding TLR4. NAMPT is structurally and functionally related to the enzyme nicotinate phosphoribosyltransferase (iNAPRT), which is rate-limiting in the NAD salvage pathway that starts from nicotinic acid. The NAD biosynthetic pathways controlled by NAMPT and NAPRT are closely interconnected and can compensate for each other. Also, NAPRT is identified as an extracellular ligand (eNAMPRT) for TLR4 and a mediator of inflammation (Managò et al., 2020). Importantly, iNAMPT and eNAMPT levels are increased in several pathologies, included inflammatory bowel disease (IBD). It has been reported that serum eNAMPT levels correlate with the stage of the pathology: in an active state of the disease the levels of NAMPT are very high, however its levels are partially reduced in a remission stage (Moschen et al., 2007). Methods First, we investigated the role of eNAMPT and eNAPRT in murine IBD models (especially in DNBS and DSS model). We took into account phenotypic effect as weight loss and colon shortening, but also the reduction of mRNA of inflammatory genes with RT-PCR, tissue damage with H&E and IHC analysis and systemic and local production through colon explant. Secondly, we determined serum eNAMPT and eNAPRT levels in a cohort of adult IBD patients. Results Both eNAMPT and eNAPRT have been found elevated in 180 IBD patients, as proinflammatory marker of the pathologies. These levels are also elevated in serum and colonic explant of DSS and DNBS preclinical models, associated to an active state of the disease, as a pro-inflammatory response developed locally and systemically. Moreover, we performed ELISA analysis on sera of 100 IBD patients, eligible for anti-TNF treatment, both pediatric and adults. Serum eNAMPT levels are increased before the treatment, responsive patients verified a reduction of these levels, while no-responsive ones verified higher levels. Conclusion eNAMPT and eNAPRT could be considered pro-inflammatory markers of IBD and possible druggable targets

Neutralization of extracellular NAMPT (nicotinamide phosphoribosyltransferase) ameliorates experimental murine colitis

Extracellular nicotinamide phosphoribosyltransferase (eNAMPT) is increased in inflammatory bowel disease (IBD) patients, and its serum levels correlate with a worse prognosis. In the present manuscript, we show that eNAMPT serum levels are increased in IBD patients that fail to respond to anti-TNF\u3b1 therapy (infliximab or adalimumab) and that its levels drop in patients that are responsive to these therapies, with values comparable with healthy subjects. Furthermore, eNAMPT administration in dinitrobenzene sulfonic acid (DNBS)-treated mice exacerbates the symptoms of colitis, suggesting a causative role of this protein in IBD. To determine the druggability of this cytokine, we developed a novel monoclonal antibody (C269) that neutralizes in vitro the cytokine-like action of eNAMPT and that reduces its serum levels in rodents. Of note, this newly generated antibody is able to significantly reduce acute and chronic colitis in both DNBS- and dextran sulfate sodium (DSS)-induced colitis. Importantly, C269 ameliorates the symptoms by reducing pro-inflammatory cytokines. Specifically, in the lamina propria, a reduced number of inflammatory monocytes, neutrophils, Th1, and cytotoxic T lymphocytes are found upon C269 treatment. Our data demonstrate that eNAMPT participates in IBD and, more importantly, that eNAMPT-neutralizing antibodies are endowed with a therapeutic potential in IBD. Key messages: What are the new findings?Higher serum eNAMPT levels in IBD patients might decrease response to anti-TNF therapy.The cytokine-like activity of eNAMPT may be neutralized with a monoclonal antibody.Neutralization of eNAMPT ameliorates acute and chronic experimental colitis.Neutralization of eNAMPT limits the expression of IBD inflammatory signature.Neutralization of eNAMPT impairs immune cell infiltration in lamina propria

The NAMPT inhibitor FK866 reverts the damage in spinal cord injury

<p>Abstract</p> <p>Background</p> <p>Emerging data implicate nicotinamide phosphoribosyl transferase (NAMPT) in the pathogenesis of cancer and inflammation. NAMPT inhibitors have proven beneficial in inflammatory animal models of arthritis and endotoxic shock as well as in autoimmune encephalitis. Given the role of inflammatory responses in spinal cord injury (SCI), the effect of NAMPT inhibitors was examined in this setting.</p> <p>Methods</p> <p>We investigated the effects of the NAMPT inhibitor FK866 in an experimental compression model of SCI.</p> <p>Results</p> <p>Twenty-four hr following induction of SCI, a significant functional deficit accompanied widespread edema, demyelination, neuron loss and a substantial increase in TNF-α, IL-1β, PAR, NAMPT, Bax, MPO activity, NF-κB activation, astrogliosis and microglial activation was observed. Meanwhile, the expression of neurotrophins BDNF, GDNF, NT3 and anti-apoptotic Bcl-2 decreased significantly. Treatment with FK866 (10 mg/kg), the best known and characterized NAMPT inhibitor, at 1 h and 6 h after SCI rescued motor function, preserved perilesional gray and white matter, restored anti-apoptotic and neurotrophic factors, prevented the activation of neutrophils, microglia and astrocytes and inhibited the elevation of NAMPT, PAR, TNF-α, IL-1β, Bax expression and NF-κB activity.</p> <p>We show for the first time that FK866, a specific inhibitor of NAMPT, administered after SCI, is capable of reducing the secondary inflammatory injury and partly reduce permanent damage. We also show that NAMPT protein levels are increased upon SCI in the perilesional area which can be corrected by administration of FK866.</p> <p>Conclusions</p> <p>Our findings suggest that the inflammatory component associated to SCI is the primary target of these inhibitors.</p

NAMPT: A pleiotropic modulator of monocytes and macrophages

Nicotinamide phosphoribosyltransferase (NAMPT) is the bottleneck enzyme of the NAD salvage pathway and thereby is a controller of intracellular NAD concentrations. It has been long known that the same enzyme can be secreted by a number of cell types and acts as a cytokine, although its receptor is at present unknown. Investigational compounds have been developed that target the enzymatic activity as well as the extracellular action (i.e. neutralizing antibodies). The present contribution reviews the evidence that links intracellular and extracellular NAMPT to myeloid biology, for example governing monocyte/macrophage differentiation, polarization and migration. Furthermore, it reviews the evidence that links this protein to some disorders in which myeloid cells have a prominent role (acute infarct, inflammatory bowel disease, acute lung injury and rheumatoid arthritis) and the data showing that inhibition of the enzymatic activity or the neutralization of the cytokine is beneficial in preclinical animal models

Prostaglandin E2 and cancer: Insight into tumor progression and immunity

The involvement of inflammation in cancer progression has been the subject of research for many years. Inflammatory milieu and immune response are associated with cancer progression and recurrence. In different types of tumors, growth and metastatic phenotype characterized by the epithelial mesenchymal transition (EMT) process, stemness, and angiogenesis, are increasingly associated with intrinsic or extrinsic inflammation. Among the inflammatory mediators, prostaglandin E2 (PGE2) supports epithelial tumor aggressiveness by several mechanisms, including growth promotion, escape from apoptosis, transactivation of tyrosine kinase growth factor receptors, and induction of angiogenesis. Moreover, PGE2 is an important player in the tumor microenvironment, where it suppresses antitumor immunity and regulates tumor immune evasion, leading to increased tumoral progression. In this review, we describe the current knowledge on the pro-tumoral activity of PGE2 focusing on its role in cancer progression and in the regulation of the tumor microenvironment