Nitric Oxide and Immune Responses in Cancer: Searching for New Therapeutic Strategies

2021 ◽  
Vol 28 ◽  
Author(s):  
Adeleh Sahebnasagh ◽  
Fatemeh Saghafi ◽  
Sina Negintaji ◽  
Tingyan Hu ◽  
Mojtaba Shabani-Boroujeni ◽  
...  

: In recent years, there has been an increasing interest in understanding the mysterious functions of nitric oxide (NO) and how this pleiotropic signaling molecule contributes to tumorigenesis. This review attempts to expose and discuss the information available on the immunomodulatory role of NO in cancer and recent approaches to the role of NO donors in the area of immunotherapy. To address the goal, the following databases were searched to identify relevant literature concerning empirical evidence: The Cochrane Library, Pubmed, Medline, EMBASE from 1980 through March 2020. Valuable attempts have been made to develop distinctive NO-based cancer therapy. Although the data do not allow generalization, the evidence seems to indicate that low / moderate levels may favor tumorigenesis while higher levels would exert anti-tumor effects. In this sense, the use of NO donors could have an important therapeutic potential within immunotherapy, although there are still no clinical trials. The emerging understanding of NO-regulated immune responses in cancer may help unravel the recent features of this “double-edged sword” in cancer physiological and pathologic processes and its potential use as a therapeutic agent for cancer treatment. In short, in this review, we discuss the complex cellular mechanism in which NO, as a pleiotropic signaling molecule, participates in cancer pathophysiology. We also debate the dual role of NO in cancer and tumor progression, and clinical approaches for inducible nitric oxide synthase (iNOS) based therapy against cancer.

1999 ◽  
Vol 276 (6) ◽  
pp. G1313-G1316 ◽  
Author(s):  
Marcelo N. Muscará ◽  
John L. Wallace

Nitric oxide is a crucial mediator of gastrointestinal mucosal defense, but, paradoxically, it also contributes to mucosal injury in several situations. Inhibitors of nitric oxide synthesis and compounds that release nitric oxide have been useful pharmacological tools for evaluating the role of nitric oxide in gastrointestinal physiology and pathophysiology. Newer inhibitors with selectivity for one of the isoforms of nitric oxide synthase are even more powerful tools and may have utility as therapeutic agents. Also, agents that can scavenge nitric oxide or peroxynitrite are promising as drugs to prevent nitric oxide-associated tissue injury. Compounds that release nitric oxide in small amounts over a prolonged period of time may also be very useful for prevention of gastrointestinal injury associated with shock and with the use of drugs that have ulcerogenic effects. Indeed, the coupling of a nitric oxide-releasing moiety to nonsteroidal anti-inflammatory drugs has proven to be a valid means of substantially reducing the gastrointestinal toxicity of these drugs without decreasing their efficacy.


2004 ◽  
Vol 359 (1446) ◽  
pp. 1021-1044 ◽  
Author(s):  
Claire E. Sears ◽  
Euan A. Ashley ◽  
Barbara Casadei

Nitric oxide (NO) has been shown to regulate cardiac function, both in physiological conditions and in disease states. However, several aspects of NO signalling in the myocardium remain poorly understood. It is becoming increasingly apparent that the disparate functions ascribed to NO result from its generation by different isoforms of the NO synthase (NOS) enzyme, the varying subcellular localization and regulation of NOS isoforms and their effector proteins. Some apparently contrasting findings may have arisen from the use of non–isoform–specific inhibitors of NOS, and from the assumption that NO donors may be able to mimic the actions of endogenously produced NO. In recent years an at least partial explanation for some of the disagreements, although by no means all, may be found from studies that have focused on the role of the neuronal NOS (nNOS) isoform. These data have shown a key role for nNOS in the control of basal and adrenergically stimulated cardiac contractility and in the autonomic control of heart rate. Whether or not the role of nNOS carries implications for cardiovascular disease remains an intriguing possibility requiring future study.


2018 ◽  
Vol 16 (2) ◽  
pp. 194-199
Author(s):  
Wioletta Ratajczak-Wrona ◽  
Ewa Jablonska

Background: Polymorphonuclear neutrophils (PMNs) play a crucial role in the innate immune system’s response to microbial pathogens through the release of reactive nitrogen species, including Nitric Oxide (NO). </P><P> Methods: In neutrophils, NO is produced by the inducible Nitric Oxide Synthase (iNOS), which is regulated by various signaling pathways and transcription factors. N-nitrosodimethylamine (NDMA), a potential human carcinogen, affects immune cells. NDMA plays a major part in the growing incidence of cancers. Thanks to the increasing knowledge on the toxicological role of NDMA, the environmental factors that condition the exposure to this compound, especially its precursors- nitrates arouse wide concern. Results: In this article, we present a detailed summary of the molecular mechanisms of NDMA’s effect on the iNOS-dependent NO production in human neutrophils. Conclusion: This research contributes to a more complete understanding of the mechanisms that explain the changes that occur during nonspecific cellular responses to NDMA toxicity.


Circulation ◽  
1997 ◽  
Vol 96 (9) ◽  
pp. 3104-3111 ◽  
Author(s):  
Yoshihiro Fukumoto ◽  
Hiroaki Shimokawa ◽  
Toshiyuki Kozai ◽  
Toshiaki Kadokami ◽  
Kouichi Kuwata ◽  
...  

2000 ◽  
Vol 279 (6) ◽  
pp. F1110-F1115 ◽  
Author(s):  
Lieming Xu ◽  
Ethan P. Carter ◽  
Mamiko Ohara ◽  
Pierre-Yves Martin ◽  
Boris Rogachev ◽  
...  

Cirrhosis is typically associated with a hyperdynamic circulation consisting of low blood pressure, low systemic vascular resistance (SVR), and high cardiac output. We have recently reported that nonspecific inhibition of nitric oxide synthase (NOS) with nitro-l-arginine methyl ester reverses the hyperdynamic circulation in rats with advanced liver cirrhosis induced by carbon tetrachloride (CCl4). Although an important role for endothelial NOS (eNOS) is documented in cirrhosis, the role of neuronal NOS (nNOS) has not been investigated. The present study was carried out to specifically investigate the role of nNOS during liver cirrhosis. Specifically, physiological, biochemical, and molecular approaches were employed to evaluate the contribution of nNOS to the cirrhosis-related hyperdynamic circulation in CCl4-induced cirrhotic rats with ascites. Cirrhotic animals had a significant increase in water and sodium retention. In the aorta from cirrhotic animals, both nNOS protein expression and cGMP concentration were significantly elevated compared with control. Treatment of cirrhotic rats for 7 days with the specific nNOS inhibitor 7-nitroindazole (7-NI) normalized the low SVR and mean arterial pressure, elevated cardiac index, and reversed the positive sodium balance. Increased plasma arginine vasopressin concentrations in the cirrhotic animals were also repressed with 7-NI in association with diminished water retention. The circulatory changes were associated with a reduction in aortic nNOS expression and cGMP. However, 7-NI treatment did not restore renal function in cirrhotic rats (creatinine clearance: 0.76 ± 0.03 ml · min−1· 100 g body wt−1in cirrhotic rats vs. 0.79 ± 0.05 ml · min−1· 100 g body wt−1in cirrhotic rats+7-NI; P NS.). Taken together, these results indicate that nNOS-derived NO contributes to the development of the hyperdynamic circulation and fluid retention in cirrhosis.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Merle T. Bartling ◽  
Susanne Thümecke ◽  
José Herrera Russert ◽  
Andreas Vilcinskas ◽  
Kwang-Zin Lee

AbstractHoneybees are essential pollinators of many agricultural crops and wild plants. However, the number of managed bee colonies has declined in some regions of the world over the last few decades, probably caused by a combination of factors including parasites, pathogens and pesticides. Exposure to these diverse biotic and abiotic stressors is likely to trigger immune responses and stress pathways that affect the health of individual honeybees and hence their contribution to colony survival. We therefore investigated the effects of an orally administered bacterial pathogen (Pseudomonas entomophila) and low-dose xenobiotic pesticides on honeybee survival and intestinal immune responses. We observed stressor-dependent effects on the mean lifespan, along with the induction of genes encoding the antimicrobial peptide abaecin and the detoxification factor cytochrome P450 monooxygenase CYP9E2. The pesticides also triggered the immediate induction of a nitric oxide synthase gene followed by the delayed upregulation of catalase, which was not observed in response to the pathogen. Honeybees therefore appear to produce nitric oxide as a specific defense response when exposed to xenobiotic stimuli. The immunity-related and stress-response genes we tested may provide useful stressor-dependent markers for ecotoxicological assessment in honeybee colonies.


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