Lipopolysaccharides increase the risk of colorectal cancer recurrence and metastasis due to the induction of neutrophil extracellular traps after curative resection

Targeting neutrophil extracellular traps in cancer progression and metastasis

Neutrophils serve as pivotal effectors and regulators of the intricate immune system. Their contributions are indispensable, encompassing the obliteration of pathogens and a significant role in both cancer initiation and progression. Conversely, malignancies profoundly affect neutrophil activity, maturation, and lifespans. Cancer cells manipulate their biology to enhance or suppress the key functions of neutrophils. This manipulation is one of the most remarkable defensive mechanisms used by neutrophils, including the formation of neutrophil extracellular traps (NETs). NETs are filamentous structures comprising DNA, histones, and proteins derived from cytotoxic granules. In this review, we discuss the bidirectional interplay in which cancer elicits NET formation, and NETs concurrently facilitate cancer progression. Here, we discuss how vascular dysfunction and thrombosis induced by neutrophils and NETs contribute to an elevated risk of mortality from cardiovascular complications in patients with cancer. Ultimately, we propose a series of therapeutic strategies that hold promise for effectively targeting NETs in clinical settings.

MPO and its role in cancer, cardiovascular and neurological disorders: An update

Myeloperoxidase (MPO) is an enzyme that contains a heme group, found mostly in neutrophils and in small amounts in monocytes and plays a major role in their anti-microbial activity. However, excessive levels of MPO have been linked to various disorders and identified as a major cause of tissue destruction. Inhibiting its activity can reduce the severity and extent of tissue damage. Over activity of MPO during chronic inflammation has been shown to be involved in tumorigenesis by inducing a hyper-mutagenic environment through oxidant interaction with DNA, causing DNA modification. Vascular endothelium is one of the most important targets of MPO and high levels have been associated with increased rates of cardiomyopathy, ischemic stroke, heart failure, myocardial infarction, and atrial fibrillation. Therefore, it may be considered a therapeutic target in the treatment of cardiovascular disorders. MPO also participates in the pathogenesis of neurodegenerative diseases. For example, an increase in MPO levels has been observed in the brain tissue of patients with Alzheimer's, Multiple sclerosis (MS), and Parkinson's diseases. In Alzheimer's disease, active MPO is mostly found in the location of beta amyloids and microglia. Therefore, targeting MPO may be a potential treatment and prevention strategy for neurological disorders. This review will discuss MPO's physiological and pathological role in cancer, cardiovascular, and neurological disorders.

Inflammation and Immunity in Liver Neoplasms: Implications for Future Therapeutic Strategies

Over the past two decades, the "hallmarks of cancer" have revolutionized cancer research and highlighted the crucial roles of inflammation and immunity. Protumorigenic inflammation promotes cancer development along with inhibition of antitumor immunity, shaping the tumor microenvironment (TME) toward a tumor-permissive state and further enhancing the malignant potential of cancer cells. This immunosuppressive TME allows tumors to evade immunosurveillance. Thus, understanding the complex interplay between tumors and the immune system within the TME has become pivotal, especially with the advent of immunotherapy. Although immunotherapy has achieved notable success in many malignancies, primary liver cancer, particularly hepatocellular carcinoma, presents unique challenges. The hepatic immunosuppressive environment poses obstacles to the effectiveness of immunotherapy, along with high mortality rates and limited treatment options for patients with liver cancer. In this review, we discuss current understanding of the complex immune-mediated mechanisms underlying liver neoplasms, focusing on hepatocellular carcinoma and liver metastases. We describe the molecular and cellular heterogeneity within the TME, highlighting how this presents unique challenges and opportunities for immunotherapy in liver cancers. By unraveling the immune landscape of liver neoplasms, this review aims to contribute to the development of more effective therapeutic interventions, ultimately improving clinical outcomes for patients with liver cancer.

Neutrophils: From Inflammatory Bowel Disease to Colitis-Associated Colorectal Cancer

Inflammatory bowel disease (IBD) is a non-specific inflammatory disease of digestive tract, primarily manifesting as ulcerative colitis (UC) and Crohn's disease (CD). The precise etiology of IBD remains elusive. The interplay of genetic factors, environmental influences, and intestinal microbiota contributes to the establishment of an uncontrolled immune environment within the intestine, which can progressively lead to atypical hyperplasia and ultimately to malignancy over a long period. This colorectal malignant tumor that arises from chronic IBD is referred to as colitis-associated colorectal cancer (CAC). Dysregulation in the quantity and functionality of neutrophils plays a significant role in the onset, progression, and recurrence of IBD, as well as in the transition from IBD to CAC. Neutrophils affect the pathophysiology of IBD through various mechanisms, including the production of reactive oxygen species (ROS), degranulation, the release of inflammatory mediators and chemokines, and the formation of neutrophil extracellular traps (NETs). These processes can induce DNA mutations, thereby facilitating the development of colon cancer. Given the incomplete understanding of the disease mechanisms underlying IBD and CAC, effective treatment and prevention strategies remain challenging. Consequently, a comprehensive review of the functional roles of neutrophils in IBD and CAC is essential for advancing our understanding of IBD pathogenesis and identifying potential therapeutic targets.

Lipopolysaccharide-Educated Cancer-Associated Fibroblasts Facilitate Malignant Progression of Ovarian Cancer Cells via the NF-kB/IL-6/JAK2 Signal Transduction

Gram-negative bacteria increase in ovarian cancer (OC) tissues, but its association with OC progression remains largely unknown. The present study aimed to investigate whether and how cancer-associated fibroblasts (CAFs) pretreated by the main components of bacterial outer membrane lipopolysaccharide (LPS) influence the malignancy of OC cells. Specifically, the culture medium of LPS-preconditioned CAFs (LPS-CM) further accelerated cell proliferation, colony formation and tumorigenesis of OC cells SKOV3 and HEY A8, compared with culture medium of CAFs. Next, we found that LPS pretreatment activated the nuclear factor-kappa B (NF-kB) pathway in CAFs to secret cytokines, including interleukin 1β (IL-1β), interleukin 6 (IL-6), vascular endothelial growth factor (VEGF), etc. Neutralization of IL-6 in LPS-CM abolished the promoting effect of LPS-CM on cell proliferation, survival and epithelial-mesenchymal transition (EMT) in SKOV3 and HEY A8 cells. Mechanistically, LPS-CM activated the Janus kinases 2 (JAK2)/signal transducer and activator of transcription 3 (STAT3) signaling pathway, while application with JAK2 inhibitor also reversed the promoting effect of LPS-CM on malignancy of OC cells. In summary, LPS-pretreated CAFs IL-6-dependently accelerate OC progression via activating the JAK2/STAT3 signal pathway, which enriches our understanding of the molecular mechanisms underlying ovaries-colonized gram-negative bacteria in OC progression.

Tumor metastasis and recurrence: The role of perioperative NETosis

Although surgical resection of tumor mass remains the mainstay of curative therapeutic management for solid tumors, accumulating studies suggest that these procedures promote tumor recurrence and metastasis. Regarded as the first immune cells to fight against infectious or inflammatory insults from surgery, neutrophils along with their ability of neutrophil extracellular traps (NETs) production has attracted much attention. A growing body of evidence suggests that NETs promote cancer metastasis by stimulating various stages, including local invasion, colonization, and growth. Therefore, we discussed the mechanism of NETosis induced by surgical stress and tumor cells, and the contribution of NETs on tumor metastasis: aid in the tumor cell migration and proliferation, evasion of immune surveillance, circulating tumor cell adhesion and establishment of a metastatic niche. Lastly, we summarized existing NET-targeting interventions, offering recent insights into potential targets for clinical intervention.

Endothelial Dysfunction and Liver Cirrhosis: Unraveling of a Complex Relationship

Endothelial dysfunction (ED) is the in the background of multiple metabolic diseases and a key process in liver disease progression and cirrhosis decompensation. ED affects liver sinusoidal endothelial cells (LSECs) in response to different damaging agents, causing their progressive dedifferentiation, unavoidably associated with an increase in intrahepatic resistance that leads to portal hypertension and hyperdynamic circulation with increased cardiac output and low peripheral artery resistance. These changes are driven by a continuous interplay between different hepatic cell types, invariably leading to increased reactive oxygen species (ROS) formation, increased release of pro-inflammatory cytokines and chemokines, and reduced nitric oxide (NO) bioavailability, with a subsequent loss of proper vascular tone regulation and fibrosis development. ED evaluation is often accomplished by serum markers and the flow-mediated dilation (FMD) measurement of the brachial artery to assess its NO-dependent response to shear stress, which usually decreases in ED. In the context of liver cirrhosis, the ED assessment could help understand the complex hemodynamic changes occurring in the early and late stages of the disease. However, the instauration of a hyperdynamic state and the different NO bioavailability in intrahepatic and systemic circulation-often defined as the NO paradox-must be considered confounding factors during FMD analysis. The primary purpose of this review is to describe the main features of ED and highlight the key findings of the dynamic and intriguing relationship between ED and liver disease. We will also focus on the significance of FMD evaluation in this setting, pointing out its key role as a therapeutic target in the never-ending battle against liver cirrhosis progression.

Neutrophil extracellular traps in homeostasis and disease

Neutrophil extracellular traps (NETs), crucial in immune defense mechanisms, are renowned for their propensity to expel decondensed chromatin embedded with inflammatory proteins. Our comprehension of NETs in pathogen clearance, immune regulation and disease pathogenesis, has grown significantly in recent years. NETs are not only pivotal in the context of infections but also exhibit significant involvement in sterile inflammation. Evidence suggests that excessive accumulation of NETs can result in vessel occlusion, tissue damage, and prolonged inflammatory responses, thereby contributing to the progression and exacerbation of various pathological states. Nevertheless, NETs exhibit dual functionalities in certain pathological contexts. While NETs may act as autoantigens, aggregated NET complexes can function as inflammatory mediators by degrading proinflammatory cytokines and chemokines. The delineation of molecules and signaling pathways governing NET formation aids in refining our appreciation of NETs' role in immune homeostasis, inflammation, autoimmune diseases, metabolic dysregulation, and cancer. In this comprehensive review, we delve into the multifaceted roles of NETs in both homeostasis and disease, whilst discussing their potential as therapeutic targets. Our aim is to enhance the understanding of the intricate functions of NETs across the spectrum from physiology to pathology.

Toll-like receptors in health and disease

Toll-like receptors (TLRs) are inflammatory triggers and belong to a family of pattern recognition receptors (PRRs) that are central to the regulation of host protective adaptive immune responses. Activation of TLRs in innate immune myeloid cells directs lymphocytes to produce the most appropriate effector responses to eliminate infection and maintain homeostasis of the body's internal environment. Inappropriate TLR stimulation can lead to the development of general autoimmune diseases as well as chronic and acute inflammation, and even cancer. Therefore, TLRs are expected to be targets for therapeutic treatment of inflammation-related diseases, autoimmune diseases, microbial infections, and human cancers. This review summarizes the recent discoveries in the molecular and structural biology of TLRs. The role of different TLR signaling pathways in inflammatory diseases, autoimmune diseases such as diabetes, cardiovascular diseases, respiratory diseases, digestive diseases, and even cancers (oral, gastric, breast, colorectal) is highlighted and summarizes new drugs and related clinical treatments in clinical trials, providing an overview of the potential and prospects of TLRs for the treatment of TLR-related diseases.

FGF19-Induced Inflammatory CAF Promoted Neutrophil Extracellular Trap Formation in the Liver Metastasis of Colorectal Cancer

Liver metastasis is the main cause of death in patients with colorectal cancer (CRC); thus, necessitating effective biomarkers and therapeutic targets for colorectal cancer liver metastasis (CRLM). Fibroblast growth factor 19 (FGF19) is a protumorigenic gene in numerous human malignancies. In this study, it is shown that FGF19 plays an indispensable role in CRLM. FGF19 expression and secretion are markedly correlated with liver metastasis and lower overall survival rates of patients with CRC. An in vivo metastasis model shows that FGF19 overexpression confers stronger liver-metastatic potential in CRC cells. Mechanistically, FGF19 exerts an immunomodulatory function that creates an environment conducive for metastasis in CRLM. FGF19 mediates the polarization of hepatic stellate cells to inflammatory cancer-associated fibroblasts (iCAFs) by activating the autocrine effect of IL-1α via the FGFR4-JAK2-STAT3 pathway. FGF19-induced iCAFs promote neutrophil infiltration and mediate neutrophil extracellular trap (NET) formation in liver metastatic niches via the production of complement C5a and IL-1β, which in turn accelerates the liver colonization of CRC cells. Importantly, targeting FGF19 signaling with fisogatinib efficiently suppresses FGF19-induced liver metastasis in a mouse model. In summary, this study describes the mechanism by which FGF19 regulates CRLM, thereby providing a novel target for CRLM intervention.

Plants against cancer: the immune-boosting herbal microbiome: not of the plant, but in the plant. Basic concepts, introduction, and future resource for vaccine adjuvant discovery

The presence of microorganism communities (MOCs) comprised of bacteria, fungi, archaea, algae, protozoa, viruses, and the like, are ubiquitous in all living tissue, including plant and animal. MOCs play a significant role in establishing innate and acquired immunity, thereby influencing susceptibility and resistance to disease. This understanding has fostered substantial advancements in several fields such as agriculture, food science/safety, and the development of vaccines/adjuvants, which rely on administering inactivated-attenuated MOC pathogens. Historical evidence dating back to the 1800s, including reports by Drs Busch, Coley, and Fehleisen, suggested that acute febrile infection in response to "specific microbes" could trigger spontaneous tumor remission in humans. This discovery led to the purposeful administration of the same attenuated strains, known as "Coley's toxin," marking the onset of the first microbial (pathogen) associated molecular pattern (MAMPs or PAMPs)-based tumor immunotherapy, used clinically for over four decades. Today, these same MAMPS are consumed orally by billions of consumers around the globe, through "specific" mediums (immune boosting "herbal supplements") as carriers of highly concentrated MOCs accrued in roots, barks, hulls, sea algae, and seeds. The American Herbal Products Association (AHPA) mandates microbial reduction in botanical product processing but does not necessitate the removal of dead MAMP laden microbial debris, which we ingest. Moreover, while existing research has focused on the immune-modulating role of plant phytochemicals, the actual immune-boosting properties might instead reside solely in the plant's MOC MAMP laden biomass. This assertion is logical, considering that antigenic immune-provoking epitopes, not phytochemicals, are known to stimulate immune response. This review explores a neglected area of research regarding the immune-boosting effects of the herbal microbiome - a presence which is indirectly corroborated by various peripheral fields of study and poses a fundamental question: Given that food safety focuses on the elimination of harmful pathogens and crop science acknowledges the existence of plant microbiomes, what precisely are the immune effects of ingesting MAMPs of diverse structural composition and concentration, and where are these distributed in our botanicals? We will discuss the topic of concentrated edible MAMPs as acid and thermally stable motifs found in specific herbs and how these would activate cognate pattern recognition receptors (PPRs) in the upper gut-associated lymphoid tissue (GALT), including Peyer's patches and the lamina propria, to boost antibody titers, CD8+ and CD4+ T cells, NK activity, hematopoiesis, and facilitating M2 to M1 macrophage phenotype transition in a similar manner as vaccines. This new knowledge could pave the way for developing bioreactor-grown/heat-inactivated MOC therapies to boost human immunity against infections and improve tumor surveillance.

Moonlighting chromatin: when DNA escapes nuclear control

Extracellular chromatin, for example in the form of neutrophil extracellular traps (NETs), is an important element that propels the pathological progression of a plethora of diseases. DNA drives the interferon system, serves as autoantigen, and forms the extracellular scaffold for proteins of the innate immune system. An insufficient clearance of extruded chromatin after the release of DNA from the nucleus into the extracellular milieu can perform a secret task of moonlighting in immune-inflammatory and occlusive disorders. Here, we discuss (I) the cellular events involved in the extracellular release of chromatin and NET formation, (II) the devastating consequence of a dysregulated NET formation, and (III) the imbalance between NET formation and clearance. We include the role of NET formation in the occlusion of vessels and ducts, in lung disease, in autoimmune diseases, in chronic oral disorders, in cancer, in the formation of adhesions, and in traumatic spinal cord injury. To develop effective therapies, it is of utmost importance to target pathways that cause decondensation of chromatin during exaggerated NET formation and aggregation. Alternatively, therapies that support the clearance of extracellular chromatin are conceivable.

Endotoxemia and Gastrointestinal Cancers: Insight into the Mechanisms Underlying a Dangerous Relationship

Lipopolysaccharide (LPS), also known as endotoxin, is a component of the membrane of gram-negative bacteria and a well-recognized marker of sepsis. In case of disruption of the intestinal barrier, as occurs with unhealthy diets, alcohol consumption, or during chronic diseases, the microbiota residing in the gastrointestinal tract becomes a crucial factor in amplifying the systemic inflammatory response. Indeed, the translocation of LPS into the bloodstream and its interaction with toll-like receptors (TLRs) triggers molecular pathways involved in cytokine release and immune dysregulation. This is a critical step in the exacerbation of many diseases, including metabolic disorders and cancer. Indeed, the role of LPS in cancer development is widely recognized, and examples include gastric tumor related to Helicobacter pylori infection and hepatocellular carcinoma, both of which are preceded by a prolonged inflammatory injury; in addition, the risk of recurrence and development of metastasis appears to be associated with endotoxemia. Here, we review the mechanisms that link the promotion and progression of tumorigenesis with endotoxemia, and the possible therapeutic interventions that can be deployed to counteract these events.

The emerging role of neutrophil extracellular traps in cancer: from lab to ward

Neutrophil extracellular traps (NETs) are web-like structures derived from neutrophils, which typically consist of DNA, released from the nucleus or mitochondria, and decorated with histones and granule proteins. They are well known as an important structure in innate immunity to eliminate pathogenic bacteria, similar to neutrophils. Initially, NETs are reported to take part in the progression of inflammatory diseases; now, they have also been implicated in the progression of sterile inflammation such as autoimmune disease, diabetes, and cancer. In this review, we will describe the recent studies which have investigated the role of NETs in the development of cancer, especially metastasis. We also prescribe the strategies for targeting NETs in the multiple cancer types, which suggest that NETs are a promising treatment for cancer patients.

Emerging Role of Neutrophil Extracellular Traps in Gastrointestinal Tumors: A Narrative Review

Neutrophil extracellular traps (NETs) are extracellular fibrous networks consisting of depolymerized chromatin DNA skeletons with a variety of antimicrobial proteins. They are secreted by activated neutrophils and play key roles in host defense and immune responses. Gastrointestinal (GI) malignancies are globally known for their high mortality and morbidity. Increasing research suggests that NETs contribute to the progression and metastasis of digestive tract tumors, among them gastric, colon, liver, and pancreatic cancers. This article explores the formation of NETs and reviews the role that NETs play in the gastrointestinal oncologic microenvironment, tumor proliferation and metastasis, tumor-related thrombosis, and surgical stress. At the same time, we analyze the qualitative and quantitative detection methods of NETs in recent years and found that NETs are specific markers of coronavirus disease 2019 (COVID-19). Then, we explore the possibility of NET inhibitors for the treatment of digestive tract tumor diseases to provide a new, efficient, and safe solution for the future therapy of gastrointestinal tumors.

Physiotherapeutic Protocol and ZnO Nanoparticles: A Combined Novel Treatment Program against Bacterial Pyomyositis

Myositis tropicans or pyomyositis is a muscle inflammation resulting from a bacterial infection of skeletal muscle (commonly caused by Staphylococcus aureus) that usually leads to hematogenous muscle seeding. The present study was designed to estimate the role of ZnO-NPs and a physiotherapeutic program in the management of induced biceps femoris atrophy in rats through histological, biochemical, and radiological examinations at different time intervals. At the beginning, several bacterial strains were evaluated through a proteolytic enzyme activity assay and the highest activity was recorded with the Staphylococcus aureus strain. ZnO-NPs were synthesized with the arc discharge method with an average size of 19.4 nm. The antibacterial activity of ZnO-NPs was investigated and it was revealed that the prepared ZnO-NPs showed a minimum inhibitory concentration of 8 µg/mL against the tested bacterium. The cytotoxicity of the prepared ZnO-NPs was tested in C2C12 myoblast cells, and it was elaborated that CC50 was 344.16 µg/mL. Biceps femoris pyomyositis was induced with a potent strain (Staphylococcus aureus); then, a physiotherapeutic program combined with the prepared ZnO-NPs treatment protocol was applied and evaluated. The combined program claimed antibacterial properties, preventing muscle atrophy, and resulted in the most comparable value of muscle mass.

Casting a NET on cancer: the multiple roles for neutrophil extracellular traps in cancer

PURPOSE OF REVIEW

The role of the innate immune system has become widely appreciated in cancer and cancer-associated disorders. Neutrophils, the most abundant circulating leukocytes, have prognostic value in determining cancer progression and survival. One of the ways by which neutrophils negatively impact outcome is by formation of neutrophil extracellular traps (NETs) which result in release of nuclear chromatin and bioactive proteins into the extracellular space. Here, we review the evidence for NETs contributions to cancer progression, metastasis, and cancer-associated thrombosis (CAT).

RECENT FINDINGS

NETs are increased across several cancer types and predict progression and adverse outcome. Several preclinical and clinical observations implicate NETs in promoting tumor growth, angiogenesis and metastasis via distinct pathways. Furthermore, NETs are shown to contribute to resistance to immunotherapy. NETs also emerge as key players in the prothrombotic phenotype associated with cancer that can result in potentially life-threatening arterial and venous thrombosis. Recent mechanistic insights expose several potential targets to inhibit NET formation and disrupt the interaction between NETs and tumor cells.

SUMMARY

Clinical and translational insights highlight the central role of NETs in cancer progression and metastasis, disease resistance and CAT. Targeting NETs and NET-associated pathways may represent a novel approach to treat cancer.

Neutrophil Extracellular Traps in Digestive Cancers: Warrior or Accomplice

Characterized as a complex of extracellular DNA fibers and granule proteins, neutrophil extracellular traps (NETs) are generated specifically by neutrophils which play a critical role in host defense and immune regulation. NETs have been initially found crucial for neutrophil anti-microbial function. Recent studies suggest that NETs are involved in tumorigenesis and cancer progression. However, the function of NETs in cancer remains unclear, which might be due to the variation of research models and the heterogeneity of cancers. Although most of malignant tumors have similar biological behaviors, significant differences indeed exist in various systems. Malignant tumors of the digestive system cause the most incidence and mortality of cancer worldwide. In this review, we would focus on research developments on NETs in digestive cancers to provide insights on their role in digestive cancer progression and future research directions.