Bladder cancer patients have increased NETosis and impaired DNaseI-mediated NET degradation that can be therapeutically restored in vitro

Neutrophil extracellular traps in cancer: From mechanisms to treatments

Neutrophil extracellular traps (NETs) are reticular ultrastructures released by activated neutrophils. As the reaction products of neutrophils, NETs have been identified as crucial effectors in pathogen defence and autoimmune diseases. Recently, increasing evidence suggest that this process also occurs in cancer. The formation and clearance of NETs are dynamically influenced by the tumour microenvironment, while NETs reciprocally play a dual role in either promoting or inhibiting tumour progression through their DNA scaffold, proteases and other granule-derived proteins. Given the interplay between NETs and tumours, active exploration is currently underway to harness their potential as tumour biomarkers and therapeutic targets. Here, we delve into the biochemical and immunological mechanisms underlying NETs formation within the tumour microenvironment, along with recent advances elucidating their multifaceted roles in tumourigenesis, metastasis and tumour-associated co-morbidities. Furthermore, we present emerging strategies for NETs-based tumour diagnostic approaches and therapeutics, with a special focus on the challenging questions that need to be answered within this field. KEY POINTS: The formation and clearance of NETs are dynamically influenced by the tumor microenvironment. NETs are engaged in tumorigenesis, formation, metastatic spread, and cancer-associated co-morbidities. NETs-based tumor biomarkers and therapeutic strategies warrant significant attention.

Neutrophil extracellular traps and reactive oxygen species: Predictors of prognosis in bladder cancer

Neutrophils, the most abundant leukocytes in circulation, have become the subject of intensive research due to growing evidence of their role as modulators of cancer with both anti- and pro-tumorigenic effects. However, their prognostic function related to the release of neutrophil extracellular traps (NETs) and production of reactive oxygen species (ROS) has not yet been elucidated in the context of bladder cancer (BC). This study aimed to evaluate the ability of circulating neutrophils from BC patients to undergo NETosis and produce ROS-both spontaneously and following activation with phorbol 12-myristate 13-acetate (PMA)-using flow cytometry and immunofluorescence techniques. Their relevance to clinicopathological characteristics was also evaluated. Our results showed that PMA-treated neutrophils had increased early NETosis in patients with stage II (P = 0.048) and T2 (P = 0.014) compared to those with stage III and T3, respectively. These cells also showed a significant increase in ROS production in patients with T2 compared to those with T3 (P = 0.026) and T4 (P = 0.014), as well as in patients with stage II compared to stage IV (P = 0.048). Additionally, spontaneous ROS production was higher in patients without lymphovascular invasion than in those with invasion (P = 0.013). The increased activity of neutrophils observed in earlier stages (stage II and T2) suggests a potential protective mechanism in the early phases of cancer progression. It also highlights NETosis and ROS production by neutrophils as possible biomarkers for assessing disease progression. These findings provide insights into the complex interactions of neutrophils within the tumor microenvironment and lay the groundwork for further investigations into targeted therapies, potentially improving prognostic evaluations and treatment outcomes for patients.

Interplay between NETosis and the lncRNA-microRNA regulatory axis in the immunopathogenesis of cancer

Neutrophil extracellular traps (NETs), web-like complex structures secreted by neutrophils, have emerged as key players in the modulation of immune responses and the immunopathogenesis of immune disorders. Initially described for their antimicrobial function, NETs now play a part in the fundamental processes of cancer biology, including cancer initiation, metastatic dissemination, and immune evasion strategies. NETs hijack anti-tumor immunity by entrapping circulating cancer cells, fostering the growth of tumors, and reorganizing the tumor microenvironment such that it is pro-malignancy. Emerging evidence emphasizes the role of NETosis coupled with non-coding RNAs-long non-coding RNAs (lncRNAs) and microRNAs (miRNAs)-as key regulators of gene expression and controllers of processes vital for cancer growth, such as immune response and programmed cell death processes like apoptosis, necroptosis, pyroptosis, and ferroptosis. Aberrantly expressed non-coding RNAs have been attributed to immune dysregulation and excessive NET production, promoting tumor growth. NETs are also associated with a myriad of pathological conditions, such as autoimmune disorders, cystic fibrosis, sepsis, and thrombotic disorders. New therapeutic approaches-such as DNase therapy and PAD4 inhibitors-target NET production and their degradation to modify immune function and the efficiency of immunotherapies. Further clarification of the intricate interactions of NETosis, lncRNAs, and miRNAs has the potential to establish new strategies for the suppression of the growth of tumors and preventing immune evasion. This review seeks to elucidate the interactions between NETosis and the regulatory networks involving non-coding RNAs that significantly contribute to the immunopathogenesis of cancer.

Key immune cells and their crosstalk in the tumor microenvironment of bladder cancer: insights for innovative therapies

Bladder cancer (BC) is a heterogeneous disease associated with high mortality if not diagnosed early. BC is classified into non-muscle-invasive BC (NMIBC) and muscle-invasive BC (MIBC), with MIBC linked to poor systemic therapy response and high recurrence rates. Current treatments include transurethral resection with Bacillus Calmette-Guérin (BCG) therapy for NMIBC and radical cystectomy with chemotherapy and/or immunotherapy for MIBC. The tumor microenvironment (TME) plays a critical role in cancer progression, metastasis, and therapeutic efficacy. A comprehensive understanding of the TME's complex interactions holds substantial translational significance for developing innovative treatments. The TME can contribute to therapeutic resistance, particularly in immune checkpoint inhibitor (ICI) therapies, where resistance arises from tumor-intrinsic changes or extrinsic TME factors. Recent advancements in immunotherapy highlight the importance of translational research to address these challenges. Strategies to overcome resistance focus on remodeling the TME to transform immunologically "cold" tumors, which lack immune cell infiltration, into "hot" tumors that respond better to immunotherapy. These strategies involve disrupting cancer-microenvironment interactions, inhibiting angiogenesis, and modulating immune components to enhance anti-tumor responses. Key mechanisms include cytokine involvement [e.g., interleukin-6 (IL-6)], phenotypic alterations in macrophages and natural killer (NK) cells, and the plasticity of cancer-associated fibroblasts (CAFs). Identifying potential therapeutic targets within the TME can improve outcomes for MIBC patients. This review emphasizes the TME's complexity and its impact on guiding novel therapeutic approaches, offering hope for better survival in MIBC.

Cell-free Tumor DNA: a Promising Technology for Diagnosis, Surveillance and Therapeutic Decision in Urothelial Carcinoma of the Bladder

PURPOSE OF REVIEW

This narrative review aims to discuss the latest evidence for cell-free tumor DNA (ctDNA) use in bladder cancer, future perspectives and challenges in implementing this technology in clinical practice.

RECENT FINDINGS

Recent papers describe promising findings regarding ctDNA analysis in blood samples and in urine of bladder cancer patients. This biomarker can be used as a diagnostic tool, in prognostic evaluation and as additional data for treatment indication and surveillance.

Pulmozyme Ameliorates LPS-Induced Lung Fibrosis but Provokes Residual Inflammation by Modulating Cell-Free DNA Composition and Controlling Neutrophil Phenotype

Pulmonary fibrosis, a chronic progressive lung disorder, can be the result of previous acute inflammation-associated lung injury and involves a wide variety of inflammatory cells, causing the deposition of extracellular matrix (ECM) components in the lungs. Such lung injury is often associated with excessive neutrophil function and the formation of DNA networks in the lungs, which are also some of the most important factors for fibrosis development. Acute lung injury with subsequent fibrosis was initiated in C57Bl/6 mice by a single intranasal (i.n.) administration of LPS. Starting from day 14, human recombinant DNase I in the form of Pulmozyme for topical administration was instilled i.n. twice a week at a dose of 50 U/mouse. Cell-free DNA (cfDNA), DNase activity, and cell content were analyzed in blood serum and bronchoalveolar lavage fluid (BALF). Inflammatory and fibrotic changes in lung tissue were evaluated by histological analysis. The gene expression profile in spleen-derived neutrophils was analyzed by RT-qPCR. We demonstrated that Pulmozyme significantly reduced connective tissue expansion in the lungs. However, despite the reliable antifibrotic effect, complete resolution of inflammation in the respiratory system of mice treated with Pulmozyme was not achieved, possibly due to enhanced granulocyte recruitment and changes in the nuclear/mitochondrial cfDNA balance in the BALF. Moreover, Pulmozyme introduction caused the enrichment of the spleen-derived neutrophil population by those with an unusual phenotype, combining pro-inflammatory and anti-inflammatory features, which can also maintain lung inflammation. Pulmozyme can be considered a promising drug for lung fibrosis management; however, the therapy may be accompanied by residual inflammation.

Delving into the clinical impact of NETs in pediatric cancer

Pediatric cancer, a complex and heterogeneous group of diseases, continues to challenge medical research and treatment strategies. Despite advances in precision medicine and immunotherapy, certain aggressive subtypes of pediatric cancer are resistant to conventional therapies, requiring further exploration of potential therapeutic targets. Neutrophil extracellular traps (NETs), net-like structures released by neutrophils, have emerged as a potential player in the pediatric cancer landscape. However, our understanding of their role in pediatric oncology remains limited. This systematic review examines the current state of the NETs literature in pediatric cancer, focusing on the most frequent subtypes. The review reveals the scarcity of research in this area, highlighting the need for further investigation. The few studies available suggest that NETs may influence infection risk, treatment resistance and prognosis in certain pediatric malignancies. Although the field is still in its infancy, it holds great promise for advancing our understanding of pediatric cancer biology and potential therapeutic pathways. IMPACT: This review identifies a significant gap in research on neutrophil extracellular traps (NETs) in pediatric cancer. It provides a summary of existing studies and their promising findings and potential, as well as a comprehensive overview of current research on NETs in certain tumor types. It also emphasizes the lack of specific studies in pediatric cancer. The review encourages the prioritization of NET research in pediatric oncology, with the aim of improving prognosis and developing new treatments through increased understanding and targeted studies.

Prognostic role of the neutrophil/lymphocyte ratio in high-risk BCG-naïve non-muscle-invasive bladder cancer treated with intravesical gemcitabine/docetaxel

OBJECTIVES

To investigate the role of pretreatment neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) in the prediction of response to sequential intravesical therapy, gemcitabine and docetaxel (Gem/Doce), given to patients with bacille Calmette-Guérin (BCG)- naïve high-risk non-muscle-invasive bladder cancer (NMIBC).

PATIENTS AND METHODS

A retrospective analysis was conducted on 115 patients who received intravesical Gem/Doce for high-risk NMIBC between January 2011 and December 2021. Data were computed as the median (interquartile range [IQR]) or mean (standard deviation [sd]). Cox regression analysis was performed to determine if neutrophilia, NLR, platelet counts, and PLR before instillation therapy were predictive of recurrence-free survival (RFS) and overall survival (OS). Predictive performance was estimated using Uno's C-statistic.

RESULTS

The median (IQR) follow-up for the overall cohort was 23 (13-36) months. The mean (sd) values for NLR, PLR and platelet counts were 3.4 (2.3), 142.2 (85.5), and 225.2 (75.1) × 109/L, respectively. NLR was associated with RFS, with a hazard ratio of 1.32 (95% confidence interval CI 1.19-1.46). Concordance analysis showed that NLR had a good ability to predict RFS (C-index: 0.7, P < 0.01). The PLR and platelet count were not associated with RFS and did not predict recurrence. In terms of OS, none of these cellular inflammatory markers showed any prediction value.

CONCLUSION

Pre-treatment NLR provides some predictive accuracy for RFS in high-risk BCG-naïve patients receiving Gem/Doce. Further prospective trials are needed to validate this finding.

Dysregulated neutrophil extracellular traps and haemostatic biomarkers as diagnostic tools and therapeutic targets in periprosthetic joint infection

Aims

Bacterial infection activates neutrophils to release neutrophil extracellular traps (NETs) in bacterial biofilms of periprosthetic joint infections (PJIs). The aim of this study was to evaluate the increase in NET activation and release (NETosis) and haemostasis markers in the plasma of patients with PJI, to evaluate whether such plasma induces the activation of neutrophils, to ascertain whether increased NETosis is also mediated by reduced DNaseI activity, to explore novel therapeutic interventions for NETosis in PJI in vitro, and to evaluate the potential diagnostic use of these markers.

Methods

We prospectively recruited 107 patients in the preoperative period of prosthetic surgery, 71 with a suspicion of PJI and 36 who underwent arthroplasty for non-septic indications as controls, and obtained citrated plasma. PJI was confirmed in 50 patients. We measured NET markers, inflammation markers, DNaseI activity, haemostatic markers, and the thrombin generation test (TGT). We analyzed the ability of plasma from confirmed PJI and controls to induce NETosis and to degrade in vitro-generated NETs, and explored the therapeutic restoration of the impairment to degrade NETs of PJI plasma with recombinant human DNaseI. Finally, we assessed the contribution of these markers to the diagnosis of PJI.

Results

Patients with confirmed PJI had significantly increased levels of NET markers (cfDNA (p < 0.001), calprotectin (p < 0.001), and neutrophil elastase (p = 0.022)) and inflammation markers (IL-6; p < 0.001) in plasma. Moreover, the plasma of patients with PJI induced significantly more neutrophil activation than the plasma of the controls (p < 0.001) independently of tumour necrosis factor alpha. Patients with PJI also had a reduced DNaseI activity in plasma (p < 0.001), leading to a significantly impaired degradation of NETs (p < 0.001). This could be therapeutically restored with recombinant human DNaseI to the level in the controls. We developed a model to improve the diagnosis of PJI with cfDNA, calprotectin, and the start tail of TGT as predictors, though cfDNA alone achieved a good prediction and is simpler to measure.

Conclusion

We confirmed that patients with PJI have an increased level of NETosis in plasma. Their plasma both induced NET release and had an impaired ability to degrade NETs mediated by a reduced DNaseI activity. This can be therapeutically restored in vitro with the approved Dornase alfa, Pulmozyme, which may allow novel methods of treatment. A combination of NETs and haemostatic biomarkers could improve the diagnosis of PJI, especially those patients in whom this diagnosis is uncertain.

Calprotectin as a new inflammatory marker of abdominal aortic aneurysm: A pilot study

INTRODUCTION

Abdominal aortic aneurysm (AAA) is a relevant clinical problem due to the risk of rupture of progressively dilated infrarenal aorta. It is characterized by degradation of elastic fibers, extracellular matrix, and inflammation of the arterial wall. Though neutrophil infiltration is a known feature of AAA, markers of neutrophil activation are scarcely analyzed; hence, the main objective of this study.

METHODS

Plasma levels of main neutrophil activation markers were quantified in patients with AAA and a double control group (CTL) formed by healthy volunteers (HV) and patients with severe atherosclerosis submitted for carotid endarterectomy (CE). Calprotectin, a cytoplasmic neutrophil protein, was quantified, by Western blot, in arterial tissue samples from patients with AAA and organ donors. Colocalization of calprotectin and neutrophil elastase was assessed by immunofluorescence.

RESULTS

Plasma calprotectin and IL-6 were both elevated in patients with AAA compared with CTL (p ⩽ 0.0001) and a strong correlation was found between both molecules (p < 0.001). This difference was maintained when comparing with HV and CE for calprotectin but only with HV for IL-6. Calprotectin was also elevated in arterial tissue samples from patients with AAA compared with organ donors (p < 0.0001), and colocalized with neutrophils in the arterial wall.

CONCLUSIONS

Circulating calprotectin could be a specific AAA marker and a potential therapeutical target. Calprotectin is related to inflammation and neutrophil activation in arterial wall and independent of other atherosclerotic events.