Neutrophils Alter DNA Repair Landscape to Impact Survival and Shape Distinct Therapeutic Phenotypes of Colorectal Cancer

Tissue-specific reprogramming leads to angiogenic neutrophil specialization and tumor vascularization in colorectal cancer

Neutrophil (PMN) tissue accumulation is an established feature of ulcerative colitis (UC) lesions and colorectal cancer (CRC). To assess the PMN phenotypic and functional diversification during the transition from inflammatory ulceration to CRC we analyzed the transcriptomic landscape of blood and tissue PMNs. Transcriptional programs effectively separated PMNs based on their proximity to peripheral blood, inflamed colon, and tumors. In silico pathway overrepresentation analysis, protein-network mapping, gene signature identification, and gene-ontology scoring revealed unique enrichment of angiogenic and vasculature development pathways in tumor-associated neutrophils (TANs). Functional studies utilizing ex vivo cultures, colitis-induced murine CRC, and patient-derived xenograft models demonstrated a critical role for TANs in promoting tumor vascularization. Spp1 (OPN) and Mmp14 (MT1-MMP) were identified by unbiased -omics and mechanistic studies to be highly induced in TANs, acting to critically regulate endothelial cell chemotaxis and branching. TCGA data set and clinical specimens confirmed enrichment of SPP1 and MMP14 in high-grade CRC but not in patients with UC. Pharmacological inhibition of TAN trafficking or MMP14 activity effectively reduced tumor vascular density, leading to CRC regression. Our findings demonstrate a niche-directed PMN functional specialization and identify TAN contributions to tumor vascularization, delineating what we believe to be a new therapeutic framework for CRC treatment focused on TAN angiogenic properties.

Predictive effect of the systemic inflammation response index (SIRI) on the efficacy and prognosis of neoadjuvant chemoradiotherapy in patients with locally advanced rectal cancer

BACKGROUND

Inflammation is a part of tumours, and inflammatory cells can affect the proliferation, invasion, and development of tumour cells. An increasing number of peripheral blood inflammatory markers have been found to play very important roles in the treatment and prognosis of cancer patients. The systemic inflammatory response index (SIRI) is a newer inflammatory marker, and its role in colorectal cancer, especially in locally advanced rectal cancer, is still unclear.

METHODS

From 2015 to 2020, 198 patients with locally advanced rectal cancer (LARC) who underwent surgery following neoadjuvant chemoradiotherapy (Neo-CRT) were analysed. Patients were categorized into good- and poor- response groups according to their pathological results, and clinical characteristics and baseline parameters were compared between the two groups. The optimal cutoff values for inflammatory indicators were determined using receiver operating characteristic (ROC) analysis. Univariate and multivariate analyses were performed using the Cox proportional hazard model. Survival analysis was performed via the Kaplan‒Meier method.

RESULTS

After patients were grouped into good and poor response groups, indicator differences were found in CEA, neutrophil-to-lymphocyte ratio (NLR), systemic immune-inflammation index (SII), and SIRI. According to the ROC analysis, the NLR (P = 0.015), SII (P = 0.001), and SIRI (P = 0.029) were significant prognostic factors. After univariate and multivariate analyses of the Cox proportional hazards regression model, only the SIRI was found to be an independent prognostic factor for overall survival (OS) and disease-free survival (DFS). Finally, Kaplan‒Meier survival curves also confirmed the ability of the SIRI to predict survival.

CONCLUSION

The preoperative SIRI can be used to predict the response to Neo-CRT in LARC patients and is an independent predictor of OS and DFS in postoperative patients. A high SIRI was associated with poor radiotherapy response and predicted poor OS and DFS.

ERCC4: a potential regulatory factor in inflammatory bowel disease and inflammation-associated colorectal cancer

The pathogenesis of inflammatory bowel disease (IBD) remains unclear and is associated with an increased risk of developing colitis-associated cancer (CAC). Under sustained inflammatory stimulation in the intestines, loss of early DNA damage response genes can lead to tumor formation. Many proteins are involved in the pathways of DNA damage response and play critical roles in protecting genes from various potential damages that DNA may undergo. ERCC4 is a structure-specific endonuclease that participates in the nucleotide excision repair (NER) pathway. The catalytic site of ERCC4 determines the activity of NER and is an indispensable gene in the NER pathway. ERCC4 may be involved in the imbalanced process of DNA damage and repair in IBD-related inflammation and CAC. This article primarily reviews the function of ERCC4 in the DNA repair pathway and discusses its potential role in the processes of IBD-related inflammation and carcinogenesis. Finally, we explore how this knowledge may open novel avenues for the treatment of IBD and IBD-related cancer.

Neutrophils at the Crossroads: Unraveling the Multifaceted Role in the Tumor Microenvironment

Over the past decade, research has prominently established neutrophils as key contributors to the intricate landscape of tumor immune biology. As polymorphonuclear granulocytes within the innate immune system, neutrophils play a pivotal and abundant role, constituting approximately ∼70% of all peripheral leukocytes in humans and ∼10-20% in mice. This substantial presence positions them as the frontline defense against potential threats. Equipped with a diverse array of mechanisms, including reactive oxygen species (ROS) generation, degranulation, phagocytosis, and the formation of neutrophil extracellular traps (NETs), neutrophils undeniably serve as indispensable components of the innate immune system. While these innate functions enable neutrophils to interact with adaptive immune cells such as T, B, and NK cells, influencing their functions, they also engage in dynamic interactions with rapidly dividing tumor cells. Consequently, neutrophils are emerging as crucial regulators in both pro- and anti-tumor immunity. This comprehensive review delves into recent research to illuminate the multifaceted roles of neutrophils. It explores their diverse functions within the tumor microenvironment, shedding light on their heterogeneity and their impact on tumor recruitment, progression, and modulation. Additionally, the review underscores their potential anti-tumoral capabilities. Finally, it provides valuable insights into clinical therapies targeting neutrophils, presenting a promising approach to leveraging innate immunity for enhanced cancer treatment.

Phenotypic and Functional Diversity of Neutrophils in Gut Inflammation and Cancer

Neutrophils [polymorphonuclear leukocytes (PMNs)] execute important effector functions protecting the host against invading pathogens. However, their activity in tissue can exacerbate inflammation and inflammation-associated tissue injury and tumorigenesis. Until recently, PMNs were considered to be short-lived, terminally differentiated phagocytes. However, this view is rapidly changing with the emerging evidence of increased PMN lifespan in tissues, PMN plasticity, and phenotypic heterogeneity. Specialized PMN subsets have been identified in inflammation and in developing tumors, consistent with both beneficial and detrimental functions of PMNs in these conditions. Because PMN and tumor-associated neutrophil activity and the resulting beneficial/detrimental impacts primarily occur after homing to inflamed tissue/tumors, studying the underlying mechanisms of PMN/tumor-associated neutrophil trafficking is of high interest and clinical relevance. This review summarizes some of the key findings from over a decade of work from my laboratory and others on the regulation of PMN recruitment and identification of phenotypically and functionally diverse PMN subtypes as they pertain to gut inflammation and colon cancer.

FOXO3 Deficiency in Neutrophils Drives Colonic Inflammation and Tumorigenesis

Inflammatory bowel disease (IBD), characterized by infiltration of polymorphonuclear neutrophils (PMNs), increases the risk of colon cancer. PMN activation corresponds to the accumulation of intracellular Lipid Droplets (LDs). As increased LDs are negatively regulated by transcription factor Forkhead Box O3 (FOXO3), we aim to determine the significance of this regulatory network in PMN-mediated IBD and tumorigenesis. Affected tissue of IBD and colon cancer patients, colonic and infiltrated immune cells, have increased LDs' coat protein, PLIN2. Mouse peritoneal PMNs with stimulated LDs and FOXO3 deficiency have elevated transmigratory activity. Transcriptomic analysis of these FOXO3-deficient PMNs showed differentially expressed genes (DEGs; FDR < 0.05) involved in metabolism, inflammation, and tumorigenesis. Upstream regulators of these DEGs, similar to colonic inflammation and dysplasia in mice, were linked to IBD and human colon cancer. Additionally, a transcriptional signature representing FOXO3-deficient PMNs (PMN-FOXO3₃₈₉) separated transcriptomes of affected tissue in IBD (p = 0.00018) and colon cancer (p = 0.0037) from control. Increased PMN-FOXO3₃₈₉ presence predicted colon cancer invasion (lymphovascular p = 0.015; vascular p = 0.046; perineural p = 0.03) and poor survival. Validated DEGs from PMN-FOXO3₃₈₉ (P2RX1, MGLL, MCAM, CDKN1A, RALBP1, CCPG1, PLA2G7) are involved in metabolism, inflammation, and tumorigenesis (p < 0.05). These findings highlight the significance of LDs and FOXO3-mediated PMN functions that promote colonic pathobiology.

Clinical and prognostic significance of perioperative change in red cell distribution width in patients with esophageal squamous cell carcinoma

BACKGROUND

Numerous studies have reported the prognostic significance of the red cell distribution width (RDW) in patients with esophageal squamous cell carcinoma (ESCC), but the relationship between the perioperative change in RDW (delta RDW) and survival in patients with ESCC after surgery has not been evaluated.

METHODS

A total of 594 patients with newly diagnosed ESCC after surgery were enrolled in the study. Delta RDW (delta RDW = Postoperative RDW-Preoperative RDW) was counted based on data within one week before surgery and two weeks after surgery. To investigate the relationship between delta RDW and overall survival (OS), the median delta RDW was chosen as the cut-off value.

RESULTS

99 (16.7%) patients had pathological stage 1a-1b, 202 (34.0%) patients had pathological stage 2a-2b, and 293 (49.3%) patients had pathological stage 3a-3c.There were 179 (30.1%) patients who had vessel invasive, and 415 (69.9%) patients without vessel invasive. There were 216 (36.4%) patients with nerve infiltration, and 378 (63.6%) without nerve infiltration. In univariate analysis, five parameters including delta RDW(≥ 0.44 vs.<0.44) (P = 0.039, HR = 1.337, 95% CI = 1.014-1.762) significantly correlated with worse OS. Multivariate analysis revealed that delta RDW(≥ 0.44 vs.<0.44) was an independent prognostic marker for OS (P = 0.033, HR = 1.356, 95% CI = 1.025-1.793). Kaplan-Meier curves showed that delta RDW ≥ 0.44 was significantly associated with worse OS (P = 0.039). Subgroup analysis suggested that delta RDW ≥ 0.44 indicated worse survival in patients with ESCC exclusively in these subtypes such as female patients, age > 60 patients, patients with lymph node metastasis, and patients with vessel invasive.

CONCLUSIONS

Perioperative change in red cell distribution width predicts worse survival in patients with ESCC after surgery.

NETworking with cancer: The bidirectional interplay between cancer and neutrophil extracellular traps

Neutrophils are major effectors and regulators of the immune system. They play critical roles not only in the eradication of pathogens but also in cancer initiation and progression. Conversely, the presence of cancer affects neutrophil activity, maturation, and lifespan. By promoting or repressing key neutrophil functions, cancer cells co-opt neutrophil biology to their advantage. This co-opting includes hijacking one of neutrophils' most striking pathogen defense mechanisms: the formation of neutrophil extracellular traps (NETs). NETs are web-like filamentous extracellular structures of DNA, histones, and cytotoxic granule-derived proteins. Here, we discuss the bidirectional interplay by which cancer stimulates NET formation, and NETs in turn support disease progression. We review how vascular dysfunction and thrombosis caused by neutrophils and NETs underlie an elevated risk of death from cardiovascular events in cancer patients. Finally, we propose therapeutic strategies that may be effective in targeting NETs in the clinical setting.

Clinicopathological significance of neutrophil-rich colorectal carcinoma

AIMS

The importance of the interaction between tumour cells and neutrophils has recently begun to emerge. However, the significance of tumour-infiltrating neutrophil (TIN) in colorectal carcinomas (CRCs) remains unclear. The aim of this study was to investigate the prognostic significance of TIN in CRCs.

METHODS

CRCs were evaluated for TIN and were classified as neutrophil-rich (NR), neutrophil-intermediate (NI) and neutrophil-poor (NP) based on the presence of >15, 5-15 and <5 TIN per 100 tumour cells, respectively. Various clinicopathological parameters were recorded in each case including age, gender, histological grade, tumour, node, metastasis (TNM) stage, tumour location and DNA mismatch repair (MMR) status.

RESULTS

Among the 348 CRC cases reviewed, 38 cases were NR, 43 cases were NI and 267 cases were NP. High TIN was associated with higher histological grade (p=0.0222), right-sided tumour location (p=0.0025), advanced TNM stage (p=0.0346) and higher rate of MMR-deficient CRCs (p=0.0027). Patients with NR CRCs had significantly poorer 5-year recurrence-free survival comparing to patients with NI or NP CRCs on Kaplan-Meier analysis (p=0.0001) and high TIN remained an independent risk factor with multivariate analysis (p=0.0137; HR: 1.930, 95% CI: 1.144 to 3.255). NR CRCs are more commonly seen in MMR-deficient than in MMR-proficient CRCs (p=0.0006). Patients with MMR-deficient NR CRCs showed similar 5-year recurrence-free survival compared with MMR-proficient NR CRCs.

CONCLUSIONS

Our findings reveal that high TIN confers poorer patient prognosis in both MMR-proficient and MMR-deficient CRCs.

The role of extracellular vesicles and interleukin-8 in regulating and mediating neutrophil-dependent cancer drug resistance

Tumor drug resistance is a multifactorial and heterogenous condition that poses a serious burden in clinical oncology. Given the increasing incidence of resistant tumors, further understanding of the mechanisms that make tumor cells able to escape anticancer drug effects is pivotal for developing new effective treatments. Neutrophils constitute a considerable proportion of tumor infiltrated immune cells, and studies have linked elevated neutrophil counts with poor prognosis. Tumor-associated neutrophils (TANs) can acquire in fact immunoregulatory capabilities, thus regulating tumor progression and resistance, or response to therapy. In this review, we will describe TANs' actions in the tumor microenvironment, with emphasis on the analysis of the role of interleukin-8 (IL-8) and extracellular vesicles (EVs) as crucial modulators and mediators of TANs biology and function in tumors. We will then discuss the main mechanisms through which TANs can induce drug resistance, finally reporting emerging therapeutic approaches that target these mechanisms and can thus be potentially used to reduce or overcome neutrophil-mediated tumor drug resistance.

Discovery and Validation of Potential Serum Biomarkers with Pro-Inflammatory and DNA Damage Activities in Ulcerative Colitis: A Comprehensive Untargeted Metabolomic Study

Ulcerative colitis is a type of non-specific inflammatory bowel disease with unclear etiology. It is considered a progressive disease with risks of bowel motility disorders, anorectal dysfunction, and even colorectal cancer. Commonly used diagnostic markers have poor specificity and cannot predict the development of ulcerative colitis. In this study, 77 serum samples (31 patients, 46 healthy controls) were analyzed using high performance liquid chromatography-quadrupole time-of-flight mass spectrometry and 31 metabolites with significant level changes were found, revealing the relationship of ulcerative colitis to disturbed glutathione metabolism and caffeine metabolism. In addition, pyroglutamic acid, a biomarker of cervical cancer and gastric cancer, was identified with elevated levels in the serum of ulcerative colitis patients. The role of pyroglutamic acid was further analyzed, and the results indicated its positive correlation with the upregulation of inflammatory factors and increased levels of phosphorylated histone H2AX (γH2AX) in IEC-6 cells, which are related to DNA damage. All these results suggest that pyroglutamic acid is not only a biomarker for distinguishing ulcerative colitis status, but that it is also a potential effective metabolite that promotes the transformation of ulcerative colitis to colorectal cancer.

Non-Canonical Functions of Myeloperoxidase in Immune Regulation, Tissue Inflammation and Cancer

Myeloperoxidase (MPO) is one of the most abundantly expressed proteins in neutrophils. It serves as a critical component of the antimicrobial defense system, facilitating microbial killing via generation of reactive oxygen species (ROS). Interestingly, emerging evidence indicates that in addition to the well-recognized canonical antimicrobial function of MPO, it can directly or indirectly impact immune cells and tissue responses in homeostatic and disease states. Here, we highlight the emerging non-canonical functions of MPO, including its impact on neutrophil longevity, activation and trafficking in inflammation, its interactions with other immune cells, and how these interactions shape disease outcomes. We further discuss MPO interactions with barrier forming endothelial and epithelial cells, specialized cells of the central nervous system (CNS) and its involvement in cancer progression. Such diverse function and the MPO association with numerous inflammatory disorders make it an attractive target for therapies aimed at resolving inflammation and limiting inflammation-associated tissue damage. However, while considering MPO inhibition as a potential therapy, one must account for the diverse impact of MPO activity on various cellular compartments both in health and disease.

A microRNA panel that regulates proinflammatory cytokines as diagnostic and prognosis biomarkers in colon cancer

Colon cancer (CC) is the third most common neoplasm and the fourth cause of cancer-related death worldwide in both sexes. It has been established that inflammation plays a critical role in tumorigenesis and progression of CC. Immune, stromal and tumor cells supply the tumor microenvironment with pro-inflammatory cytokines such as interleukin 1β, TNFα, IL-6 and IL-11, to hyperactivate signaling pathways linked to cancerous processes. Recent findings suggest a putative role of microRNAs (miRNAs) in the progression and management of the inflammatory response in intestinal diseases. Moreover, miRNAs are able to regulate expression of molecular mediators that are linking inflammation and cancer. In this work a miRNA panel differentially expressed between healthy, inflammatory bowel disease (IBD) and CC tissue was established. Identified miRNAs regulate signaling pathways related to inflammation and cancer progression. An inflammation associated-miRNA panel composed of 11-miRNAs was found to be overexpressed in CC but not in inflamed or normal tissues (miR-21-5p, miR-304-5p, miR-577, miR-335-5p, miR-21-3p, miR-27b-5p, miR-335-3p, miR-215-5p, miR-30b-5p, miR-192-5p, miR-3065-5p). The association of top hit miRNAs, miR-3065-5p and miR-30b-5p expression with overall survival of CC patients was demonstrated using Kaplan-Meier tests. Finally, differential miRNA expression was validated using an inflammation-associated CC model induced by Azoxymethane/Dextran Sodium Sulfate (AOM/DSS) to compare miRNA expression in normal and inflamed tissue versus CC tissues. Based on these findings we propose the identified inflammatory miRNA panel as a potent diagnostic tool for CC determination.

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A miRNA group distinguishes colon cancer tissues, since early stages, from inflamed or healthy colon tissues.

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The miRNA panel regulates signaling pathways related to cancer progression.

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The levels of pro-inflammatory cytokines are regulated by the miRNAs of the panel.

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Inflammation-related miRNAs are colon cancer prognosis biomarkers.

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A miRNA signature is specific biomarker for colitis-associated colon carcinogenesis.

Experimental Colitis Enhances Temporal Variations in CX3CR1 Cell Colonization of the Gut and Brain Following Irradiation

Peripheral monocyte-derived CX3C chemokine receptor 1 positive (CX3CR1⁺) cells play important roles in tissue homeostasis and gut repopulation. Increasing evidence also supports their role in immune repopulation of the brain parenchyma in response to systemic inflammation. Adoptive bone marrow transfer from CX3CR1 fluorescence reporter mice and high-resolution confocal microscopy was used to assess the time course of CX3CR1⁺ cell repopulation of steady-state and dextran sodium sulfate (DSS)-inflamed small intestine/colon and the brain over 4 weeks after irradiation. CX3CR1⁺ cell colonization and morphologic polarization into fully ramified cells occurred more rapidly in the small intestine than in the colon. For both organs, the crypt/mucosa was more densely populated than the serosa/muscularis layer, indicating preferential temporal and spatial occupancy. Repopulation of the brain was delayed compared with that of gut tissue, consistent with the immune privilege of this organ. However, DSS-induced colon injury accelerated the repopulation. Expression analyses confirmed increased chemokine levels and macrophage colonization within the small intestine/colon and the brain by DSS-induced injury. Early increases of transmembrane protein 119 and ionized calcium binding adaptor molecule 1 expression within the brain after colon injury suggest immune-priming effect of brain resident microglia in response to systemic inflammation. These findings identify temporal differences in immune repopulation of the gut and brain in response to inflammation and show that gut inflammation can impact immune responses within the brain.

Neutrophils and micronuclei: An emerging link between genomic instability and cancer-driven inflammation

Two recent studies by Bui and Butin-Israeli et al. have established the novel contribution of neutrophils to genomic instability induction and aberrant shaping of the DNA repair landscape, particularly observed in patients with inflammatory bowel diseases (IBD) and/or progressive colorectal cancer (CRC). In addition, these back-to-back studies uncovered a sharp increase in the numbers of micronuclei and lagging chromosomes in pre-cancerous and cancerous epithelium in response to prolonged PMN exposure. Given the emerging link between neutrophils and micronuclei as well as the established role of micronuclei in cGAS/STING activation, this special commentary aims to elaborate on the mechanisms by which CRC cells may adapt to neutrophil-driven genomic instability while concurrently sustain an inflamed tumor niche. We postulate that such tumor microenvironment with constant immune cell presence, inflammatory milieu, and cumulative DNA damage can drive tumor adaptation and resistance to therapeutic interventions. Finally, we discuss potential novel therapeutic approaches that can be leveraged to target this emerging neutrophil-micronuclei pathological axis, thereby preventing perpetual CRC inflammation and unwanted tumor adaptation.

Neutrophils in cancer carcinogenesis and metastasis

In recent years, neutrophils have attracted increasing attention because of their cancer-promoting effects. An elevated neutrophil-to-lymphocyte ratio is considered a prognostic indicator for patients with cancer. Neutrophils are no longer regarded as innate immune cells with a single function, let alone bystanders in the pathological process of cancer. Their diversity and plasticity are being increasingly recognized. This review summarizes previous studies assessing the roles and mechanisms of neutrophils in cancer initiation, progression, metastasis and relapse. Although the findings are controversial, the fact that neutrophils play a dual role in promoting and suppressing cancer is undeniable. The plasticity of neutrophils allows them to adapt to different cancer microenvironments and exert different effects on cancer. Given the findings from our own research, we propose a reasonable hypothesis that neutrophils may be reprogrammed into a cancer-promoting state in the cancer microenvironment. This new perspective indicates that neutrophil reprogramming in the course of cancer treatment is a problem worthy of attention. Preventing or reversing the reprogramming of neutrophils may be a potential strategy for adjuvant cancer therapy.

Tumor-associated neutrophils: orchestrating cancer pathobiology and therapeutic resistance

Introduction: Neutrophils or polymorphonuclear cells (PMNs) account for a considerable portion of the tumor immune stroma. Emerging single-cell transcriptomic analyses have elucidated the striking cellular heterogeneity of PMNs during homeostasis and pathologic conditions and have established their diverse roles in cancer. PMNs have emerged as important players in cancer pathobiology and therapeutic resistance. Tumor-associated neutrophils (TANs) effector functions influence tumor development and resistance or response to therapy.Areas covered: This review focuses on PMN heterogeneity and functional diversity in the context of carcinogenesis. TANs, by activating diverse signaling pathways, contribute to cancer progression and resistance to therapies. Mechanisms by which TANs impact therapeutic resistance include alterations of the tumoral DNA damage response, angiogenesis, reactivation of cancer dormancy, enhancement of tumor cell proliferation/survival and immune evasion.Expert opinion: With the emerging phenotypic and function heterogeneity of TANs, targeting specific TAN functions in developing tumors can lead to translatable therapeutic approaches and limit drug resistance. We propose that combining specific targeting of TAN activity with standard cancer therapy can help patients achieving a complete response and prevent cancer relapse.