Neutrophils: Accomplices in metastasis

S100A7 orchestrates neutrophil chemotaxis and drives neutrophil extracellular traps (NETs) formation to facilitate lymph node metastasis in cervical cancer patients

Neutrophil extracellular traps (NETs) have been shown to promote the metastatic potential of many kinds of tumors. Our study aimed to investigate the role and mechanisms of NETs in lymph node metastasis (LNM) of cervical cancer (CCa), and evaluated the therapeutic value of targeting NETs in CCa. Immunohistochemistry demonstrated that neutrophil infiltration and NETs formation were increased in CCa patients with LNM, as well as confirming a positive correlation between S100A7 expression and neutrophil infiltration in CCa. NETs enhanced the migratory capability of CCa by activating the P38-MAPK/ERK/NFκB pathway through interaction with TLR2. Digesting NETs with deoxyribonuclease 1 (DNase 1) or inhibiting TLR2 with chloroquine eliminated the NETs-induced metastatic potential of CCa. Additionally, NETs promoted lymphangiogenesis and increased the permeability of lymphatic vessels, thus facilitating translymphatic movement of CCa. CCa-derived S100A7 exhibited a chemotactic effect on neutrophils and promoted NETs generation by elevating ROS levels rather than activating autophagy in neutrophils. The mouse model with footpad implantation illustrated that DNase 1 effectively reduced LNM in LPS-induced mice and in mice seeded with S100A7-overexpressing CCa cells. In conclusion, our study reveals a new tumor-promoting mechanism of S100A7, clarifies the crucial role and mechanism of NETs in LNM of CCa, and indicates that the NETs-targeted therapy emerges as a promising anti-metastasis therapy in CCa.

CTC-neutrophil interaction: A key driver and therapeutic target of cancer metastasis

Circulating tumor cells (CTCs) are cancer cells that detach from the primary tumor and enter the bloodstream, where they can seed new metastatic lesions in distant organs. CTCs are often associated with white blood cells (WBCs), especially neutrophils, the most abundant and versatile immune cells in the blood. Neutrophils can interact with CTCs through various mechanisms, such as cell-cell adhesion, cytokine secretion, protease release, and neutrophil extracellular traps (NETs) formation. These interactions can promote the survival, proliferation, invasion, and extravasation of CTCs, as well as modulate the pre-metastatic niche and the tumor microenvironment. Therefore, inhibiting CTC-neutrophils interaction could be a potential strategy to reduce tumor metastasis and improve the prognosis of cancer patients. In this review, we summarize the current literature on CTC-neutrophils interaction' role in tumor metastasis and discuss the possible therapeutic approaches to target this interaction.

Neutrophils exposed to a cholesterol metabolite secrete extracellular vesicles that promote epithelial-mesenchymal transition and stemness in breast cancer cells

Small extracellular vesicles (sEVs) are emerging as critical mediators of intercellular communication in the tumor microenvironment (TME). Here, we investigate the mechanisms by which sEVs derived from neutrophils treated with the cholesterol metabolite, 27-hydroxycholesterol (27HC), influence breast cancer progression. sEVs released from 27HC treated neutrophils enhance epithelial-mesenchymal transition (EMT) and stem-like properties in breast cancer cells, resulting in loss of adherence, increased migratory capacity and resistance to cytotoxic chemotherapy. Decreased microRNAs (miRs) within the sEVs resulted in activation of the WNT/β-catenin signaling pathway in recipient cells and suggest that this may be a predominant pathway for stem-like phenotype and EMT. Our findings underscore a novel mechanism by which 27HC-modulated neutrophils contribute to breast cancer pathophysiology through EV-mediated intercellular communication, suggesting potential therapeutic targets in cancer treatment.

A causal link between circulating leukocytes and three major urologic cancers: a mendelian randomization investigation

Purpose

This study aimed to explore the influence of serum leukocytes on urologic cancers (UC) using observation-based investigations. In the present study, Mendelian randomization (MR) was employed to assess the link between leukocyte count (LC) and the risk of UC development.

Methods

Five LC and three major UC patient prognoses were obtained for MR analysis from genome-wide association studies (GWAS). Furthermore, in order to evaluate reverse causality, bidirectional studies were conducted. Finally, a sensitivity analysis using multiple methods was carried out.

Results

There was no significant correlation found in the genetic assessment of differential LC between the co-occurrence of bladder cancer (BCA) and renal cell carcinoma (RCC). Conversely, an individual 1-standard deviation (SD) rise in neutrophil count was strongly linked to a 9.3% elevation in prostate cancer (PCA) risk ([odd ratio]OR = 1.093, 95% [confidence interval]CI = 0.864-1.383, p = 0.002). Reverse MR analysis suggested that PCA was unlikely to cause changes in neutrophil count. Additional sensitivity studies revealed that the outcomes of all MR evaluations were similar, and there was no horizontal pleiotropy. Primary MR analysis using inverse-variance weighted (IVW) revealed that differential lymphocyte count significantly influenced RCC risk (OR = 1.162, 95%CI = 0.918-1.470, p = 0.001). Moreover, altered basophil count also affected BCA risk (OR = 1.249, 95% CI = 0.904-1.725, p = 0.018). Nonetheless, these causal associations were not significant in the sensitivity analysis.

Conclusion

In summary, the results revealed that increased neutrophil counts represent a significant PCA risk factor. The current research indicates a significant relationship between immune cell activity and the cause of UC.

Neutrophil hitchhiking: Riding the drug delivery wave to treat diseases

Neutrophils are a crucial component of the innate immune system and play a pivotal role in various physiological processes. From a physical perspective, hitchhiking is considered a phenomenon of efficient transportation. The combination of neutrophils and hitchhikers has given rise to effective delivery systems both in vivo and in vitro, thus neutrophils hitchhiking become a novel approach to disease treatment. This article provides an overview of the innovative and feasible application of neutrophils as drug carriers. It explores the mechanisms underlying neutrophil function, elucidates the mechanism of drug delivery mediated by neutrophil-hitchhiking, and discusses the potential applications of this strategy in the treatment of cancer, immune diseases, inflammatory diseases, and other medical conditions.

Can inflammatory indices predict sentinel lymph node status in patients with early-stage breast cancer?

Breast cancer research has focused on the early detection and treatment of breast cancer. Axillary lymph node status is essential for primary breast cancer staging, recurrence, and survival. The current quest for precision medicine is to identify predictive markers that offer the advantage of individualized treatment options. This study aimed to investigate the value of inflammatory indices in predicting positive sentinel nodes in breast cancer. We studied 602 patients with early-stage breast cancer who underwent sentinel lymph node biopsies (SLNB) at the Bülent Ecevit University General Surgery Clinic. We obtained data, including the clinical and demographic characteristics of the patients, such as age, histological type, and sentinel lymph nodes. Neutrophil, lymphocyte, platelet, and monocyte counts were obtained from preoperative complete blood count test data from the patient registry. The neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), lymphocyte-to-monocyte ratio (LMR), systemic inflammatory index (SII), and sentinel lymph node biopsy were analyzed. Sentinel LAP was negative in 391 (65%) patients and positive in 211 (35%). In the receiver operating characteristic curve analysis, no significant difference was found between SLNB positivity and negativity in terms of NLR, PLR, LMR, or SII. In contrast to previous research, NLR, PLR, LMR, or SII did not affect SLNB positivity prediction in our study.

Liver metastasis from colorectal cancer: pathogenetic development, immune landscape of the tumour microenvironment and therapeutic approaches

Colorectal cancer liver metastasis (CRLM) is one of the leading causes of death among patients with colorectal cancer (CRC). Although immunotherapy has demonstrated encouraging outcomes in CRC, its benefits are minimal in CRLM. The complex immune landscape of the hepatic tumour microenvironment is essential for the development of a premetastatic niche and for the colonisation and metastasis of CRC cells; thus, an in-depth understanding of these mechanisms can provide effective immunotherapeutic targets for CRLM. This review summarises recent studies on the immune landscape of the tumour microenvironment of CRLM and highlights therapeutic prospects for targeting the suppressive immune microenvironment of CRLM.

Multi-Site Attack, Neutrophil Membrane-Camouflaged Nanomedicine with High Drug Loading for Enhanced Cancer Therapy and Metastasis Inhibition

Background

Advanced breast cancer is a highly metastatic tumor with high mortality. Simultaneous elimination of primary tumor and inhibition of neutrophil-circulation tumor cells (CTCs) cluster formation are urgent issues for cancer therapy. Unfortunately, the drug delivery efficiency to tumors and anti-metastasis efficacy of nanomedicine are far from satisfactory.

Methods

To address these problems, we designed a multi-site attack, neutrophil membrane-camouflaged nanoplatform encapsulating hypoxia-responsive dimeric prodrug hQ-MMAE₂ (hQNM-PLGA) for enhanced cancer and anti-metastasis therapy.

Results

Encouraged by the natural tendency of neutrophils to inflammatory tumor sites, hQNM-PLGA nanoparticles (NPs) could target delivery of drug to tumor, and the acute hypoxic environment of advanced 4T1 breast tumor promoted hQ-MMAE₂ degradation to release MMAE, thus eliminating the primary tumor cells to achieve remarkable anticancer efficacy. Alternatively, NM-PLGA NPs inherited the similar adhesion proteins of neutrophils so that NPs could compete with neutrophils to interrupt the formation of neutrophil-CTC clusters, leading to a reduction in extravasation of CTCs and inhibition of tumor metastasis. The in vivo results further revealed that hQNM-PLGA NPs possessed a perfect safety and ability to inhibit tumor growth and spontaneous lung metastasis.

Conclusion

This study demonstrates the multi-site attack strategy provides a prospective avenue with the potential to improve anticancer and anti-metastasis therapeutic efficacy.

From the Catastrophic Objective Irreproducibility of Cancer Research and Unavoidable Failures of Molecular Targeted Therapies to the Sparkling Hope of Supramolecular Targeted Strategies

The unprecedented non-reproducibility of the results published in the field of cancer research has recently come under the spotlight. In this short review, we try to highlight some general principles in the organization and evolution of cancerous tumors, which objectively lead to their enormous variability and, consequently, the irreproducibility of the results of their investigation. This heterogeneity is also extremely unfavorable for the effective use of molecularly targeted medicine. Against the seemingly comprehensive background of this heterogeneity, we single out two supramolecular characteristics common to all tumors: the clustered nature of tumor interactions with their microenvironment and the formation of biomolecular condensates with tumor-specific distinctive features. We suggest that these features can form the basis of strategies for tumor-specific supramolecular targeted therapies.

Label-free tumor cell screening based on IDO1-mediated tryptophan metabolism at single cell level

Indoleamine 2,3-dioxygenase 1 (IDO1) plays a critical role in inflammatory and immunometabolism programming through catalyzing the oxidation of tryptophan (Trp) into downstream N-formylkynurenine. IDO1 is typically up-regulated in malignant tumors, making it a potential biomarker for cancer diagnosis. Here we show an effective strategy for tumor cell detection by integrating IDO1 activity assay with single cell-encapsulated droplets on a microfluidic platform for high-throughput bioanalysis. Mixed cells, as well as other cofactors, are encapsulated in individual droplets, which act as dynamic microreactors for IDO1-catalyzed oxidation of Trp. After pico-injection of a biosensing ensemble consisting of the macrocycle cucurbit [8]uril (Q8) and a fluorescent guest, rapid and robust screening of tumor cells by fluorescence signal is achieved in a few minutes reporting to Trp depletion, expanding the scope of conventional antibody-based detection of protein biomarkers. The results represent the first example of quantifying IDO1 enzymatic activity at the single cell level with a high-throughput performance, therefore promising warning signs and early diagnosis of tumor cells.

Polysialic Acid Self-assembled Nanocomplexes for Neutrophil-Based Immunotherapy to Suppress Lung Metastasis of Breast Cancer

The role of neutrophils in tumor metastasis has recently attracted widespread interest. Neutrophils are the most abundant immune cells in human peripheral blood, and large numbers can spontaneously migrate to metastatic sites, where they form an immunosuppressive microenvironment. Polysialic acid (PSA) can target peripheral blood neutrophils (PBNs) mediated by L-selectin, and abemaciclib (ABE) and mitoxantrone (MIT) can treat immunosuppressive microenvironments. Here, we aimed to inhibit lung metastasis of breast cancer and improve chemoimmunotherapy by designing a PSA-modified ABE and MIT co-delivery system (AM-polyion complex (PIC)) to target PBNs in mice with metastatic tumors. We found that through electrostatic interactions between the strong negative charge of PSA and the positive charge of the drug can form stable nanocomplexes and that spontaneous migration of neutrophils can mediate the aggregation of these complexes in the lungs, induce antimetastatic immune responses, enhance the effectiveness of cytotoxic T lymphocytes (CTLs), and inhibit regulatory T cell (Treg) proliferation in vivo and in vitro. Pharmacodynamic results suggested that neutrophil-mediated AM-PIC chemoimmunotherapy inhibited tumor metastasis in mice with lung metastasis of 4T1 breast cancer. Overall, PSA-modified nanocomplexes offer promising neutrophil-mediated, targeted drug delivery systems to treat lung metastasis of breast cancer.

Platelet to lymphocyte ratio is associated with tumor localization and outcomes in metastatic colorectal cancer

The aim of this study was to investigate the predictive and prognostic value of PLR, and the relationship between PLR and tumor localization.A total of 229 patients with de-novo metastatic CRC were retrospectively analyzed. The cutoff value for PLR was defined by the receiver operating characteristic (ROC) curve analysis and threshold value of 196.5 as best cut-off value was found.The higher rate of BRAF mutation was significantly detected for patients with PLRhigh (> 196.5) compared to those with PLRlow (≤196.5) (P = .001). PLR was significantly higher in tumors located on the right colon (P = .012). PLR, tumor localization, the presence of surgery for primary tumor, the presence of curative surgery, the presence of metastasectomy for progression-free survival (PFS) and PLR, gender, BRAF mutation, tumor localization, the presence of surgery for primary tumor, the presence of metastasectomy for overall survival (OS) were found to be prognostic factors by univariate analysis. Multivariate analysis showed that PLR, the presence of curative surgery and the presence of metastasectomy for both PFS and OS were found to be independent prognostic factors. Moreover, a logistic regression analysis indicated that PLR and tumor localization were found to be an independent factors for predicting response to systemic treatment (P < .001 and P = .023 respectively).Our results showed that pretreatment PLR was readily feasible and simple biomarker predicting response to treatment and survival, in addition it was significantly associated with tumor localization.

Tumor-Derived Factors Differentially Affect the Recruitment and Plasticity of Neutrophils

Neutrophils play a key role in cancer biology. In contrast to circulating normal-density neutrophils (NDN), the amount of low-density neutrophils (LDN) significantly increases with tumor progression. The correlation between these neutrophil subpopulations and intratumoral neutrophils (TANs) is still under debate. Using 4T1 (breast) and AB12 (mesothelioma) tumor models, we aimed to elucidate the source of TANs and to assess the mechanisms driving neutrophils' plasticity in cancer. Both NDN and LDN were found to migrate in response to CXCL1 and CXCL2 exposure, and co-infiltrate the tumor site ex vivo and in vivo, although LDN migration into the tumor was higher than NDN. Tumor-derived factors and chemokines, particularly CXCL1, were found to drive neutrophil phenotypical plasticity, inducing NDN to transition towards a low-density state (LD-NDN). LD-NDN appeared to differ from NDN by displaying a phenotypical profile similar to LDN in terms of nuclear morphology, surface receptor markers, decreased phagocytic abilities, and increased ROS production. Interestingly, all three subpopulations displayed comparable cytotoxic abilities towards tumor cells. Our data suggest that TANs originate from both LDN and NDN, and that a portion of LDN derives from NDN undergoing phenotypical changes. NDN plasticity resulted in a change in surface marker expression and functional activity, gaining characteristics of LDN.

What are the applications of single-cell RNA sequencing in cancer research: a systematic review

Single-cell RNA sequencing (scRNA-seq) is a tool for studying gene expression at the single-cell level that has been widely used due to its unprecedented high resolution. In the present review, we outline the preparation process and sequencing platforms for the scRNA-seq analysis of solid tumor specimens and discuss the main steps and methods used during data analysis, including quality control, batch-effect correction, normalization, cell cycle phase assignment, clustering, cell trajectory and pseudo-time reconstruction, differential expression analysis and gene set enrichment analysis, as well as gene regulatory network inference. Traditional bulk RNA sequencing does not address the heterogeneity within and between tumors, and since the development of the first scRNA-seq technique, this approach has been widely used in cancer research to better understand cancer cell biology and pathogenetic mechanisms. ScRNA-seq has been of great significance for the development of targeted therapy and immunotherapy. In the second part of this review, we focus on the application of scRNA-seq in solid tumors, and summarize the findings and achievements in tumor research afforded by its use. ScRNA-seq holds promise for improving our understanding of the molecular characteristics of cancer, and potentially contributing to improved diagnosis, prognosis, and therapeutics.

N6-methyladenosine-dependent signalling in cancer progression and insights into cancer therapies

The N6-methyladenosine (m6A) modification is a dynamic and reversible epigenetic modification, which is co-transcriptionally deposited by a methyltransferase complex, removed by a demethylase, and recognized by reader proteins. Mechanistically, m6A modification regulates the expression levels of mRNA and nocoding RNA by modulating the fate of modified RNA molecules, such as RNA splicing, nuclear transport, translation, and stability. Several studies have shown that m6A modification is dysregulated in the progression of multiple diseases, especially human tumors. We emphasized that the dysregulation of m6A modification affects different signal transduction pathways and involves in the biological processes underlying tumor cell proliferation, apoptosis, invasion and migration, and metabolic reprogramming, and discuss the effects on different cancer treatment.

Single-cell RNA sequencing in cancer research

Single-cell RNA sequencing (scRNA-seq), a technology that analyzes transcriptomes of complex tissues at single-cell levels, can identify differential gene expression and epigenetic factors caused by mutations in unicellular genomes, as well as new cell-specific markers and cell types. scRNA-seq plays an important role in various aspects of tumor research. It reveals the heterogeneity of tumor cells and monitors the progress of tumor development, thereby preventing further cellular deterioration. Furthermore, the transcriptome analysis of immune cells in tumor tissue can be used to classify immune cells, their immune escape mechanisms and drug resistance mechanisms, and to develop effective clinical targeted therapies combined with immunotherapy. Moreover, this method enables the study of intercellular communication and the interaction of tumor cells and non-malignant cells to reveal their role in carcinogenesis. scRNA-seq provides new technical means for further development of tumor research and is expected to make significant breakthroughs in this field. This review focuses on the principles of scRNA-seq, with an emphasis on the application of scRNA-seq in tumor heterogeneity, pathogenesis, and treatment.

circSETD3 regulates MAPRE1 through miR-615-5p and miR-1538 sponges to promote migration and invasion in nasopharyngeal carcinoma

Circular RNAs (circRNAs) play an essential role in tumorigenesis and development. However, they have rarely been investigated in nasopharyngeal carcinoma (NPC). This study aimed to investigate the role of circRNA in the invasion and metastasis of NPC. We screened and verified the high expression of circSETD3 in NPC cell lines using RNA sequencing (RNA-Seq) and verified the results of NPC biopsy samples using real-time quantitative polymerase chain reaction (qRT-PCR) and in situ hybridization (ISH). In vivo and in vitro experiments indicated that circSETD3 could promote NPC cell invasion and migration. We compared the proteomic data of NPC cells before and after the overexpression or knockdown of circSETD3 in combination with bioinformatics prediction and experimental verification. It was found that circSETD3 competitively adsorbs to miR-615-5p and miR-1538 and negates their inhibitory effect on MAPRE1 mRNA, thereby upregulating the expression of MAPRE1. The upregulated MAPRE1 then inhibits the acetylation of α-tubulin, promotes the dynamic assembly of microtubules, and enhances the invasion and migration capabilities of NPC cells. The results of this study suggest that circSETD3 is a novel molecular marker and a potential target for NPC diagnosis and treatment.

EBV-miR-BART12 accelerates migration and invasion in EBV-associated cancer cells by targeting tubulin polymerization-promoting protein 1

Epstein-Barr virus (EBV) infection leads to cancers with an epithelial origin, such as nasopharyngeal cancer and gastric cancer, as well as multiple blood cell-based malignant tumors, such as lymphoma. Interestingly, EBV is also the first virus found to carry genes encoding miRNAs. EBV encodes 25 types of pre-miRNAs which are finally processed into 44 mature miRNAs. Most EBV-encoded miRNAs were found to be involved in the occurrence and development of EBV-related tumors. However, the function of EBV-miR-BART12 remains unclear. The findings of the current study revealed that EBV-miR-BART12 binds to the 3'UTR region of Tubulin Polymerization-Promoting Protein 1 (TPPP1) mRNA and downregulates TPPP1, thereby promoting the invasion and migration of EBV-related cancers, such as nasopharyngeal cancer and gastric cancer. The mechanism underlying this process was found to be the inhibition of TPPP1 by EBV-miRNA-BART12, which, in turn, inhibits the acetylation of α-tubulin, and promotes the dynamic assembly of microtubules, remodels the cytoskeleton, and enhances the acetylation of β-catenin. β-catenin activates epithelial to mesenchymal transition (EMT). These two processes synergistically promote the invasion and metastasis of tumor cells. To the best of our knowledge, this is the first study to reveal the role of EBV-miRNA-BART12 in the development of EBV-related tumors as well as the mechanism underlying this process, and suggests potential targets and strategies for the treatment of EBV-related tumors.

CircARHGAP12 promotes nasopharyngeal carcinoma migration and invasion via ezrin-mediated cytoskeletal remodeling

An increasing number of studies have shown that circular RNAs (circRNAs) play important roles in malignant tumor initiation and progression; however, many circRNAs are yet unidentified, and the role of circRNAs in nasopharyngeal carcinoma (NPC) is unclear. Using RNA sequencing, we discovered a novel circRNA, termed circARHGAP12, that was processed from the pre-mRNA of the ARHGAP12 gene. CircARHGAP12 was significantly upregulated in NPC tissues and cell lines and promoted NPC cell migration and invasion. Overexpression or knockdown experiments revealed that circARHGAP12 regulates the expression of cytoskeletal remodeling-related proteins EZR, TPM3, and RhoA. CircARHGAP12 was found to bind directly to the 3' UTR of EZR mRNA and promote its stability; moreover, EZR protein interacted with TPM3 and RhoA and formed a complex to promote NPC cell invasion and metastasis. This study identified the novel circRNA circARHGAP12, characterized its biological function and mechanism, and increased our understanding of circRNAs in NPC pathogenesis. In particular, circARHGAP12 was found to promote the malignant biological phenotype of NPC via cytoskeletal remodeling, thus providing a clue for targeted therapy of NPC.