The regulation of pre-metastatic niche formation by neutrophils

Triple-negative breast cancer modifies the systemic immune landscape and alters neutrophil functionality

Cancer disrupts intratumoral innate-adaptive immune crosstalk, but how the systemic immune landscape evolves during breast cancer progression remains unclear. We profiled circulating immune cells in stage I-III and stage IV triple-negative breast cancer (TNBC) patients and healthy donors (HDs). Metastatic TNBC (mTNBC) patients had reduced T cells, dendritic cells, and differentiated B cells compared to non-metastatic TNBC patients and HDs, partly linked to prior chemotherapy. Vδ1 γδ T cells from mTNBC patients produced more IL17 than those from HDs. Chemotherapy-naïve mTNBC patients showed increased classical monocytes and neutrophils. Transcriptional, proteomic, and functional analyses revealed that neutrophils in mTNBC exhibited enhanced migratory capacity, elevated granule proteins, and higher ROS production. Some immune changes, such as reduced non-switched B cells and heightened neutrophil migration, were evident in earlier TNBC stages. This study comprehensively maps systemic immunity in TNBC, guiding future research on patient stratification and immunomodulation strategies.

Bidirectional role of neutrophils in tumor development

Neutrophils, traditionally considered as non-specific components of the innate immune system, have garnered considerable research interest due to their dual roles in both promoting and inhibiting tumor progression. This paper seeks to clarify the specific mechanisms by which neutrophils play a bidirectional role in tumor immunity and the factors that influence these roles. By conducting a comprehensive analysis and synthesis of a vast array of relevant literature, it has become evident that neutrophils can influence tumor development and invasive migration through various mechanisms, thereby exerting their anti-tumor effects. Conversely, they can also facilitate tumorigenesis and proliferation, as well as affect the normal physiological functions of other immune cells, thus exerting pro-tumor effects. Moreover, neutrophils are influenced by tumor cells and their unique microenvironment, which in turn affects their heterogeneity and plasticity. Neutrophils interact with tumor cells to regulate various aspects of their life activities precisely. This paper also identifies unresolved issues in the research concerning the bidirectional role of neutrophils in tumorigenesis and tumor development, offering new opportunities and challenges for advancing our understanding. This, in turn, can aid in the proper application of these insights to clinical treatment strategies.

Neutrophils in cancer: from biology to therapy

The view of neutrophils has shifted from simple phagocytic cells, whose main function is to kill pathogens, to very complex cells that are also involved in immune regulation and tissue repair. These cells are essential for maintaining and regaining tissue homeostasis. Neutrophils can be viewed as double-edged swords in a range of situations. The potent killing machinery necessary for immune responses to pathogens can easily lead to collateral damage to host tissues when inappropriately controlled. Furthermore, some subtypes of neutrophils are potent pathogen killers, whereas others are immunosuppressive or can aid in tissue healing. Finally, in tumor immunology, many examples of both protumorigenic and antitumorigenic properties of neutrophils have been described. This has important consequences for cancer therapy, as targeting neutrophils can lead to either suppressed or stimulated antitumor responses. This review will discuss the current knowledge regarding the pro- and antitumorigenic roles of neutrophils, leading to the concept of a confused state of neutrophil-driven pro-/antitumor responses.

Ex vivo assessment of human neutrophil motility and migration

Neutrophils are pivotal in orchestrating tumor-induced systemic inflammation and are increasingly recognized for their critical involvement in both the initiation and progression of cancer. A fundamental facet of neutrophil biology is their migratory capacity, which enables them to extravasate and infiltrate tumors in other tissues, where they carry out essential effector functions. Unraveling the intricate mechanisms of neutrophil motility and migration is crucial for comprehending immune responses and inflammatory processes, shedding light on their substantial contribution to cancer progression. Here, we provide a comprehensive protocol to assess direct ex vivo motility and migration of freshly isolated human neutrophils, offering valuable insights into their behavior.

Neutrophils in the premetastatic niche: key functions and therapeutic directions

Metastasis has been one of the primary reasons for the high mortality rates associated with tumours in recent years, rendering the treatment of current malignancies challenging and representing a significant cause of recurrence in patients who have undergone surgical tumour resection. Halting tumour metastasis has become an essential goal for achieving favourable prognoses following cancer treatment. In recent years, increasing clarity in understanding the mechanisms underlying metastasis has been achieved. The concept of premetastatic niches has gained widespread acceptance, which posits that tumour cells establish a unique microenvironment at distant sites prior to their migration, facilitating their settlement and growth at those locations. Neutrophils serve as crucial constituents of the premetastatic niche, actively shaping its microenvironmental characteristics, which include immunosuppression, inflammation, angiogenesis and extracellular matrix remodelling. These characteristics are intimately associated with the successful engraftment and subsequent progression of tumour cells. As our understanding of the role and significance of neutrophils in the premetastatic niche deepens, leveraging the presence of neutrophils within the premetastatic niche has gradually attracted the interest of researchers as a potential therapeutic target. The focal point of this review revolves around elucidating the involvement of neutrophils in the formation and shaping of the premetastatic niche (PMN), alongside the introduction of emerging therapeutic approaches aimed at impeding cancer metastasis.

The temporal progression of lung immune remodeling during breast cancer metastasis

Tumor metastasis requires systemic remodeling of distant organ microenvironments that impacts immune cell phenotypes, population structure, and intercellular communication. However, our understanding of immune phenotypic dynamics in the metastatic niche remains incomplete. Here, we longitudinally assayed lung immune transcriptional profiles in the polyomavirus middle T antigen (PyMT) and 4T1 metastatic breast cancer models from primary tumorigenesis, through pre-metastatic niche formation, to the final stages of metastatic outgrowth at single-cell resolution. Computational analyses of these data revealed a TLR-NFκB inflammatory program enacted by both peripherally derived and tissue-resident myeloid cells that correlated with pre-metastatic niche formation and mirrored CD14+ "activated" myeloid cells in the primary tumor. Moreover, we observed that primary tumor and metastatic niche natural killer (NK) cells are differentially regulated in mice and human patient samples, with the metastatic niche featuring elevated cytotoxic NK cell proportions. Finally, we identified cell-type-specific dynamic regulation of IGF1 and CCL6 signaling during metastatic progression that represents anti-metastatic immunotherapy candidate pathways.

Neoadjuvant immunotherapy for head and neck squamous cell carcinoma

The neoadjuvant immunotherapy approach marks a significant shift in the treatment paradigm of potentially curable HNSCC. Here, current therapies, despite being highly individualized and advanced, often fall short in achieving satisfactory long-term survival rates and are frequently associated with substantial morbidity.The primary advantage of this approach lies in its potential to intensify and enhance treatment regimens, offering a distinct modality that complements the existing triad of surgery, radiotherapy, and chemotherapy. Checkpoint inhibitors have been at the forefront of this evolution. Demonstrating moderate yet significant survival benefits in the recurrent-metastatic setting with a relatively better safety profile compared to conventional treatments, these agents hold promise when considered for earlier stages of HNSCC.On the other hand, a significant potential benefit of introducing immunotherapy in the neoadjuvant phase is the possibility of treatment de-escalation. By reducing the tumor burden before surgery, this strategy could lead to less invasive surgical interventions. The prospect of organ-sparing protocols becomes a realistic and highly valued goal in this context. Further, the early application of immunotherapy might catalyze a more effective and durable immune response. The induction of an immune memory may potentially lead to a more effective surveillance of residual disease, decreasing the rates of local, regional, and distant recurrences, thereby enhancing overall and recurrence-free survival.However, neoadjuvant immunotherapy is not without its challenges. One of the primary concerns is the safety and adverse events profile. While data suggest that adverse events are relatively rare and manageable, the long-term safety profile in the neoadjuvant setting, especially in the context of curative intent, remains a subject for ongoing research. Another unsolved issue lies in the accurate assessment of treatment response. The discrepancy between radiographic assessment using RECIST criteria and histological findings has been noted, indicating a gap in current imaging techniques' ability to accurately reflect the true efficacy of immunotherapy. This gap underscores the necessity for improved imaging methodologies and the development of new radiologic and pathologic criteria tailored to evaluate the response to immunotherapy accurately.Treatment combinations and timing represent another layer of complexity. There is a vast array of possibilities in combining immunotherapy agents with conventional chemotherapy, targeted therapy, radiation, and other experimental treatments. Determining the optimal treatment regimen for individual patients becomes an intricate task, especially when comparing small, single-arm, non-randomized trials with varying regimens and outcome measures.Moreover, one needs to consider the importance of pre- and intraoperative decision-making in the context of neoadjuvant immunotherapy. As experience with this treatment paradigm grows, there is potential for more tailored surgical approaches based on the patient's remaining disease post-neoadjuvant treatment. This consideration is particularly relevant in extensive surgeries, where organ-sparing protocols could be evaluated.In practical terms, the multi-modal nature of this treatment strategy introduces complexities, especially outside clinical trial settings. Patients face challenges in navigating the treatment landscape, which involves coordination across multiple medical disciplines, highlighting the necessity for streamlined care pathways at specialized centers to facilitate effective treatment management if the neoadjuvant approach is introduced to the real-world.These potential harms and open questions underscore the critical need for meticulously designed clinical trials and correlational studies to ensure patient safety and efficacy. Only these can ensure that this new treatment approach is introduced in a safe way and fulfils the promise it theoretically holds.

Neutrophil Nanodecoys Inhibit Tumor Metastasis by Blocking the Interaction between Tumor Cells and Neutrophils

Cancer metastasis is the main cause of cancer-related deaths and involves the interaction between tumor cells and neutrophils. In this study, we developed activated neutrophil membrane-coated nanoparticles (aNEM NPs) as nanodecoys to block neutrophil-mediated cancer metastasis. The aNEM NPs were fabricated by cloaking poly(lactic acid) nanoparticles with membranes derived from activated neutrophils and inherited the functional proteins of activated neutrophils. We demonstrated that aNEM NPs could interfere with the recruitment of neutrophils to the primary tumor and premetastatic niches, inhibit the adhesion of neutrophils to tumor vascular endothelium and circulating tumor cells (CTCs), and disrupt the formation of CTC-neutrophil clusters in vitro and in vivo. In 4T1-bearing mice, aNEM NPs could effectively reduce breast cancer metastasis to various organs in mice. Our results suggest that aNEM NPs are a promising nanomedicine for preventing or treating cancer metastasis by acting as neutrophil nanodecoys.

Characterizing the Inflammatory Profile of Neutrophil-Rich Triple-Negative Breast Cancer

Breast cancer (BC) is one of the most common types of cancer in women in the United Arab Emirates. Immunogenic tumours, such as triple-negative breast cancer (TNBC), show increased neutrophil infiltration, which is associated with poor prognosis and limited efficacy of immunotherapy. This study aims to investigate in vitro the bidirectional effect of neutrophils on metastatic TNBC (MDA-MB-231) compared to less-metastatic luminal breast cancer (MCF-7) cell lines. We found that BC cells or their conditioned medium (CM) reduced the viability of neutrophil-like cells (HL60). This was supported by increased cellular stress and NETosis in differentiated HL60 cells (dHL60) upon exposure to MDA-MB-231 compared to MCF-7-CM using nucleic acid staining essays. Flow cytometry showed comparable expression of inflammatory markers by polymorphonuclear cells (PMN) when treated with MDA-MB-231-CM and standard polarizing cocktails. Furthermore, MDA-MB-231-CM triggered an inflammatory pattern with evidence of stronger adhesion (CD62L) and degranulation (CD11b and CD66b) phenotypes. The proinflammatory polarization of dHL60 by MDA-MB-231-CM was additionally confirmed by the elevated CD54 expression, myeloperoxidase, and CD11b protein levels, which matched an increased transwell migratory capacity. In conclusion, BC might use neutrophils to their benefit through NETosis and complement system activation, which makes this crosstalk a potential mechanism for understanding tumour progression.

Unveiling the role of osteosarcoma-derived secretome in premetastatic lung remodelling

BACKGROUND

Lung metastasis is the most adverse clinical factor and remains the leading cause of osteosarcoma-related death. Deciphering the mechanisms driving metastatic spread is crucial for finding open therapeutic windows for successful organ-specific interventions that may halt or prevent lung metastasis.

METHODS

We employed a mouse premetastatic lung-based multi-omics integrative approach combined with clinical features to uncover the specific changes that precede lung metastasis formation and identify novel molecular targets and biomarker of clinical utility that enable the design of novel therapeutic strategies.

RESULTS

We found that osteosarcoma-bearing mice or those preconditioned with the osteosarcoma cell secretome harbour profound lung structural alterations with airway damage, inflammation, neutrophil infiltration, and extracellular matrix remodelling with increased deposition of fibronectin and collagens by resident stromal activated fibroblasts, favouring the adhesion of disseminated tumour cells. Systemic-induced microenvironmental changes, supported by transcriptomic and histological data, promoted and accelerated lung metastasis formation. Comparative proteome profiling of the cell secretome and mouse plasma identified a large number of proteins involved in extracellular-matrix organization, cell-matrix adhesion, neutrophil degranulation, and cytokine-mediated signalling, consistent with the observed lung microenvironmental changes. Moreover, we identified EFEMP1, an extracellular matrix glycoprotein exclusively secreted by metastatic cells, in the plasma of mice bearing a primary tumour and in biopsy specimens from osteosarcoma patients with poorer overall survival. Depletion of EFEMP1 from the secretome prevents the formation of lung metastasis.

CONCLUSIONS

Integration of our data uncovers neutrophil infiltration and the functional contribution of stromal-activated fibroblasts in ECM remodelling for tumour cell attachment as early pro-metastatic events, which may hold therapeutic potential in preventing or slowing the metastatic spread. Moreover, we identified EFEMP1, a secreted glycoprotein, as a metastatic driver and a potential candidate prognostic biomarker for lung metastasis in osteosarcoma patients. Osteosarcoma-derived secreted factors systemically reprogrammed the lung microenvironment and fostered a growth-permissive niche for incoming disseminated cells to survive and outgrow into overt metastasis. Daily administration of osteosarcoma cell secretome mimics the systemic release of tumour-secreted factors of a growing tumour in mice during PMN formation; Transcriptomic and histological analysis of premetastatic lungs revealed inflammatory-induced stromal fibroblast activation, neutrophil infiltration, and ECM remodelling as early onset pro-metastatic events; Proteome profiling identified EFEMP1, an extracellular secreted glycoprotein, as a potential predictive biomarker for lung metastasis and poor prognosis in osteosarcoma patients. Osteosarcoma patients with EFEMP1 expressing biopsies have a poorer overall survival.

Discovery of a new marker to identify myeloid cells associated with metastatic breast tumours

BACKGROUND

Myeloid cells play an essential role in cancer metastasis. The phenotypic diversity of these cells during cancer development has attracted great interest; however, their functional heterogeneity and plasticity have limited their role as prognostic markers and therapeutic targets.

METHODS

To identify markers associated with myeloid cells in metastatic tumours, we compared transcriptomic data from immune cells sorted from metastatic and non-metastatic mammary tumours grown in BALB/cJ mice. To assess the translational relevance of our in vivo findings, we assessed human breast cancer biopsies and evaluated the association between arginase 1 protein expression in breast cancer tissues with tumour characteristics and patient outcomes.

RESULTS

Among the differentially expressed genes, arginase 1 (ARG1) showed a unique expression pattern in tumour-infiltrating myeloid cells that correlated with the metastatic capacity of the tumour. Even though ARG1-positive cells were found almost exclusively inside the metastatic tumour, ARG1 protein was also present in the plasma. In human breast cancer biopsies, the presence of ARG1-positive cells was strongly correlated with high-grade proliferating tumours, poor prognosis, and low survival.

CONCLUSION

Our findings highlight the potential use of ARG1-positive myeloid cells as an independent prognostic marker to evaluate the risk of metastasis in breast cancer patients.

Effect of Thoracic Epidural Anesthesia on Perioperative Neutrophil Extracellular Trapping Markers in Patients Undergoing Anesthesia and Surgery for Colorectal Cancer: A Randomized, Controlled Trial

BACKGROUND

Neutrophil extracellular trapping (NETosis) is an immunologic mechanism strongly linked with increased metastatic risk in colorectal cancer. The authors hypothesized that patients who received propofol-epidural anesthesia (PEA) would exhibit decreases in the expression of serum neutrophil myeloperoxidase (MPO) and citrullinated histone H3 (H3Cit) levels compared with patients who received general anesthesia (GA).

METHODS

Colorectal cancer surgery patients were randomly assigned to the PEA (n = 30) or GA (n = 30) group. Serum MPO, H3Cit, and metalloproteinase-9 (MMP-9) levels before surgery and 24 h after surgery were measured, and visual analogue scale (VAS) scores were recorded.

RESULTS

The patients who received PEA showed decreases in MPO (28.06 ± 11.23 vs 20.54 ± 7.29 ng/ ml; P = 0.004) and H3Cit [3.22 ± 0.86 vs 2.73 ± 0.94 ng/ ml; P = 0.042) 24 h after surgery compared with the patients subjected to GA. In addition, there was no difference in MMP-9 levels (75.98 ± 26.9 vs 73.45 ± 28.4 ng/ ml; P = 0.726). The visual analogue scale scores 2 h and 24 h after operation were significantly lower in PEA group (P < 0.05). The number of postoperative analgesia pump pressings and sufentanil consumptions within 48 h after surgery were significantly lower in the PEA group (P < 0.001).

CONCLUSIONS

Propofol-epidural anesthesia reduces the expression of NETosis (MPO and H3Cit) in serum during colorectal cancer surgery.

CLINICAL TRIAL REGISTRATION

ChiCTR2200066708 ( www.chictr.org.cn ).

Common nutritional/inflammatory indicators are not effective tools in predicting the overall survival of patients with small cell lung cancer undergoing first-line chemotherapy

Objective

Various studies have investigated the predictive significance of numerous peripheral blood biomarkers in patients with small cell lung cancer (SCLC). However, their predictive values have not been validated. This study assessed and evaluated the ability of common nutritional or inflammatory indicators to predict overall survival (OS) in patients with SCLC who received first-line chemotherapy.

Methods

Between January 2008 and July 2019, 560 patients with SCLC were enrolled at the Sichuan University West China Hospital. Eleven nutritional or inflammatory indices obtained before chemotherapy were evaluated. The cutoff values of continuous peripheral blood indices were confirmed through maximally selected rank statistics. The relationship of peripheral blood indices with OS was investigated through univariate and multivariate Cox regression analyses. Harrell's concordance (C-index) and time-dependent receiver operating characteristic curve were used to evaluate the performance of these indices.

Results

A total of 560 patients with SCLC were enrolled in the study. All the patients received first-line chemotherapy. In the univariate Cox analysis, all indices, except the Naples score, were related to OS. In the multivariate analysis, albumin-globulin ratio was an independent factor linked with prognosis. All indices exhibited poor performance in OS prediction, with the area under the curve ranging from 0.500 to 0.700. The lactic dehydrogenase (LDH) and prognostic nutritional index (PNI) were comparatively superior predictors with C-index of 0.568 and 0.550, respectively. The LDH showed incremental predictive values, whereas the PNI showed diminishing values as survival time prolonged, especially for men or smokers. The LDH with highest sensitivity (0.646) and advanced lung cancer inflammation index (ALI) with highest specificity (0.952) were conducive to identifying death and survival at different time points.

Conclusion

Common inflammatory or nutritional biomarkers are only marginally useful in predicting outcomes in patients with SCLC receiving first-line chemotherapy. Among them, LDH, PNI, and ALI are relatively promising biomarkers for prognosis evaluation.

Neutrophils in triple-negative breast cancer: an underestimated player with increasingly recognized importance

Triple-negative breast cancer (TNBC) is the most lethal subtype of breast cancer, with limited therapeutic options readily available. Immunotherapy such as immune checkpoint inhibition has been investigated in TNBC but still encounters low overall response. Neutrophils, the most abundant leukocytes in the body, are increasingly recognized as an active cancer-modulating entity. In the bloodstream, neutrophils escort circulating tumor cells to promote their survival and stimulate their proliferation and metastasis. In the tumor microenvironment, neutrophils modulate the immune milieu through polarization between the anti-tumor and the pro-tumor phenotypes. Through a comprehensive review of recently published literature, it is evident that neutrophils are an important player in TNBC immunobiology and can be used as an important prognostic marker of TNBC. Particularly, in their pro-tumor form, neutrophils facilitate TNBC metastasis through formation of neutrophil extracellular traps and the pre-metastatic niche. These findings will help advance the potential utilization of neutrophils as a therapeutic target in TNBC.

The temporal progression of immune remodeling during metastasis

Tumor metastasis requires systemic remodeling of distant organ microenvironments which impacts immune cell phenotypes, population structure, and intercellular communication networks. However, our understanding of immune phenotypic dynamics in the metastatic niche remains incomplete. Here, we longitudinally assayed lung immune cell gene expression profiles in mice bearing PyMT-driven metastatic breast tumors from the onset of primary tumorigenesis, through formation of the pre-metastatic niche, to the final stages of metastatic outgrowth. Computational analysis of these data revealed an ordered series of immunological changes that correspond to metastatic progression. Specifically, we uncovered a TLR-NFκB myeloid inflammatory program which correlates with pre-metastatic niche formation and mirrors described signatures of CD14+ 'activated' MDSCs in the primary tumor. Moreover, we observed that cytotoxic NK cell proportions increased over time which illustrates how the PyMT lung metastatic niche is both inflammatory and immunosuppressive. Finally, we predicted metastasis-associated immune intercellular signaling interactions involving Igf1 and Ccl6 which may organize the metastatic niche. In summary, this work identifies novel immunological signatures of metastasis and discovers new details about established mechanisms that drive metastatic progression.

Graphical abstract

In brief

McGinnis et al. report a longitudinal scRNA-seq atlas of lung immune cells in mice bearing PyMT-driven metastatic breast tumors and identify immune cell transcriptional states, shifts in population structure, and rewiring of cell-cell signaling networks which correlate with metastatic progression.

Highlights

Longitudinal scRNA-seq reveals distinct stages of immune remodeling before, during, and after metastatic colonization in the lungs of PyMT mice.TLR-NFκB inflammation correlates with pre-metastatic niche formation and involves both tissue-resident and bone marrow-derived myeloid cell populations. Inflammatory lung myeloid cells mirror 'activated' primary tumor MDSCs, suggesting that primary tumor-derived cues induce Cd14 expression and TLR-NFκB inflammation in the lung. Lymphocytes contribute to the inflammatory and immunosuppressive lung metastatic microenvironment, highlighted by enrichment of cytotoxic NK cells in the lung over time. Cell-cell signaling network modeling predicts cell type-specific Ccl6 regulation and IGF1-IGF1R signaling between neutrophils and interstitial macrophages.

Estradiol Augments Tumor-Induced Neutrophil Production to Promote Tumor Cell Actions in Lymphangioleiomyomatosis Models

Lymphangioleiomyomatosis (LAM) is a rare cystic lung disease caused by smooth muscle cell-like tumors containing tuberous sclerosis (TSC) gene mutations and found almost exclusively in females. Patient studies suggest LAM progression is estrogen dependent, an observation supported by in vivo mouse models. However, in vitro data using TSC-null cell lines demonstrate modest estradiol (E2) responses, suggesting E2 effects in vivo may involve pathways independent of direct tumor stimulation. We previously reported tumor-dependent neutrophil expansion and promotion of TSC2-null tumor growth in an E2-sensitive LAM mouse model. We therefore hypothesized that E2 stimulates tumor growth in part by promoting neutrophil production. Here we report that E2-enhanced lung colonization of TSC2-null cells is indeed dependent on neutrophils. We demonstrate that E2 induces granulopoiesis via estrogen receptor α in male and female bone marrow cultures. With our novel TSC2-null mouse myometrial cell line, we show that factors released from these cells drive E2-sensitive neutrophil production. Last, we analyzed single-cell RNA sequencing data from LAM patients and demonstrate the presence of tumor-activated neutrophils. Our data suggest a powerful positive feedback loop whereby E2 and tumor factors induce neutrophil expansion, which in turn intensifies tumor growth and production of neutrophil-stimulating factors, resulting in continued TSC2-null tumor growth.

Breast tumors interfere with endothelial TRAIL at the premetastatic niche to promote cancer cell seeding

Endothelial cells (ECs) grant access of disseminated cancer cells to distant organs. However, the molecular players regulating the activation of quiescent ECs at the premetastatic niche (PMN) remain elusive. Here, we find that ECs at the PMN coexpress tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) and its cognate death receptor 5 (DR5). Unexpectedly, endothelial TRAIL interacts intracellularly with DR5 to prevent its signaling and preserve a quiescent vascular phenotype. In absence of endothelial TRAIL, DR5 activation induces EC death and nuclear factor κB/p38-dependent EC stickiness, compromising vascular integrity and promoting myeloid cell infiltration, breast cancer cell adhesion, and metastasis. Consistently, both down-regulation of endothelial TRAIL at the PMN by proangiogenic tumor-secreted factors and the presence of the endogenous TRAIL inhibitors decoy receptor 1 (DcR1) and DcR2 favor metastasis. This study discloses an intracrine mechanism whereby TRAIL blocks DR5 signaling in quiescent endothelia, acting as gatekeeper of the vascular barrier that is corrupted by the tumor during cancer cell dissemination.

Neutrophil interactions with T cells, platelets, endothelial cells, and of course tumor cells

Neutrophils sense microbes and host inflammatory mediators, and traffic to sites of infection where they direct a broad armamentarium of antimicrobial products against pathogens. Neutrophils are also activated by damage-associated molecular patterns (DAMPs), which are products of cellular injury that stimulate the innate immune system through pathways that are similar to those activated by microbes. Neutrophils and platelets become activated by injury, and cluster and cross-signal to each other with the cumulative effect of driving antimicrobial defense and hemostasis. In addition, neutrophil extracellular traps are extracellular chromatin and granular constituents that are generated in response to microbial and damage motifs and are pro-thrombotic and injurious. Although neutrophils can worsen tissue injury, neutrophils may also have a role in facilitating wound repair following injury. A central theme of this review relates to how critical functions of neutrophils that evolved to respond to infection and damage modulate the tumor microenvironment (TME) in ways that can promote or limit tumor progression. Neutrophils are reprogrammed by the TME, and, in turn, can cross-signal to tumor cells and reshape the immune landscape of tumors. Importantly, promising new therapeutic strategies have been developed to target neutrophil recruitment and function to make cancer immunotherapy more effective.

Monitoring Blood Immune Cells in Patients with Advanced Small Cell Lung Cancer Undergoing a Combined Immune Checkpoint Inhibitor/Chemotherapy

In this exploratory prospective observational study on 40 small cell lung cancer (SCLC) patients treated with a combination of chemotherapy and immune checkpoint inhibitors, blood immune cells were characterized by multi-color flow cytometry at the baseline and at the third therapy cycle. The numbers of neutrophils and of T-, B-, and NK cells, as well as the frequency of HLA-DR^low monocytes, 6-SulfoLacNAc (slan)+ non-classical monocytes and circulating dendritic cell (DC) subtypes were determined. The prognostic value of the parameters was evaluated by the patient's survival analysis with overall survival (OS) as the primary endpoint. In addition, blood cell parameters from SCLC patients were compared to those from non-SCLC (NSCLC). The global median OS of patients was 10.4 ± 1.1 months. Disease progression (15% of patients) correlated with a higher baseline neutrophil/lymphocyte ratio (NLR), more HLA-DR^low monocytes, and lower NK cell and DC numbers. The risk factors for poor OS were the presence of brain/liver metastases, a baseline NLR ≥ 6.1, HLA-DR^low monocytes ≥ 21% of monocytes, slan+ non-classical monocytes < 0.12%, and/or CD1c+ myeloid DC < 0.05% of leukocytes. Lymphocytic subpopulations did not correlate with OS. When comparing biomarkers in SCLC versus NSCLC, SCLC had a higher frequency of brain/liver metastases, a higher NLR, the lowest DC frequencies, and lower NK cell numbers. Brain/liver metastases had a substantial impact on the survival of SCLC patients. At the baseline, 45% of SCLC patients, but only 24% of NSCLC patients, had between three and five risk factors. A high basal NLR, a high frequency of HLA-DR^low monocytes, and low levels of slan+ non-classical monocytes were associated with poor survival in all lung cancer histotypes. Thus, the blood immune cell signature might contribute to a better prediction of SCLC patient outcomes and may uncover the pathophysiological peculiarities of this tumor entity.

Unobvious Neutrophil Extracellular Traps Signification in the Course of Oral Squamous Cell Carcinoma: Current Understanding and Future Perspectives

Background: The current standards of treatment for oral squamous cell carcinoma (OSCC) include surgery, radiotherapy, and chemotherapy. In recent years, research on the effectiveness of immunotherapy in the treatment of OSCC has also been conducted.Purpose: Studies indicate that nonspecific immune mechanisms involved in the course of the anticancer response also need to be taken into account.Research Design: This review summarizes the results of our research on the active participation of neutrophils, which are previously underestimated, in the antitumor response in the course of OSCC, taking into account the ability of these cells to generate neutrophil extracellular traps (NETs).Results: We proved that the formation of NETs accompanies not only inflammatory changes but also the neoplastic process and that lipopolysaccharide (LPS) or interleukin 17 (IL-17) plays a critical role in inducing the formation of NETs during the OSCC. The greatest achievement of our published findings was the demonstration of the formation and release of NETs from neutrophils cocultured with tumor cells, as well as after stimulation with supernatant from the SCC culture with a PI3K-independent Akt kinase activation mechanism. Moreover, the pioneering achievement of our studies was the localization of NET structures in the tumor tissue, as well as the observation of high concentrations of NET markers in the serum of OSCC patients with low concentrations in the saliva, indicating the differences in the course of immune response between the periphery and the local reactions.Conclusions: The data presented here provide surprising but important information on the role of NETs in the course of OSCC, thus pointing to a promising new direction in the development of management strategies for early noninvasive diagnosis and monitoring of the disease course, and perhaps immunotherapy. Furthermore, this review raises further questions and elaborates on the process of NETosis in cancer.

Immune cell-camouflaged surface-engineered nanotherapeutics for cancer management

Nanocarriers (NCs) have shown potential in delivering hydrophobic cytotoxic drugs and tumor-specific targeting. However, the inability to penetrate the tumor microenvironment and entrapment by macrophages has limited their clinical translation. Various cell-based drug delivery systems have been explored for their ability to improve circulation half-life and tumor accumulation capabilities. Tumors are characterized by high inflammation, which aids in tumor progression and metastasis. Immune cells show natural tumor tropism and penetration inside the tumor microenvironment (TME) and are a topic of great interest in cancer drug delivery. However, the TME is immunosuppressive and can polarize immune cells to pro-tumor. Thus, the use of immune cell membrane-coated NCs has gained popularity. Such carriers display immune cell-specific surface receptors for tumor-specific accumulation but lack cell machinery. The lack of immune cell machinery makes them unaffected by the immunosuppressive TME, meanwhile maintaining the inherent tumor tropism. In this review, we discuss the molecular mechanism behind the movement of various immune cells toward TME, the preparation and characterization of membrane-coated NCs, and the efficacy of immune cell-mimicking NCs in tumor therapy. Regulatory guidelines and the bottlenecks in clinical translation are also highlighted. STATEMENT OF SIGNIFICANCE: Nanocarriers have been explored for the site-specific delivery of chemotherapeutics. However, low systemic circulation half-life, extensive entrapment by macrophages, and poor accumulation inside the tumor microenvironment prevent the clinical translation of conventional nanotherapeutics. Immune cells possess the natural tropism towards the tumor along the chemokine gradient. Hence, coating the nanocarriers with immune cell-derived membranes can improve the accumulation of nanocarriers inside the tumor. Moreover, coating with membranes derived autologous immune cells will prevent engulfment by the macrophages.

Relationship between Tumor Infiltrating Immune Cells and Tumor Metastasis and Its Prognostic Value in Cancer

Tumor metastasis is an important reason for the difficulty of tumor treatment. Besides the tumor cells themselves, the tumor microenvironment plays an important role in the process of tumor metastasis. Tumor infiltrating immune cells (TIICs) are one of the main components of TME and plays an important role in every link of tumor metastasis. This article mainly reviews the role of tumor-infiltrating immune cells in epithelial mesenchymal transformation, extracellular matrix remodeling, tumor angiogenesis and formation of pre-metastatic niche. The value of TIICs in the prognosis of cervical cancer, lung cancer and breast cancer was also discussed. We believe that accurate prognosis of cancer treatment outcomes is conducive to further improving treatment regimens, determining personalized treatment strategies, and ultimately achieving successful cancer treatment. This paper elucidates the relationship between tumor and TIICs in order to explore the function of immune cells in different diseases and provide new ideas for the treatment of cancer.

Pathological features of tissues and cell populations during cancer cachexia

Cancers remain among the most devastating diseases in the human population in spite of considerable advances in limiting their impact on lifespan and healthspan. The multifactorial nature of cancers, as well as the number of tissues and organs that are affected, have exposed a considerable diversity in mechanistic features that are reflected in the wide array of therapeutic strategies that have been adopted. Cachexia is manifested in a number of diseases ranging from cancers to diabetes and ageing. In the context of cancers, a majority of patients experience cachexia and succumb to death due to the indirect effects of tumorigenesis that drain the energy reserves of different organs. Considerable information is available on the pathophysiological features of cancer cachexia, however limited knowledge has been acquired on the resident stem cell populations, and their function in the context of these diseases. Here we review current knowledge on cancer cachexia and focus on how tissues and their resident stem and progenitor cell populations are individually affected.

The cellular and molecular mediators of metastasis to the lung

Organ-specific metastasis to secondary organs is dependent on the formation of a supportive pre-metastatic niche. This tissue-specific microenvironmental response is thought to be mediated by mutational and epigenetic changes to primary tumour cells resulting in altered cross-talk between cell types. This response is augmented through the release of tumour and stromal signalling mediators including cytokines, chemokines, exosomes and growth factors. Although researchers have elucidated some of the cancer-promoting features that are bespoke to organotropic metastasis to the lungs, it remains unclear if these are organ-specific or generic between organs. Understanding the mechanisms that mediate the metastasis-promoting synergy between the host microenvironment, immunity, and pulmonary structures may elucidate predictive, prognostic and therapeutic markers that could be targeted to reduce the metastatic burden of disease. Herein, we give an updated summary of the known cellular and molecular mechanisms that contribute to the formation of the lung pre-metastatic niche and tissue-specific metastasis.

Biomimetic Nanotherapeutics: Employing Nanoghosts to fight Melanoma

Melanoma is a cancer of melanocytes present at the basal layer of the skin. Nanomedicine has armed us with competent platform to manage such fatal neoplastic diseases. Nevertheless, it suffers from numerous pitfalls such as rapid clearance and opsonization of surface-functionalized carriers, biocompatibility and idiopathic reactions which could be difficult to predict in the patient. Biomimetic approach, a novel step towards personalized medicine bridges these drawbacks by employing endogenous cell membranes to traverse physiological barriers. Camouflaged carriers coated with natural cell membranes possess unique characteristics such as high circulatory periods, and the absence of allogenic and xenogenic responses. Proteins residing on the cell membranes render a diverse range of utilities to the coated nanoparticles including natural efficiency to identify cellular targets, homologous targeting, reticuloendothelial system evasion, biocompatibility and reduced adverse and idiopathic effects. In the present article, we have focused on cell membrane camouflaged nanocarriers for melanoma management. We have discussed various types of biomimetic systems, their processing and coating approaches, and their characterization. We have also enumerated novel avenues in melanoma treatment and the combination of biomimetic systems with smart nanoparticulate systems with the potential to bring breakthroughs in the near future. Additionally, immunotherapy-based biomimetic systems to combat melanoma have been highlighted. Hurdles towards clinical translation and ways to overcome them have been explained in detail.

HAO1-mediated oxalate metabolism promotes lung pre-metastatic niche formation by inducing neutrophil extracellular traps

Metabolic reprogramming has been shown to be involved in cancer-induced pre-metastatic niche (PMN) formation, but the underlying mechanisms have been insufficiently explored. Here, we showed that hydroxyacid oxidase 1 (HAO1), a rate-limiting enzyme of oxalate synthesis, was upregulated in the alveolar epithelial cells of mice bearing metastatic breast cancer cells at the pre-metastatic stage, leading to oxalate accumulation in lung tissue. Lung oxalate accumulation induced neutrophil extracellular trap (NET) formation by activating NADPH oxidase, which facilitated the formation of pre-metastatic niche. In addition, lung oxalate accumulation promoted the proliferation of metastatic cancer cells by activating the MAPK signaling pathway. Pharmacologic inhibition of HAO1 could effectively suppress the lung oxalate accumulation induced by primary cancer, consequently dampening lung metastasis of breast cancer. Breast cancer cells induced HAO1 expression and oxalate accumulation in alveolar epithelial cells by activating TLR3-IRF3 signaling. Collectively, these findings underscore the role of HAO1-mediated oxalate metabolism in cancer-induced lung PMN formation and metastasis. HAO1 could be an appealing therapeutic target for preventing lung metastasis of cancer.

The Liver Pre-Metastatic Niche in Pancreatic Cancer: A Potential Opportunity for Intervention

Cancer-related mortality is primarily a consequence of metastatic dissemination and associated complications. Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal malignancies and tends to metastasize early, especially in the liver. Emerging evidence suggests that organs that develop metastases exhibit microscopic changes that favor metastatic growth, collectively known as "pre-metastatic niches". By definition, a pre-metastatic niche is chronologically established before overt metastatic outgrowth, and its generation involves the release of tumor-derived secreted factors that modulate cells intrinsic to the recipient organ, as well as recruitment of additional cells from tertiary sites, such as bone marrow-all orchestrated by the primary tumor. The pre-metastatic niche is characterized by tumor-promoting inflammation with tumor-supportive and immune-suppressive features, remodeling of the extracellular matrix, angiogenic modulation and metabolic alterations that support growth of disseminated tumor cells. In this paper, we review the current state of knowledge of the hepatic pre-metastatic niche in PDAC and attempt to create a framework to guide future diagnostic and therapeutic studies.

NETs biomarkers in saliva and serum OSCC patients: One hypothesis, two conclusions

PURPOSE

The actual role of neutrophils and neutrophil extracellular traps (NETs) in the course of cancer has not been clearly defined. The aim of this study was to determine the clinical usefulness of NETs biomarkers in saliva in confrontation with the blood serum and tumor tissue as a potential prognostic and therapeutic target in patients with oral squamous cell carcinoma (OSCC).

MATERIAL AND METHODS

Expression of myeloperoxidase (MPO), and histones H2A, H2B, H3 in the tumor tissue, was investigated using immunohistochemistry. The expression of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase subunits: p47-phox, p67-phox (neutrophil cytosolic factor 2, NCF2) and panRac, as well as citrullinated histone H3 (CitH3) in peripheral blood neutrophil lysates, was assessed via Western blot. ELISA tests were employed to measure the concentrations of circulating free DNA (cfDNA) and MPO in saliva only, and NOX1, NCF2, DNASE1 in saliva and serum.

RESULTS

Extracellular expression of MPO and histones was localized within tumor tissue. Significantly lower expression of p67-phox, panRac, and CitH3 was determined in OSCC patients. Considerably lower concentrations of NOX1, NCF2, and DNASE1 in the saliva samples of cancer patients were observed. However, the levels of NOX1, NCF2, and DNASE1 in the serum of patients with cancer were substantially higher.

CONCLUSIONS

The results obtained from the saliva of cancer patients suggest an impairment of the immunological homeostasis within the oral cavity related to NET formation, the causes of which should be sought in deficient activation of NADPH oxidase.

The dual role of neutrophils in cancer

For the past decade, the role and importance of neutrophils in cancer is being increasingly appreciated. Research has focused on the ability of cancer-related neutrophils to either support tumor growth or interfere with it, showing diverse mechanisms through which the effects of neutrophils take place. In contrast to the historic view of neutrophils as terminally differentiated cells, mounting evidence has demonstrated that neutrophils are a plastic and diverse population of cells. These dynamic and plastic abilities allow them to perform varied and sometimes opposite functions simultaneously. In this review, we summarize and detail clinical and experimental evidence for, and underlying mechanisms of, the dual impact of neutrophils' functions, both supporting and inhibiting cancer development. We first discuss the effects of various basic functions of neutrophils, namely direct cytotoxicity, secretion of reactive oxygen species (ROS), nitric oxide (NO) and proteases, NETosis, autophagy and modulation of other immune cells, on tumor growth and metastatic progression. We then describe the clinical evidence for pro- vs anti-tumor functions of neutrophils in human cancer. We believe and show that the "net" impact of neutrophils in cancer is the sum of a complex balance between contradicting effects which occur simultaneously.

The Colorectal Cancer Tumor Microenvironment and Its Impact on Liver and Lung Metastasis

Simple Summary

Colorectal cancer (CRC) is the third most common cancer worldwide. Metastasis to secondary organs, such as the liver and lungs, is a key driver of CRC-related mortality. The tumor microenvironment, which consists of the primary cancer cells, as well as associated support and immune cells, significantly affects the behavior of CRC cells at the primary tumor site, as well as in metastatic lesions. In this paper, we review the role of the individual components of the tumor microenvironment on tumor progression, immune evasion, and metastasis, and we discuss the implications of these components on antitumor therapies.

Abstract

Colorectal cancer (CRC) is the third most common malignancy and the second most common cause of cancer-related mortality worldwide. A total of 20% of CRC patients present with distant metastases, most frequently to the liver and lung. In the primary tumor, as well as at each metastatic site, the cellular components of the tumor microenvironment (TME) contribute to tumor engraftment and metastasis. These include immune cells (macrophages, neutrophils, T lymphocytes, and dendritic cells) and stromal cells (cancer-associated fibroblasts and endothelial cells). In this review, we highlight how the TME influences tumor progression and invasion at the primary site and its function in fostering metastatic niches in the liver and lungs. We also discuss emerging clinical strategies to target the CRC TME.

IL4/IL4R signaling promotes the osteolysis in metastatic bone of CRC through regulating the proliferation of osteoclast precursors

BACKGROUND

Bone metastasis of colorectal cancer (CRC) often indicates a poor prognosis. Osteolysis can be observed in metastatic sites, implying an aberrant activation of osteoclasts. However, how osteoclastogenesis is regulated in metastatic microenvironment caused by colorectal cancer is still unclear.

METHODS

In this study, mice bone metastatic model of CRC was established through injection of MC-38 or CT-26 cells. BrdU assays showed primary CD115 ( +) osteoclast precursors (OCPs) proliferated at the first 2 weeks. Transcriptomic profiling was performed to identify differentially expressing genes and pathways in OCPs indirectly co-cultured with CRC cells RESULTS: The expression of IL4Rα was found to be significantly upregulated in OCPs stimulated by tumor conditioned medium (CM). Further investigation indicated that IL-4 signaling regulated proliferation of OPCs through interacting with type I IL4 receptor, and neutrophils were the main source of IL-4 in bone marrow. The proliferation of OCPs can be inhibited in IL4 deficiency mice. In addition, ERK pathway was activated by IL4/IL4R signaling. Ravoxertinib, an ERK antagonists, could significantly prevent bone destruction through inhibiting the proliferation of OCPs.

CONCLUSION

Our study indicates the essential role of IL4/IL4R signaling for the proliferation of OCPs in early metastasis of CRC predominantly through activating ERK pathway, which remarkedly impacts the number of osteoclasts in later stage and leads to osteolytic lesions. Moreover, Ravoxertinib could be a new therapeutical target for bone metastasis of CRC.

Electrochemical measuring of reactive oxygen species levels in the blood to detect ratio of high-density neutrophils, suitable to alarm presence of cancer in suspicious cases

Here for the first time, a real-time electrochemical assay on unprocessed blood was designed to detect the presence of cancer in patients. The system has been based on the recently approved pathway, which indicates that the abundance of immature and mature low-density neutrophils (LDNs) with reduced ROS production in peripheral blood is increased with the presence of active cancer tumors. Reduced ROS/H₂O₂ released from LDNs play the main role in determining the ROS/H₂O₂ levels of peripheral blood. In contrast, HDNs with increased levels of released ROS/H₂O₂ have higher concentrations than LDNs in normal cases. Hence, the reduced level of ROS species in peripheral blood recorded by our carbon nanostructure decorated sensor in less than 30 seconds showed a great pre-warning about the presence of non-treated cancer in patients with suspicious mass who have been sent for further evaluations.

Cell Membrane-Coated Mimics: A Methodological Approach for Fabrication, Characterization for Therapeutic Applications, and Challenges for Clinical Translation

Cell membrane-coated (CMC) mimics are micro/nanosystems that combine an isolated cell membrane and a template of choice to mimic the functions of a cell. The design exploits its physicochemical and biological properties for therapeutic applications. The mimics demonstrate excellent biological compatibility, enhanced biointerfacing capabilities, physical, chemical, and biological tunability, ability to retain cellular properties, immune escape, prolonged circulation time, and protect the encapsulated drug from degradation and active targeting. These properties and the ease of adapting them for personalized clinical medicine have generated a significant research interest over the past decade. This review presents a detailed overview of the recent advances in the development of cell membrane-coated (CMC) mimics. The primary focus is to collate and discuss components, fabrication methodologies, and the significance of physiochemical and biological characterization techniques for validating a CMC mimic. We present a critical analysis of the two main components of CMC mimics: the template and the cell membrane and mapped their use in therapeutic scenarios. In addition, we have emphasized on the challenges associated with CMC mimics in their clinical translation. Overall, this review is an up to date toolbox that researchers can benefit from while designing and characterizing CMC mimics.

Pre-metastatic Niche Formation by Neutrophils in Different Organs

Metastasis is a multistep process requiring tumor cell detachment from the primary tumor and migration to secondary target organs through the lymphatic or blood circulatory systems. In certain cancers, specific organs are predisposed to metastases. Metastatic homing to distant organs is orchestrated by the formation of supportive metastatic microenvironment in such organs, called pre-metastatic niche. Formation of pre-metastatic niche depends on the primary tumor-mediated recruitment of bone marrow-derived myeloid cells, including neutrophils. The contribution of neutrophils to the formation of the pre-metastatic niche is recently getting growing attention. Of note, these cells can either stimulate or inhibit metastatic seeding, depending on the activation of these cells. Here, we concentrate on pro-metastatic functions of neutrophils and the mechanisms involved in this process. Pro-tumor neutrophils support the formation of pre-metastatic niche, attract tumor cells, and directly stimulate proliferation of these cells. Moreover, immunosuppressive neutrophils, also called granulocytic MDSC, promote metastatic progression by the inhibition of antitumor T-cells. Altogether, neutrophil pro-tumor properties significantly affect metastatic spread in the host. Here, we provide an up-to-date overview of roles neutrophils play in the regulation of metastatic processes in different organs.

Leveling Up the Controversial Role of Neutrophils in Cancer: When the Complexity Becomes Entangled

Neutrophils are the most abundant immune cell in the circulation of human and act as gatekeepers to discard foreign elements that have entered the body. They are essential in initiating immune responses for eliminating invaders, such as microorganisms and alien particles, as well as to act as immune surveyors of cancer cells, especially during the initial stages of carcinogenesis and for eliminating single metastatic cells in the circulation and in the premetastatic organs. Since neutrophils can secrete a whole range of factors stored in their many granules as well as produce reactive oxygen and nitrogen species upon stimulation, neutrophils may directly or indirectly affect carcinogenesis in both the positive and negative directions. An intricate crosstalk between tumor cells, neutrophils, other immune cells and stromal cells in the microenvironment modulates neutrophil function resulting in both anti- and pro-tumor activities. Both the anti-tumor and pro-tumor activities require chemoattraction towards the tumor cells, neutrophil activation and ROS production. Divergence is seen in other neutrophil properties, including differential secretory repertoire and membrane receptor display. Many of the direct effects of neutrophils on tumor growth and metastases are dependent on tight neutrophil–tumor cell interactions. Among them, the neutrophil Mac-1 interaction with tumor ICAM-1 and the neutrophil L-selectin interaction with tumor-cell sialomucins were found to be involved in the neutrophil-mediated capturing of circulating tumor cells resulting in increased metastatic seeding. On the other hand, the anti-tumor function of neutrophils was found to rely on the interaction between tumor-surface-expressed receptor for advanced glycation end products (RAGE) and Cathepsin G expressed on the neutrophil surface. Intriguingly, these two molecules are also involved in the promotion of tumor growth and metastases. RAGE is upregulated during early inflammation-induced carcinogenesis and was found to be important for sustaining tumor growth and homing at metastatic sites. Cathepsin G was found to be essential for neutrophil-supported lung colonization of cancer cells. These data level up the complexity of the dual role of neutrophils in cancer.

ARG2, MAP4K5 and TSTA3 as Diagnostic Markers of Steroid-Induced Osteonecrosis of the Femoral Head and Their Correlation With Immune Infiltration

Background

The diagnosis for steroid-induced osteonecrosis of the femoral head (SONFH) is hard to achieve at the early stage, which results in patients receiving ineffective treatment options and a poor prognosis for most cases. The present study aimed to find potential diagnostic markers of SONFH and analyze the effect exerted by infiltration of immune cells in this pathology.

Materials and Methods

R software was adopted for identifying differentially expressed genes (DEGs) and conducting functional investigation based on the microarray dataset. Then we combined SVM-RFE, WGCNA, LASSO logistic regression, and random forest (RF) algorithms for screening the diagnostic markers of SONFH and further verification by qRT-PCR. The diagnostic values were assessed through receiver operating characteristic (ROC) curves. CIBERSORT was then adopted for assessing the infiltration of immune cells and the relationship of infiltration-related immune cells and diagnostic markers.

Results

We identified 383 DEGs overall. This study found ARG2, MAP4K5, and TSTA3 (AUC = 0.980) to be diagnostic markers of SONFH. The results of qRT-PCR showed a statistically significant difference in all markers. Analysis of infiltration of immune cells indicated that neutrophils, activated dendritic cells and memory B cells were likely to show the relationship with SONFH occurrence and progress. Additionally, all diagnostic markers had different degrees of correlation with T cell follicular helper, neutrophils, memory B cells, and activated dendritic cells.

Conclusion

ARG2, MAP4K5, and TSTA3 are potential diagnostic genes for SONFH, and infiltration of immune cells may critically impact SONFH occurrence and progression.

Cancers Cells in Traps? The Pathways of NETs Formation in Response to OSCC in Humans-A Pilot Study

The aim of the experiment was to evaluate the process of neutrophil extracellular traps (NETs) formation in patients with oral squamous cell carcinoma (OSCC) in response to direct or indirect contact with SCC cells in comparison to results obtained in the cells of healthy subjects. To fulfill study objectives CAL 27 cell line and blood were obtained from cancer patients and control subjects. Parameters related to NETs formation were analyzed utilizing flow cytometry, fluorescence microscopy, and ELISA-type tests. The expression of selected phosphorylated proteins of the PI3K/Akt/PBK pathway in neutrophils was evaluated using the Western blot method. An increase in NETs formation was observed in a coculture of neutrophils with SCC cells, with the largest amount of NETs formed after stimulation with a supernatant obtained from the SCC culture. The enhanced process of NETs formation was accompanied by changes in the expression of proteins from the PI3K/Akt/PBK pathway. The obtained results prove the existence of interactions between neutrophils and cancer cells resulting in NETosis with the participation of the PI3K/Akt/PBK pathway in patients with OSCC.

Evolution of fibroblasts in the lung metastatic microenvironment is driven by stage-specific transcriptional plasticity

Mortality from breast cancer is almost exclusively a result of tumor metastasis, and lungs are one of the main metastatic sites. Cancer-associated fibroblasts are prominent players in the microenvironment of breast cancer. However, their role in the metastatic niche is largely unknown. In this study, we profiled the transcriptional co-evolution of lung fibroblasts isolated from transgenic mice at defined stage-specific time points of metastases formation. Employing multiple knowledge-based platforms of data analysis provided powerful insights on functional and temporal regulation of the transcriptome of fibroblasts. We demonstrate that fibroblasts in lung metastases are transcriptionally dynamic and plastic, and reveal stage-specific gene signatures that imply functional tasks, including extracellular matrix remodeling, stress response, and shaping the inflammatory microenvironment. Furthermore, we identified Myc as a central regulator of fibroblast rewiring and found that stromal upregulation of Myc transcriptional networks is associated with disease progression in human breast cancer.

Osteoimmuno-Oncology: Therapeutic Opportunities for Targeting Immune Cells in Bone Metastasis

Immunotherapies provide a potential treatment option for currently incurable bone metastases. Bone marrow is an important secondary lymphoid organ with a unique immune contexture. Even at non-disease state immune cells and bone cells interact with each other, bone cells supporting the development of immune cells and immune cells regulating bone turnover. In cancer, tumor cells interfere with this homeostatic process starting from formation of pre-metastatic niche and later supporting growth of bone metastases. In this review, we introduce a novel concept osteoimmuno-oncology (OIO), which refers to interactions between bone, immune and tumor cells in bone metastatic microenvironment. We also discuss therapeutic opportunities of targeting immune cells in bone metastases, and associated efficacy and safety concerns.

Simultaneous blockage of contextual TGF-β by cyto-pharmaceuticals to suppress breast cancer metastasis

It remains challenging to treat tumor metastasis currently in the light of multiple cascade processes of tumor metastasis. Additionally, multiple clinical drugs for metastasis have quite limited therapeutic potential and even facilitate metastasis in preclinical models. Thus, potential metastasis targets and novel metastasis-directed drugs are urgently needed to be further developed. Herein, transforming growth factor-β (TGF-β) is verified to contribute to lung metastasis in a context-dependent manner in the 4T1 orthotopic tumor-bearing mice model, which induces epithelial-mesenchymal-transition (EMT) to promote tumor dissemination from the primary site and dampens the anti-tumor response of neutrophils to support tumor colonization at the metastatic niche. In view of neutrophils' superior tropism towards both inflammatory primary tumor and metastatic niche, SB525334, a TGF-β receptor inhibitor, is loaded into cationic liposome (SBLP) which is subsequently incorporated into neutrophils to yield the cyto-pharmaceuticals (SBLP/NE). The systemically infused SBLP/NE can simultaneously migrate into both primary and metastatic sites, then release SB525334 in response to tumor stimuli, and contextually inhibit TGF-β-mediated-EMT and phenotype reversal of infiltrated neutrophils, showing substantial metastasis suppression efficacy without causing any detectable toxicities. This project shifts the paradigm for metastasis suppression therapy by simultaneous blockage of contextual TGF-β using metastatic-cascades-targeting neutrophil cyto-pharmaceuticals.

Current and future biomarkers for outcomes with immunotherapy in non-small cell lung cancer

Immune checkpoint inhibitors (ICI) have been validated as an effective new treatment strategy in several tumoral types including lung cancer. This remarkable shift in the therapeutic paradigm is in large part due to the duration of responses and long-term survival seen with ICI. However, despite this, the majority of cancer patients do not experience benefit from ICI. Even among patients who initially respond to ICI, disease progression may ultimately occur. Moreover, in some patients, these drugs may be associated with new patterns of progression such as pseudo-progression and hyper-progressive disease, and different toxicity profiles with immune-related adverse events. Therefore, the identification of predictive biomarkers may help to select those patients most likely to obtain a true benefit from these drugs, and avoid exposure to potential toxicity in patients who will not obtain clinical benefit, while also reducing the economic impact. In this review, we summarize current and promising potential predictive biomarkers of ICI in patients with non-small cell lung cancer (NSCLC), as well as pitfalls encountered with their use and areas of focus to optimize their routine clinical implementation.

Neutrophil and Nanoparticles Delivery to Tumor: Is It Going to Carry That Weight?

The application of cell carriers for transporting nanodrugs to the tumor draws much attention as the alternative to the passive drug delivery. In this concept, the neutrophil (NΦ) is of special interest as this cell is able to uptake nanoparticles (NPs) and cross the vascular barrier in response to tumor signaling. There is a growing body of literature describing NP-NΦ interactions in vitro and in vivo that demonstrates the opportunity of using these cells to improve the efficacy of cancer therapy. However, a number of conceptual and technical issues need to be resolved for translating the technology into clinics. The current review summarizes the recent advances and challenges associated with NP-NΦ interactions, with the special focus on the complex interplay between the NP internalization pathways and the modulation of NΦ activity, and its potential consequences for nanodrug delivery.

The cellular and molecular components involved in pre-metastatic niche formation in colorectal cancer liver metastasis

Introduction: Liver metastasis is the main cause of death in colorectal cancer (CRC). Premetastatic niche (PMN), a favorable microenvironment for cancer cells colonization at the distant organ, plays a pivotal role in CRC liver metastasis (CRCLM). Our understanding of the mechanisms mediating the formation of liver PMN in CRC has been significantly advanced in recent years, there are still many challenges and questions that remain.Areas covered: This review covers cellular and molecular components, and the interaction of theprimary cancer with the resident microenvironment of the distant organ that leads to PMN formation in CRCLM based on the latest literature.Expert Opinion: Various cellular and molecular events are involved in the liver PMN formation in CRC such as bone marrow-derived cells (BMDCs), hepatic stellate cells, Kupffer cells, extracellular matrix, and CRC-derived factors. The formation of the liver PMN depends on a complex interaction of CRC with the liver microenvironment including BMDCs recruitment, vascularization, immunosuppression, inflammatory response, and extracellular matrix remodeling. This review firstly discusses on the cellular and molecular components contributing to the formation of the liver PMN in CRC, so as to provide new ideas for designing effective therapeutic strategies and prognostic markers for CRCLM.

Identification of prognostic biomarkers associated with metastasis and immune infiltration in osteosarcoma

Osteosarcoma is the most common primary malignancy of the bones, and is associated with a high rate of metastasis and a poor prognosis. A tight association between the tumor microenvironment (TME) and osteosarcoma metastasis has been established. In the present study, the Estimation of STromal and Immune cells in MAlignant Tumor tissues using Expression data (ESTIMATE) algorithm was applied to calculate the immune and stromal scores of patients with osteosarcoma based on data from The Cancer Genome Atlas database. A metagene approach and deconvolution method were used to reveal distinct TME landscapes in patients with osteosarcoma. Bioinformatics analysis was used to identify differentially expressed genes (DEGs) associated with metastasis and immune infiltration in osteosarcoma, and a risk model was constructed using the DEGs with potential prognostic significance. Subsequently, gene set enrichment and Spearman's correlation analyses were used to delineate the biological processes associated with these prognostic biomarkers. Finally, immunohistochemical (IHC) analysis was performed to evaluate the expression levels of immune infiltrates and prognostic biomarkers in clinical osteosarcoma tissues. The results of the ESTIMATE demonstrated that patients with non-metastatic osteosarcoma presented with higher immune/stromal scores and a more favorable prognosis compared with those with metastatic osteosarcoma. The TME landscapes in patients with osteosarcoma suggested that high levels of tumor-infiltrating immune cells (TIICs) may suppress metastasis. Increased numbers of CD56bright natural killer cells, immature B cells, M1 macrophages and neutrophils, and lower levels of M2 macrophages were observed in the non-metastatic tissues compared with those in the metastatic tissues. A total of 69 DEGs were identified to be associated with metastasis and immune infiltration in osteosarcoma. Of these, GATA3, LPAR5, EVI2B, RIAM and CFH exhibited prognostic potential and were highly expressed in non-metastatic osteosarcoma tissues based on the IHC analysis results. These biomarkers were involved in various immune-related biological processes and were positively associated with multiple TIICs and immune signatures. The risk model constructed using these prognostic biomarkers demonstrated high predictive accuracy for the prognosis of osteosarcoma. In conclusion, the present study proposed a five-biomarker prognostic signature for the prediction of metastasis and immune infiltration in patients with osteosarcoma.

Characteristics of pre-metastatic niche: the landscape of molecular and cellular pathways

Metastasis is a major contributor to cancer-associated deaths. It involves complex interactions between primary tumorigenic sites and future metastatic sites. Accumulation studies have revealed that tumour metastasis is not a disorderly spontaneous incident but the climax of a series of sequential and dynamic events including the development of a pre-metastatic niche (PMN) suitable for a subpopulation of tumour cells to colonize and develop into metastases. A deep understanding of the formation, characteristics and function of the PMN is required for developing new therapeutic strategies to treat tumour patients. It is rapidly becoming evident that therapies targeting PMN may be successful in averting tumour metastasis at an early stage. This review highlights the key components and main characteristics of the PMN and describes potential therapeutic strategies, providing a promising foundation for future studies.

Nicotine promotes breast cancer metastasis by stimulating N2 neutrophils and generating pre-metastatic niche in lung

Smoking has a profound impact on tumor immunity, and nicotine, which is the major addictive component of smoke, is known to promote tumor progression despite being a non-carcinogen. In this study, we demonstrate that chronic exposure of nicotine plays a critical role in the formation of pre-metastatic niche within the lungs by recruiting pro-tumor N2-neutrophils. This pre-metastatic niche promotes the release of STAT3-activated lipocalin 2 (LCN2), a secretory glycoprotein from the N2-neutrophils, and induces mesenchymal-epithelial transition of tumor cells thereby facilitating colonization and metastatic outgrowth. Elevated levels of serum and urine LCN2 is elevated in early-stage breast cancer patients and cancer-free females with smoking history, suggesting that LCN2 serve as a promising prognostic biomarker for predicting increased risk of metastatic disease in female smoker(s). Moreover, natural compound, salidroside effectively abrogates nicotine-induced neutrophil polarization and consequently reduced lung metastasis of hormone receptor-negative breast cancer cells. Our findings suggest a pro-metastatic role of nicotine-induced N2-neutrophils for cancer cell colonization in the lungs and illuminate the therapeutic use of salidroside to enhance the anti-tumor activity of neutrophils in breast cancer patients.

Smoking is known to impact tumor immunity and promote tumor progression. Here, the authors show that chronic nicotine exposure promotes the lung pre-metastatic niche formation by recruiting pro-tumor N2-neutrophils that release lipocalin-2.

The cancer cell secretome drives cooperative manipulation of the tumour microenvironment to accelerate tumourigenesis

Cellular secretions are a fundamental aspect of cell-cell and cell-matrix interactions in vivo. In malignancy, cancer cells have an aberrant secretome compared to their non-malignant counterparts, termed the "cancer cell secretome". The cancer cell secretome can influence every stage of the tumourigenic cascade. At the primary site, cancer cells can secrete a multitude of factors that facilitate invasion into surrounding tissue, allowing interaction with the local tumour microenvironment (TME), driving tumour development and progression. In more advanced disease, the cancer cell secretome can be involved in extravasation and metastasis, including metastatic organotropism, pre-metastatic niche (PMN) preparation, and metastatic outgrowth. In this review, we will explore the latest advances in the field of cancer cell secretions, including its dynamic and complex role in activating the TME and potentiating invasion and metastasis, with comments on how these secretions may also promote therapy resistance.

Emerging biomarkers for neoadjuvant immune checkpoint inhibitors in operable non-small cell lung cancer

The advent of immune checkpoint inhibitors (ICIs) has dramatically changed the treatment of patients with locally advanced unresectable and metastatic non-small cell lung cancer (NSCLC). Now, ICIs are undergoing evaluation as neoadjuvant therapy in patients with early-stage, resectable NSCLC using candidate surrogate endpoints of clinical efficacy, i.e., major pathologic response (MPR, ≤10% viable tumor cells in resected tumors). The initial results from early, small-scale trials are encouraging; however, they also reveal that a substantial number of patients with operable disease may not benefit from neoadjuvant ICIs. Consequently, much investigative effort is currently directed toward identifying mechanisms of resistance to ICI therapy in resectable NSCLC. There is also an urgent need for biomarkers that could be used to guide the clinical decision-making process and maximize the clinical benefit of ICIs in patients with early-stage, resectable NSCLC. Here, we summarize the initial results from the trials of neoadjuvant ICIs in patients with early-stage and locally advanced operable NSCLC and review the findings of studies investigating emerging biomarkers associated with those trials.