Recruitment of monocytes/macrophages by tissue factor-mediated coagulation is essential for metastatic cell survival and premetastatic niche establishment in mice

Macrophages in the premetastatic and metastatic niche: key functions and therapeutic directions

Metastasis plays a significant role in the high mortality rates associated with cancer and is usually the endpoint of a series of sequential and dynamic events. A crucial step in metastasis development and progression is the formation of a premetastatic niche (PMN), which provides a conducive microenvironment for the settlement and colonization of disseminated tumor cells at distant metastatic sites. Extensive research has demonstrated the significance of macrophage populations within primary tumors in promoting metastatic progression. Nevertheless, the contribution of macrophages at secondary sites to the regulation of PMN formation is frequently overlooked. This review systematically explores the role of macrophages in priming the PMN to facilitate cancer metastasis. Additionally, we provide a compendium of existing strategies to target macrophages in cancer therapy.

Immune Evasion in Cancer Metastasis: An Unappreciated Role of Monocytes

Metastasis is the leading cause of cancer-related deaths. During the metastatic cascade, cancer cells tightly interact with immune cells influencing each other in the tumor microenvironment and systemically. Monocytes are important components of immune evasion and critical regulators of cancer progression. They circulate through the bloodstream and contribute to the formation of a pro-tumor microenvironment both in the tumor and pre-metastatic niche. Whereas monocyte participation in cancer development and response to therapy has been described extensively, its impact on metastasis remains a completely uncovered area. This review first summarizes data concerning the influence of monocytes on metastasis formation during their presence in the circulation, primary tumor, and pre-metastatic niche. We also highlight the latest examinations into the clinical relevance of targeting monocytes to prevent metastasis.

The roles of immune cells and non-immune cells in Pre-Metastatic Niche of Breast Cancer

Distant metastasis is a pivotal and important event in patients with breast cancer, and inhibition of metastasis has always been the focus of clinical research. Recent advances have established that the metastasis of breast cancer is exacerbated not only by cancer cells and the tumor microenvironment but also by the pre-metastatic niche (PMN). Primary tumor secretory factors, immune cells including bone marrow-derived cells mobilized by tumors and non-immune cells within the local matrix microenvironment of the host are three key factors for PMN formation. This article reviews the roles of bone marrow-derived cells, lymphocytes, fibroblasts, endothelial cells, epithelial cells and cancer stem cells in the establishment of PMN before metastasis to further understand the metastasis mechanism of breast cancer and to explore clues for the inhibition of distant metastasis. Different cells play distinct but important roles in the establishment of the PMN and the induction of breast cancer metastasis. The interaction between different cells and tumor cells determines whether CTCs can be attached, survive and proliferate to promote distant metastasis.

The prognostic role of systemic immune-inflammation index, SII, in Metastatic Castration-Resistant Prostate Cancer patients

Our study aimed to examine the predictive relevance of the Systemic Immune-Inflammation Index (SII) in patients with metastatic castration-resistant prostate cancer (mCRPC). A total of 113 mCRPC patients were assessed. In this descriptive study, SII was calculated using the formula (neutrophil count × platelet count)/lymphocyte count. The optimal threshold for SII, determined via the ROC curve, was 700. Patients with SII ≤ 700 were classified as SII-low, while those with SII > 700 were categorized as SII-high. The median overall survival (mOS) was significantly longer in the low SII group compared to the high SII group (*P = 0.015). In multivariate analysis, Gleason score, albumin levels, CHAARTED volume, and SII were identified as significant prognostic factors. Our findings indicate that SII has a strong correlation with survival and can serve as an independent prognostic marker in mCRPC patients.

Tissue factor promotes TREX1 protein stability to evade cGAS-STING innate immune response in pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) remains the most challenging human malignancy that urgently needs effective therapy. Tissue factor (TF) is expressed in ~80% of PDAC and represents a potential therapeutic target. While a novel TF-ADC (MRG004A) demonstrated efficacy for PDAC and TNBC in a Phase I/II trial [Ref. 18], the functional role of TF in PDAC remains incompletely understood. We investigated the relationship between TF and the innate STING pathway. We found that patients with TF-overexpression had poor survival, very low levels of P-STING/P-TBK1, reduced amounts of ISGs and chemokines as well as low numbers of cytotoxic immunocytes in their tumor. In experimental models of mouse and human PDAC, tumor cell-intrinsic TF expression played a major role in silencing the cytosolic micronuclei sensing and cGAS-STING activation. This process involved a TREX1 exonuclease-dependent clearance of micronucleus-DNA accumulated in tumor cells. Treatment of tumors with TF-KO/shRNA or anti-TF antibody HuSC1-39 (parent antibody of MRG004A) triggered a rapid and proteasome-dependent degradation of TREX1 thereby restoring the STING/TBK1 cascade phosphorylation. TF-inhibition therapy promoted a robust STING/IRF3-dependent IFN/CCL5/CXCL9-11 production, immune effector cell infiltration and antitumor efficacy. Moreover, in the PBMC and cancer cell co-culture, TF-inhibition synergized with a STING agonist compound. A covalently conjugated TF antibody-STING agonist ADC strongly increased the efficacy of tumor-targeted STING agonism on chemokine secretion and tumor inhibition in vitro and in vivo. Thus, TF-inhibition reshapes an "immune hot" tumor environment. TF-targeted therapy warrants clinical investigation as a single agent or in combination with immunotherapy for treating TF-positive PDAC and TNBC.

Fibrinogen: A new player and target on the formation of pre-metastatic niche in tumor metastasis

Tumor metastasis involves a series of complex and coordinated processes, which is the main cause of patient death and still a significant challenge in cancer treatment. Pre-metastatic niches (PMN), a specialized microenvironment that develops in distant organs prior to the arrival of metastatic cancer cells, plays a crucial role in driving tumor metastasis. The development of PMN depends on a complex series of cellular and molecular components including tumor-derived factors, bone marrow-derived cells, resident immune cells, and extracellular matrix. Fibrinogen, a key factor in the typical blood clotting process, is related to tumor metastasis and prognosis, according to a growing body of evidence in recent years. Fibrinogen has emerged as an important factor in mediating the formation of tumor microenvironment. Nevertheless, a clear and detailed mechanism by which fibrinogen promotes tumor metastasis remains unknown. In this review, we first explore the roles of fibrinogen in the development of PMN from four perspectives: immunosuppression, inflammation, angiogenesis, and extracellular matrix remodeling. We highlight the significance of fibrinogen in shaping PMN and discuss its potential therapeutic values, opening new avenues for targeting fibrinogen to prevent or treat metastasis.

Platelet-mediated circulating tumor cell evasion from natural killer cell killing through immune checkpoint CD155-TIGIT

BACKGROUND AND AIMS

Circulating tumor cells (CTCs) are precursors of cancer metastasis. However, how CTCs evade immunosurveillance during hematogenous dissemination remains unclear.

APPROACH AND RESULTS

We identified CTC-platelet adhesions by single-cell RNA sequencing and multiplex immunofluorescence of blood samples from multiple cancer types. Clinically, CTC-platelet aggregates were associated with significantly shorter progression-free survival and overall survival in patients with HCC. In vitro, ex vivo, and in vivo assays demonstrated direct platelet adhesions gifted cancer cells with an evasive ability from NK cell killing by upregulating inhibitory checkpoint CD155 (PVR cell adhesion molecule), therefore facilitating distant metastasis. Mechanistically, CD155 was transcriptionally regulated by the FAK/JNK/c-Jun cascade in a platelet contact-dependent manner. Further competition assays and cytotoxicity experiments revealed that CD155 on CTCs inhibited NK-cell cytotoxicity only by engaging with immune receptor TIGIT, but not CD96 and DNAM1, another 2 receptors for CD155. Interrupting the CD155-TIGIT interactions with a TIGIT antibody restored NK-cell immunosurveillance on CTCs and markedly attenuated tumor metastasis.

CONCLUSIONS

Our results demonstrated CTC evasion from NK-cell-mediated innate immunosurveillance mainly through immune checkpoint CD155-TIGIT, potentially offering an immunotherapeutic strategy for eradicating CTCs.

A novel classification method for LUAD that guides personalized immunotherapy on the basis of the cross-talk of coagulation- and macrophage-related genes

Purpose

The coagulation process and infiltration of macrophages affect the progression and prognosis of lung adenocarcinoma (LUAD) patients. This study was designed to explore novel classification methods that better guide the precise treatment of LUAD patients on the basis of coagulation and macrophages.

Methods

Weighted gene coexpression network analysis (WGCNA) was applied to identify M2 macrophage-related genes, and TAM marker genes were acquired through the analysis of scRNA-seq data. The MSigDB and KEGG databases were used to obtain coagulation-associated genes. The intersecting genes were defined as coagulation and macrophage-related (COMAR) genes. Unsupervised clustering analysis was used to evaluate distinct COMAR patterns for LUAD patients on the basis of the COMAR genes. The R package "limma" was used to identify differentially expressed genes (DEGs) between COMAR patterns. A prognostic risk score model, which was validated through external data cohorts and clinical samples, was constructed on the basis of the COMAR DEGs.

Results

In total, 33 COMAR genes were obtained, and three COMAR LUAD subtypes were identified on the basis of the 33 COMAR genes. There were 341 DEGs identified between the three COMAR subtypes, and 60 prognostic genes were selected for constructing the COMAR risk score model. Finally, 15 prognosis-associated genes (CORO1A, EPHA4, FOXM1, HLF, IFIH1, KYNU, LY6D, MUC16, PPARG, S100A8, SPINK1, SPINK5, SPP1, VSIG4, and XIST) were included in the model, which was efficient and robust in predicting LUAD patient prognosis and clinical outcomes in patients receiving anti-PD-1/PD-L1 immunotherapy.

Conclusions

LUAD can be classified into three subtypes according to COMAR genes, which may provide guidance for precise treatment.

Cancer stem cells and tumor-associated macrophages as mates in tumor progression: mechanisms of crosstalk and advanced bioinformatic tools to dissect their phenotypes and interaction

Cancer stem cells (CSCs) are a small subset within the tumor mass significantly contributing to cancer progression through dysregulation of various oncogenic pathways, driving tumor growth, chemoresistance and metastasis formation. The aggressive behavior of CSCs is guided by several intracellular signaling pathways such as WNT, NF-kappa-B, NOTCH, Hedgehog, JAK-STAT, PI3K/AKT1/MTOR, TGF/SMAD, PPAR and MAPK kinases, as well as extracellular vesicles such as exosomes, and extracellular signaling molecules such as cytokines, chemokines, pro-angiogenetic and growth factors, which finely regulate CSC phenotype. In this scenario, tumor microenvironment (TME) is a key player in the establishment of a permissive tumor niche, where CSCs engage in intricate communications with diverse immune cells. The "oncogenic" immune cells are mainly represented by B and T lymphocytes, NK cells, and dendritic cells. Among immune cells, macrophages exhibit a more plastic and adaptable phenotype due to their different subpopulations, which are characterized by both immunosuppressive and inflammatory phenotypes. Specifically, tumor-associated macrophages (TAMs) create an immunosuppressive milieu through the production of a plethora of paracrine factors (IL-6, IL-12, TNF-alpha, TGF-beta, CCL1, CCL18) promoting the acquisition by CSCs of a stem-like, invasive and metastatic phenotype. TAMs have demonstrated the ability to communicate with CSCs via direct ligand/receptor (such as CD90/CD11b, LSECtin/BTN3A3, EPHA4/Ephrin) interaction. On the other hand, CSCs exhibited their capacity to influence immune cells, creating a favorable microenvironment for cancer progression. Interestingly, the bidirectional influence of CSCs and TME leads to an epigenetic reprogramming which sustains malignant transformation. Nowadays, the integration of biological and computational data obtained by cutting-edge technologies (single-cell RNA sequencing, spatial transcriptomics, trajectory analysis) has significantly improved the comprehension of the biunivocal multicellular dialogue, providing a comprehensive view of the heterogeneity and dynamics of CSCs, and uncovering alternative mechanisms of immune evasion and therapeutic resistance. Moreover, the combination of biology and computational data will lead to the development of innovative target therapies dampening CSC-TME interaction. Here, we aim to elucidate the most recent insights on CSCs biology and their complex interactions with TME immune cells, specifically TAMs, tracing an exhaustive scenario from the primary tumor to metastasis formation.

Flow Cytometry Evaluation of Blood-Cell-Bound Surface FVIII in Hemophilia A and Thrombosis

Hemophilia A (HA) is associated with FVIII coagulation insufficiency or inactivity leading to excessive bleeding. Elevated FVIII, on the contrary, is associated with thrombophilia, thrombosis, myocardial infarctions, and stroke. Active FVIII (aFVIII) uses its C2 domain to bind to blood cells' membranes, consequently carrying out its coagulative function. We developed a reliable flow cytometry (FC) method for FVIII detection that can be utilized for assessing surface-bound FVIII on leukocytes in different coagulation/clinical states; we analyzed 49 pediatric subjects, encompassing patients with HA, other coagulopathies, venous thrombosis, and normal coagulation. Interestingly, the total leukocyte surface FVIII showed a declining trend across thrombosis, normal, and hypo-coagulation states. As expected, the leukocytes of HA patients displayed significantly lower levels of cellular-surface FVIII in comparison to patients with thrombosis. However, no significant correlation was observed between circulating levels of FVIII in plasma and the levels of FVIII bound to leukocytes, indicating that the differences in FVIII surface binding are not directly proportional to the availability of FVIII in the circulation and suggesting a specific binding mechanism governing the interaction between FVIII and leukocytes. Intriguingly, when analyzing the distinct blood subpopulations, we observed that surface FVIII levels were significantly elevated in classical monocytes of thrombosis patients compared to HA patients, healthy controls, and patients with other coagulopathies. Our study highlights the reliability of our FC platform in assessing FVIII abundance on leukocytes' membranes across coagulation states. Monocytes, particularly in cases of thrombosis, exhibit active binding of FVIII on their surface, suggesting a potential role in the pathophysiology of thrombosis that requires further investigation.

Reprogramming tumor-associated macrophages with lipid nanosystems reduces PDAC tumor burden and liver metastasis

BACKGROUND

Pancreatic ductal adenocarcinoma (PDAC) requires innovative therapeutic strategies to counteract its progression and metastatic potential. Since the majority of patients are diagnosed with advanced metastatic disease, treatment strategies targeting not only the primary tumor but also metastatic lesions are needed. Tumor-Associated Macrophages (TAMs) have emerged as central players, significantly influencing PDAC progression and metastasis. Our objective was to validate an innovative therapeutic strategy involving the reprogramming of TAMs using lipid nanosystems to prevent the formation of a pro-metastatic microenvironment in the liver.

RESULTS

In vitro results demonstrate that M2-polarized macrophages lose their M2-phenotype following treatment with lipid nanoemulsions composed of vitamin E and sphingomyelin (VitE:SM), transitioning to an M0/M1 state. Specifically, VitE:SM nanoemulsion treatment decreased the expression of macrophage M2 markers such as Arg1 and Egr2, while M1 markers such as Cd86, Il-1b and Il-12b increased. Additionally, the TGF-βR1 inhibitor Galunisertib (LY2157299) was loaded into VitE:SM nanoemulsions and delivered to C57BL/6 mice orthotopically injected with KPC PDAC tumor cells. Treated mice showed diminished primary tumor growth and reduced TAM infiltration in the liver. Moreover, we observed a decrease in liver metastasis with the nanoemulsion treatment in an intrasplenic model of PDAC liver metastasis. Finally, we validated the translatability of our VitE:SM nanosystem therapy in a human cell-based 3D co-culture model in vivo, underscoring the pivotal role of macrophages in the nanosystem's therapeutic effect in the context of human PDAC metastasis.

CONCLUSIONS

The demonstrated effectiveness and safety of our nanosystem therapy highlights a promising therapeutic approach for PDAC, showcasing its potential in reprogramming TAMs and mitigating the occurrence of liver metastasis.

Macrophages promote pre-metastatic niche formation of breast cancer through aryl hydrocarbon receptor activity

Macrophages that acquire an immunosuppressive phenotype play a crucial role in establishing the pre-metastatic niche (PMN), which is essential for facilitating breast cancer metastasis to distant organs. Our study showed that increased activity of the aryl hydrocarbon receptor (AHR) in lung macrophages plays a crucial role in establishing the immunosuppressive PMN in breast cancer. Specifically, AHR activation led to high expression of PD-L1 on macrophages by directly binding to the promoter of Pdl1. This upregulation of PD-L1 promoted the differentiation of regulatory T cells (Tregs) within the PMN, further enhancing immunosuppressive conditions. Mice with Ahr conditional deletion in macrophages had reduced lung metastasis of breast cancer. The elevated AHR levels in PMN macrophages were induced by GM-CSF, which was secreted by breast cancer cells. Mechanistically, the activated STAT5 signaling pathway induced by GM-CSF prevented AHR from being ubiquitinated, thereby sustaining its activity in macrophages. In breast cancer patients, the expression of AHR and PD-L1 was correlated with increased Treg cell infiltration, and higher levels of AHR were associated with a poor prognosis. These findings reveal that the crosstalk of breast cancer cells, lung macrophages, and Treg cells via the GM-CSF-STAT5-AHR-PD-L1 cascade modulates the lung pre-metastatic niche during breast cancer progression.

Cancer-induced systemic pre-conditioning of distant organs: building a niche for metastatic cells

From their early genesis, tumour cells integrate with the surrounding normal cells to form an abnormal structure that is tightly integrated with the host organism via blood and lymphatic vessels and even neural associations. Using these connections, emerging cancers send a plethora of mediators that efficiently perturb the entire organism and induce changes in distant tissues. These perturbations serendipitously favour early metastatic establishment by promoting a more favourable tissue environment (niche) that supports the persistence of disseminated tumour cells within a foreign tissue. Because the establishment of early metastatic niches represents a key limiting step for metastasis, the creation of a more suitable pre-conditioned tissue strongly enhances metastatic success. In this Review, we provide an updated view of the mechanisms and mediators of primary tumours described so far that induce a pro-metastatic conditioning of distant organs, which favours early metastatic niche formation. We reflect on the nature of cancer-induced systemic conditioning, considering that non-cancer-dependent perturbations of tissue homeostasis are also able to trigger pro-metastatic conditioning. We argue that a more holistic view of the processes catalysing metastatic progression is needed to identify preventive or therapeutic opportunities.

Targeting of TAMs: can we be more clever than cancer cells?

АBSTRACT: With increasing incidence and geography, cancer is one of the leading causes of death, reduced quality of life and disability worldwide. Principal progress in the development of new anticancer therapies, in improving the efficiency of immunotherapeutic tools, and in the personification of conventional therapies needs to consider cancer-specific and patient-specific programming of innate immunity. Intratumoral TAMs and their precursors, resident macrophages and monocytes, are principal regulators of tumor progression and therapy resistance. Our review summarizes the accumulated evidence for the subpopulations of TAMs and their increasing number of biomarkers, indicating their predictive value for the clinical parameters of carcinogenesis and therapy resistance, with a focus on solid cancers of non-infectious etiology. We present the state-of-the-art knowledge about the tumor-supporting functions of TAMs at all stages of tumor progression and highlight biomarkers, recently identified by single-cell and spatial analytical methods, that discriminate between tumor-promoting and tumor-inhibiting TAMs, where both subtypes express a combination of prototype M1 and M2 genes. Our review focuses on novel mechanisms involved in the crosstalk among epigenetic, signaling, transcriptional and metabolic pathways in TAMs. Particular attention has been given to the recently identified link between cancer cell metabolism and the epigenetic programming of TAMs by histone lactylation, which can be responsible for the unlimited protumoral programming of TAMs. Finally, we explain how TAMs interfere with currently used anticancer therapeutics and summarize the most advanced data from clinical trials, which we divide into four categories: inhibition of TAM survival and differentiation, inhibition of monocyte/TAM recruitment into tumors, functional reprogramming of TAMs, and genetic enhancement of macrophages.

Multi-Functional Biomaterial for the Treatment and Prevention of Central Line-Associated Bloodstream Infections

Central venous catheters are among the most used medical devices in hospitals today. Despite advances in modern medicine, catheter infections remain prevalent, causing significant morbidity and mortality worldwide. Here, SteriGel is reported, which is a multifunctional hydrogel engineered to prevent and treat central line-associated bloodstream infections (CLABSI). The mechanical properties of SteriGel are optimized to ensure appropriate gelation kinetics, bio-adhesiveness, stretchability, and recoverability to promote durability upon application and to provide persistent protection against infection. In vitro assays demonstrated that SteriGel exhibits long-term antimicrobial efficacy and has bactericidal effects against highly resistant patient-derived pathogens known to be frequently associated with CLABSI. SteriGel outperformed Biopatch, which is a clinically used device for CLABSI, in ex vivo cadaver studies that simulate clinical scenarios. Furthermore, SteriGel has biocompatible, pro-healing, and anti-inflammatory properties in vitro and in a rat subcutaneous injection model, suggesting a potential synergistic effect in the prevention and treatment of CLABSI. SteriGel is a multifunctional adherent biomaterial with potent antimicrobial effects for sustained sterility while promoting healing of the catheter incision site to protect against infection.

Macrophage diversity in cancer dissemination and metastasis

Invasion and metastasis are hallmarks of cancer. In addition to the well-recognized hematogenous and lymphatic pathways of metastasis, cancer cell dissemination can occur via the transcoelomic and perineural routes, which are typical of ovarian and pancreatic cancer, respectively. Macrophages are a universal major component of the tumor microenvironment and, in established tumors, promote growth and dissemination to secondary sites. Here, we review the role of tumor-associated macrophages (TAMs) in cancer cell dissemination and metastasis, emphasizing the diversity of myeloid cells in different tissue contexts (lungs, liver, brain, bone, peritoneal cavity, nerves). The generally used models of lung metastasis fail to capture the diversity of pathways and tissue microenvironments. A better understanding of TAM diversity in different tissue contexts may pave the way for tailored diagnostic and therapeutic approaches.

Clinical landscape of macrophage-reprogramming cancer immunotherapies

Tumour-associated macrophages (TAMs) sustain a tumour-supporting and immunosuppressive milieu and therefore aggravate cancer prognosis. To modify TAM behaviour and unlock their anti-tumoural potential, novel TAM-reprogramming immunotherapies are being developed at an accelerating rate. At the same time, scientific discoveries have highlighted more sophisticated TAM phenotypes with complex biological functions and contradictory prognostic associations. To understand the evolving clinical landscape, we reviewed current and past clinically evaluated TAM-reprogramming cancer therapeutics and summarised almost 200 TAM-reprogramming agents investigated in more than 700 clinical trials. Observable overall trends include a high frequency of overlapping strategies against the same therapeutic targets, development of more complex strategies to improve previously ineffective approaches and reliance on combinatory strategies for efficacy. However, strong anti-tumour efficacy is uncommon, which encourages re-directing efforts on identifying biomarkers for eligible patient populations and comparing similar treatments earlier. Future endeavours will benefit from considering the shortcomings of past treatment strategies and accommodating the emerging complexity of TAM biology.

Conversion of anti-tissue factor antibody sequences to chimeric antigen receptor and bi-specific T-cell engager format

BACKGROUND

The efficacy of antibody-targeted therapy of solid cancers is limited by the lack of consistent tumour-associated antigen expression. However, tumour-associated antigens shared with non-malignant cells may still be targeted using conditionally activated-antibodies, or by chimeric antigen receptor (CAR) T cells or CAR NK cells activated either by the tumour microenvironment or following 'unlocking' via multiple antigen-recognition. In this study, we have focused on tissue factor (TF; CD142), a type I membrane protein present on a range of solid tumours as a basis for future development of conditionally-activated BiTE or CAR T cells. TF is frequently upregulated on multiple solid tumours providing a selective advantage for growth, immune evasion and metastasis, as well as contributing to the pathology of thrombosis via the extrinsic coagulation pathway.

METHODS

Two well-characterised anti-TF monoclonal antibodies (mAb) were cloned into expression or transposon vectors to produce single chain (scFv) BiTE for assessment as CAR and CD28-CD3-based CAR or CD3-based BiTE. The affinities of both scFv formats for TF were determined by surface plasmon resonance. Jurkat cell line-based assays were used to confirm the activity of the BiTE or CAR constructs.

RESULTS

The anti-TF mAb hATR-5 and TF8-5G9 mAb were shown to maintain their nanomolar affinities following conversion into a single chain (scFv) format and could be utilised as CD28-CD3-based CAR or CD3-based BiTE format.

CONCLUSION

Because of the broad expression of TF on a range of solid cancers, anti-TF antibody formats provide a useful addition for the development of conditionally activated biologics for antibody and cellular-based therapy.

CXCL5 impedes CD8+ T cell immunity by upregulating PD-L1 expression in lung cancer via PXN/AKT signaling phosphorylation and neutrophil chemotaxis

BACKGROUND

Lung cancer remains one of the most prevalent cancer types worldwide, with a high mortality rate. Upregulation of programmed cell death protein 1 (PD-1) and its ligand (PD-L1) may represent a key mechanism for evading immune surveillance. Immune checkpoint blockade (ICB) antibodies against PD-1 or PD-L1 are therefore widely used to treat patients with lung cancer. However, the mechanisms by which lung cancer and neutrophils in the microenvironment sustain PD-L1 expression and impart stronger inhibition of CD8+ T cell function remain unclear.

METHODS

We investigated the role and underlying mechanism by which PD-L1+ lung cancer and PD-L1+ neutrophils impede the function of CD8+ T cells through magnetic bead cell sorting, quantitative real-time polymerase chain reaction (RT-PCR), western blotting, enzyme-linked immunosorbent assays, confocal immunofluorescence, gene silencing, flow cytometry, etc. In vivo efficacy and safety studies were conducted using (Non-obeseDiabetes/severe combined immune deficiency) SCID/NOD mice. Additionally, we collected clinical and prognostic data from 208 patients who underwent curative lung cancer resection between 2017 and 2018.

RESULTS

We demonstrated that C-X-C motif chemokine ligand 5 (CXCL5) is markedly overexpressed in lung cancer cells and is positively correlated with a poor prognosis in patients with lung cancer. Mechanistically, CXCL5 activates the phosphorylation of the Paxillin/AKT signaling cascade, leading to upregulation of PD-L1 expression and the formation of a positive feedback loop. Moreover, CXCL5 attracts neutrophils, compromising CD8+ T cell-dependent antitumor immunity. These PD-L1+ neutrophils aggravate CD8+ T cell exhaustion following lung cancer domestication. Combined treatment with anti-CXCL5 and anti-PD-L1 antibodies significantly inhibits tumor growth in vivo.

CONCLUSIONS

Our findings collectively demonstrate that CXCL5 promotes immune escape through PD-L1 upregulation in lung cancer and neutrophils chemotaxis through autocrine and paracrine mechanisms. CXCL5 may serve as a potential therapeutic target in synergy with ICBs in lung cancer immunotherapy.

An update to experimental and clinical aspects of tumor-associated macrophages in cancer development: hopes and pitfalls

Tumor-associated macrophages (TAMs) represent one of the most abundant tumor-infiltrating stromal cells, and their normal function in tumor microenvironment (TME) is to suppress tumor cells by producing cytokines which trigger both direct cell cytotoxicity and antibody-mediated immune response. However, upon prolonged exposure to TME, the classical function of these so-called M1-type TAMs can be converted to another type, "M2-type," which are recruited by tumor cells so that they promote tumor growth and metastasis. This is the reason why the accumulation of TAMs in TME is correlated with poor prognosis in cancer patients. Both M1- and M2-types have high degree of plasticity, and M2-type cells can be reprogrammed to M1-type for therapeutic purposes. This characteristic introduces TAMs as promising target for developing novel cancer treatments. In addition, inhibition of M2-type cells and blocking their recruitment in TME, as well as their depletion by inducing apoptosis, are other approaches for effective immunotherapy of cancer. In this review, we summarize the potential of TAMs to be targeted for cancer immunotherapy and provide an up-to-date about novel strategies for targeting TAMs.

Radiotherapy and immunology

The majority of cancer patients receive radiotherapy during the course of treatment, delivered with curative intent for local tumor control or as part of a multimodality regimen aimed at eliminating distant metastasis. A major focus of research has been DNA damage; however, in the past two decades, emphasis has shifted to the important role the immune system plays in radiotherapy-induced anti-tumor effects. Radiotherapy reprograms the tumor microenvironment, triggering DNA and RNA sensing cascades that activate innate immunity and ultimately enhance adaptive immunity. In opposition, radiotherapy also induces suppression of anti-tumor immunity, including recruitment of regulatory T cells, myeloid-derived suppressor cells, and suppressive macrophages. The balance of pro- and anti-tumor immunity is regulated in part by radiotherapy-induced chemokines and cytokines. Microbiota can also influence radiotherapy outcomes and is under clinical investigation. Blockade of the PD-1/PD-L1 axis and CTLA-4 has been extensively investigated in combination with radiotherapy; we include a review of clinical trials involving inhibition of these immune checkpoints and radiotherapy.

Microtubule interacting and trafficking domain containing 1 deficiency leads to poor survival via tissue factor-mediated coagulation in bladder cancer

BACKGROUND

Patients with cancer are at an increased risk of developing a hypercoagulative phenotype and venous thromboembolism. However, no clinical trial has yet confirmed that anticoagulant therapy improves cancer prognosis, and the mechanism underlying hypercoagulation in patients with bladder cancer is not well understood.

OBJECTIVES

We hypothesized that the prognostic genes affect tumor progression via tumor-mediated coagulation.

METHODS

We detected the most significant prognostic genes of bladder cancer with The Cancer Genome Atlas dataset and validated them in 2 Gene Expression Omnibus datasets and 1 ArrayExpress dataset. Immunohistochemical tests were performed on a cohort of 80 individuals to further examine the prognostic genes. For the most reliable prognostic gene, its influence on coagulation was evaluated with gene knockdown followed by next-generation sequencing and cellular and animal experiments.

RESULTS

Depletion of microtubule interacting and trafficking domain containing 1 (MITD1), a major prognostic gene of bladder cancer, significantly increased the tissue factor (TF) expression. MITD1 deficiency led to cytokinesis arrest, which, in turn, promoted the TF expression via unfolded protein response and c-Jun. The knockdown of IRE1, an essential kinase of unfolded protein response or the inactivation of c-Jun using c-Jun N-terminal kinase inhibitors weakened MITD1 deficiency- or dithiothreitol-induced TF upregulation. Cells lacking MITD1 promoted coagulation and metastasis in the experimental metastasis assay.

CONCLUSION

Our findings suggest the novel role of tumor prognostic genes upon the development of hypercoagulative phenotype and venous thromboembolism, thereby underlining the importance of anticoagulant therapy and shedding light on the therapeutic value of targeting MITD1 in bladder cancer.

Mouse Models to Evaluate the Functional Role of the Tumor Microenvironment in Cancer Progression and Therapy Responses

The tumor microenvironment (TME) is a complex ecosystem of both cellular and noncellular components that functions to impact the evolution of cancer. Various aspects of the TME have been targeted for the control of cancer; however, TME composition is dynamic, with the overall abundance of immune cells, endothelial cells (ECs), fibroblasts, and extracellular matrix (ECM) as well as subsets of TME components changing at different stages of progression and in response to therapy. To effectively treat cancer, an understanding of the functional role of the TME is needed. Genetically engineered mouse models have enabled comprehensive insight into the complex interactions within the TME ecosystem that regulate disease progression. Here, we review recent advances in mouse models that have been employed to understand how the TME regulates cancer initiation, progression, metastasis, and response to therapy.

Immunotherapies Targeting Tumor-Associated Macrophages (TAMs) in Cancer

Tumor-associated macrophages (TAMs) are one of the most plentiful immune compositions in the tumor microenvironment, which are further divided into anti-tumor M1 subtype and pro-tumor M2 subtype. Recent findings found that TAMs play a vital function in the regulation and progression of tumorigenesis. Moreover, TAMs promote tumor vascularization, and support the survival of tumor cells, causing an impact on tumor growth and patient prognosis. Numerous studies show that reducing the density of TAMs, or modulating the polarization of TAMs, can inhibit tumor growth, indicating that TAMs are a promising target for tumor immunotherapy. Recently, clinical trials have found that treatments targeting TAMs have achieved encouraging results, and the U.S. Food and Drug Administration has approved a number of drugs for use in cancer treatment. In this review, we summarize the origin, polarization, and function of TAMs, and emphasize the therapeutic strategies targeting TAMs in cancer treatment in clinical studies and scientific research, which demonstrate a broad prospect of TAMs-targeted therapies in tumor immunotherapy.

The Biological Role of Macrophage in Lung and Its Implications in Lung Cancer Immunotherapy

The lungs are the largest surface of the body and the most important organ in the respiratory system, which are constantly exposed to the external environment. Tissue Resident Macrophages in lung constitutes the important defense against external pathogens. Macrophages connects the innate and adaptive immune system, and also plays important roles in carcinogenesis and cancer immunotherapy. Lung cancer is the leading cause of cancer-related death worldwide, with an overall five-year survival rate of only 21%. Macrophages that infiltrate or aggregate in lung tumor microenvironment are defined as tumor-associated macrophages (TAMs). TAMs are the main components of immune cells in the lung tumor microenvironment. The differentiation and maturation process of TAMs can be roughly divided into two different types: classical activation pathway produces M1 tumor-associated macrophages, and bypass activation pathway produces M2 tumor-associated macrophages. Studies have found that TAMs are related to tumor invasion, metastasis, and treatment resistance, and show potential as a new target for tumor immunotherapy. Therefore, the biological function of macrophages in lung and the role of TAMs in the occurrence, development, and treatment of lung cancer are discussed in this paper.

Apoptotic cells promote circulating tumor cell survival and metastasis

During tumor progression and especially following cytotoxic therapy, cell death of both tumor and stromal cells is widespread. Despite clinical observations that high levels of apoptotic cells correlate with poorer patient outcomes, the physiological effects of dying cells on tumor progression remain incompletely understood. Here, we report that circulating apoptotic cells robustly enhance tumor cell metastasis to the lungs. Using intravenous metastasis models, we observed that the presence of apoptotic cells, but not cells dying by other mechanisms, supports circulating tumor cell (CTC) survival following arrest in the lung vasculature. Apoptotic cells promote CTC survival by recruiting platelets to the forming metastatic niche. Apoptotic cells externalize the phospholipid phosphatidylserine to the outer leaflet of the plasma membrane, which we found increased the activity of the coagulation initiator Tissue Factor, thereby triggering the formation of platelet clots that protect proximal CTCs. Inhibiting the ability of apoptotic cells to induce coagulation by knocking out Tissue Factor, blocking phosphatidylserine, or administering the anticoagulant heparin abrogated the pro-metastatic effect of apoptotic cells. This work demonstrates a previously unappreciated role for apoptotic cells in facilitating metastasis by establishing CTC-supportive emboli, and suggests points of intervention that may reduce the pro-metastatic effect of apoptotic cells.

GRAPHICAL ABSTRACT

Immune Cell Migration to Cancer

Immune cell migration is required for the development of an effective and robust immune response. This elegant process is regulated by both cellular and environmental factors, with variables such as immune cell state, anatomical location, and disease state that govern differences in migration patterns. In all cases, a major factor is the expression of cell surface receptors and their cognate ligands. Rapid adaptation to environmental conditions partly depends on intrinsic cellular immune factors that affect a cell's ability to adjust to new environment. In this review, we discuss both myeloid and lymphoid cells and outline key determinants that govern immune cell migration, including molecules required for immune cell adhesion, modes of migration, chemotaxis, and specific chemokine signaling. Furthermore, we summarize tumor-specific elements that contribute to immune cell trafficking to cancer, while also exploring microenvironment factors that can alter these cellular dynamics within the tumor in both a pro and antitumor fashion. Specifically, we highlight the importance of the secretome in these later aspects. This review considers a myriad of factors that impact immune cell trajectory in cancer. We aim to highlight the immunotherapeutic targets that can be harnessed to achieve controlled immune trafficking to and within tumors.

S6K1 deficiency in tumor stroma impairs lung metastasis of melanoma in mice

Accumulating data suggest that ribosomal protein S6 kinase 1 (S6K1), an effector in the mammalian target of rapamycin (mTOR) pathway, plays pleiotropic roles in tumor progression. However, to date, while the tumorigenic function of S6K1 in tumor cells has been well elucidated, its role in the tumor stroma remains poorly understood. We recently showed that S6K1 mediates vascular endothelial growth factor A (VEGF-A) production in macrophages, thereby supporting tumor angiogenesis and growth. As macrophage-derived VEGF-A is crucial for both tumor cell intravasation and extravasation across the vascular endothelium, our previous findings suggest that stromal S6K1 signaling is required for tumor metastatic spread. Therefore, we aimed to determine the impact of host S6K1 depletion on tumor metastasis using a murine model of pulmonary metastasis (S6k1-/- mice implanted with B16F10 melanoma). The ablation of S6K1 in the host microenvironment significantly reduced the metastasized B16F10 melanoma cells on the lung surface in both spontaneous and intravenous lung metastasis mouse models without affecting the incidence of metastasis to distant lymph nodes. In addition, stromal S6K1 loss decreased the number of tumor cells circulating in the peripheral blood of mice bearing B16F10 xenografts without affecting the vascular leakage induced by VEGF-A in vivo. These observations demonstrate that S6K1 signaling in host cells other than endothelial cells is required to modulate the host microenvironment to facilitate the metastatic spread of tumors via blood circulation, thus revealing its novel role in the tumor stroma during tumor progression.

Phenotypic Heterogeneity, Bidirectionality, Universal Cues, Plasticity, Mechanics, and the Tumor Microenvironment Drive Cancer Metastasis

Tumor diseases become a huge problem when they embark on a path that advances to malignancy, such as the process of metastasis. Cancer metastasis has been thoroughly investigated from a biological perspective in the past, whereas it has still been less explored from a physical perspective. Until now, the intraluminal pathway of cancer metastasis has received the most attention, while the interaction of cancer cells with macrophages has received little attention. Apart from the biochemical characteristics, tumor treatments also rely on the tumor microenvironment, which is recognized to be immunosuppressive and, as has recently been found, mechanically stimulates cancer cells and thus alters their functions. The review article highlights the interaction of cancer cells with other cells in the vascular metastatic route and discusses the impact of this intercellular interplay on the mechanical characteristics and subsequently on the functionality of cancer cells. For instance, macrophages can guide cancer cells on their intravascular route of cancer metastasis, whereby they can help to circumvent the adverse conditions within blood or lymphatic vessels. Macrophages induce microchannel tunneling that can possibly avoid mechanical forces during extra- and intravasation and reduce the forces within the vascular lumen due to vascular flow. The review article highlights the vascular route of cancer metastasis and discusses the key players in this traditional route. Moreover, the effects of flows during the process of metastasis are presented, and the effects of the microenvironment, such as mechanical influences, are characterized. Finally, the increased knowledge of cancer metastasis opens up new perspectives for cancer treatment.

Revealing profile of cancer-educated platelets and their factors to foster immunotherapy development

Among multiple hemostasis components, platelets hyperactivity plays major roles in cancer progression by providing surface and internal components for intercellular crosstalk as well as by behaving like immune cells. Since platelets participate and regulate immunity in homeostatic and disease states, we assumed that revealing platelets profile might help in conceiving novel anti-cancer immune-based strategies. The goal of this review is to compile and discuss the most recent reports on the nature of cancer-associated platelets and their interference with immunotherapy. An increasing number of studies have emphasized active communication between cancer cells and platelets, with platelets promoting cancer cell survival, growth, and metastasis. The anti-cancer potential of platelet-directed therapy has been intensively investigated, and anti-platelet agents may prevent cancer progression and improve the survival of cancer patients. Platelets can (i) reduce antitumor activity; (ii) support immunoregulatory cells and factors generation; (iii) underpin metastasis and, (iv) interfere with immunotherapy by expressing ligands of immune checkpoint receptors. Mediators produced by tumor cell-induced platelet activation support vein thrombosis, constrain anti-tumor T- and natural killer cell response, while contributing to extravasation of tumor cells, metastatic potential, and neovascularization within the tumor. Recent studies showed that attenuation of immunothrombosis, modulation of platelets and their factors have a good perspective in immunotherapy optimization. Particularly, blockade of intra-tumoral platelet-associated programmed death-ligand 1 might promote anti-tumor T cell-induced cytotoxicity. Collectively, these findings suggest that platelets might represent the source of relevant cancer staging biomarkers, as well as promising targets and carriers in immunotherapeutic approaches for combating cancer.

Intercellular Molecular Transfer Mediated by Extracellular Vesicles in Cancer

Among multiple pathways of intercellular communication operative in multicellular organisms, the trafficking of extracellular vesicles (EVs) and particles (EP) represents a unique mode of cellular information exchange with emerging roles in health and disease, including cancer. A distinctive feature of EV/EP-mediated cell-cell communication is that it involves simultaneous short- or long-range transfer of numerous molecular constituents (cargo) from donor to recipient cells. EV/EP uptake by donor cells elicits signalling or metabolic responses, or else leads to EV-re-emission or degradation. EVs are heterogeneous membranous structures released from cells via increasingly defined mechanisms involving either formation of multivesicular endosomes (exosomes) or budding from the plasma membrane (ectosomes). EPs (exomeres, supermeres) are membraneless complex particles, smaller than EVs and of less defined biogenesis and function. EVs/EPs carry complex assemblies of proteins, lipids and nucleic acids (RNA, DNA), which they shuttle into intercellular milieu, body fluids and recipient cells, via surface contact, fusion and different forms of internalization (endocytosis, micropinocytosis). While the physiological functions of EVs/EPs communication pathways continue to be investigated, their roles in cancer are increasingly well-defined. For example, EVs are involved in the transmission of cancer-specific molecular cargo, including mutant, oncogenic, transforming, or regulatory macromolecules to indolent, or normal cells, sometimes triggering their quasi-transformation-like states, or phenotypic alterations. Conversely, a reciprocal and avid uptake of stromal EVs by cancer cells may be responsible for modulating their oncogenic repertoire, as exemplified by the angiocrine effects of endothelial EVs influencing cancer cell stemness. EV exchanges during cancer progression have also been implicated in the formation of tumour stroma, angiogenesis and non-angiogenic neovascularization processes, immunosuppression, colonization of metastatic organ sites (premetastatic niche), paraneoplastic and systemic pathologies (thrombosis, diabetes, hepatotoxicity). Thus, an EV/EP-mediated horizontal transfer of cellular content emerges as a new dimension in cancer pathogenesis with functional, diagnostic, and therapeutic implications.

Tissue factor pathway-related biomarkers in liver cancer: activated factor VII-antithrombin complex and tissue factor mRNA levels are associated with mortality

Background

Tissue factor (TF), the main initiator of the coagulation cascade, plays a role in cancer progression and prognosis. Activated factor VII-antithrombin complex (FVIIa-AT) is considered an indirect marker of TF exposure by reflecting TF-FVIIa interaction.

Objectives

To assess the link between FVIIa-AT plasma levels, TF messenger RNA (mRNA) expression, and survival in cancer.

Methods

TF pathway-related coagulation biomarkers were assessed in 136 patients with cancer (52 with hepatocellular carcinoma, 41 with cholangiocarcinoma, and 43 with colon cancer) undergoing surgical intervention with curative intent. TF mRNA expression analysis in neoplastic vs nonneoplastic liver tissues was evaluated in a subgroup of 91 patients with primary liver cancer.

Results

FVIIa-AT levels were higher in patients with cancer than in 136 sex- and age-matched cancer-free controls. In patients with cancer, high levels of FVIIa-AT and total TF pathway inhibitor were associated with an increased mortality risk after adjustment for confounders, but only FVIIa-AT remained a predictor of mortality by including both FVIIa-AT and total TF pathway inhibitor in Cox regression (hazard ratio, 2.80; 95% CI, 1.23-6.39; the highest vs the lowest quartile). This association remained significant even after adjustment for extracellular vesicle-associated TF-dependent procoagulant activity. In the subgroup of patients with primary liver cancer, patients with high TF mRNA levels had an increased mortality risk compared with that for those with low TF mRNA levels (hazard ratio, 1.92; 95% CI, 1.03-3.57), and there was a consistent correlation among high FVIIa-AT levels, high TF mRNA levels, and increased risk of mortality.

Conclusion

High FVIIa-AT levels may allow the identification of patients with cancer involving high TF expression and predict a higher mortality risk in liver cancer.

Comprehensive analyses for the coagulation and macrophage-related genes to reveal their joint roles in the prognosis and immunotherapy of lung adenocarcinoma patients

Purpose

This study aims to explore novel biomarkers related to the coagulation process and tumor-associated macrophage (TAM) infiltration in lung adenocarcinoma (LUAD).

Methods

The macrophage M2-related genes were obtained by Weighted Gene Co-expression Network Analysis (WGCNA) in bulk RNA-seq data, while the TAM marker genes were identified by analyzing the scRNA-seq data, and the coagulation-associated genes were obtained from MSigDB and KEGG databases. Survival analysis was performed for the intersectional genes. A risk score model was subsequently constructed based on the survival-related genes for prognosis prediction and validated in external datasets.

Results

In total, 33 coagulation and macrophage-related (COMAR) genes were obtained, 19 of which were selected for the risk score model construction. Finally, 10 survival-associated genes (APOE, ARRB2, C1QB, F13A1, FCGR2A, FYN, ITGB2, MMP9, OLR1, and VSIG4) were involved in the COMAR risk score model. According to the risk score, patients were equally divided into low- and high-risk groups, and the prognosis of patients in the high-risk group was significantly worse than that in the low-risk group. The ROC curve indicated that the risk score model had high sensitivity and specificity, which was validated in multiple external datasets. Moreover, the model also had high efficacy in predicting the clinical outcomes of LUAD patients who received anti-PD-1/PD-L1 immunotherapy.

Conclusion

The COMAR risk score model constructed in this study has excellent predictive value for the prognosis and immunotherapeutic clinical outcomes of patients with LUAD, which provides potential biomarkers for the treatment and prognostic prediction.

Primary breast tumor induced extracellular matrix remodeling in premetastatic lungs

The premetastatic niche hypothesis proposes an active priming of the metastatic site by factors secreted from the primary tumor prior to the arrival of the first cancer cells. We investigated several extracellular matrix (ECM) structural proteins, ECM degrading enzymes, and ECM processing proteins involved in the ECM remodeling of the premetastatic niche. Our in vitro model consisted of lung fibroblasts, which were exposed to factors secreted by nonmalignant breast epithelial cells, nonmetastatic breast cancer cells, or metastatic breast cancer cells. We assessed ECM remodeling in vivo in premetastatic lungs of female mice growing orthotopic primary breast tumor xenografts, as compared to lungs of control mice without tumors. Premetastatic lungs contained significantly upregulated Collagen (Col) Col4A5, matrix metalloproteinases (MMPs) MMP9 and MMP14, and decreased levels of MMP13 and lysyl oxidase (LOX) as compared to control lungs. These in vivo findings were consistent with several of our in vitro cell culture findings, which showed elevated Col14A1, Col4A5, glypican-1 (GPC1) and decreased Col5A1 and Col15A1 for ECM structural proteins, increased MMP2, MMP3, and MMP14 for ECM degrading enzymes, and decreased LOX, LOXL2, and prolyl 4-hydroxylase alpha-1 (P4HA1) for ECM processing proteins in lung fibroblasts conditioned with metastatic breast cancer cell media as compared to control. Taken together, our data show that premetastatic priming of lungs by primary breast tumors resulted in significant ECM remodeling which could facilitate metastasis by increasing interstitial fibrillar collagens and ECM stiffness (Col14A1), disruptions of basement membranes (Col4A5), and formation of leaky blood vessels (MMP2, MMP3, MMP9, and MMP14) to promote metastasis.

Cancer metastasis: Molecular mechanisms and clinical perspectives

Metastatic progression combined with non-responsiveness towards systemic therapy often shapes the course of disease for cancer patients and commonly determines its lethal outcome. The complex molecular events that promote metastasis are a combination of both, the acquired pro-metastatic properties of cancer cells and a metastasis-permissive or -supportive tumor micro-environment (TME). Yet, dissemination is a challenging process for cancer cells that requires a series of events to enable cancer cell survival and growth. Metastatic cancer cells have to initially detach themselves from primary tumors, overcome the challenges of their intravasal journey and colonize distant sites that are suited for their metastases. The implicated obstacles including anoikis and immune surveillance, can be overcome by intricate intra- and extracellular signaling pathways, which we will summarize and discuss in this review. Further, emerging modulators of metastasis, like the immune-microenvironment, microbiome, sublethal cell death engagement, or the nervous system will be integrated into the existing working model of metastasis.

Live-imaging studies reveal how microclots and the associated inflammatory response enhance cancer cell extravasation

Previous clinical studies and work in mouse models have indicated that platelets and microclots might enable the recruitment of immune cells to the pre-metastatic cancer niche, leading to efficacious extravasation of cancer cells through the vessel wall. Here, we investigated the interaction between platelets, endothelial cells, inflammatory cells, and engrafted human and zebrafish cancer cells by live-imaging studies in translucent zebrafish larvae, and show how clotting (and clot resolution) act as foci and as triggers for extravasation. Fluorescent tagging in each lineage revealed their dynamic behaviour and potential roles in these events, and we tested function by genetic and drug knockdown of the contributing players. Morpholino knockdown of fibrinogen subunit α (fga) and warfarin treatment to inhibit clotting both abrogated extravasation of cancer cells. The inflammatory phenotype appeared fundamental, and we show that forcing a pro-inflammatory, tnfa-positive phenotype is inhibitory to extravasation of cancer cells.

In vitro cross-talk between metastasis-competent circulating tumor cells and platelets in colon cancer: a malicious association during the harsh journey in the blood

Background: Platelets are active players in hemostasis, coagulation and also tumorigenesis. The cross-talk between platelets and circulating tumor cells (CTCs) may have various pro-cancer effects, including promoting tumor growth, epithelial-mesenchymal transition (EMT), metastatic cell survival, adhesion, arrest and also pre-metastatic niche and metastasis formation. Interaction with CTCs might alter the platelet transcriptome. However, as CTCs are rare events, the cross-talk between CTCs and platelets is poorly understood. Here, we used our established colon CTC lines to investigate the colon CTC-platelet cross-talk in vitro and its impact on the behavior/phenotype of both cell types. Methods: We exposed platelets isolated from healthy donors to thrombin (positive control) or to conditioned medium from three CTC lines from one patient with colon cancer and then we monitored the morphological and protein expression changes by microscopy and flow cytometry. We then analyzed the transcriptome by RNA-sequencing of platelets indirectly (presence of a Transwell insert) co-cultured with the three CTC lines. We also quantified by reverse transcription-quantitative PCR the expression of genes related to EMT and cancer development in CTCs after direct co-culture (no Transwell insert) with platelets. Results: We observed morphological and transcriptomic changes in platelets upon exposure to CTC conditioned medium and indirect co-culture (secretome). Moreover, the expression levels of genes involved in EMT (p < 0.05) were decreased in CTCs co-cultured with platelets, but not of genes encoding mesenchymal markers (FN1 and SNAI2). The expression levels of genes involved in cancer invasiveness (MYC, VEGFB, IL33, PTGS2, and PTGER2) were increased. Conclusion: For the first time, we studied the CTC-platelet cross-talk using our unique colon CTC lines. Incubation with CTC conditioned medium led to platelet aggregation and activation, supporting the hypothesis that their interaction may contribute to preserve CTC integrity during their journey in the bloodstream. Moreover, co-culture with platelets influenced the expression of several genes involved in invasiveness and EMT maintenance in CTCs.

Macrophage-Based Therapeutic Strategies in Hematologic Malignancies

Macrophages are types of immune cells, with ambivalent functions in tumor growth, which depend on the specific environment in which they reside. Tumor-associated macrophages (TAMs) are a diverse population of immunosuppressive myeloid cells that play significant roles in several malignancies. TAM infiltration in malignancies has been linked to a poor prognosis and limited response to treatments, including those using checkpoint inhibitors. Understanding the precise mechanisms through which macrophages contribute to tumor growth is an active area of research as targeting these cells may offer potential therapeutic approaches for cancer treatment. Numerous investigations have focused on anti-TAM-based methods that try to eliminate, rewire, or target the functional mediators released by these cells. Considering the importance of these strategies in the reversion of tumor resistance to conventional therapies and immune modulatory vaccination could be an appealing approach for the immunosuppressive targeting of myeloid cells in the tumor microenvironment (TME). The combination of reprogramming and TAM depletion is a special feature of this approach compared to other clinical strategies. Thus, the present review aims to comprehensively overview the pleiotropic activities of TAMs and their involvement in various stages of cancer development as a potent drug target, with a focus on hematologic tumors.

The Brain Pre-Metastatic Niche: Biological and Technical Advancements

Metastasis, particularly brain metastasis, continues to puzzle researchers to this day, and exploring its molecular basis promises to break ground in developing new strategies for combatting this deadly cancer. In recent years, the research focus has shifted toward the earliest steps in the formation of metastasis. In this regard, significant progress has been achieved in understanding how the primary tumor affects distant organ sites before the arrival of tumor cells. The term pre-metastatic niche was introduced for this concept and encompasses all influences on sites of future metastases, ranging from immunological modulation and ECM remodeling to the softening of the blood-brain barrier. The mechanisms governing the spread of metastasis to the brain remain elusive. However, we begin to understand these processes by looking at the earliest steps in the formation of metastasis. This review aims to present recent findings on the brain pre-metastatic niche and to discuss existing and emerging methods to further explore the field. We begin by giving an overview of the pre-metastatic and metastatic niches in general before focusing on their manifestations in the brain. To conclude, we reflect on the methods usually employed in this field of research and discuss novel approaches in imaging and sequencing.

Macrophages in immunoregulation and therapeutics

Macrophages exist in various tissues, several body cavities, and around mucosal surfaces and are a vital part of the innate immune system for host defense against many pathogens and cancers. Macrophages possess binary M1/M2 macrophage polarization settings, which perform a central role in an array of immune tasks via intrinsic signal cascades and, therefore, must be precisely regulated. Many crucial questions about macrophage signaling and immune modulation are yet to be uncovered. In addition, the clinical importance of tumor-associated macrophages is becoming more widely recognized as significant progress has been made in understanding their biology. Moreover, they are an integral part of the tumor microenvironment, playing a part in the regulation of a wide variety of processes including angiogenesis, extracellular matrix transformation, cancer cell proliferation, metastasis, immunosuppression, and resistance to chemotherapeutic and checkpoint blockade immunotherapies. Herein, we discuss immune regulation in macrophage polarization and signaling, mechanical stresses and modulation, metabolic signaling pathways, mitochondrial and transcriptional, and epigenetic regulation. Furthermore, we have broadly extended the understanding of macrophages in extracellular traps and the essential roles of autophagy and aging in regulating macrophage functions. Moreover, we discussed recent advances in macrophages-mediated immune regulation of autoimmune diseases and tumorigenesis. Lastly, we discussed targeted macrophage therapy to portray prospective targets for therapeutic strategies in health and diseases.

Tissue factor overexpression in triple-negative breast cancer promotes immune evasion by impeding T-cell infiltration and effector function

Triple-negative breast cancer (TNBC) remains a most deadly human malignancy with limited response to chemotherapy, targeted therapy and immunotherapy. Tumor immunoenvironment plays an increasingly important role in therapy outcome. Tissue factor (TF) is the target of the FDA-approved ADC Tivdak. HuSC1-39 is the parent antibody of MRG004A, a clinical stage TF-ADC (NCT04843709). Here, we employed HuSC1-39 (termed "anti-TF") to investigate the role of TF in regulating immune-tolerance in TNBC. We found that patients with aberrant TF expression had a poor prognosis and low immune effector cell infiltration, characterizing as "cold tumor". In the 4T1 TNBC syngeneic mouse model, knockout of tumor cell TF inhibited tumor growth and increased tumor infiltration of effector T cell, which was not dependent on the clotting inhibition. In an immune-reconstituted M-NSG mouse model of TNBC, anti-TF inhibited tumor growth, which was further enhanced by a dual-targeting anti-TF&TGFβR fusion protein. There were diminished P-AKT and P-ERK signaling and profound tumor cell death in treated tumors. Transcriptome analyses and immunohistochemistry revealed a dramatically improved tumor immunoenvironment including the increase of effector T cells, decrease of Treg cells and the transformation of tumor into "hot tumor". Moreover, employing qPCR analysis and T cell culture, we further demonstrated that TF expression in tumor cells is sufficient to block the synthesis and secretion of T cell-recruiting chemokine CXCL9/10/11. Treatment of TF-high TNBC cells with anti-TF or TF-knockout all stimulated CXCL9/10/11 production, promoted T cell migration and effector function. Thus, we have identified a new mechanism of TF in TNBC tumor progression and therapy resistance.

The Interplay between T Cells and Cancer: The Basis of Immunotherapy

Over the past decade, immunotherapy has emerged as one of the most promising approaches to cancer treatment. The use of immune checkpoint inhibitors has resulted in impressive and durable clinical responses in the treatment of various cancers. Additionally, immunotherapy utilizing chimeric antigen receptor (CAR)-engineered T cells has produced robust responses in blood cancers, and T cell receptor (TCR)-engineered T cells are showing promising results in the treatment of solid cancers. Despite these noteworthy advancements in cancer immunotherapy, numerous challenges remain. Some patient populations are unresponsive to immune checkpoint inhibitor therapy, and CAR T cell therapy has yet to show efficacy against solid cancers. In this review, we first discuss the significant role that T cells play in the body's defense against cancer. We then delve into the mechanisms behind the current challenges facing immunotherapy, starting with T cell exhaustion due to immune checkpoint upregulation and changes in the transcriptional and epigenetic landscapes of dysfunctional T cells. We then discuss cancer-cell-intrinsic characteristics, including molecular alterations in cancer cells and the immunosuppressive nature of the tumor microenvironment (TME), which collectively facilitate tumor cell proliferation, survival, metastasis, and immune evasion. Finally, we examine recent advancements in cancer immunotherapy, with a specific emphasis on T-cell-based treatments.

The effects of morphine on vascular cell adhesion molecule 1(VCAM-1) concentration in lung cancer cells

OBJECTIVE

Vascular cell adhesion molecule 1 (VCAM-1) plays an important role in tumour cell adhesion to endothelial cells. Some tumour cells also show aberrant expression of VCAM-1. Toll-like receptor 4 (TLR4) agonists can increase VCAM-1 expression. Morphine, an opioid receptor agonist, is also a TLR4 agonist. In this study, we aimed to evaluate whether morphine increase VCAM-1 expression in a TLR4 dependent manner.

METHODS

A549 Lung cancer cells were treated with different doses of morphine and TLR4 antagonist for 24 and 48 h. TLR4 gene expression was evaluated by real-time PCR and VCAM-1 protein was measured by the enzyme-linked immunosorbent assay (ELISA).

RESULTS

Morphine enhanced mRNA expression of TLR4 and protein level of VCAM-1. TLR4 antagonist returned VCAM-1expression to the normal level.

CONCLUSION

Morphine effects VCAM-1expressions via TLR4 in lung cancer cell line.

Immune determinants of the pre-metastatic niche

Primary tumors actively and specifically prime pre-metastatic niches (PMNs), the future sites of organotropic metastasis, preparing these distant microenvironments for disseminated tumor cell arrival. While initial studies of the PMN focused on extracellular matrix alterations and stromal reprogramming, it is increasingly clear that the far-reaching effects of tumors are in great part achieved through systemic and local PMN immunosuppression. Here, we discuss recent advances in our understanding of the tumor immune microenvironment and provide a comprehensive overview of the immune determinants of the PMN's spatiotemporal evolution. Moreover, we depict the PMN immune landscape, based on functional pre-clinical studies as well as mounting clinical evidence, and the dynamic, reciprocal crosstalk with systemic changes imposed by cancer progression. Finally, we outline emerging therapeutic approaches that alter the dynamics of the interactions driving PMN formation and reverse immunosuppression programs in the PMN ensuring early anti-tumor immune responses.

Interactions between Platelets and Tumor Microenvironment Components in Ovarian Cancer and Their Implications for Treatment and Clinical Outcomes

Platelets, the primary operatives of hemostasis that contribute to blood coagulation and wound healing after blood vessel injury, are also involved in pathological conditions, including cancer. Malignancy-associated thrombosis is common in ovarian cancer patients and is associated with poor clinical outcomes. Platelets extravasate into the tumor microenvironment in ovarian cancer and interact with cancer cells and non-cancerous elements. Ovarian cancer cells also activate platelets. The communication between activated platelets, cancer cells, and the tumor microenvironment is via various platelet membrane proteins or mediators released through degranulation or the secretion of microvesicles from platelets. These interactions trigger signaling cascades in tumors that promote ovarian cancer progression, metastasis, and neoangiogenesis. This review discusses how interactions between platelets, cancer cells, cancer stem cells, stromal cells, and the extracellular matrix in the tumor microenvironment influence ovarian cancer progression. It also presents novel potential therapeutic approaches toward this gynecological cancer.

A timeline of tumour-associated macrophage biology

Tumour progression is modulated by the local microenvironment. This environment is populated by many immune cells, of which macrophages are among the most abundant. Clinical correlative data and a plethora of preclinical studies in mouse models of cancers have shown that tumour-associated macrophages (TAMs) play a cancer-promoting role. Within the primary tumour, TAMs promote tumour cell invasion and intravasation and tumour stem cell viability and induce angiogenesis. At the metastatic site, metastasis-associated macrophages promote extravasation, tumour cell survival and persistent growth, as well as maintain tumour cell dormancy in some contexts. In both the primary and metastatic sites, TAMs are suppressive to the activities of cytotoxic T and natural killer cells that have the potential to eradicate tumours. Such activities suggest that TAMs will be a major target for therapeutic intervention. In this Perspective article, we chronologically explore the evolution of our understanding of TAM biology put into the context of major enabling advances in macrophage biology.

Coadaptation fostered by the SLIT2-ROBO1 axis facilitates liver metastasis of pancreatic ductal adenocarcinoma

To explore the mechanism of coadaptation and the potential drivers of pancreatic ductal adenocarcinoma (PDAC) metastasis to the liver, we study key molecules involved in this process and their translational value. Premetastatic niche (PMN) and macrometastatic niche (MMN) formation in a mouse model is observed via CT combined with 3D organ reconstruction bioluminescence imaging, and then we screen slit guidance ligand 2 (SLIT2) and its receptor roundabout guidance receptor 1 (ROBO1) as important factors. After we confirm the expression and distribution of SLIT2 and ROBO1 in samples from PDAC patients and several mouse models, we discover that SLIT2-ROBO1-mediated coadaptation facilitated the implantation and outgrowth of PDAC disseminated tumour cells (DTCs) in the liver. We also demonstrate the dependence receptor (DR) characteristics of ROBO1 in a follow-up mechanistic study. A neutralizing antibody targeting ROBO1 significantly attenuate liver metastasis of PDAC by preventing the coadaptation effect. Thus, we demonstrate that coadaptation is supported by the DR characteristics in the PMN and MMN.

Metastatic Lung Cancer to the Head and Neck: A Clinico-Pathological Study on 21 Cases with Narrative Review of the Literature

Metastases from lung cancer to the oral cavity and to the head and neck generally are very infrequent and usually manifest in advanced stages of the disease. Even more rarely, they are the first sign of an unknown metastatic disease. Nevertheless, their occurrence always represents a challenging situation both for clinicians, in the management of very unusual lesions, and for pathologists, in the recognition of the primary site. We retrospectively studied 21 cases of metastases to the head and neck from lung cancer (sixteen males and five females, age range 43-80 years; eight cases localized to the gingiva [two of these to the peri-implant gingiva], seven to the sub-mandibular lymph nodes, two to the mandible, three to the tongue, one case to the parotid gland; in eight patients, metastasis was the first clinical manifestation of an occult lung cancer) and proposed a wide immunohistochemical panel for a proper identification of the primary tumor histotype, including CK5/6, CK8/18, CK7, CK20, p40, p63, TTF-1, CDX2, Chromogranin A, Synaptophysin, GATA-3, Estrogen Receptors, PAX8, PSA. Furthermore, we collected data from previously published studies and narratively reviewed the relevant literature.

Amoeboid migration in health and disease: Immune responses versus cancer dissemination

Cell migration is crucial for efficient immune responses and is aberrantly used by cancer cells during metastatic dissemination. Amoeboid migrating cells use myosin II-powered blebs to propel themselves, and change morphology and direction. Immune cells use amoeboid strategies to respond rapidly to infection or tissue damage, which require quick passage through several barriers, including blood, lymph and interstitial tissues, with complex and varied environments. Amoeboid migration is also used by metastatic cancer cells to aid their migration, dissemination and survival, whereby key mechanisms are hijacked from professionally motile immune cells. We explore important parallels observed between amoeboid immune and cancer cells. We also consider key distinctions that separate the lifespan, state and fate of these cell types as they migrate and/or fulfil their function. Finally, we reflect on unexplored areas of research that would enhance our understanding of how tumour cells use immune cell strategies during metastasis, and how to target these processes.

Systemic immune-inflammation index during treatment predicts prognosis and guides clinical treatment in patients with nasopharyngeal carcinoma

PURPOSE

Systemic immune-inflammation index (SII) has been demonstrated to be closely associated with the poor prognosis of nasopharyngeal carcinoma (NPC). However, the role of SII during treatment of NPC has not been reported. This study aimed to determine the prognostic value of SII during treatment for NPC patients.

METHODS

A total of 759 patients diagnosed with NPC were included in this retrospective study (393 in training cohort and 366 in validation cohort). The correlation between variables was analyzed by the chi-squared test, the Fisher's exact test or the likelihood test. Kaplan-Meier method and log-rank test were used to analyze progression-free survival (PFS) and overall survival (OS). The independent prognostic factors were determined by multivariate analysis of Cox proportional hazards regression model. The uncontrolled risk was analyzed by Logistic regression. Receiver operating characteristic (ROC) curves were used to assess prognostic value.

RESULTS

The optimal cut-off point for the SII during treatment was 937.32. High SII during treatment group had higher uncontrolled risk than low SII during treatment group (p = 0.008). In multivariate Cox proportional hazard models analysis, SII during treatment was an independent prognostic factor for 5-year PFS (p < 0.001) and 5-year OS (p < 0.001). All results were found in the training cohort and confirmed in the validation cohort.

CONCLUSIONS

The SII during treatment is a promising indicator of predicting the survival in NPC patients, especially the risk of uncontrolled occurrence. By monitoring the SII during treatment, it is possible to better evaluate the treatment effect and formulate personalized treatment.