Nuclear factor-kappaB and tumor-associated macrophages

High M2-TAM Infiltration and STAT3/NF-κB Signaling Pathway as a Predictive Factor for Tumor Progression and Death in Cervical Cancer

INTRODUCTION

The tumor microenvironment (TME) plays a crucial role in the progression, invasion, and metastasis of cervical carcinoma (CC). Tumor-associated macrophages (TAMs) are significant components of the CC TME, but studies on their correlation with CC progression are still controversial. This study aimed to investigate the relationship between TAM infiltration, the STAT3/NF-κB signaling pathway, and Overall Survival (OS) in CC patients.

METHODS

In a retrospective study, 691 CC patients who had received a definitive histopathologic diagnosis of CC scored by the FIGO staging system and not undergone preoperative treatment were selected from a database. The effect of TAM infiltration on tumor progression biomarkers using Tissue Microarray (TMA) and immunohistochemistry was evaluated. Furthermore, the impact of the expression of these biomarkers and clinical-pathological parameters on recurrence-free (RF) and OS using Kaplan-Meier and multivariable Cox regression methods was also analyzed.

RESULTS

High stromal CD163 + 204 + TAMs density and via STAT3 and NF-κB pathways was relevant to the expression of E-cadherin, Vimentin, MMP9, VEGFα, Bcl-2, Ki-67, CD25, MIF, FOXP3, and IL-17 (all p < 0.0001). In addition, elevated TNM staging IV had a strong association correlation with STAT3 and NF-κB pathways (p < 0.0001), CD25 (p < 0.001), VEGFα (p < 0.001), MIF (p < 0.0001), and Ki-67 (p < 0.0001). On the other hand, overall and recurrence survival was shown to be strongly influenced by the expression of SNAIL (HR = 1.52), E-cadherin (HR = 1.78), and Ki-67 (HR = 1.44).

CONCLUSION

M2-TAM and via STAT3/NF-κB pathways had a strong effect on CC tumor progression which reverberated in the severity of clinicopathological findings, becoming an important factor of poor prognosis.

Targeting Macrophage Polarization for Reinstating Homeostasis following Tissue Damage

Tissue regeneration and remodeling involve many complex stages. Macrophages are critical in maintaining micro-environmental homeostasis by regulating inflammation and orchestrating wound healing. They display high plasticity in response to various stimuli, showing a spectrum of functional phenotypes that vary from M1 (pro-inflammatory) to M2 (anti-inflammatory) macrophages. While transient inflammation is an essential trigger for tissue healing following an injury, sustained inflammation (e.g., in foreign body response to implants, diabetes or inflammatory diseases) can hinder tissue healing and cause tissue damage. Modulating macrophage polarization has emerged as an effective strategy for enhancing immune-mediated tissue regeneration and promoting better integration of implantable materials in the host. This article provides an overview of macrophages' functional properties followed by discussing different strategies for modulating macrophage polarization. Advances in the use of synthetic and natural biomaterials to fabricate immune-modulatory materials are highlighted. This reveals that the development and clinical application of more effective immunomodulatory systems targeting macrophage polarization under pathological conditions will be driven by a detailed understanding of the factors that regulate macrophage polarization and biological function in order to optimize existing methods and generate novel strategies to control cell phenotype.

Tumour microenvironment programming by an RNA-RNA-binding protein complex creates a druggable vulnerability in IDH-wild-type glioblastoma

Patients with IDH-wild-type glioblastomas have a poor five-year survival rate along with limited treatment efficacy due to immune cell (glioma-associated microglia and macrophages) infiltration promoting tumour growth and resistance. To enhance therapeutic options, our study investigated the unique RNA-RNA-binding protein complex LOC-DHX15. This complex plays a crucial role in driving immune cell infiltration and tumour growth by establishing a feedback loop between cancer and immune cells, intensifying cancer aggressiveness. Targeting this complex with blood-brain barrier-permeable small molecules improved treatment efficacy, disrupting cell communication and impeding cancer cell survival and stem-like properties. Focusing on RNA-RNA-binding protein interactions emerges as a promising approach not only for glioblastomas without the IDH mutation but also for potential applications beyond cancer, offering new avenues for developing therapies that address intricate cellular relationships in the body.

E2F-mediated POLA2 upregulation is correlated with macrophage infiltration and poor prognosis in hepatocellular carcinoma

Background

Hepatocellular carcinoma (HCC) is the major histological type of primary liver cancer with a relatively poor prognosis, because most HCC cases are usually diagnosed at an advanced stage. Thus, it is essential to explore novel candidate biomarkers for early diagnosis and prognosis predication of HCC.

Methods

HCC transcription sequencing data were downloaded and analyzed. POLA2 expression pattern was characterized in tumor development process. POLA2 expression was evaluated by western blotting. Kaplan-Meier plot was utilized to evaluate POLA2's ability for prognosis predication. Correlation analysis and enrichment analysis were performed to explore the functional role of POLA2 in HCC development. Knockdown of E2F1 or E2F4 was used to evaluate their ability in regulating POLA2 expression. CYBERSORT (https://cibersortx.stanford.edu/) was used to estimate the infiltration levels of immune cells.

Results

POLA2 was overexpressed in HCC. Moreover, western blotting results showed that POLA2 was upregulated by transcription factors E2F1 rather than E2F4 in HCC. POLA2 facilitated cell cycle progression, DNA replication and DNA repair. High POLA2 expression was correlated with poor overall survival in HCC patients. POLA2 induced macrophage infiltration in the tumor microenvironment by upregulating the expression CSF1 and VEGFA expression.

Conclusions

POLA2 is a novel diagnostic and prognostic biomarker of HCC with potential clinical value.

Roles of lncRNAs in NF-κB-Mediated Macrophage Inflammation and Their Implications in the Pathogenesis of Human Diseases

Over the past century, molecular biology's focus has transitioned from proteins to DNA, and now to RNA. Once considered merely a genetic information carrier, RNA is now recognized as both a vital element in early cellular life and a regulator in complex organisms. Long noncoding RNAs (lncRNAs), which are over 200 bases long but do not code for proteins, play roles in gene expression regulation and signal transduction by inducing epigenetic changes or interacting with various proteins and RNAs. These interactions exhibit a range of functions in various cell types, including macrophages. Notably, some macrophage lncRNAs influence the activation of NF-κB, a crucial transcription factor governing immune and inflammatory responses. Macrophage NF-κB is instrumental in the progression of various pathological conditions including sepsis, atherosclerosis, cancer, autoimmune disorders, and hypersensitivity. It orchestrates gene expression related to immune responses, inflammation, cell survival, and proliferation. Consequently, its malfunction is a key contributor to the onset and development of these diseases. This review aims to summarize the function of lncRNAs in regulating NF-κB activity in macrophage activation and inflammation, with a particular emphasis on their relevance to human diseases and their potential as therapeutic targets. The insights gained from studies on macrophage lncRNAs, as discussed in this review, could provide valuable knowledge for the development of treatments for various pathological conditions involving macrophages.

NF-κB: Governing Macrophages in Cancer

Tumor-associated macrophages (TAMs) are the major component of the tumor microenvironment (TME), where they sustain tumor progression and or-tumor immunity. Due to their plasticity, macrophages can exhibit anti- or pro-tumor functions through the expression of different gene sets leading to distinct macrophage phenotypes: M1-like or pro-inflammatory and M2-like or anti-inflammatory. NF-κB transcription factors are central regulators of TAMs in cancers, where they often drive macrophage polarization toward an M2-like phenotype. Therefore, the NF-κB pathway is an attractive therapeutic target for cancer immunotherapy in a wide range of human tumors. Hence, targeting NF-κB pathway in the myeloid compartment is a potential clinical strategy to overcome microenvironment-induced immunosuppression and increase anti-tumor immunity. In this review, we discuss the role of NF-κB as a key driver of macrophage functions in tumors as well as the principal strategies to overcome tumor immunosuppression by targeting the NF-κB pathway.

Targeted Mevalonate Pathway and Autophagy in Antitumor Immunotherapy

Tumors of the digestive system are currently one of the leading causes of cancer-related death worldwide. Despite considerable progress in tumor immunotherapy, the prognosis for most patients remains poor. In the tumor microenvironment (TME), tumor cells attain immune escape through immune editing and acquire immune tolerance. The mevalonate pathway and autophagy play important roles in cancer biology, antitumor immunity, and regulation of the TME. In addition, there is metabolic crosstalk between the two pathways. However, their role in promoting immune tolerance in digestive system tumors has not previously been summarized. Therefore, this review focuses on the cancer biology of the mevalonate pathway and autophagy, the regulation of the TME, metabolic crosstalk between the pathways, and the evaluation of their efficacy as targeted inhibitors in clinical tumor immunotherapy.

The Role of TAMs in the Regulation of Tumor Cell Resistance to Chemotherapy

Tumor-associated macrophages (TAMs) are the predominant cell infiltrate in the immunosuppressive tumor microenvironment (TME). TAMs are central to fostering pro-inflammatory conditions, tumor growth, metastasis, and inhibiting therapy responses. Many cancer patients are innately refractory to chemotherapy and or develop resistance following initial treatments. There is a clinical correlation between the level of TAMs in the TME and chemoresistance. Hence, the pivotal role of TAMs in contributing to chemoresistance has garnered significant attention toward targeting TAMs to reverse this resistance. A prerequisite for such an approach requires a thorough understanding of the various underlying mechanisms by which TAMs inhibit response to chemotherapeutic drugs. Such mechanisms include enhancing drug efflux, regulating drug metabolism and detoxification, supporting cancer stem cell (CSCs) resistance, promoting epithelial-mesenchymal transition (EMT), inhibiting drug penetration and its metabolism, stimulating angiogenesis, impacting inhibitory STAT3/NF-κB survival pathways, and releasing specific inhibitory cytokines including TGF-β and IL-10. Accordingly, several strategies have been developed to overcome TAM-modulated chemoresistance. These include novel therapies that aim to deplete TAMs, repolarize them toward the anti-tumor M1-like phenotype, or block recruitment of monocytes into the TME. Current results from TAM-targeted treatments have been unimpressive; however, the use of TAM-targeted therapies in combination appears promising These include targeting TAMs with radiotherapy, chemotherapy, chemokine receptor inhibitors, immunotherapy, and loaded nanoparticles. The clinical limitations of these strategies are discussed.

Production of a p65fl/fl/LysMCre mouse model with dysfunctional NF-κB signaling in bone marrow-derived macrophages

Here, we describe the production and characterization of a novel p65fl/fl/LysMCre mouse model, which lacks canonical nuclear factor-kappaB member RelA/p65 (indicated as p65 hereafter) in bone marrow-derived macrophages. Cultured bone marrow-derived macrophages that lack p65 protein reveal NF-κB signaling deficiencies, a reduction in phagocytic ability, and reduced ability to produce nitrites. Despite abnormal bone marrow-derived macrophage function, p65fl/fl/LysMCre mice do not exhibit differences in naïve systemic immune profiles or colony forming units and time to death following Salmonella infection as compared to controls. Additionally, p65fl/fl/LysMCre mice, especially females, display splenomegaly, but no other obvious physical or behavioral differences as compared to control animals. As bone marrow-derived macrophages from this transgenic model are almost completely devoid of canonical nuclear factor-kappaB pathway member p65, this model has the potential for being very useful in investigating bone marrow-derived macrophage NF-kappaB signaling in diverse biological and biomedical studies.

Surgery for colorectal liver metastases: Anatomic and non-anatomic approach

Liver resection is potentially curative for patients with colorectal liver metastasis, but an advanced understanding of tumor biology and improved adjuvant therapies have facilitated an ongoing evolution of metastatic resection, even in the setting of a significant metastatic disease burden. As indications for surgery have expanded, preferred techniques and timing have been debated. This commentary reviews the merits of anatomic versus non-anatomic approaches to colorectal liver metastasis resection, considering oncologic outcomes, overall survival, and conflicting theories in the pathophysiology of the metastatic liver spread.

Crosstalk between autophagy and immune cell infiltration in the tumor microenvironment

Autophagy is a conserved process for self-degradation and provides cells with a rescue mechanism to respond to circumstances such as stress and starvation. The role of autophagy in cancer is extremely complex and often paradoxical. Most of the related published studies on tumors are always focused on cancer cells. However, present studies gradually noticed the significance of autophagy in the tumor microenvironment. These studies demonstrate that autophagy and immunity work synergistically to affect tumor progression, indicating that autophagy could become a potential target for cancer immunotherapy. Therefore, it is crucial to clarify the correlation between autophagy and various tumor-infiltrating immune cells in the tumor microenvironment. The context-dependent role of autophagy is critical in the design of therapeutic strategies for cancer.

Autophagic reprogramming of bone marrow–derived macrophages

Macro-autophagy is a highly conserved catabolic process among eukaryotes affecting macrophages. This work studies the genetic regulatory network involving the interplay between autophagy and macrophage polarization (activation). Autophagy-related genes (Atgs) and differentially expressed genes (DEGs) of macrophage polarization (M1–M2) were predicted, and their regulatory networks constructed. Naïve (M0) mouse bone marrow–derived monocytes were differentiated into M1 and M2a. Validation of the targets of Smad1, LC3A and LC3B, Atg16L1, Atg7, IL-6, CD68, Arg-1, and Vamp7 was performed in vitro. Immunophenotyping by flow cytometry revealed three macrophage phenotypes: M0 (IL-6 + /CD68 +), M1 (IL-6 + /CD68 + /Arg-1 +), and M2a (CD68 + /Arg-1). Confocal microscopy revealed increased autophagy in both M1 and M2a and a significant increase in the pre-autophagosomes size and number. Bafilomycin A increased the expression of CD68 and Arg-1 in all cell lineages. In conclusion, our approach predicted the protein targets mediating the interplay between autophagy and macrophage polarization. We suggest that autophagy reprograms macrophage polarization via CD68, arginase 1, Atg16L1-1, and Atg16L1-3. The current findings provide a foundation for the future use of macrophages in immunotherapy of different autoimmune disorders.

Immunotherapeutic effects of intratumorally injected Zymosan-Adenovirus conjugates encoding constant active IRF3 in a melanoma mouse model

M2-like tumor-associated macrophages (TAMs) play a significant role in immunosuppressive conditions in the tumor microenvironment (TME). TAM reprogramming, a dual-pronged therapy, reduces immunosuppression and induces immune favorable conditions in the TME. In this study, recombinant adenoviruses encoding active forms of interferon regulatory factor 3 (IRF3) were conjugated to zymosan particles to target phagocytic cells to create a pro-inflammatory immunomodulatory therapy. We determined TAM reprogramming by upregulation and downregulation of M1- and M2-associated genes, respectively, as well as cytokine and transcription factor expression in vitro. The overall shift to immune favorable conditions in the TME was suggested by metabolic, cytokine, and immune cell gene expression. Our data indicated that the zymosan:adenovirus (Zym:Ad) particle itself induced a shift from M2-like to M1-like TAMs, a shift in immune status of the TME, and systemic tumor immunity as determined using a double tumor melanoma mouse model and splenocyte functional assay. Notably, direct intratumoral injection of Zym:Ad IRF3 reduced tumor growth more significantly than Zym:Ad GFP, indicating additional therapeutic benefits due to incorporation of constant active IRF3.

Manipulation of the tumor immuno-microenvironment via TAM-targeted expression of transcription factors

An immunosuppressive tumor microenvironment (TME) leads to cancer growth, metastasis, and therapeutic resistance. Immunomodulatory immunotherapy aims to skew the immunosuppressive TME back to an immune active state. Tumor-associated macrophages (TAMs) are a critical component of the TME that are actively involved in tumor-specific inflammation and immunosuppression. TAMs exhibit a diverse range of phenotypes and functions, from pro-tumor to anti-tumor. The plasticity of TAMs makes them a promising target for immunotherapy, and TAM-targeted therapies via different strategies have shown great potential. This review discusses current TAM-specific delivery targets and genes of interest for TAM-reprogramming. As phagocytic cells, TAMs have several receptors that have been used to increase TAM-targeted in vivo delivery. Furthermore, a promising approach for reprogramming TAMs is to activate or suppress specific transcription factors in the signal transducers and activators of transcription (STAT) and interferon regulatory factor (IRF) families. Altering TAM transcription factor expression results in a potent shift in cytokine expression and overall TAM function potentially tipping the balance from an immunosuppressive to an immune active TME.

Cell-Free Extracts from Human Fat Tissue with a Hyaluronan-Based Hydrogel Attenuate Inflammation in a Spinal Cord Injury Model through M2 Microglia/Microphage Polarization

Treatment for spinal cord injuries (SCIs) is often ineffective because SCIs result in a loss of nerve tissue, glial scar formation, local ischemia and secondary inflammation. The current promising strategy for SCI is the combination of bioactive materials and cytokines. Bioactive materials support the injured spinal cord, stabilize the morphology, and avoid excessive inflammatory responses. Fat extract (FE) is a cell-free liquid component containing a variety of cytokines extracted from human fat tissue using mechanical methods. In this research, a biocompatible HAMC (hyaluronan and methylcellulose) loaded with FE is used to treat a model of spinal cord contusion in mice. The composite not only inhibits death of neuro- and vascular cells and leads to the preservation of neural and vascular structure, but also modulates the inflammatory phenotype of macrophages in the locally injured region. Specifically, FE promotes the polarization of macrophages from an inflammatory M1 phenotype to an anti-inflammatory M2 phenotype. During the screening of the involved pathways, it is corroborated that activation of the STAT6/Arg-1 signaling pathway is involved in macrophage M2 polarization. In summary, FE is a promising treatment for SCI, as it is easy to obtain, nonimmunogenic, and effective.

Polypharmacological reprogramming of tumor-associated macrophages towards an inflammatory phenotype

Tumor-associated macrophages (TAM) are an important component of the tumor microenvironment (TME) that can promote tumor progression, metastasis, and resistance to therapies. Although TAMs represent a promising target for therapeutic intervention, the complexity of the TME has made the study of TAMs challenging. Here, we established a physiologically relevant in vitro TAM polarization system that recapitulates TAM pro-tumoral activities. This system was used to characterize dynamic changes in gene expression and protein phosphorylation during TAM polarization and to screen phenotypic kinase inhibitors that impact TAM programming. BMS-794833, a multi-targeted compound, was identified as a potent inhibitor of TAM polarization. BMS-794833 decreased pro-tumoral properties of TAMs in vitro and suppressed tumor growth in mouse triple-negative breast cancer models. The effect of BMS-794833 was independent of its primary targets (MET and VEGFR2) but was dependent on its effect on multiple signaling pathways, including focal adhesion kinases, SRC family kinases, STAT3, and p38 MAP kinases. Collectively, these findings underline the efficacy of polypharmacological strategies in reprogramming complex signaling cascades activated during TAM polarization.

Macrophages in tumor: An inflammatory perspective

Inflammation is a part of carefully co-ordinated healing immune exercise to eliminate injurious stimuli. However, in substantial number of cancer types, it contributes in shaping up of robust tumor microenvironment (TME). Solid TME promotes infiltration of tumor associated macrophages (TAMs) that contributes to cancer promotion. TAMs are functionally heterogeneous and display an extraordinary degree of plasticity, which allow 'Switching' of macrophages into an 'M2', phenotype, linked with immunosuppression, advancement of tumor angiogenesis with metastatic consequences. In contrary to the classical M1 macrophages, these M2 TAMs are high-IL-10, TGF-β secreting-'anti-inflammatory'. In this review, we will discuss the modes of infiltration and switching of TAMs into M2 anti-inflammatory state in the TME to promote immunosuppression and inflammation-driven cancer.

Prognostic Impact of Monocyte to Lymphocyte Ratio in Clinical Outcome of Patients with Hepatocellular Carcinoma: A Systematic Review and Meta-analysis

Background:

Lymphocyte to monocyte ratio (LMR) is a surrogate marker of systemic inflammation which is shown to be related to the patient’s survival in multiple malignancies. An important implication of this marker potentially is neoplasms in which there is no correlation between prognosis and histopathological staging and also has no reliable chemical markers associated with prognosis. Herein, this meta-analysis aimed to investigate the prognostic role of LMR in patients with hepatocellular carcinoma (HCC).

Materials and Methods:

In the current systemic review and meta-analysis, we conducted a systemic search of databases and indexing sources, including PubMed, EMBASE, Cochrane, Scopus, and ProQuest up to May 2019 toinclude studies on the prognostic significance of LMR on patients with HCC. Overall survival (OS), disease-free survival (DFS) and recurrence-free survival (RFS) values were extracted from the studies and analyzed. The pooled hazard ratio with a 95% confidence interval was explored to identify the prognostic value of the LMR in the survival of the patients with HCC.

Results:

A total of 12 studies with a total sample size of 3750 cases were included. There was significant heterogeneity among the studies; therefore, subgroup analysis was also performed. Overall analysis regarding OS showed an insignificant relationship between LMR and patient’s prognosis, dividing to subgroups based on LMR cut-offs did not yield any significant result, subgroup analysis for RFS founded statistically significant results and LMR was significantly related to DFS.

Conclusion:

High LMR was associated with increased DFS and RFS, in return this association was not observed for OS.

lncRNA DCST1-AS1 Facilitates Oral Squamous Cell Carcinoma by Promoting M2 Macrophage Polarization through Activating NF-κB Signaling

lncRNAs are related to the progression of various diseases, including oral squamous cell carcinoma (OSCC), which is a common squamous cell carcinoma of the head and neck. Tumor-associated macrophages and tumor cells are significant components of tumor microenvironment. M2 polarization of tumor-associated macrophages is a crucial actor in tumor malignancy and metastasis. In this study, we studied the molecular mechanism of lncRNA DCST1-AS1 in OSCC. Here, we reported that DCST1-AS1 was significantly increased in OSCC cells. We found that loss of DCST1-AS1 obviously inhibited the proliferation, migration, and invasion of OSCC cells and xenograft tumor growth. Meanwhile, silencing of DCST1-AS1 also repressed the percentage of macrophages expressing M2 markers CD206 and CD11b. DCST1-AS1 shRNA enhanced the percentage of macrophages expressing M1 markers CD80 and CD11c. Then, we observed that loss of DCST1-AS1 suppressed OSCC progression via inactivating NF-κB signaling. As well established, NF-κB signaling exerts critical roles in tumor progression, and our study proved that DCST1-AS1 could regulate NF-κB signaling. We proved that blocking the NF-κB pathway using antagonists greatly downregulated OSCC progression and M2 macrophage polarization induced by the overexpression of DCST1-AS1. To sum up, we reported that DCST1-AS1 plays an important role in modulating OSCC tumorigenicity and M2 macrophage polarization through regulating the NF-κB pathway.

Loss of fragile site-associated tumor suppressor promotes antitumor immunity via macrophage polarization

Common fragile sites (CFSs) are specific breakage-prone genomic regions and are present frequently in cancer cells. The (E2-independent) E3 ubiquitin-conjugating enzyme FATS (fragile site-associated tumor suppressor) has antitumor activity in cancer cells, but the function of FATS in immune cells is unknown. Here, we report a function of FATS in tumor development via regulation of tumor immunity. Fats^-/- mice show reduced subcutaneous B16 melanoma and H7 pancreatic tumor growth compared with WT controls. The reduced tumor growth in Fats^-/- mice is macrophage dependent and is associated with a phenotypic shift of macrophages within the tumor from tumor-promoting M2-like to antitumor M1-like macrophages. In addition, FATS deficiency promotes M1 polarization by stimulating and prolonging NF-κB activation by disrupting NF-κB/IκBα negative feedback loops and indirectly enhances both CD4⁺ T helper type 1 (Th1) and cytotoxic T lymphocyte (CTL) adaptive immune responses to promote tumor regression. Notably, transfer of Fats^-/- macrophages protects mice against B16 melanoma. Together, these data suggest that FATS functions as an immune regulator and is a potential target in cancer immunotherapy.

Stimulation of an anti-tumor immune response with "chromatin-damaging" therapy

Curaxins are small molecules that bind genomic DNA and interfere with DNA-histone interactions leading to the loss of histones and decondensation of chromatin. We named this phenomenon 'chromatin damage'. Curaxins demonstrated anti-cancer activity in multiple pre-clinical tumor models. Here, we present data which reveals, for the first time, a role for the immune system in the anti-cancer effects of curaxins. Using the lead curaxin, CBL0137, we observed elevated expression of several group of genes in CBL0137-treated tumor cells including interferon sensitive genes, MHC molecules, some embryo-specific antigens suggesting that CBL0137 increases tumor cell immunogenicity and improves recognition of tumor cells by the immune system. In support of this, we found that the anti-tumor activity of CBL0137 was reduced in immune deficient SCID mice when compared to immune competent mice. Anti-tumor activity of CBL0137 was abrogated in CD8+ T cell depleted mice but only partially lost when natural killer or CD4+ T cells were depleted. Further support for a key role for the immune system in the anti-tumor activity of CBL0137 is evidenced by an increased antigen-specific effector CD8+ T cell and NK cell response, and an increased ratio of effector T cells to Tregs in the tumor and spleen. CBL0137 also elevated the number of CXCR3-expressing CTLs in the tumor and the level of interferon-γ-inducible protein 10 (IP-10) in serum, suggesting IP-10/CXCR3 controls CBL0137-elicited recruitment of effector CTLs to tumors. Our collective data underscores a previously unrecognized role for both innate and adaptive immunity in the anti-tumor activity of curaxins.

Random survival forests identify pathways with polymorphisms predictive of survival in KRAS mutant and KRAS wild-type metastatic colorectal cancer patients

KRAS status serves as a predictive biomarker of response to treatment in metastatic colorectal cancer (mCRC). We hypothesize that complex interactions between multiple pathways contribute to prognostic differences between KRAS wild-type and KRAS mutant patients with mCRC, and aim to identify polymorphisms predictive of clinical outcomes in this subpopulation. Most pathway association studies are limited in assessing gene–gene interactions and are restricted to an individual pathway. In this study, we use a random survival forests (RSF) method for identifying predictive markers of overall survival (OS) and progression-free survival (PFS) in mCRC patients treated with FOLFIRI/bevacizumab. A total of 486 mCRC patients treated with FOLFIRI/bevacizumab from two randomized phase III trials, TRIBE and FIRE-3, were included in the current study. Two RSF approaches were used, namely variable importance and minimal depth. We discovered that Wnt/β-catenin and tumor associated macrophage pathway SNPs are strong predictors of OS and PFS in mCRC patients treated with FOLFIRI/bevacizumab independent of KRAS status, whereas a SNP in the sex-differentiation pathway gene, DMRT1, is strongly predictive of OS and PFS in KRAS mutant mCRC patients. Our results highlight RSF as a useful method for identifying predictive SNPs in multiple pathways.

TFEB is a master regulator of tumor-associated macrophages in breast cancer

Background

Tumor-associated macrophages (TAMs) play key roles in the development of many malignant solid tumors including breast cancer. They are educated in the tumor microenvironment (TME) to promote tumor growth, metastasis, and therapy resistance. However, the phenotype of TAMs is elusive and how to regulate them for therapeutic purpose remains unclear; therefore, TAM-targeting therapies have not yet achieved clinical success. The purposes of this study were to examine the role of transcription factor EB (TFEB) in regulating TAM gene expression and function and to determine if TFEB activation can halt breast tumor development.

Methods

Microarrays were used to analyze the gene expression profile of macrophages (MΦs) in the context of breast cancer and to examine the impact of TFEB overexpression. Cell culture studies were performed to define the mechanisms by which TFEB affects MΦ gene expression and function. Mouse studies were carried out to investigate the impact of MΦ TFEB deficiency or activation on breast tumor growth. Human cancer genome data were analyzed to reveal the prognostic value of TFEB and its regulated genes.

Results

TAM-mimic MΦs display a unique gene expression profile, including significant reduction in TFEB expression. TFEB overexpression favorably modulates TAM gene expression through multiple signaling pathways. Specifically, TFEB upregulates suppressor of cytokine signaling 3 (SOCS3) and peroxisome proliferator-activated receptor γ (PPARγ) expression and autophagy/lysosome activities, inhibits NLRP3 (NLR Family Pyrin Domain Containing 3) inflammasome and hypoxia-inducible factor (HIF)-1α mediated hypoxia response, and thereby suppresses an array of effector molecules in TAMs including arginase 1, interleukin (IL)-10, IL-1β, IL-6 and prostaglandin E2. MΦ-specific TFEB deficiency promotes, while activation of TFEB using the natural disaccharide trehalose halts, breast tumor development by modulating TAMs. Analysis of human patient genome database reveals that expression levels of TFEB, SOCS3 and PPARγ are positive prognostic markers, while HIF-1α is a negative prognostic marker of breast cancer.

Conclusions

Our study identifies TFEB as a master regulator of TAMs in breast cancer. TFEB controls TAM gene expression and function through multiple autophagy/lysosome-dependent and independent pathways. Therefore, pharmacological activation of TFEB would be a promising therapeutic approach to improve the efficacy of existing treatment including immune therapies for breast cancer by favorably modulating TAM function and the TME.

How Macrophages Become Transcriptionally Dysregulated: A Hidden Impact of Antitumor Therapy

Tumor-associated macrophages (TAMs) are the essential components of the tumor microenvironment. TAMs originate from blood monocytes and undergo pro- or anti-inflammatory polarization during their life span within the tumor. The balance between macrophage functional populations and the efficacy of their antitumor activities rely on the transcription factors such as STAT1, NF-κB, IRF, and others. These molecular tools are of primary importance, as they contribute to the tumor adaptations and resistance to radio- and chemotherapy and can become important biomarkers for theranostics. Herein, we describe the major transcriptional mechanisms specific for TAM, as well as how radio- and chemotherapy can impact gene transcription and functionality of macrophages, and what are the consequences of the TAM-tumor cooperation.

NF-κB in Cancer Immunity: Friend or Foe?

The emergence of immunotherapies has definitely proven the tight relationship between malignant and immune cells, its impact on cancer outcome and its therapeutic potential. In this context, it is undoubtedly critical to decipher the transcriptional regulation of these complex interactions. Following early observations demonstrating the roles of NF-κB in cancer initiation and progression, a series of studies converge to establish NF-κB as a master regulator of immune responses to cancer. Importantly, NF-κB is a family of transcriptional activators and repressors that can act at different stages of cancer immunity. In this review, we provide an overview of the selective cell-intrinsic contributions of NF-κB to the distinct cell types that compose the tumor immune environment. We also propose a new view of NF-κB targeting drugs as a new class of immunotherapies for cancer.

Role of platelets and breast cancer stem cells in metastasis

The high mortality rate of breast cancer is mainly caused by the metastatic ability of cancer cells, resistance to chemotherapy and radiotherapy, and tumor regression capacity. In recent years, it has been shown that the presence of breast cancer stem cells is closely associated with the migration and metastatic ability of cancer cells, as well as with their resistance to chemotherapy and radiotherapy. The tumor microenvironment is one of the main molecular factors involved in cancer and metastatic processes development, in this sense it is interesting to study the role of platelets, one of the main communicator cells in the human body which are activated by the signals they receive from the microenvironment and can generate more than one response. Platelets can ingest and release RNA, proteins, cytokines and growth factors. After the platelets interact with the tumor microenvironment, they are called "tumor-educated platelets." Tumor-educated platelets transport material from the tumor microenvironment to sites adjacent to the tumor, thus helping to create microenvironments conducive for the development of primary and metastatic tumors. It has been observed that the clone capable of carrying out the metastatic process is a cancer cell with stem cell characteristics. Cancer stem cells go through a series of processes, including epithelial-mesenchymal transition, intravasation into blood vessels, movement through blood vessels, extravasation at the site of the establishment of a metastatic focus, and site colonization. Tumor-educated platelets support all these processes. 

Sirtuins' control of autophagy and mitophagy in cancer

Mammalian cells use a specialized and complex machinery for the removal of altered proteins or dysfunctional organelles. Such machinery is part of a mechanism called autophagy. Moreover, when autophagy is specifically employed for the removal of dysfunctional mitochondria, it is called mitophagy. Autophagy and mitophagy have important physiological implications and roles associated with cellular differentiation, resistance to stresses such as starvation, metabolic control and adaptation to the changing microenvironment. Unfortunately, transformed cancer cells often exploit autophagy and mitophagy for sustaining their metabolic reprogramming and growth to a point that autophagy and mitophagy are recognized as promising targets for ongoing and future antitumoral therapies. Sirtuins are NAD+ dependent deacylases with a fundamental role in sensing and modulating cellular response to external stresses such as nutrients availability and therefore involved in aging, oxidative stress control, inflammation, differentiation and cancer. It is clear, therefore, that autophagy, mitophagy and sirtuins share many common aspects to a point that, recently, sirtuins have been linked to the control of autophagy and mitophagy. In the context of cancer, such a control is obtained by modulating transcription of autophagy and mitophagy genes, by post translational modification of proteins belonging to the autophagy and mitophagy machinery, by controlling ROS production or major metabolic pathways such as Krebs cycle or glutamine metabolism. The present review details current knowledge on the role of sirtuins, autophagy and mitophagy in cancer to then proceed to discuss how sirtuins can control autophagy and mitophagy in cancer cells. Finally, we discuss sirtuins role in the context of tumor progression and metastasis indicating glutamine metabolism as an example of how a concerted activation and/or inhibition of sirtuins in cancer cells can control autophagy and mitophagy by impinging on the metabolism of this fundamental amino acid.

The role of caspase-8 in the tumor microenvironment of ovarian cancer

Caspase-8 is an aspartate-specific cysteine protease, which is best known for its apoptotic functions. Caspase-8 is placed at central nodes of multiple signal pathways, regulating not only the cell cycle but also the invasive and metastatic cell behavior, the immune cell homeostasis and cytokine production, which are the two major components of the tumor microenvironment (TME). Ovarian cancer often has dysregulated caspase-8 expression, leading to imbalance between its apoptotic and non-apoptotic functions within the tumor and the surrounding milieu. The downregulation of caspase-8 in ovarian cancer seems to be linked to high aggressiveness with chronic inflammation, immunoediting, and immune resistance. Caspase-8 plays therefore an essential role not only in the primary tumor cells but also in the TME by regulating the immune response, B and T lymphocyte activation, and macrophage differentiation and polarization. The switch between M1 and M2 macrophages is possibly associated with changes in the caspase-8 expression. In this review, we are discussing the non-apoptotic functions of caspase-8, highlighting this protein as a modulator of the immune response and the cytokine composition in the TME. Considering the low survival rate among ovarian cancer patients, it is urgently necessary to develop new therapeutic strategies to optimize the response to the standard treatment. The TME is highly heterogenous and provides a variety of opportunities for new drug targets. Given the variety of roles of caspase-8 in the TME, we should focus on this protein in the development of new therapeutic strategies against the TME of ovarian cancer.

Deciphering the Role of Innate Immune NF-ĸB Pathway in Pancreatic Cancer

Simple Summary

Chronic inflammation is a major mechanism that underlies the aggressive nature and treatment resistance of pancreatic cancer. In many ways, the molecular mechanisms that drive chronic inflammation in pancreatic cancer are very similar to our body’s normal innate immune response to injury or invading microorganisms. Therefore, during cancer development, pancreatic cancer cells hijack the innate immune pathway to foster a chronically inflamed tumor environment that helps shield them from immune attack and therapeutics. While blocking the innate immune pathway is theoretically reasonable, untoward side effects must also be addressed. In this review, we comprehensively summarize the literature that describe the role of innate immune signaling in pancreatic cancer, emphasizing the specific role of this pathway in different cell types. We review the interaction of the innate immune pathway and cancer-driving signaling in pancreatic cancer and provide an updated overview of novel therapeutic opportunities against this mechanism.

Abstract

Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal cancers with no effective treatment option. A predominant hallmark of PDAC is the intense fibro-inflammatory stroma which not only physically collapses vasculature but also functionally suppresses anti-tumor immunity. Constitutive and induced activation of the NF-κB transcription factors is a major mechanism that drives inflammation in PDAC. While targeting this pathway is widely supported as a promising therapeutic strategy, clinical success is elusive due to a lack of safe and effective anti-NF-κB pathway therapeutics. Furthermore, the cell type-specific contribution of this pathway, specifically in neoplastic cells, stromal fibroblasts, and immune cells, has not been critically appraised. In this article, we highlighted seminal and recent literature on molecular mechanisms that drive NF-κB activity in each of these major cell types in PDAC, focusing specifically on the innate immune Toll-like/IL-1 receptor pathway. We reviewed recent evidence on the signaling interplay between the NF-κB and oncogenic KRAS signaling pathways in PDAC cells and their collective contribution to cancer inflammation. Lastly, we reviewed clinical trials on agents that target the NF-κB pathway and novel therapeutic strategies that have been proposed in preclinical studies.

Tumor Microenvironment in Ovarian Cancer: Function and Therapeutic Strategy

Ovarian cancer is one of the leading causes of death in patients with gynecological malignancy. Despite optimal cytoreductive surgery and platinum-based chemotherapy, ovarian cancer disseminates and relapses frequently, with poor prognosis. Hence, it is urgent to find new targeted therapies for ovarian cancer. Recently, the tumor microenvironment has been reported to play a vital role in the tumorigenesis of ovarian cancer, especially with discoveries from genome-, transcriptome- and proteome-wide studies; thus tumor microenvironment may present potential therapeutic target for ovarian cancer. Here, we review the interactions between the tumor microenvironment and ovarian cancer and various therapies targeting the tumor environment.

Potential Prognostic Value and Mechanism of Stromal-Immune Signature in Tumor Microenvironment for Stomach Adenocarcinoma

Stomach adenocarcinoma (STAD) is one of the most common malignancies. But the molecular mechanism is unknown. In this study, we downloaded the transcriptional profiles and clinical data of 344 STAD and 30 normal samples from The Cancer Genome Atlas (TCGA) database. Stromal and immune scores of STAD were calculated by the Estimation of Stromal and Immune cells in Malignant Tumor tissues using Expression data (ESTIMATE) algorithm, and association of stromal/immune scores with tumor differentiation/T/N/M stage and survival was investigated. The differentially expressed genes (DEGs) between high and low score groups (based on media) were identified, and prognostic genes over-/underexpressed in both STAD and stromal/immune signature were retrieved. Furthermore, proportions of 22 infiltrating immune cells for the cohort from TCGA were estimated by the Cell-type Identification By Estimating Relative Subsets Of RNA Transcripts (CIBERSORT) algorithm, and association of 22 immune cells with tumor differentiation/T/N/M stage and survival was investigated. Next, coexpression analysis of 22 immune cells and intersection genes over-/underexpressed in both STAD and stromal signature was conducted. We found high stromal and immune scores and macrophage infiltration predicting poor tumor differentiation and severe local invasion, obtained a list of prognostic genes based on stromal-immune signature, and explored the interaction of collagen, chemokines such as CXCL9, CXCL10, and CXCL11, and macrophage through coexpression analysis and may provide novel prognostic biomarkers and immunotherapeutic targets for STAD.

Cathepsin regulation on microglial function

Microglia, the resident mononuclear phagocyte population in the brain, have long been implicated in the pathology of neurodegenerative age-associated disorders. However, activated microglia have now been identified as homeostatic keepers in the brain, because they are involved in the initiation and resolution of neuropathology. The complex roles of activated microglia appear to be linked to change from inflammatory and neurotoxic to anti-inflammatory and neuroprotective phenotypes. Increased expression and secretion of various cathepsins support roles of activated microglia in chronic neuroinflammation, the neurotoxic M1-like polarization and neuronal death. Moreover, changes in expression and localization of microglial cathepsin B play a critical role in the acceleration of the brain aging. Beyond the role as brain-resident macrophages, many lines of evidence have shown that microglia have essential roles in the maturation and maintenance of neuronal circuits in the developing and adult brain. Cathepsin S secreted from microglia induces the diurnal variation of spine density of cortical neurons though proteolytic modification of peri-synaptic extracellular matrix molecules. In this review, I highlight the emerging roles of cathepsins that support the roles of microglia in both normal healthy and pathological brains. In addition, I discuss cathepsin inhibitors as potential therapeutic targets for brain disorders.

Life, death, and autophagy in cancer: NF-κB turns up everywhere

Escaping programmed cell death is a hallmark of cancer. NF-κB transcription factors are key regulator of cell survival and aberrant NF-κB signaling has been involved in the pathogenesis of most human malignancies. Although NF-κB is best known for its antiapoptotic role, other processes regulating the life/death balance, such as autophagy and necroptosis, seem to network with NF-κB. This review discusses how the reciprocal regulation of NF-κB, autophagy and programmed cell death affect cancer development and progression.

Kinsenoside attenuates osteoarthritis by repolarizing macrophages through inactivating NF-κB/MAPK signaling and protecting chondrocytes

The objective was to investigate the effect of kinsenoside (Kin) treatments on macrophage polarity and evaluate the resulting protection of chondrocytes to attenuate osteoarthritis (OA) progression. RAW264.7 macrophages were polarized to M1/M2 subtypes then administered with different concentrations of Kin. The polarization transitions were evaluated with quantitative real-time polymerase chain reaction (qRT-PCR), confocal observation and flow cytometry analysis. The mechanism of Kin repolarizing M1 macrophages was evaluated by Western blot. Further, macrophage conditioned medium (CM) and IL-1β were administered to chondrocytes. Micro-CT scanning and histological observations were conducted in vivo on anterior cruciate ligament transection (ACLT) mice with or without Kin treatment. We found that Kin repolarized M1 macrophages to the M2 phenotype. Mechanistically, Kin inhibited the phosphorylation of IκBα, which further reduced the downstream phosphorylation of P65 in nuclear factor-κB (NF-κB) signaling. Moreover, Kin inhibited mitogen-activated protein kinases (MAPK) signaling molecules p-JNK, p-ERK and p-P38. Additionally, Kin attenuated macrophage CM and IL-1β-induced chondrocyte damage. In vivo, Kin reduced the infiltration of M1 macrophages, promoted M2 macrophages in the synovium, inhibited subchondral bone destruction and reduced articular cartilage damage induced by ACLT. All the results indicated that Kin is an effective therapeutic candidate for OA treatment.

Selective targeting of tumor cells and tumor associated macrophages separately by twin-like core-shell nanoparticles for enhanced tumor-localized chemoimmunotherapy

Tumor associated macrophage (TAM)-based immunotherapy has been presented as a promising strategy in cancer therapy. The combination of TAM-based immunotherapy with sorafenib (SF) could be conceivably quite more effective in hepatocellular carcinoma (HCC) treatment. A co-delivery system was superior in improving the co-accumulation of two drugs in tumor tissues for chemoimmunotherapy, while in the case of selective targeting of separated cells such as tumor cells and immune cells, a novel targeted co-delivery strategy was badly required. In this study, twin-like core-shell nanoparticles (TCN) were developed for synchronous biodistribution and separated cell targeting delivery of SF and TAM re-polarization agents IMD-0354 to cancer cells and TAM to enhance tumor-localized chemoimmunotherapy, respectively. First of all, SF loaded cationic lipid-based nanoparticles (SF-CLN) and mannose-modified IMD-0354 loaded cationic lipid-based nanoparticles (M-IMD-CLN) were prepared, respectively. SF on the surface of SF-CLN and mannose on the M-IMD-CLN were regarded as targeting ligands for selective targeting delivery of SF-CLN and M-IMD-CLN to cancer cells and TAM separately. Then, pH-responsive charge reversal polymer O-carboxymethyl-chitosan (CMCS) was coated on the SF-CLN and M-IMD-CLN to obtain twin-like CMCS/SF-CLN and CMCS/M-IMD-CLN, respectively. The results of cellular uptake assay on Hepa1-6 cells and RAW 264.7 cells in vitro, respectively, as well as the results of tumor tissue distribution of SF and IMD-0354 in vivo suggested that CMCS/SF-CLN and CMCS/M-IMD-CLN exhibited similar properties in vitro and synchronous biodistribution in vivo, and were efficient at separated cell targeting delivery. What's more, the results of antitumor efficiency in vivo and phenotype analysis of TAM in tumor tissues proved that CMCS/SF-CLN and CMCS/M-IMD-CLN exhibited superior synergistic antitumor efficacy and M2-type TAM polarization ability compared with SF treatment in Hepa1-6 tumor bearing mice. Consequently, TCN which was the combination of co-administration and nano-drug delivery systems has great potential to be used in tumor-localized chemoimmunotherapy in clinics.

Hypoxia-induced ZEB1 promotes cervical cancer progression via CCL8-dependent tumour-associated macrophage recruitment

The accumulation of tumour-associated macrophages (TAMs) in the hypoxic tumour microenvironment (TME) is associated with malignant progression in cancer. However, the mechanisms by which the hypoxic TME facilitates TAM infiltration are not fully understood. This study showed that high ZEB1 expression in hypoxic cervical cancer cell islets was positively correlated with CD163+ TAM accumulation. ZEB1 in hypoxic cancer cells promoted the migration of TAMs in vitro and altered the expression of multiple chemokines, especially CCL8. Mechanistically, hypoxia-induced ZEB1 activated the transcription of CCL8, which attracted macrophages via the CCR2-NF-κB pathway. Furthermore, ZEB1 and CCL8 were independent prognostic factors in cervical cancer patients based on The Cancer Genome Atlas (TCGA) data analysis. In conclusion, hypoxia-induced ZEB1 exerts unexpected functions in cancer progression by fostering a prometastatic environment through increased CCL8 secretion and TAM recruitment; thus, ZEB1 may serve as a candidate biomarker of tumour progression and provide a potential target for disrupting hypoxia-mediated TME remodelling.

Nerve modulation therapy in gouty arthritis: targeting increased sFRP2 expression in dorsal root ganglion regulates macrophage polarization and alleviates endothelial damage

Gouty arthritis (GA) is a form of arthritis caused by uric acid deposition in the joints that result in intense inflammation and pain. Accumulating evidence showed the importance of the sensory neurons signal upon immune cells by releasing neuropeptides and chemokines to regulate associated immune-inflammatory response. In this study, we investigated the significance of sensory neuron neuropeptides and chemokine signals on inflammation-induced macrophages polarization during GA.

Methods: We screened the mRNA expression profile during GA in dorsal root ganglion (DRG) neurons to identify the most likely candidate that mediates the neuro-immune communication. Then, we silenced specific gene expression in the DRG by lentiviral vectors in the monosodium urate (MSU)-induced ankle GA mouse model and evaluated alterations in the inflammatory response. In vitro, primary macrophages were used to investigate the neural impact on M1/M2 subtype polarization, proinflammatory cytokine production and downstream endothelial damage. Mechanism by which macrophage inflammation is induced in the DRG was evaluated by Western blot, immunofluorescence, and immunoprecipitation.

Results: We found that secreted frizzled-related protein 2 (sFRP2) was the most upregulated gene in dorsal root ganglion (DRG) neurons in response to monosodium urate (MSU) deposition. Injection of LV-sFRP2-shRNA into the L4 and L5 DRG significantly suppressed inflammatory cell infiltration and M1 polarization in the synovial membrane, attenuating hyperalgesia and ankle swelling in the GA mouse model. In vitro, DRG neurons-derived sFRP2 promoted M1 polarization and macrophage migration, thereby upregulating the production of proinflammatory cytokines and preventing endothelial apoptosis. Furthermore, DRG-derived sFRP2 activated the nuclear factor (NF)-κB pathway by destabilizing the β-catenin and p65 complex.

Conclusion: We demonstrated the involvement of a sensory neuron-macrophage axis in GA pathology that was regulated by sFRP2 expression in a paracrine manner. Targeting increased sFRP2 expressions in DRG provide novel insights for future GA research in both pain alleviation and treatment of gout inflammation.

Wnt5a is a TLR2/4-ligand that induces tolerance in human myeloid cells

Innate immune responses are rapid, dynamic and highly regulated to avoid overt reactions. This regulation is executed by innate immune tolerance mechanisms that remain obscure. Wnt5a is a signalling protein mainly involved in developmental processes and cancer. The effect of Wnt5a on inflammatory myeloid cells is controversial. Here, we combine primary cell cultures, in vitro binding studies, mass spectrometry and Drosophila protein modelling to show that Wnt5a is a direct ligand of toll-like receptor (TLR) 2 and 4. The binding promotes a MyD88-non-canonical nuclear factor of kappa B (NFκB) and AP-1 signalling cascade, with contradictory profiles in mouse (pro-inflammatory) and human (anti-inflammatory) myeloid immune cells. These data reveal that the true nature of Wnt5a in inflammatory cells, is to regulate TLR signals, and in human myeloid cells it acts as an endogenous, tolerance-associated molecular pattern (TAMP), inducing IL-10 and innate immune tolerance.

Colony‑stimulating factor 1 receptor inhibition blocks macrophage infiltration and endometrial cancer cell proliferation

Tumor-associated macrophages (TAMs) promote the progression of endometrial cancer (EC), but the mechanism of TAM in EC cell proliferation remains unclear. It was found that colony stimulating factor (CSF)-1 and CSF-1 receptor (CSF-1R) were highly expressed in EC tissues of patients and two EC cell lines (ECC-1 and HEC-1A). Using wound-healing and chemotactic migration assays to evaluate the role of EC cells in the induction of macrophage migration, it was found that the supernatant of EC cells promoted macrophage cell line (U937) migration; however, the migration capacity of U937 weakened when CSF-1R was blocked. Subsequently, inhibition of CSF-1 expression in EC cells also restrained U937 migration. Additionally, blocking CSF-1R by PLX3397 treatment in U937 cells inhibited EC cell proliferation in a co-culture system by inhibiting the expression of proliferation-associated proteins (Janus kinase-1, phosphoinositide 3-kinase, AKT, cyclin kinase 2, 4 and retinoblastoma-associated protein). Together, these results demonstrated that CSF-1 secreted by EC cells promoted macrophage migration; similarly, CSF-1-stimulated macrophages promoted EC cell proliferation. These results suggested that the interaction between CSF-1 and its receptor served an important role in promoting macrophage infiltration and progression of EC.

Inflammatory and cytotoxic effects of bifenthrin in primary microglia and organotypic hippocampal slice cultures

BACKGROUND

Pyrethroids, such as bifenthrin (BF), are among the most widely used class of insecticides that pose serious risks to human and wildlife health. Pyrethroids are proposed to affect astrocytic functions and to cause neuron injury in the central nervous system (CNS). Microglia are key cells involved in innate immune responses in the CNS, and microglia activation has been linked to inflammation and neurotoxicity. However, little information is known about the effects of BF-induced toxicity in primary microglial cells as well as in organotypic hippocampal slice cultures (OHSCs).

METHODS

Oxidative stress and inflammatory responses induced by BF were evaluated in primary microglial cells and OHSCs incubated with different concentrations of BF (1-20 μM) for 4 and 24 h. mRNA and protein synthesis of cyclooxygenase-2 (COX-2), tumor necrosis factor-alpha (TNF-alpha), interleukin-6 (IL-6), nuclear erythroid-2 like factor-2 (Nrf-2), and microsomal prostaglandin synthase-1 (mPGES-1) was also studied by qPCR and Western blot. Cell viability was analyzed by MTT-tetrazolio (MTT) and lactate dehydrogenase (LDH) assays. Neurotoxicity in OHSCs was analyzed by propidium iodide (PI) staining and confocal microscopy.

RESULTS

Exposure of microglial cells to BF for 24 h resulted in a dose-dependent reduction in the number of viable cells. At sub-cytotoxic concentrations, BF increased reactive oxygen species (ROS), TNF-alpha synthesis, and prostaglandin E2 (PGE2) production, at both 4- and 24-h time points, respectively. Furthermore, BF incubation decreased superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) activities and increased lipid peroxidation, protein oxidation, and H2O2 formation. In addition, BF significantly induced protein synthesis and mRNA expression of oxidative and inflammatory mediators after 4 and 24 h, including Nrf-2, COX-2, mPGES-1, and nuclear factor kappaB (NF-kappaB). A 24-h exposure of OHSCs to BF also increased neuronal death compared to untreated controls. Furthermore, depletion of microglia from OHSCs potently enhanced neuronal death induced by BF.

CONCLUSIONS

Overall, BF exhibited cytotoxic effects in primary microglial cells, accompanied by the induction of various inflammatory and oxidative stress markers including the Nrf-2/COX-2/mPGES-1/NF-kappaB pathways. Moreover, the study provided evidence that BF induced neuronal death in OHSCs and suggests that microglia exert a protective function against BF toxicity.

Elevated AEG-1 expression in macrophages promotes hypopharyngeal cancer invasion through the STAT3-MMP-9 signaling pathway

Macrophages play a critical role in tumor invasion and metastasis, which remain major causes of mortality in patients with hypopharyngeal cancer. Here we investigate the effect of an oncogene, AEG-1 expressed in macrophages on the invasion of hypopharyngeal cancer cells. AEG-1 is more highly expressed in macrophages of human hypopharyngeal cancer samples compared with adjacent non-tumor controls. Using matrigel invasion assay system, THP-1-derived macrophages with forced AEG-1 overexpression enhance FaDu cell invasion whereas macrophages with AEG-1 silence inhibit. Matrix metalloproteinase 9 (MMP-9), which is important in tumor invasion and metastasis through degrading extracellular matrix, is up-reulated by AEG-1 partly through NF-κB p65 in macrophages. Intriguingly, macrophage AEG-1 also induces MMP-9 up-regulated expression in FaDu cells. Furthermore, macrophage AEG-1 activates signal transducer and activator of transcription 3 (STAT3) in FaDu cells, which is responsible for macrophage AEG-1-induced an increase in MMP-9 expression and invasion of FaDu cells. This is the first to demonstrate that macrophage AEG-1 promotes tumor invasion through up-regulation of MMP-9 in both macrophages and cancer cells. Thus, the results provide evidences that macrophage AEG-1 contributes to promotion of tumor invasion, and represents as a potential target in hypopharyngeal cancer therapy.

Signal regulatory protein α associated with the progression of oral leukoplakia and oral squamous cell carcinoma regulates phenotype switch of macrophages

Signal regulatory protein α (SIRPα) is a cell-surface protein expressed on macrophages that are regarded as an important component of the tumor microenvironment. The expression of SIRPα in oral leukoplakia (OLK) and oral squamous cell carcinoma (OSCC), and further explored the role of SIRPα on the phenotype, phagocytosis ability, migration, and invasion of macrophages in OSCC were investigated. The expression of SIRPα in OLK was higher than in OSCC, correlating with the expression of CD68 and CD163 on macrophages. After cultured with the conditioned media of oral cancer cells, the expression of SIRPα on THP-1 cells was decreased gradually. In co-culture system, macrophages were induced into M2 phenotype by oral cancer cells. Blockade of SIRPα inhibited phagocytosis ability and IL-6, TNF-α productions of macrophages. In addition, the proliferation, migration, and IL-10, TGF-β productions of macrophages were upregulated after blockade of SIRPα. Macrophages upregulated the expression of SIRPα and phagocytosis ability, and inhibited the migration and invasion when the activation of NF-κB was inhibited by pyrrolidine dithiocarbamate ammonium (PDTC). Hence, SIRPα might play an important role in the progression of OLK and oral cancer, and could be a pivotal therapeutic target in OSCC by regulating the phenotype of macrophages via targeting NF-κB.

Infective Larvae of Brugia malayi Induce Polarization of Host Macrophages that Helps in Immune Evasion

Filarial parasites suppress, divert, or polarize the host immune response to aid their survival. However, mechanisms that govern the polarization of host MΦs during early filarial infection are not completely understood. In this study, we infected BALB/c mice with infective larvae stage-3 of Brugia malayi (Bm-L3) and studied their effect on the polarization of splenic MΦs. Results showed that MΦs displayed M2-phenotype by day 3 p.i. characterized by upregulated IL-4, but reduced IL-12 and Prostaglandin-D2 secretion. Increased arginase activity, higher arginase-1 but reduced NOS2 expression and poor phagocytic and antigen processing capacity was also observed. M2 MΦs supported T-cell proliferation and characteristically upregulated p-ERK but downregulated NF-κB-p65 and NF-κB-p50/105. Notably, Bm-L3 synergized with host regulatory T-cells (Tregs) and polarized M2 MΦs to regulatory MΦs (Mregs) by day 7 p.i., which secreted copious amounts of IL-10 and prostaglandin-E2. Mregs also showed upregulated expression levels of MHC-II, CD80, and CD86 and exhibited increased antigen-processing capacity but displayed impaired activation of NF-κB-p65 and NF-κB-p50/105. Neutralization of Tregs by anti-GITR + anti-CD25 antibodies checked the polarization of M2 MΦs to Mregs, decreased accumulation of regulatory B cells and inflammatory monocytes, and reduced secretion of IL-10, but enhanced IL-4 production and percentages of eosinophils, which led to Bm-L3 killing. In summary, we report hitherto undocumented effects of early Bm-L3 infection on the polarization of splenic MΦs and show how infective larvae deftly utilize the functional plasticity of host MΦs to establish themselves inside the host.

Neuroendocrine-like cells -derived CXCL10 and CXCL11 induce the infiltration of tumor-associated macrophage leading to the poor prognosis of colorectal cancer

Our previous study revealed that neuroendocrine differentiation in colorectal cancer is one of the important factors leading to worse prognosis. In this study, we apply immunohistochemical staining, Western-blot, RT-PCR and ELISA to investigate the underlying mechanism that how the neuroendocrine differentiation to affect the prognosis of colorectal cancer. The interaction of colorectal cancer cells, neuroendocrine-like cells and tumor-associated macrophages in colorectal cancer progress is also investigated. By analyzing 82 cases of colorectal cancer patients treated in our institution, we found that colorectal adenocarcinoma with neuroendocrine differentiation had increasing number of tumor-associated macrophages and worse prognosis. Further evaluation of cytology showed that neuroendocrine cells have the ability to recruit tumor-associated macrophages to infiltrate the tumor tissue, and the tumor-associated macrophages enhance the proliferation and invasion abilities of the colon cancer cells. Moreover, we confirmed that CXCL10 and CXCL11 are the key chemokines in neuroendocrine-like cells and they promote the chemotaxis activity of tumor-associated macrophages. The secretion of CXCL10 and CXCL11 by neuroendocrine-like cells can recruit tumor-associated macrophages to infiltrate in tumor tissues. The latter enhances the proliferation and invasion of colorectal cancer cell and lead to poor prognosis.

Canonical NFκB signaling in myeloid cells is required for the glioblastoma growth

Tumor development and therapeutic resistance are linked with tumor-associated macrophage (TAM) and myeloid-derived suppressor cell (MDSC) infiltration in tumors via chemokine axis. Chemokine expression, which determines the pro or anti-inflammatory status of myeloid cells, are partly regulated by the nuclear factor-kappa B (NF-κB) pathway. Here, we identified that conditional deletion of canonical NF-κB signaling (p65) in myeloid cells inhibited syngeneic glioblastoma (GBM) through decreased CD45 infiltration in tumors, as characterized by decreased TAMs (CD206+) and MDSCs (Gr1+ CD11b+), increased dendritic cells (CD86+) and cytotoxic T cells (CD8+) in the p65 knockout (KO) mice. Proinflammatory cytokines (IFNγ, MCP1, MIP1α, and TNFα) and myeloid differentiation factor (Endoglin) were increased in myeloid cells from p65 KO tumor, which demonstrated an influence on CD8+T cell proliferation. In contrast, p65KO athymic chimeric mice with human GBM, failed to inhibit tumor growth, confirming the contribution of T cells in an immune competent model. The analysis of human datasets and GBM tumors revealed higher expression of p65 in GBM-associated CD68+ macrophages compared to neighboring stroma. Thus, canonical NF-κB signaling has an anti-inflammatory role and is required for macrophage polarization, immune suppression, and GBM growth. Combining an NF-κB inhibitor with standard therapy could improve antitumor immunity in GBM.

Anti-Jagged Immunotherapy Inhibits MDSCs and Overcomes Tumor-Induced Tolerance

Myeloid-derived suppressor cells (MDSC) are a major obstacle to promising forms of cancer immunotherapy, but tools to broadly limit their immunoregulatory effects remain lacking. In this study, we assessed the therapeutic effect of the humanized anti-Jagged1/2-blocking antibody CTX014 on MDSC-mediated T-cell suppression in tumor-bearing mice. CTX014 decreased tumor growth, affected the accumulation and tolerogenic activity of MDSCs in tumors, and inhibited the expression of immunosuppressive factors arginase I and iNOS. Consequently, anti-Jagged therapy overcame tumor-induced T-cell tolerance, increased the infiltration of reactive CD8⁺ T cells into tumors, and enhanced the efficacy of T-cell-based immunotherapy. Depletion of MDSC-like cells restored tumor growth in mice treated with anti-Jagged, whereas coinjection of MDSC-like cells from anti-Jagged-treated mice with cancer cells delayed tumor growth. Jagged1/2 was induced in MDSCs by tumor-derived factors via NFkB-p65 signaling, and conditional deletion of NFkB-p65 blocked MDSC function. Collectively, our results offer a preclinical proof of concept for the use of anti-Jagged1/2 to reprogram MDSC-mediated T-cell suppression in tumors, with implications to broadly improve the efficacy of cancer therapy. Cancer Res; 77(20); 5628-38. ©2017 AACR.

PA-MSHA induces apoptosis and suppresses metastasis by tumor associated macrophages in bladder cancer cells

BACKGROUND

The aim of the present study was to investigate effects of Pseudomonas aeruginosa-mannose-sensitive hemagglutinin (PA-MSHA) on the inhibition of the proliferation of bladder cancer cell lines and to further define its functional mechanisms.

METHODS

A rat model of bladder tumor was induced by intravesical N-methyl-N nitrosourea. The dynamic growth of tumor was measured by whole-body fluorescent imaging system. Morphological analysis was observed by hematoxylin-eosin staining and microscopic examination. The expression of Caspase 3 and E-Ca were detected by immunohistochemistry technique. Macrophages were separated by flow cytometry. The expression of cytokines was measured by qRT-PCR and western blot. Apoptosis ability was conducted by means of annexin V and propidium iodide. The abilities of invasion and migration were determined by transwell migration assay and scratch assay.

RESULTS

PA-MSHA and PA-MSHA + Fisetin groups inhibited the growth of tumor and increased the ratio of M1/M2. For one thing, PA-MSHA suppressed the invasive ability of the bladder tumor cell and promoted bladder tumor cell apoptosis. For another, it facilitated the expression of M1 cytokines and reduced expression of M2 cytokines. Furthermore, treated with PA-MSHA, mouse M1 phagocytosis rates were higher than that of M2 macrophages for bladder cancer lines.

CONCLUSIONS

The data revealed that PA-MSHA might promote apoptosis and inhibit proliferation, invasion and migration of mouse bladder cancer cells by inducing M1 polarization.

Antitumor effect of Batf2 through IL-12 p40 up-regulation in tumor-associated macrophages

The development of effective treatments against cancers is urgently needed, and the accumulation of CD8⁺ T cells within tumors is especially important for cancer prognosis. Although their mechanisms are still largely unknown, growing evidence has indicated that innate immune cells have important effects on cancer progression through the production of various cytokines. Here, we found that basic leucine zipper transcription factor ATF-like 2 (Batf2) has an antitumor effect. An s.c. inoculated tumor model produced fewer IL-12 p40⁺ macrophages and activated CD8⁺ T cells within the tumors of Batf2^-/- mice compared with WT mice. In vitro studies also revealed that the IL-12 p40 expression was significantly lower in Batf2^-/- macrophages following their stimulation by toll-like receptor ligands, such as R848. Additionally, we found that BATF2 interacts with p50/p65 and promotes IL-12 p40 expression. In conclusion, Batf2 has an antitumor effect through the up-regulation of IL-12 p40 in tumor-associated macrophages, which eventually induces CD8⁺ T-cell activation and accumulation within the tumor.

Cancer secretome and inflammation: The bright and the dark sides of NF-κB

Tumour promoting inflammation is widely recognized as a hallmark of cancer. The source of this chronic inflammation in cancer has been ascribed to the progressive activation over time of immune cells, mostly of the innate arm of the immune system. However, recent evidence has shown that chronic inflammation may also derive, at least in part, from senescent cells. Hence, due to the prominent role of inflammation in cancer, the cancer secretome definition includes all the secretory factors ensuing from the crosstalk between the cancer cell and the tumour microenvironment. The mechanistic basis underlying the paracrine signalling between the cancer cell and the surrounding tumour microenvironment in malignancy have been widely investigated by using in vivo models of cancers, thus identifying the NF-κB transcription factor as the molecular hub linking inflammation and cancer. In this review, we highlight the roles of NF-κB in regulating the inflammation-derived secretome emanating from immune and senescent cells, with a special focus on the bright and the dark sides of their pro-inflammatory signalling on tumorigenesis.