The Prognostic and Clinicopathological Significance of Tumor-Associated Macrophages in Patients with Gastric Cancer: A Meta-Analysis

CSF1R Inhibition in Patients with Advanced Solid Tumors or Tenosynovial Giant Cell Tumor: A Phase I Study of Vimseltinib

PURPOSE

Tenosynovial giant cell tumor (TGCT) is a locally aggressive neoplasm caused by dysregulation of the colony-stimulating factor 1 (CSF1) gene and overexpression of the CSF1 ligand. Surgery is the standard of care for most patients, but there are limited treatment options for patients with TGCT not amenable to surgery. This study evaluates vimseltinib, an investigational, oral, switch-control tyrosine kinase inhibitor designed to selectively and potently inhibit the CSF1 receptor.

PATIENTS AND METHODS

This first-in-human, multicenter, open-label phase I/II study of vimseltinib in patients with malignant solid tumors (N = 37) or TGCT not amenable to surgery (N = 32) followed a pharmacologically guided 3 + 3 study design (NCT03069469). The primary objectives were to assess safety and tolerability, determine the recommended phase II dose, and characterize the pharmacokinetics; exploratory objectives included pharmacodynamics and efficacy.

RESULTS

Vimseltinib was well tolerated; the majority of non-laboratory treatment-emergent adverse events were of grade 1/2 severity. There was no evidence of cholestatic hepatotoxicity or drug-induced liver injury. The recommended phase II dose was determined to be 30 mg twice weekly (no loading dose), and vimseltinib plasma exposure increased with the dose. In patients with TGCT, the median treatment duration was 25.1 months (range, 0.7-46.9), and the objective response rate as assessed by independent radiological review using RECIST version 1.1 was 72%.

CONCLUSIONS

Vimseltinib demonstrated long-term tolerability, manageable safety, dose-dependent exposure, and robust antitumor activity in patients with TGCT not amenable to surgery.

Macrophage-based cancer immunotherapy: Challenges and opportunities

Macrophages play crucial roles in the tumor microenvironment (TME), exerting diverse functions ranging from promoting tumor growth and metastasis to orchestrating anti-tumor immune responses. Their plasticity allows them to adopt distinct activation states, often called M1-like (pro-inflammatory) and M2-like (anti-inflammatory or pro-tumoral), significantly influencing tumor progression and response to therapy. Harnessing the potential of macrophages in cancer immunotherapy has emerged as a promising strategy, with increasing interest in targeting these cells directly or modulating their functions within the TME. This review explores the intricate interplay between macrophages, the TME, and immunotherapeutic approaches. We discuss the dynamic phenotypic and functional heterogeneity of tumor-associated macrophages (TAMs), their impact on disease progression, and the mechanisms underlying their response to immunotherapy. Furthermore, we highlight recent advancements in macrophage-based immunotherapeutic strategies, including macrophage-targeting agents, adoptive cell transfer, and engineering approaches. Understanding the complex crosstalk between macrophages and the TME is essential for developing effective immunotherapeutic interventions that exploit the immunomodulatory functions of macrophages to enhance anti-tumor immunity and improve clinical outcomes for cancer patients.

A novel M2-like tumor associated macrophages-related gene signature for predicting the prognosis and immunotherapy efficacy in gastric cancer

BACKGROUND

M2-like tumor-associated macrophages (M2-like TAMs) play key roles in tumor progression and the immune response. However, the clinical significance and prognostic value of M2-like TAMs-associated regulatory genes in gastric cancer (GC) have not been clarified.

METHODS

Herein, we identified M2-like TAM-related genes by weighted gene coexpression network analysis of TCGA-STAD and GSE84437 cohort. Lasso-Cox regression analyses were then performed to screen for signature genes, and a novel signature was constructed to quantify the risk score for each patient. Tumor mutation burden (TMB), survival outcomes, immune cells, and immune function were analyzed in the risk groups to further reveal the immune status of GC patients. A gene-drug correlation analysis and sensitivity analysis of anticancer drugs were used to identify potential therapeutic agents. Finally, we verified the mRNA expression of signature genes in patient tissues by qRT-PCR, and analyzed the expression distribution of these genes by IHC.

RESULTS

A 4-gene (SERPINE1, MATN3, CD36, and CNTN1) signature was developed and validated, and the risk score was shown to be an independent prognostic factor for GC patients. Further analyses revealed that GC patients in the high-risk group had a worse prognosis than those in the low-risk group, with significant differences in TMB, clinical features, enriched pathways, TIDE score, and tumor microenvironment features. Finally, we used qRT-PCR and IHC analysis to verify mRNA and protein level expression of signature genes.

CONCLUSION

These findings highlight the importance of M2-like TAMs, provide a new perspective on individualized immunotherapy for GC patients.

Correlation of tumor-associated macrophage density and proportion of M2 subtypes with the pathological stage of colorectal cancer

BACKGROUND

Colorectal cancer (CRC) is a prevalent global malignancy with complex prognostic factors. Tumor-associated macrophages (TAMs) have shown paradoxical associations with CRC survival, particularly concerning the M2 subset.

AIM

We aimed to establish a simplified protocol for quantifying M2-like TAMs and explore their correlation with clinicopathological factors.

METHODS

A cross-sectional study included histopathological assessment of paraffin-embedded tissue blocks obtained from 43 CRC patients. Using CD68 and CD163 immunohistochemistry, we quantified TAMs in tumor stroma and front, focusing on M2 proportion. Demographic, histopathological, and clinical parameters were collected.

RESULTS

TAM density was significantly higher at the tumor front, with the M2 proportion three times greater in both zones. The tumor front had a higher M2 proportion, which correlated significantly with advanced tumor stage (P = 0.04), pathological nodal involvement (P = 0.04), and lymphovascular invasion (LVI, P = 0.01). However, no significant association was found between the M2 proportion in the tumor stroma and clinicopathological factors.

CONCLUSION

Our study introduces a simplified protocol for quantifying M2-like TAMs in CRC tissue samples. We demonstrated a significant correlation between an increased M2 proportion at the tumor front and advanced tumor stage, nodal involvement, and LVI. This suggests that M2-like TAMs might serve as potential indicators of disease progression in CRC, warranting further investigation and potential clinical application.

Tumor and Peritoneum-Associated Macrophage Gene Signature as a Novel Molecular Biomarker in Gastric Cancer

A spectrum of immune states resulting from tumor resident macrophages and T-lymphocytes in the solid tumor microenvironment correlates with patient outcomes. We hypothesized that in gastric cancer (GC), macrophages in a polarized immunosuppressive transcriptional state would be prognostic of poor survival. We derived transcriptomic signatures for M2 (M2TS, MRC1; MS4A4A; CD36; CCL13; CCL18; CCL23; SLC38A6; FGL2; FN1; MAF) and M1 (M1TS, CCR7; IL2RA; CXCL11; CCL19; CXCL10; PLA1A; PTX3) macrophages, and cytolytic T-lymphocytes (CTLTS, GZMA; GZMB; GZMH; GZMM; PRF1). Primary GC in a TCGA stomach cancer dataset was evaluated for signature expressions, and a log-rank test determined overall survival (OS) and the disease-free interval (DFI). In 341 TCGA GC entries, high M2TS expression was associated with histological types and later stages. Low M2TS expression was associated with significantly better 5-year OS and DFI. We validated M2TS in prospectively collected peritoneal fluid of a GC patient cohort (n = 28). Single-cell RNA sequencing was used for signature expression in CD68+CD163+ cells and the log-rank test compared OS. GC patients with high M2TS in CD68+CD163+ cells in their peritoneal fluid had significantly worse OS than those with low expression. Multivariate analyses confirmed M2TS was significantly and independently associated with survival. As an independent predictor of poor survival, M2TS may be prognostic in primary tumors and peritoneal fluid of GC patients.

Epithelial-to-mesenchymal transition in cancer progression: unraveling the immunosuppressive module driving therapy resistance

Cancer cells undergo phenotypic switching (cancer cell plasticity) in response to microenvironmental cues, including exposure to therapy/treatment. Phenotypic plasticity enables the cancer cells to acquire more mesenchymal traits promoting cancer cells' growth, survival, therapy resistance, and disease recurrence. A significant program in cancer cell plasticity is epithelial-to-mesenchymal transition (EMT), wherein a comprehensive reprogramming of gene expression occurs to facilitate the translational shift from epithelial-to-mesenchymal phenotypes resulting in increased invasiveness and metastasis. In addition, EMT plays a pivotal role in facilitating cancer cells' escape from the body's immune system using several mechanisms, such as the downregulation of major histocompatibility complex-mediated antigen presentation, upregulation of immune checkpoint molecules, and recruitment of immune-suppressive cells. Cancer cells' ability to undergo phenotypic switching and EMT-driven immune escape presents a formidable obstacle in cancer management, highlighting the need to unravel the intricate mechanisms underlying these processes and develop novel therapeutic strategies. This article discusses the role of EMT in promoting immune evasion and therapy resistance. We also discuss the ongoing research on developing therapeutic approaches targeting intrinsic and induced cell plasticity within the immune suppressive microenvironment. We believe this review article will update the current research status and equip researchers, clinicians, and other healthcare professionals with valuable insights enhancing their existing knowledge and shedding light on promising directions for future cancer research. This will facilitate the development of innovative strategies for managing therapy-resistant cancers and improving patient outcomes.

Multiplexed analysis of macrophage polarisation in pulmonary metastases of microsatellite stable colorectal cancer

Tumour-associated macrophages (TAMs) express a continuum of phenotypes ranging from an anti-tumoural M1-like phenotype to a pro-tumoural M2-like phenotype. During cancer progression, TAMs may shift to a more M2-like polarisation state, but the role of TAMs in CRC metastases is unclear. We conducted a comprehensive spatial and prognostic analysis of TAMs in CRC pulmonary metastases and corresponding primary tumours using multiplexed immunohistochemistry and machine learning-based image analysis. We obtained data from 106 resected pulmonary metastases and 74 corresponding primary tumours. TAMs in the resected pulmonary metastases were located closer to the cancer cells and presented a more M2-like polarised state in comparison to the primary tumours. Higher stromal M2-like macrophage densities in the invasive margin of pulmonary metastases were associated with worse 5-year overall survival (HR 3.19, 95% CI 1.35-7.55, p = 0.008). The results of this study highlight the value of multiplexed analysis of macrophage polarisation in cancer metastases and might have clinical implications in future cancer therapy.

A prognostic marker LTBP1 is associated with epithelial mesenchymal transition and can promote the progression of gastric cancer

LTBP1 is closely related to TGF-β1 function as an essential component, which was unclear in gastric cancer (GC). Harbin Medical University (HMU)-GC cohort and The Cancer Genome Atlas (TCGA) dataset were combined to form a training cohort to calculate the connection between LTBP1 mRNA expression, prognosis and clinicopathological features. The training cohort was also used to verify the biological function of LTBP1 and its relationship with immune microenvironment and chemosensitivity. In the tissue microarrays (TMAs), immunohistochemical (IHC) staining was performed to observe LTBP1 protein expression. The correlation between LTBP1 protein expression level and prognosis was also analyzed, and a nomogram model was constructed. Western blotting (WB) was used in cell lines to assess LTBP1 expression. Transwell assays and CCK-8 were employed to assess LTBP1's biological roles. In compared to normal gastric tissues, LTBP1 expression was upregulated in GC tissues, and high expression was linked to a bad prognosis for GC patients. Based on a gene enrichment analysis, LTBP1 was primarily enriched in the TGF-β and EMT signaling pathways. Furthermore, high expression of LTBP1 in the tumor microenvironment was positively correlated with an immunosuppressive response. We also found that LTBP1 expression (p = 0.006) and metastatic lymph node ratio (p = 0.044) were independent prognostic risk factors for GC patients. The prognostic model combining LTBP1 expression and lymph node metastasis ratio reliably predicted the prognosis of GC patients. In vitro proliferation and invasion of MKN-45 GC cells were inhibited and their viability was decreased by LTBP1 knockout. LTBP1 plays an essential role in the development and progression of GC, and is a potential prognostic biomarker and therapeutic target for GC.

Impact of the peripheral blood inflammatory indices and modified nomogram-revised risk index on survival of Extranodal Nasal-Type Natural Killer/T-Cell lymphoma

BACKGROUND

At present, peripheral blood markers are easily accessible information and clinically valuable prognostic indicators in extranodal nasal-type natural killer/T-cell lymphoma (ENKTCL). Nevertheless, the role of its comprehensive score in ENKTCL remains to be determined.

OBJECTIVE

Therefore, this study aimed to investigate the prognostic effect of the peripheral inflammation score on ENKTCL.

METHODS

The retrospective study included 183 patients with ENKTCL. Univariate Cox regression analyses and least absolute shrinkage and selection operator (LASSO) Cox regression were used to construct the inflammation-related prognostic index named Risk. Univariate and multivariate Cox regression analyses and regression adjustment with propensity score matching (PSM) were used to evaluate the prognostic ability of risk. The performance of the modified nomogram-revised risk index (NRI) by integrating risk was evaluated with the area under the time-dependent receiver operating characteristic (ROC) curve (AUC), decision curve analysis (DCA), and integrated Brier score (IBS).

RESULTS

The risk cut-off value, constructed by the lymphocyte count, platelet count, albumin level, LMR, and PNI, was -1.3486. Before PSM, multivariate analysis showed that risk was significantly associated with OS (HR = 2.577, 95% CI = 1.614-4.114, P< 0.001) and PFS (HR = 2.679, 95% CI = 1.744-4.114, P< 0.001). After PSM adjustment, risk was still an independent factor for OS (HR = 2.829, 95% CI = 1.601-5.001, P< 0.001) and PFS (HR = 2.877, 95% CI = 1.735-4.770, P< 0.001). With the NRI, the modified NRI by integrating risk increased the AUC and clinical net benefit and decreased the IBS.

CONCLUSIONS

Risk is an easily accessible and inexpensive indicator that may be used as a prognostic marker and could improve NRI predictive power in patients with ENKTCL.

The emerging role of glycolysis and immune evasion in gastric cancer

Gastric cancer (GC) is the fifth most common malignancy and the third leading cause of cancer-related deaths worldwide. Similar to other types of tumors, GC cells undergo metabolic reprogramming and switch to a "predominantly glycolytic" metabolic pattern to promote its survival and metastasis, also known as "the Warburg effect", which is characterized by enhanced glucose uptake and lactate production. A large number of studies have shown that targeting cancer cells to enhanced glycolysis is a promising strategy, that can make cancer cells more susceptible to other conventional treatment methods of treatment, including chemotherapy, radiotherapy and immunotherapy, and so on. Therefore, this review summarizes the metabolic characteristics of glycolysis in GC cells and focuses on how abnormal lactate concentration can lead to immunosuppression through its effects on the differentiation, metabolism, and function of infiltrating immune cells, and how targeting this phenomenon may be a potential strategy to improve the therapeutic efficacy of GC.

Constructing a prognostic model for head and neck squamous cell carcinoma based on glucose metabolism related genes

Background

Glucose metabolism (GM) plays a crucial role in cancer cell proliferation, tumor growth, and survival. However, the identification of glucose metabolism-related genes (GMRGs) for effective prediction of prognosis in head and neck squamous cell carcinoma (HNSC) is still lacking.

Methods

We conducted differential analysis between HNSC and Normal groups to identify differentially expressed genes (DEGs). Key module genes were obtained using weighted gene co-expression network analysis (WGCNA). Intersection analysis of DEGs, GMRGs, and key module genes identified GMRG-DEGs. Univariate and multivariate Cox regression analyses were performed to screen prognostic-associated genes. Independent prognostic analysis of clinical traits and risk scores was implemented using Cox regression. Gene set enrichment analysis (GSEA) was used to explore functional pathways and genes between high- and low-risk groups. Immune infiltration analysis compared immune cells between the two groups in HNSC samples. Drug prediction was performed using the Genomics of Drug Sensitivity in Cancer (GDSC) database. Quantitative real-time fluorescence PCR (qRT-PCR) validated the expression levels of prognosis-related genes in HNSC patients.

Results

We identified 4973 DEGs between HNSC and Normal samples. Key gene modules, represented by black and brown module genes, were identified. Intersection analysis revealed 76 GMRG-DEGs. Five prognosis-related genes (MTHFD2, CDKN2A, TPM2, MPZ, and DNMT1) were identified. A nomogram incorporating age, lymph node status (N), and risk score was constructed for survival prediction in HNSC patients. Immune infiltration analysis showed significant differences in five immune cell types (Macrophages M0, memory B cells, Monocytes, Macrophages M2, and Dendritic resting cells) between the high- and low-risk groups. GDSC database analysis identified 53 drugs with remarkable differences between the groups, including A.443654 and AG.014699. DNMT1 and MTHFD2 were up-regulated, while MPZ was down-regulated in HNSC.

Conclusion

Our study highlights the significant association of five prognosis-related genes (MTHFD2, CDKN2A, TPM2, MPZ, and DNMT1) with HNSC. These findings provide further evidence of the crucial role of GMRGs in HNSC.

Stromal circuits involving tumor-associated macrophages and cancer-associated fibroblasts

The tumor associated macrophages (TAM) represent one of most abundant subpopulations across several solid cancers and their number/frequency is associated with a poor clinical outcome. It has been clearly demonstrated that stromal cells, such as the cancer associated fibroblasts (CAFs), may orchestrate TAM recruitment, survival and reprogramming. Today, single cell-RNA sequencing (sc-RNA seq) technologies allowed a more granular knowledge about TAMs and CAFs phenotypical and functional programs. In this mini-review we discuss the recent discoveries in the sc-RNA seq field focusing on TAM and CAF identity and their crosstalk in the tumor microenvironment (TME) of solid cancers.

Integrated bioinformatics analysis for conducting a prognostic model and identifying immunotherapeutic targets in gastric cancer

BACKGROUND

Gastric cancer is the third leading cause of death from cancer worldwide and has a poor prognosis. Practical risk scores and prognostic models for gastric cancer are lacking. While immunotherapy has succeeded in some cancers, few gastric cancer patients benefit from immunotherapy. Immune genes and the tumor microenvironment (TME) are essential for cancer progression and immunotherapy response. However, the roles of immune genes and the tumor microenvironment in immunotherapy remain unclear. The study aimed to construct a prognostic prediction model and identify immunotherapeutic targets for gastric cancer (GC) patients by exploring immune genes and the tumor microenvironment.

RESULTS

An immune-related risk score (IRRS) model, including APOH, RNASE2, F2R, DEFB126, CXCL6, and CXCL3 genes, was constructed for risk stratification. Patients in the low-risk group, which was characterized by elevated tumor mutation burden (TMB) have higher survival rate. The risk level was remarkably correlated with tumor-infiltrating immune cells (TIICs), the immune checkpoint molecule expression, and immunophenoscore (IPS). CXCL3 and CXCL6 were significantly upregulated in gastric cancer tissues compared with normal tissues using the UALCAN database and RT-qPCR. The nomogram showed good calibration and moderate discrimination in predicting overall survival (OS) at 1-, 3-, and 5- year for gastric cancer patients using risk-level and clinical characteristics.

CONCLUSION

Our findings provided a risk stratification and prognosis prediction tool for gastric cancer patients and further the research into immunotherapy in gastric cancer.

Elevated LILRB1 expression predicts poor prognosis and is associated with tumor immune infiltration in patients with glioma

BACKGROUND

Leukocyte immunoglobulin-like receptor subfamily B1 (LILRB1) is regarded as an inhibitory molecule. However, the importance of LILRB1 expression in glioma has not yet been determined. This investigation examined the immunological signature, clinicopathological importance and prognostic value of LILRB1 expression in glioma.

METHODS

We used data from the UCSC XENA database, the Cancer Genome Atlas (TCGA) database, the Chinese Glioma Genome Atlas (CGGA) database, the STRING database, the MEXPRESS database and our clinical glioma samples to perform bioinformatic analysis and used vitro experiments to examine the predictive value and potential biological roles of LILRB1 in glioma.

RESULTS

Higher LILRB1 expression was considerably present in the higher WHO grade glioma group and was linked to a poorer prognosis in patients with glioma. Gene set enrichment analysis (GSEA) revealed that LILRB1 was positively correlated with the JAK/STAT signaling pathway. LILRB1 combined with tumor mutational burden (TMB) and microsatellite instability (MSI) may be a promising indicator for the effectiveness of immunotherapy in patients with glioma. Increased LILRB1 expression was positively linked with the hypomethylation, M2 macrophage infiltration, immune checkpoints (ICPs) and M2 macrophage makers. Univariate and multivariate Cox regression analyses determined that increased LILRB1 expression was a standalone causal factor for glioma. Vitro experiments determined that LILRB1 positively enhanced the proliferation, migration and invasion in glioma cells. MRI images demonstrated that higher LILRB1 expression was related with larger tumor volume in patients with glioma.

CONCLUSION

Dysregulation of LILRB1 in glioma is correlated with immune infiltration and is a standalone causal factor for glioma.

A Real-Time Image-Based Efferocytosis Assay for the Discovery of Functionally Inhibitory Anti-MerTK Antibodies

Efferocytosis is a phagocytic process by which apoptotic cells are cleared by professional and nonprofessional phagocytic cells. In tumors, efferocytosis of apoptotic cancer cells by tumor-associated macrophages prevents Ag presentation and suppresses the host immune response against the tumor. Therefore, reactivating the immune response by blockade of tumor-associated macrophage-mediated efferocytosis is an attractive strategy for cancer immunotherapy. Even though several methods have been developed to monitor efferocytosis, an automated and high-throughput quantitative assay should offer highly desirable advantages for drug discovery. In this study, we describe a real-time efferocytosis assay with an imaging system for live-cell analysis. Using this assay, we successfully discovered potent anti-MerTK Abs that block tumor-associated macrophage-mediated efferocytosis in mice. Furthermore, we used primary human and cynomolgus monkey macrophages to identify and characterize anti-MerTK Abs for potential clinical development. By studying the phagocytic activities of different types of macrophages, we demonstrated that our efferocytosis assay is robust for screening and characterization of drug candidates that inhibit unwanted efferocytosis. Moreover, our assay is also applicable to investigating the kinetics and molecular mechanisms of efferocytosis/phagocytosis.

Role of tumor-associated macrophages in common digestive system malignant tumors

Many digestive system malignant tumors are characterized by high incidence and mortality rate. Increasing evidence has revealed that the tumor microenvironment (TME) is involved in cancer initiation and tumor progression. Tumor-associated macrophages (TAMs) are a predominant constituent of the TME, and participate in the regulation of various biological behaviors and influence the prognosis of digestive system cancer. TAMs can be mainly classified into the antitumor M1 phenotype and protumor M2 phenotype. The latter especially are crucial drivers of tumor invasion, growth, angiogenesis, metastasis, immunosuppression, and resistance to therapy. TAMs are of importance in the occurrence, development, diagnosis, prognosis, and treatment of common digestive system malignant tumors. In this review, we summarize the role of TAMs in common digestive system malignant tumors, including esophageal, gastric, colorectal, pancreatic and liver cancers. How TAMs promote the development of tumors, and how they act as potential therapeutic targets and their clinical applications are also described.

The prognostic value of tumor-associated macrophages detected by immunostaining in diffuse large B cell lymphoma: A meta-analysis

Background

The prognostic implication of tumor-associated macrophages (TAMs) in the microenvironment of diffuse large B cell lymphoma (DLBCL) remains controversial.

Methods

A systematic and comprehensive search of relevant studies was performed in PubMed, Embase and Web of Science databases. The quality of the included studies was estimated using Newcastle-Ottawa Scale (NOS).

Results

Twenty-three studies containing a total of 2992 DLBCL patients were involved in this study. They were all high-quality studies scoring ≥ 6 points. High density of M2 TAMs in tumor microenvironment significantly associated with both advanced disease stage (OR= 1.937, 95% CI: 1.256-2.988, P = 0.003) and unfavorable overall survival (OS) (HR = 1.750, 95% CI: 1.188-2.579, P = 0.005) but not associated with poor progression free survival (PFS) (HR = 1.672, 95% CI: 0.864-3.237, P = 0.127) and international prognostic index (IPI) (OR= 1.705, 95% CI: 0.843-3.449, P = 0.138) in DLBCL patients. No significant correlation was observed between the density of CD68+ TAMs and disease stage (OR= 1.433, 95% CI: 0.656-3.130, P = 0.366), IPI (OR= 1.391, 95% CI: 0.573-3.379, P = 0.466), OS (HR=0.929, 95% CI: 0.607-1.422, P = 0.734) or PFS (HR= 0.756, 95% CI: 0.415-1.379, P = 0.362) in DLBCL patients.

Conclusion

This meta-analysis demonstrated that high density of M2 TAMs in the tumor microenvironment was a robust predictor of adverse outcome for DLBCL patients.

Systematic review registration

https://www.crd.york.ac.uk/PROSPERO, identifier CRD42022343045.

Turning adversity into opportunity: Small extracellular vesicles as nanocarriers for tumor-associated macrophages re-education

Currently, small extracellular vesicles (sEV) as a nanoscale drug delivery system, are undergoing biotechnological scaling and clinical validation. Nonetheless, preclinical pharmacokinetic studies revealed that sEV are predominantly uptaken by macrophages. Although this "sEV-macrophage" propensity represents a disadvantage in terms of sEV targeting and their bioavailability as nanocarriers, it also represents a strategic advantage for those therapies that involve macrophages. Such is the case of tumor-associated macrophages (TAMs), which can reprogram/repolarize their predominantly immunosuppressive and tumor-supportive phenotype toward an immunostimulatory and anti-tumor phenotype using sEV as nanocarriers of TAMs reprogramming molecules. In this design, sEV represents an advantageous delivery system, providing precision to the therapy by simultaneously matching their tropism to the therapeutic cell target. Here, we review the current knowledge of the role of TAMs in the tumoral microenvironment and the effect generated by the reprogramming of these phagocytic cells fate using sEV. Finally, we discuss how these vesicles can be engineered by different bioengineering techniques to improve their therapeutic cargo loading and preferential uptake by TAMs.

HSF1 expression in tumor-associated macrophages promotes tumor cell proliferation and indicates poor prognosis in esophageal squamous cell carcinoma

PURPOSE

Tumor-associated macrophages (TAMs), are crucial for the survival and development of tumor cells. Heat shock factor 1 (HSF1) is a potent, complex carcinogenesis modulator, and esophageal cancer (EC) patients have a bad prognosis when HSF1 is highly expressed. HSF1's clinical importance and biological role in TAMs are still unknown.

METHODS

The HSF1 expression profile and patient survival information were analyzed from the TCGA database. The infiltration of different types of immune cells in EC was evaluated based on HSF1 gene expression by Sangerbox 3.0. Immunochemistry was employed to assess HSF1 protein expression in 134 individuals with esophageal squamous cell carcinoma (ESCC), proceeded by association with clinicopathological variables. The role of macrophage-driven HSF1 were observed using HSF1-knockdown THP1 cells.

RESULTS

High level of HSF1 have a poorer prognosis in individuals with EC. The expressing level of HSF1 was positively related to infiltration of M2 macrophages (P < 0.05). The expression of HSF1 in macrophages was an independent factor for DFS (P = 0.002) and OS (P = 0.002) in ESCC cases. HSF1 was up-regulated in IL-4 stimulation THP1 cells in a time-dependent manner. Under the heat stimulation condition, THP1-derived macrophages were more sensitive than tumor cells. Compared to IL-4 induced-THP1 cells control, the HSF1 knockdown in THP1 cell inhibited the growth and proliferation of ESCC cells.

CONCLUSIONS

The up-regulation of HSF1 was more rapid and could affect the proliferation of tumor cells in IL4-induced macrophages. The expression of HSF1 in TAMs can also serve as a marker for ESCC prognosis.

Immunomodulatory role of metalloproteases in cancers: Current progress and future trends

Metalloproteinases (MPs) is a large family of proteinases with metal ions in their active centers. According to the different domains metalloproteinases can be divided into a variety of subtypes mainly including Matrix Metalloproteinases (MMPs), A Disintegrin and Metalloproteases (ADAMs) and ADAMs with Thrombospondin Motifs (ADAMTS). They have various functions such as protein hydrolysis, cell adhesion and remodeling of extracellular matrix. Metalloproteinases expressed in multiple types of cancers and participate in many pathological processes involving tumor genesis and development, invasion and metastasis by regulating signal transduction and tumor microenvironment. In this review, based on the current research progress, we summarized the structure of MPs, their expression and especially immunomodulatory role and mechanisms in cancers. Additionally, a relevant and timely update of recent advances and future directions were provided for the diagnosis and immunotherapy targeting MPs in cancers.

Immune Cells in Head-and-Neck Tumor Microenvironments

Head-and-neck cancers constitute a heterogeneous group of aggressive tumors with high incidence and low survival rates, collectively being the sixth most prevalent cancer type globally. About 90% of head-and-neck cancers are classified as squamous cell carcinomas (HNSCC). The innate and adaptive immune systems, indispensable for anti-cancer immune surveillance, largely define the rates of HNSCC emergence and progression. HNSCC microenvironments harbor multiple cell types that infiltrate the tumors and interact both with tumor cells and among themselves. Gradually, tumor cells learn to manipulate the immune system, either by adapting their own immunogenicity or through the release of immunosuppressive molecules. These interactions continuously evolve and shape the tumor microenvironment, both structurally and functionally, facilitating angiogenesis, proliferation and metastasis. Our understanding of this evolution is directly related to success in the development of advanced therapies. This review focuses on the key mechanisms that rule HNSCC infiltration, featuring particular immune cell types and their roles in the pathogenesis. A close focus on the tumor-immunity interactions will help identify new immunotherapeutic targets in patients with HNSCC.

Macrophages in melanoma: A double‑edged sword and targeted therapy strategies (Review)

Melanoma, which evolves from melanocytes, is the most malignant skin cancer and is highly fatal, although it only accounts for 4% of all skin cancers. Numerous studies have demonstrated that melanoma has a large tumor mutational burden, which means that melanoma has great potential to achieve immune evasion. Tumor-associated macrophages (TAMs) are an important component of both the immune system and tumor microenvironment. Several studies have demonstrated their double-edged sword effects on melanoma. The present review focuses on the role of TAMs in melanoma development, including regulation of proliferation, invasion, metastasis, angiogenesis and chemical resistance of melanoma. Furthermore, the existing mechanisms of action of the TAM-targeting treatments for melanoma are reviewed. More broadly, the weak points of existing research and the direction of future research are finally identified and described.

Tumor-Associated Macrophages Correlate With Prognosis in Medulloblastoma

Purpose

Macrophage polarization plays an essential role in the tumor microenvironment of brain tumors. However, the role of tumor-associated macrophages (TAMs) in medulloblastoma still remains controversial. Thus, we investigated the distribution of macrophages in medulloblastoma tissues and analyzed the association of TAM recruitment and medulloblastoma patients’ outcomes.

Methods

We obtained a total of 71 paraffin sections from patients with medulloblastoma, and detected the activated phenotype (M1/M2) by monoclonal antibodies for CD68, HLA-DR and CD163 with multiple fluorescence immunohistochemistry method. The number of polarized macrophages was quantified using the InForm software. Outcomes were analyzed according to clinical data and quantified macrophage data.

Results

The study revealed that TAMs were significantly higher in sonic hedgehog (SHH) medulloblastoma than in other subgroups, and M1 macrophages in metastatic group were significantly higher than those in non-metastatic group. A Kaplan-Meier survival analysis and multivariate Cox regression model showed the correlation of high percentage of total macrophages (P = 0.038, HR = 0.241) and M1 macrophages (P = 0.034, HR = 0.333) with good 5-year progression-free survival (PFS); however, M2 macrophages had no correlation with survival of medulloblastoma patients (P> 0.05).

Conclusion

High percentage of total macrophages and M1 macrophages are correlated with good outcome of medulloblastoma patients. TAMs might be a target of therapy.

A Four-Gene Prognostic Signature Based on the TEAD4 Differential Expression Predicts Overall Survival and Immune Microenvironment Estimation in Lung Adenocarcinoma

Background: TEA domain transcription factor 4 (TEAD4) is a member of the transcriptional enhancer factor (TEF) family of transcription factors, which is studied to be linked to the tumorigenesis and progression of various forms of cancers, including lung adenocarcinoma (LUAD). However, the specific function of this gene in the progression of LUAD remains to be explored.

Method: A total of 19 genes related to the Hippo pathway were analyzed to identify the significant genes involved in LUAD progression. The TCGA-LUAD data (n = 585) from public databases were mined, and the differentially expressed genes (DEGs) in patients with the differential level of TEAD4 were identified. The univariate Cox regression, zero LASSO regression coefficients, and multivariate Cox regression were performed to identify the independent prognostic signatures. The immune microenvironment estimation in the two subgroups, including immune cell infiltration, HLA family genes, and immune checkpoint genes, was assessed. The Gene Set Enrichment Analysis (GSEA) and GO were conducted to analyze the functional enrichment of DEGs between the two risk groups. The potential drugs for the high-risk subtypes were forecasted via the mode of action (moa) module of the connectivity map (CMap) database.

Results:TEAD4 was found to be significantly correlated with poor prognosis in LUAD-patients. A total of 102 DEGs in TEAD4-high vs. TEAD4-low groups were identified. Among these DEGs, four genes (CPS1, ANLN, RHOV, and KRT6A) were identified as the independent prognostic signature to conduct the Cox risk model. The immune microenvironment estimation indicated a strong relationship between the high TEAD4 expression and immunotherapeutic resistance. The GSEA and GO showed that pathways, including cell cycle regulation, were enriched in the high-risk group, while immune response-related and metabolism biological processes were enriched in the low-risk group. Several small molecular perturbagens targeting CFTR or PLA2G1B, by the mode of action (moa) modules of the glucocorticoid receptor agonist, cyclooxygenase inhibitor, and NFkB pathway inhibitor, were predicted to be suited for the high-risk subtypes based on the high TEAD4 expression.

Conclusion: The current study revealed TEAD4 is an immune regulation–related predictor of prognosis and a novel therapeutic target for LUAD.

Bone marrow-independent adventitial macrophage progenitor cells contribute to angiogenesis

Pathological angiogenesis promotes tumor growth, metastasis, and atherosclerotic plaque rupture. Macrophages are key players in these processes. However, whether these macrophages differentiate from bone marrow-derived monocytes or from local vascular wall-resident stem and progenitor cells (VW-SCs) is an unresolved issue of angiogenesis. To answer this question, we analyzed vascular sprouting and alterations in aortic cell populations in mouse aortic ring assays (ARA). ARA culture leads to the generation of large numbers of macrophages, especially within the aortic adventitia. Using immunohistochemical fate-mapping and genetic in vivo-labeling approaches we show that 60% of these macrophages differentiate from bone marrow-independent Ly6c⁺/Sca-1⁺ adventitial progenitor cells. Analysis of the NCX^−/− mouse model that genetically lacks embryonic circulation and yolk sac perfusion indicates that at least some of those progenitor cells arise yolk sac-independent. Macrophages represent the main source of VEGF in ARA that vice versa promotes the generation of additional macrophages thereby creating a pro-angiogenetic feedforward loop. Additionally, macrophage-derived VEGF activates CD34⁺ progenitor cells within the adventitial vasculogenic zone to differentiate into CD31⁺ endothelial cells. Consequently, depletion of macrophages and VEGFR2 antagonism drastically reduce vascular sprouting activity in ARA. In summary, we show that angiogenic activation induces differentiation of macrophages from bone marrow-derived as well as from bone marrow-independent VW-SCs. The latter ones are at least partially yolk sac-independent, too. Those VW-SC-derived macrophages critically contribute to angiogenesis, making them an attractive target to interfere with pathological angiogenesis in cancer and atherosclerosis as well as with regenerative angiogenesis in ischemic cardiovascular disorders.

Comparison between Heat-Clearing Medicine and Antirheumatic Medicine in Treatment of Gastric Cancer Based on Network Pharmacology, Molecular Docking, and Tumor Immune Infiltration Analysis

Background

Clinical research found that TCM is therapeutic in treating gastric cancer. Clearing heat is the most common method, while some antirheumatic medicines are widely used in treatment as well. To explore the pharmacological mechanism, we researched the comparison between heat-clearing medicine and antirheumatic medicine in treating gastric cancer.

Methods

First, related ingredients and targets were searched, respectively, and are shown in an active ingredient-target network. Combining the relevant targets of gastric cancer, we constructed a PPI network and MCODE network. Then, GO and KEGG enrichment analyses were conducted. Molecular docking experiments were performed to verify the affinity of targets and ligands. Finally, we analyzed the tumor immune infiltration on gene expression, somatic CNA, and clinical outcome.

Results

A total of 31 ingredients and 90 targets of heat-clearing medicine, 31 ingredients and 186 targets of antirheumatic medicine, and 12,155 targets of gastric cancer were collected. Antirheumatic medicine ranked the top in all the enrichment analyses. In the KEGG pathway, both types of medicines were related to pathways in cancer. In the KEGG map, AR, MMP2, ERBB2, and TP53 were the most crucial targets. Key targets and ligands were docked with low binding energy. Analysis of tumor immune infiltration showed that the expressions of AR and ERBB2 were correlated with the abundance of immune infiltration and made a difference in clinical outcomes.

Conclusions

Quercetin is an important ingredient in both heat-clearing medicine and antirheumatic medicine. AR signaling pathway exists in both types of medicines. The mechanism of the antitumor effect in antirheumatic medicine was similar to trastuzumab, a targeted drug aimed at ERBB2. Both types of medicines were significant in tumor immune infiltration. The immunology of gastric tumor deserves further research.

Prognostic Role of Tumor Microenvironment in DLBCL and Relation to Patients’ Clinical Outcome: A Clinical and Immunohistochemical Study

Diffuse large B cell lymphoma is the most common type of lymphoma in Egypt with an unfavorable prognosis. The tumor microenvironment is rich in immune response either T cells or macrophages. The current study is aimed at testing CD4, CD8, CD68, and MMP9 immunohistochemistry of DLBCL activities with the prognosis of the tumor. The results showed no positive relation between T cell and macrophage reaction to the tumor prognosis suggesting that this reaction is part of the tumor process and not a defense mechanism from the surrounding stroma.

Immune evasion mechanisms and therapeutic strategies in gastric cancer

Gastric cancer (GC) is a malignancy with a high incidence and mortality. The tumor immune microenvironment plays an important role in promoting cancer development and supports GC progression. Accumulating evidence shows that GC cells can exert versatile mechanisms to remodel the tumor immune microenvironment and induce immune evasion. In this review, we systematically summarize the intricate crosstalk between GC cells and immune cells, including tumor-associated macrophages, neutrophils, myeloid-derived suppressor cells, natural killer cells, effector T cells, regulatory T cells, and B cells. We focus on how GC cells alter these immune cells to create an immunosuppressive microenvironment that protects GC cells from immune attack. We conclude by compiling the latest progression of immune checkpoint inhibitor-based immunotherapies, both alone and in combination with conventional therapies. Anti-cytotoxic T-lymphocyte-associated protein 4 and anti-programmed cell death protein 1/programmed death-ligand 1 therapy alone does not provide substantial clinical benefit for GC treatment. However, the combination of immune checkpoint inhibitors with chemotherapy or targeted therapy has promising survival advantages in refractory and advanced GC patients. This review provides a comprehensive understanding of the immune evasion mechanisms of GC, and highlights promising immunotherapeutic strategies.

Roles of tumor-associated macrophages in tumor progression: implications on therapeutic strategies

Macrophages are heterogeneous cells that present as different functional phenotypes due to their plasticity. They can be classified into two categories, namely M1- and M2-like macrophages, which are involved in processes as diverse as anti-tumor activity and immunosuppressive tumor promotion. Tumor-associated macrophages (TAMs) are defined as being of an M2-type and are considered as the active component in tumor microenvironment. TAMs are involved in multiple processes of tumor progression through the expression of cytokines, chemokines, growth factors, protein hydrolases and more, which lead to enhance tumor cell proliferation, angiogenesis, and immunosuppression, which in turn supports invasion and metastasis. It is assumed that the abundance of TAMs in major solid tumors is correlated to a negative patient prognosis. Because of the currently available data of the TAMs’ role in tumor development, these cells have emerged as a promising target for novel cancer treatment strategies. In this paper, we will briefly describe the origins and types of TAMs and will try to comprehensively show how TAMs contribute to tumorigenesis and disease progression. Finally, we will present the main TAM-based therapeutic strategies currently available.

Targeting macrophage-mediated tumor cell phagocytosis: An overview of phagocytosis checkpoints blockade, nanomedicine intervention, and engineered CAR-macrophage therapy

Immunotherapy has been developing at an unprecedented speed with promising therapeutic outcomes in the wide spectrum of cancers. Up until now, most immunotherapies have focused on adaptive immunity; however, investigating the potential of macrophage phagocytosis and consequent adaptive immune cross-priming has led to a growing interest in exploiting macrophages in cancer therapy. In light of the positive evidence from preclinical studies and early clinical data, targeting macrophage phagocytosis has become a promising therapeutic strategy. Here, we review therapies based on harnessing and amplifying macrophage phagocytosis, such as blocking phagocytosis checkpoints and exploiting nanoparticles as efficient approaches in elevating macrophages-mediated phagocytosis. The present study introduces CAR-macrophage as the state-of-the-art modality serving as the bridge between the innate and adaptive immune system to mount a superior anti-tumor response in the treatment of cancer. We also take a look at the recent reports of therapies based on CAR-engineered macrophages with the hope of providing a future research direction for expanding the application of CAR-macrophage therapy.

Tumor Associated Macrophages: Origin, Recruitment, Phenotypic Diversity, and Targeting

The tumor microenvironment (TME) is known to have a strong influence on tumorigenesis, with various components being involved in tumor suppression and tumor growth. A protumorigenic TME is characterized by an increased infiltration of tumor associated macrophages (TAMs), where their presence is strongly associated with tumor progression, therapy resistance, and poor survival rates. This association between the increased TAMs and poor therapeutic outcomes are stemming an increasing interest in investigating TAMs as a potential therapeutic target in cancer treatment. Prominent mechanisms in targeting TAMs include: blocking recruitment, stimulating repolarization, and depletion methods. For enhancing targeting specificity multiple nanomaterials are currently being explored for the precise delivery of chemotherapeutic cargo, including the conjugation with TAM-targeting peptides. In this paper, we provide a focused literature review of macrophage biology in relation to their role in tumorigenesis. First, we discuss the origin, recruitment mechanisms, and phenotypic diversity of TAMs based on recent investigations in the literature. Then the paper provides a detailed review on the current methods of targeting TAMs, including the use of nanomaterials as novel cancer therapeutics.

Tumor-associated macrophages in osteosarcoma

Osteosarcoma (OS) is the most common primary bone tumor in children and adolescents. It is an aggressive tumor with a tendency to spread to the lung, which is the most common site of metastasis. Patients with advanced OS with metastases have poor prognoses despite the application of chemotherapy, thus highlighting the need for novel therapeutic targets. The tumor microenvironment (TME) of OS is confirmed to be essential for and supportive of tumor growth and dissemination. The immune component of the OS microenvironment is mainly composed of tumor-associated macrophages (TAMs). In OS, TAMs promote tumor growth and angiogenesis and upregulate the cancer stem cell-like phenotype. However, TAMs inhibit the metastasis of OS. Therefore, much attention has been paid to investigating the mechanism of TAMs in OS development and the progression of immunotherapy for OS. In this article, we aim to summarize the roles of TAMs in OS and the major findings on the application of TAMs in OS treatment.

Omental Macrophagic "Crown-like Structures" Are Associated with Poor Prognosis in Advanced-Stage Serous Ovarian Cancer

The tumor microenvironment is a well-recognized framework in which immune cells present in the tumor microenvironment promote or inhibit cancer formation and development. A crown-like structure (CLS) has been reported as a dying or dead adipocyte surrounded by a 'crown' of macrophages within adipose tissue, which is a histologic hallmark of the inflammatory process in this tissue. CLSs have also been found to be related to formation, progression and prognosis of some types of cancer. However, the presence of CLSs in the omentum of advanced-stage high-grade serous ovarian carcinoma (HGSOC) has not been thoroughly investigated. By using CD68, a pan-macrophage marker, and CD163, an M2-like polarization macrophage marker, immunohistochemistry (IHC) was performed to identify tumor-associated macrophages (TAMs) and CLSs. This retrospective study analyzed 116 patients with advanced-stage HGSOC who received complete treatment and had available clinical data from July 2008 through December 2016 at National Cheng Kung University Hospital (NCKUH) (Tainan, Taiwan). Based on multivariate Cox regression analysis, patients with omental CD68⁺ CLSs had poor OS (median survival: 24 vs. 38 months, p = 0.001, hazard ratio (HR): 2.26, 95% confidence interval (CI): 1.41-3.61); patients with omental CD163⁺ CLSs also had poor OS (median survival: 22 vs. 36 months, HR: 2.14, 95%CI: 1.33-3.44, p = 0.002). Additionally, patients with omental CD68⁺ or CD163⁺ CLSs showed poor PFS (median survival: 11 vs. 15 months, HR: 2.28, 95%CI: 1.43-3.64, p = 0.001; median survival: 11 vs. 15 months, HR: 2.17, 95%CI: 1.35-3.47, respectively, p = 0.001). Conversely, the density of CD68⁺ or CD163⁺ TAMs in ovarian tumors was not associated with patient prognosis in advanced-stage HGSOC in our cohort. In conclusion, we, for the first time, demonstrate that the presence of omental CLSs is associated with poor prognosis in advanced-stage HGSOC.

Poor Prognosis and Therapeutic Responses in LILRB1-Expressing M2 Macrophages-Enriched Gastric Cancer Patients

Immunosuppressive molecules are valuable prognostic biomarkers across different cancer types. Leukocyte immunoglobulin like receptor subfamily B1 (LILRB1) is considered to be an immunosuppressive molecule, which is an important receptor of human leukocyte antigen G. However, the clinical significance of LILRB1 expression in gastric cancer remains unexplored. We analyzed the immunohistochemistry data of 166 gastric cancer patients to determine the clinicopathologic and survival significance of LILRB1. Immunofluorescence was conducted to detect the co-localization of LILRB1 with infiltrating immune cells. Additionally, we also assessed the immune contexture, immune cell functions and tumor microenvironment state related to LILRB1. We found that LILRB1 was mainly present in tumor stroma which was higher in tumor tissues compared with matched adjacent tissues. High-LILRB1 expression was associated with more advanced tumor stage, higher recurrence risk and worse survival. Immunohistochemistry and bioinformatic analysis showed that LILRB1 had a significant positive correlation with M2 tumor-associated macrophages (TAMs) infiltration. Immunofluorescence confirmed that M2 TAMs were the primary immune cells expressing LILRB1. Dense infiltration of LILRB1+ M2 TAMs yielded an immunosuppressive microenvironment manifested as enriched exhausted CD8+ T cells and increased immunosuppressive cytokines. Moreover, patients with high infiltration of both LILRB1+ cells and M2 TAMs indicated poor prognosis and inferior therapeutic responsiveness to adjuvant chemotherapy. In conclusion, LILRB1+ M2 TAMs were associated with a pro-tumor immune contexture and determine poor prognosis in gastric cancer. Further studies are essential to explore therapeutic targeting LILRB1+ M2 TAMs.

Macrophage targeting in cancer

Tumorigenesis is not only determined by the intrinsic properties of cancer cells but also by their interactions with components of the tumor microenvironment (TME). Tumor-associated macrophages (TAMs) are among the most abundant immune cells in the TME. During initial stages of tumor development, macrophages can either directly promote antitumor responses by killing tumor cells or indirectly recruit and activate other immune cells. As genetic changes occur within the tumor or T helper 2 (TH 2) cells begin to dominate the TME, TAMs begin to exhibit an immunosuppressive protumor phenotype that promotes tumor progression, metastasis, and resistance to therapy. Thus, targeting TAMs has emerged as a strategy for cancer therapy. To date, TAM targeting strategies have focused on macrophage depletion and inhibition of their recruitment into the TME. However, these strategies have shown limited therapeutic efficacy, although trials are still underway with combination therapies. The fact that macrophages have the potential for antitumor activity has moved the TAM targeting field toward the development of TAM-reprogramming strategies to support this antitumor immune response. Here, we discuss the various roles of TAMs in cancer therapy and their immunosuppressive properties, as well as implications for emerging checkpoint inhibitor-based immunotherapies. We review state-of-the-art TAM-targeting strategies, focusing on current ones at the preclinical and clinical trial stages that aim to reprogram TAMs as an oncological therapy.

Turning enemies into allies-reprogramming tumor-associated macrophages for cancer therapy

Checkpoint blockade therapies that target inhibitory receptors on T cells have revolutionized clinical oncology. Antibodies targeting CTLA-4 or the PD-1/PD-L1 axis are now successfully used alone or in combination with chemotherapy for numerous tumor types. Despite the clinical success of checkpoint blockade therapies, tumors exploit multiple mechanisms to escape or subvert the anti-tumor T cell response. Within the tumor microenvironment, tumor-associated macrophages (TAM) can suppress T cell responses and facilitate tumor growth in various ways, ultimately debilitating clinical responses to T cell checkpoint inhibitors. There is therefore significant interest in identifying biologicals and drugs that target immunosuppressive TAM within the tumor microenvironment and can be combined with immune checkpoint inhibitors. Here we review approaches that are currently being evaluated to convert immunosuppressive TAM into immunostimulatory macrophages that promote T cell responses and tumor elimination. Tumor-associated macrophages (TAMs) are a major component of the tumor microenvironment that impact anti-tumor immune responses and susceptibility to checkpoint blockade. TAMs are very heterogeneous and can be either immunosuppressive or immunostimulatory. Here, Molgora and Colonna review current strategies that aim to reprogram TAMs to enhance rather than inhibit immune responses.

Chemokines orchestrate tumor cells and the microenvironment to achieve metastatic heterogeneity

Chemokines, a subfamily of the cell cytokines, are low molecular weight proteins known to induce chemotaxis in leukocytes in response to inflammatory and pathogenic signals. A plethora of literature demonstrates that chemokines and their receptors regulate tumor progression and metastasis. With these diverse functionalities, chemokines act as a fundamental link between the tumor cells and their microenvironment. Recent studies demonstrate that the biology of chemokines and their receptor in metastasis is complex as numerous chemokines are involved in regulating site-specific tumor growth and metastasis. Successful treatment of disseminated cancer is a significant challenge. The most crucial problem for treating metastatic cancer is developing therapy regimes capable of overcoming heterogeneity problems within primary tumors and among metastases and within metastases (intralesional). This heterogeneity of malignant tumor cells can be related to metastatic potential, response to chemotherapy or specific immunotherapy, and many other factors. In this review, we have emphasized the role of chemokines in the process of metastasis and metastatic heterogeneity. Individual chemokines may not express the full potential to address metastatic heterogeneity, but chemokine networks need exploration. Understanding the interplay between chemokine-chemokine receptor networks between the tumor cells and their microenvironment is a novel approach to overcome the problem of metastatic heterogeneity. Recent advances in the understanding of chemokine networks pave the way for developing a potential targeted therapeutic strategy to treat metastatic cancer.

Host Factors Independently Associated With Prognosis in Patients With Oral Cavity Cancer

Importance

The association and interaction of host characteristics with prognosis in patients with oral cavity squamous cell carcinoma (OSCC) are poorly understood. There is increasing evidence that host characteristics are associated with treatment outcomes of many cancers.

Objectives

To examine the host factors associated with prognosis in patients with OSCC and their interactions to create a numerical index that quantifies the prognostic capacity of these host characteristics.

Design, Setting, and Participants

This retrospective cohort study included patients with OSCC treated surgically at a tertiary care center from January 1, 1998, to December 31, 2015. From a departmental OSCC database of 1377 previously untreated patients, 68 patients with missing data on any host variable of interest within a month before the start of treatment were excluded, leaving 1309 patients. Data analysis was performed from October 21, 2019, to December 10, 2019.

Exposure

Primary surgery for OSCC.

Main Outcomes and Measures

Overall survival (OS) was the primary end point, and disease-specific survival (DSS) was the secondary end point. Optimal cutoffs for each variable were identified using recursive-partitioning analysis with the classification and regression tree method using OS as the dependent variable. Body mass index (BMI) and pretreatment peripheral blood leukocyte count, platelet count, hemoglobin level, and albumin level were analyzed. A host index (H-index) was developed using independent factors associated with OS.

Results

A total of 1309 patients (731 [55.8%] male; mean [SD] age, 62 [14.3] years) participated in the study. When including all the host-related factors in a multivariable analysis, all except BMI (hazard ratio [HR], 1.14; 95% CI, 0.80-1.63) were independently associated with outcomes. For example, compared with a hemoglobin level of 14.1 g/dL or greater, the HR for a level of 12.9 to 14.0 g/dL was 1.42 (95% CI, 1.13-1.77) and for a level of 12.8 g/dL or less was 1.51 (95% CI, 1.18-1.94), and compared with an albumin level of 4.3 g/dL or greater, the HR for a level of 3.7 to 4.2 g/dL was 1.18 (95% CI, 0.95-1.45) and for a level of 3.6 g/dL or less was 3.64 (95% CI, 2.37-5.58). An H-index of 1.4 or less was associated with a 74% 5-year OS, an H-index of 1.5 to 3.5 with a 65% 5-year OS, and an H-index of 3.6 or higher with a 38% 5-year OS; for DSS, the 5-year survival was 84%, 80%, and 64%, respectively. Compared with patients with an H-index score of 1.4 or less, patients with H-index scores of 1.5 to 3.5 (hazard ratio, 1.474; 95% CI, 1.208-1.798) and 3.6 or higher (hazard ratio, 3.221; 95% CI, 2.557-4.058) had a higher risk of death.

Conclusions and Relevance

The findings suggest that pretreatment values of neutrophils, monocytes, lymphocytes, hemoglobin, and albumin are independently associated with prognosis in patients with OSCC. The interactions between these host factors were incorporated into a novel H-index that quantified the prognostic capacity of host characteristics associated with OSCC.

Identification of prognostic tumor-infiltrating immune cells in endometrial adenocarcinoma

To identify prognostic tumor-infiltrating immune cells of endometrial adenocarcinoma.The gene expression profiles of endometrial adenocarcinoma were downloaded from the Cancer Genome Atlas (TCGA). The abundance of tumor-infiltrating immune cells in endometrial adenocarcinoma samples was calculated by CIBERSORT algorithm. Kaplan-Meier analysis was used to identify prognostic tumor-infiltrating immune cells.This study identified 22 kinds of tumor-infiltrating immune cells. Macrophages M0 and CD8 T cells were prognostic factors of endometrial adenocarcinoma. The abundance of macrophages M0 (P = .038) was significantly correlated with better prognosis of endometrial adenocarcinoma. In contrast, the abundance of CD8 T cells (P = .049) was associated with poor prognosis of endometrial adenocarcinoma.Tumor-infiltrati macrophages M0 and CD8 T cells were prognostic factors of endometrial adenocarcinoma.

Human Gastric Cancer Stem Cell (GCSC) Markers Are Prognostic Factors Correlated With Immune Infiltration of Gastric Cancer

The prognosis of patients with gastric cancer (GC) is still unsatisfying. Numerous markers of gastric cancer stem cells (GCSCs) have been identified and were thought to be related to cancer aggressiveness. However, the roles of GCSC markers in GC patients’ prognosis and immune infiltration remain unknown. Expression of GCSC markers was analyzed using Oncomine and Gene Expression Profiling Interactive Analysis (GEPIA). Their associations with clinicopathological parameters were analyzed using UALCAN and LinkedOmics. Alternations and protein expression of GCSC markers were analyzed by cBioPortal and the Human Protein Atlas databases, respectively. The prognostic significance of GCSC markers was evaluated using Kaplan-Meier plotter. Correlations between the expression of GCSC markers and immune infiltration along with biomarkers of tumor-infiltrating immune cells (TIICs) were assessed combined Tumor Immune Estimation Resource and GEPIA. GeneMANIA was used to discover the interactive genes of GCSC markers, and enrichment analysis was performed using Database for Annotation, Visualization, and Integrated Discovery server. We identified six GCSC markers significantly up-expressed in GC, compared with normal stomach tissues. Among them, the overexpression of ICAM1, THY1, and CXCR4 significantly indicated adverse, while EPCAM indicated beneficial clinicopathological features of GC patients. The up-regulation of CXCR4 showed unfavorable prognostic significance, whereas EPCAM and TFRC showed the opposite. The six GCSC markers were all correlated with the infiltration and activation of distinct TIICs. Especially, ICAM1, THY1, and CXCR4 showed strongly positive correlations with tumor-associated macrophages. Besides, chemokine, Toll-like receptor, NF-kappa B, and HIF-1 signaling pathways might be involved in the regulation of GCSC markers on cancer development. This study proposed that GCSC markers might be promising targets of GC treatment to weaken cancer stem-like properties and strengthen anticancer immunity.

Prognostic Value of Tumor-Associated Macrophages in Clear Cell Renal Cell Carcinoma: A Systematic Review and Meta-Analysis

Background

Tumor-associated macrophages (TAMs) are the major immune cells in tumor microenvironment. The prognostic significance of TAMs has been confirmed in various tumors. However, whether TAMs can be prognostic factors in clear cell renal cell carcinoma (ccRCC) is unclear. In this study, we aimed to clarify the prognostic value of TAMs in ccRCC.

Methods

We searched PubMed, Embase, and the Web of Science for relevant published studies before December 19, 2020. Evidence from enrolled studies were pooled and analyzed by a meta-analysis. Hazard ratios (HRs) and odd ratios (ORs) with 95% confidence intervals (CIs) were computed to evaluate the pooled results.

Results

Both of high CD68+ TAMs and M2-TAMs were risk factors for poor prognosis in ccRCC patients. The pooled HRs indicated that elevated CD68+ TAMs correlated with poor OS and PFS (HR: 3.97, 95% CI 1.39–11.39; HR: 5.73, 95% CI 2.36–13.90, respectively). For M2-TAMs, the pooled results showed ccRCC patients with high M2-TAMs suffered a worse OS and shorter PFS, with HR 1.32 (95% CI 1.16–1.50) and 1.40 (95% CI 1.14–1.72), respectively. Also, high density of TAMs was associated with advanced clinicopathological features in ccRCC.

Conclusions

TAMs could be potential biomarkers for prognosis and novel targets for immunotherapy in ccRCC. Further researches are warranted to validate our results.

Tissue-Resident and Recruited Macrophages in Primary Tumor and Metastatic Microenvironments: Potential Targets in Cancer Therapy

Macrophages within solid tumors and metastatic sites are heterogenous populations with different developmental origins and substantially contribute to tumor progression. A number of tumor-promoting phenotypes associated with both tumor- and metastasis-associated macrophages are similar to innate programs of embryonic-derived tissue-resident macrophages. In contrast to recruited macrophages originating from marrow precursors, tissue-resident macrophages are seeded before birth and function to coordinate tissue remodeling and maintain tissue integrity and homeostasis. Both recruited and tissue-resident macrophage populations contribute to tumor growth and metastasis and are important mediators of resistance to chemotherapy, radiation therapy, and immune checkpoint blockade. Thus, targeting various macrophage populations and their tumor-promoting phenotypes holds therapeutic promise. Here, we discuss various macrophage populations as regulators of tumor progression, immunity, and immunotherapy. We provide an overview of macrophage targeting strategies, including therapeutics designed to induce macrophage depletion, impair recruitment, and induce repolarization. We also provide a perspective on the therapeutic potential for macrophage-specific acquisition of trained immunity as an anti-cancer agent and discuss the therapeutic potential of exploiting macrophages and their traits to reduce tumor burden.

A signature of seven immune-related genes predicts overall survival in male gastric cancer patients

Background

Gastric cancer (GC) has a high mortality rate and is one of the most fatal malignant tumours. Male sex has been proven as an independent risk factor for GC. This study aimed to identify immune-related genes (IRGs) associated with the prognosis of male GC.

Methods

RNA sequencing and clinical data were obtained from The Cancer Genome Atlas (TCGA) database. Differentially expressed IRGs between male GC and normal tissues were identified by integrated bioinformatics analysis. Univariate and multivariate Cox regression analyses were applied to screen survival-associated IRGs. Then, GC patients were separated into high- and low-risk groups based on the median risk score. Furthermore, a nomogram was constructed based on the TCGA dataset. The prognostic value of the risk signature model was evaluated by Kaplan-Meier curve, receiver operating characteristic (ROC), Harrell’s concordance index and calibration curves. In addition, the gene expression dataset from the Gene Expression Omnibus (GEO) was also downloaded for external validation. The relative proportions of 22 types of infiltrating immune cells in each male GC sample were evaluated using CIBERSORT.

Results

A total of 276 differentially expressed IRGs were screened, including 189 up-regulated and 87 down-regulated genes. Subsequently, a seven-IRGs signature (LCN12, CCL21, RNASE2, CGB5, NRG4, AGTR1 and NPR3) was identified to be significantly associated with the overall survival (OS) of male GC patients. Survival analysis indicated that patients in the high-risk group exhibited a poor clinical outcome. The results of multivariate analysis revealed that the risk score was an independent prognostic factor. The established nomogram could be used to evaluate the prognosis of individual male GC patients. Further analysis showed that the prognostic model had excellent predictive performance in both TCGA and validated cohorts. Besides, the results of tumour-infiltrating immune cell analysis indicated that the seven-IRGs signature could reflect the status of the tumour immune microenvironment.

Conclusions

Our study developed a novel seven-IRGs risk signature for individualized survival prediction of male GC patients.

Is there still a place for conventional histopathology in the age of molecular medicine? Laurén classification, inflammatory infiltration and other current topics in gastric cancer diagnosis and prognosis

Gastric cancer (GC) is the fifth most common cancer and the third cause of cancer-related deaths worldwide. In western countries, more than half of GC patients are diagnosed at advanced stages and 5-year survival rates range between 20-30%. The only curative treatment is surgery, and despite recent advances in oncological therapies, GC prognosis is still poor. The main prognostic tool for patient categorization and treatment selection is the TNM classification, but its limitations are being increasingly recognized. Early recurrences may occur in early-stage disease, and patients at the same stage show heterogeneous outcomes. Thus, there is a need to improve GC stratification and to identify new prognostic factors, which may allow us to select drug-susceptible populations, refine patient grouping for clinical trials and discover new therapeutic targets. Molecular classifications have been developed, but they have not been translated to the clinical practice. On the other hand, histological assessment is cheap and widely available, and it is still a mainstay in the era of molecular medicine. Furthermore, histological features are acquiring new roles as reflectors of the genotype-phenotype correlation, and their potential impact on patient management is currently being analyzed. The aim of this literature review is to provide a modern overview of the histological assessment of GC. In this study, we discuss recent topics on the histological diagnosis of GC, focusing on the current role of Laurén classification and the potential value of new histological features in GC, such as inflammatory infiltration and tumor budding.

Expression of PD1/PDL1 in gastric cancer at different microsatellite status and its correlation with infiltrating immune cells in the tumor microenvironment

Objective: The microsatellite status and tumor immune microenvironment have a remarkable influence on tumor immunotherapy. This study was performed to investigate programmed cell death protein 1/programmed death ligand 1 (PD1/PDL1) expression and their correlations with CD8+ T cell/CD68+ macrophage (CD68+ M) densities in gastric cancer (GC) at different microsatellite statuses.

Methods: The expression of MLH1, PMS2, MSH2, and MSH6 was detected via immunohistochemistry (IHC) to determine the microsatellite status in 215 GC samples obtained from surgical resections. Furthermore, the expression of PD1, PDL1, CD8, and CD68 was detected in the samples via IHC, and the differences and correlations in GC at different microsatellite statuses were then analyzed. PDL1 expression in tumor cells was labeled as PDL1[T], while expression of PD1 and PDL1 in tumor-infiltrating immune cells was labeled as PD1 and PDL1, respectively. Kaplan-Meier analysis was used to evaluate the significance of PD1/PDL1 expression in determining overall survival. Multivariate Cox regression analysis was performed using SPSS software. P-values were determined using the log-rank test.

Results: Our results indicated that PD1, PDL1[T], and PDL1 positivity rates were 59%, 35%, and 57% in 46 microsatellite unstable (MSI) GCs and 45%, 22%, and 40% in 169 microsatellite stable (MSS) GCs, respectively. Compared with MSS GC, PD1, PDL1[T], and PDL1 expression was higher in MSI GC (P = 0.109, 0.090, and 0.044, respectively). Additionally, CD8+ T cell and CD68+ M densities were higher in MSI GC than in MSS GC (P = 0.537 and <0.001, respectively). Additionally, CD8+ T cell/CD68+ M densities were evaluated according to tumor center and invasion front. We found that PD1 expression was significantly correlated with CD8+ T cell density at the invasion front of the MSI GC (P = 0.031), whereas PDL1 expression was significantly correlated to high CD68+ M density in the tumor center and invasion front of MSS GC (P = 0.001 and 0.014, respectively). Survival analysis showed that patients with PD1-positive and PDL1[T]/PDL1-negative GC had better prognosis (P = 0.012, 0.005, and 0.022, respectively). Multivariate Cox survival analysis showed that PDL1[T] was an independent prognostic factor for GC.

Conclusion: The results suggested that PD1/PDL1 expression and immune response varied at different microsatellite statuses in GC. PD1/PDL1 expression was correlated with CD8+ T cell/CD68+ M densities in GC at different microsatellite statuses, especially at the invasion front. The patients exhibiting high PD1/PDL1 expression or high CD8+ T cell/CD68+ M densities MSI GC might be potential beneficiaries of PD1/PDL1 immunotherapy.

Tumor Microenvironment and Immunotherapy Response in Head and Neck Cancer

The tumor microenvironment (TME) encompasses cellular and non-cellular components which play an important role in tumor evolution, invasion, and metastasis. A complicated interplay between tumor cells and adjacent TME cells, such as stromal cells, immune cells, inflammatory cells, and cytokines, leads to severe immunosuppression and the proliferation of cancer cells in several solid tumors. An immunosuppressive TME has a significant impact on treatment resistance and may guide response to immunotherapy. In head and neck cancer (HNC), immunotherapeutic drugs have been incorporated in everyday clinical practice. However, despite an exceptional rate of durable responses, only a low percentage of patients respond. In this review, we will focus on the complex interactions occurring in this dynamic system, the TME, which orchestrate key events that lead to tumor progression, immune escape, and resistance. Furthermore, we will summarize current clinical trials that depict the TME as a potential therapeutic target for improved patient selection.

The immune contexture and Immunoscore in cancer prognosis and therapeutic efficacy

The international American Joint Committee on Cancer/Union for International Cancer Control (AJCC/UICC) tumour-node-metastasis (TNM) staging system provides the current guidelines for the classification of cancer. However, among patients within the same stage, the clinical outcome can be very different. More recently, a novel definition of cancer has emerged, implicating at all stages a complex and dynamic interaction between tumour cells and the immune system. This has enabled the definition of the immune contexture, representing the pre-existing immune parameters associated with patient survival. Even so, the role of distinct immune cell types in modulating cancer progression is increasingly emerging. An immune-based assay named the 'Immunoscore' was defined to quantify the in situ T cell infiltrate and was demonstrated to be superior to the AJCC/UICC TNM classification for patients with colorectal cancer. This Review provides a broad overview of the main immune parameters positively or negatively shaping cancer development, including the Immunoscore, and their prognostic and predictive value. The importance of the immune system in cancer control is demonstrated by the requirement for a pre-existing intratumour adaptive immune response for effective immunotherapies, such as checkpoint inhibitors. Finally, we discuss how the combination of multiple immune parameters, rather than individual ones, might increase prognostic and/or predictive power.

Crosstalk Between Mesenchymal Stromal Cells and Tumor-Associated Macrophages in Gastric Cancer

Tumor microenvironment (TME) consisting of distinct cell types including stromal cells and immune cells has recently emerged as a pivotal player in tumor development and progression. Mesenchymal stromal cells (MSCs) and tumor-associated macrophages (TAMs) are two representative cells in the TME with plastic properties. This review will focus on the evolution of phenotypes and functions of either MSCs or TAMs, which is “educated” by the TME, as well as interactions between MSCs and TAMs contributing to the distinct stages of tumor biology in gastric cancer. MSCs exert immunoregulatory effects on macrophages and polarize them toward M2-like TAMs, via cell–cell contact and paracrine or extracellular vesicle (EV) transfer mechanism. In turn, M2-TAMs modulate the transition of “naive” MSCs into tumor-derived MSCs, which possess a more potent pro-tumor role than the parent. Moreover, the cross talk between MSCs and TAMs could contribute to cancer biology by inducing the EMT process, metastasis, immune invasion, and immunotherapy resistance in cancer cells. However, molecular mechanisms underlying interactions between MSCs and TAMs in gastric cancer progression need to be thoroughly elucidated, which may provide attractive targets for making promising novel strategies for gastric cancer therapy.

Intraoperative Molecular Imaging Utilizing a Folate Receptor-Targeted Near-Infrared Probe Can Identify Macroscopic Gastric Adenocarcinomas

PURPOSE

Current methods of assessing disease burden in gastric adenocarcinoma are imperfect. Improved visualization during surgery with intraoperative molecular imaging (IMI) could improve gastric adenocarcinoma staging and guide surgical decision-making. The goal of this study was to evaluate if IMI with a folate receptor-targeted near-infrared fluorescent agent, OTL38, could identify gastric adenocarcinomas during surgery.

PROCEDURES

Five patients were enrolled in an IMI clinical trial. Patients received a folate receptor-targeted near-infrared dye (OTL38) 1.5-6 h prior to surgery. During staging laparoscopy and gastric resection, IMI was utilized to identify the primary tumor and any fluorescent lymph nodes. Resected tumors were analyzed for folate receptor alpha (FRα) and CD68 expression using immunohistochemistry. Microscopic OTL38 accumulation was examined with immunofluorescence.

RESULTS

Four out of five patients underwent total or subtotal gastrectomy; one had a staging laparoscopy only. All four patients who underwent gastric resection had invasive gastric adenocarcinoma; three had fluorescent tumors, mean tumor to background ratio (TBR) 4.1 ± 2.9. The one patient with a non-fluorescent tumor had a T1a tumor with two 0.4 cm tumor foci within a larger polyp. In each case with a fluorescent tumor, the fluorescence was evident from the exterior of the stomach. Two of the fluorescent tumors had modest FRα expression and no CD68 expression. One fluorescent tumor had high CD68 expression and no FRα expression.

CONCLUSIONS

Intraoperative molecular imaging of gastric adenocarcinoma with OTL38 is feasible. Further studies should evaluate the clinical utility of this technique.

Prognostic significance of tumor-associated macrophages in patients with nasopharyngeal carcinoma: A meta-analysis

BACKGROUND

To explore the prognostic value of diverse subsets of tumor-associated macrophages (TAMs) in prognosis in patients with nasopharyngeal carcinoma (NPC) using meta-analysis.

METHODS

Relevant studies were searched in the database of PubMed, Web of Science, Embase, Cochrane Library, Scopus, China National Knowledge Infrastructure (CNKI), and Wanfang till November 2019. The relationship between TAMs and survival outcomes was estimated by pooling hazard ratios (HRs) and 95% confidence intervals (CIs); and the correlation of TAMs and clinicopathological factors was evaluated by using odds ratios (ORs) and 95%CIs.

RESULTS

Six studies with 1549 patients were included in this meta-analysis. The high expression of CD68+ TAMs was associated with favorable disease-free survival (DFS) (HR = 0.66, 95%CI = 0.50-0.88, P = .005), whereas the density of M2-like TAMs (CD163+, CD68+CCL18+, and CD206+) was correlated to poor overall survival (OS) (HR = 1.77, 95%CI = 1.22-2.56, P = .003) and DFS (HR = 1.96, 95%CI = 1.00-3.85, P = .050) in patients with NPC.

CONCLUSIONS

CD68+ TAM density is associated with superior DFS, while CD163+ M2-like TAMs predicted poor prognosis in patients with NPC.