Regulatory T cell subsets in human cancer: are they regulating for or against tumor progression?

CCL22 as an independent prognostic factor in endometrial cancer patients

OBJECTIVES

The chemokine CCL22 is recognized for recruiting immunosuppressive regulatory T-cells (Treg) that contribute to disease progression in various tumor entities helping them to evade the host immune response. Our study aims to identify the expressing cell types and to evaluate the prognostic significance of CCL22 secretion and its association with Treg invasion in endometrial cancer (EC), an immunogenic cancer.

METHODS

Specimens from 275 patients with EC and 28 healthy controls were screened immunohistochemically for CCL22. Immunofluorescence double-staining for CCL22 and different immune cell markers was performed. In vitro regulation of CCL22-expression was examined in EC cell lines (Ishikawa+, RL95-2) and human PBMCs in coculture settings via qPCR and ELISA.

RESULTS

Elevated CCL22 staining in tumor cells and CCL22-positive M1-macrophages in tumordistant areas were significantly associated with increased overall survival (OS). Conversely, high, secretory-appearing staining in the peritumoral and intratumoral stroma correlated with reduced OS. Although the analysis of the in vitro coculture model of epithelial tumor- and immune cells revealed PBMCs as the primary source of CCL22, we could confirm expression of the chemokine also in the EC epithelial cells.

CONCLUSION

Our study suggests that CCL22 in EC is associated with OS, dependent on its location and the cell type producing it. Intracellular upregulation and extracellular secretion must be considered separately when investigating CCL22 expressing cell types in EC. These results may provide evidence for CCL22-mediated Treg recruitment in EC as a potential future therapeutic target.

Exploring the therapeutic mechanisms of resveratrol for treating arecoline-induced malignant transformation in oral epithelial cells: insights into hub targets

BACKGROUND

Betel nut chewing is a significant risk factor for oral cancer due to arecoline, its primary active component. Resveratrol, a non-flavonoid polyphenol, possesses anti-cancer properties. It has been shown to inhibit arecoline-induced oral malignant cells in preliminary experiments but the underlying mechanism remains unclear. This research therefore aimed to explore the potential therapeutic targets of resveratrol in treating arecoline-induced oral cancer.

METHODS

Data mining identified common targets and hub targets of resveratrol in arecoline-induced oral cancer. Gene set variation analysis (GSVA) was used to score and validate the expression and clinical significance of these hub targets in head and neck cancer (HNC) tissues. Molecular docking analysis was conducted on the hub targets. The effect of resveratrol intervention on hub targets was verified by experiments.

RESULTS

Sixty-one common targets and 15 hub targets were identified. Hub targets were highly expressed in HNC and were associated with unfavorable prognoses. They played a role in HNC metastasis, epithelial-mesenchymal transition, and invasion. Their expression also affected immune cell infiltration and correlated negatively with sensitivity to chemotherapeutic agents such as bleomycin and docetaxel. Experiments demonstrated that resveratrol down-regulated the expression of the hub targets, inhibited their proliferation and invasion, and induced apoptosis.

CONCLUSION

Resveratrol inhibits the arecoline-induced malignant phenotype of oral epithelial cells by regulating the expression of some target genes, suggesting that resveratrol may be used not only as an adjuvant treatment for oral cancer, but also as an adjuvant for oral cancer prevention due to its low toxicity and high efficacy. © 2024 Society of Chemical Industry.

Immunotherapies of acute myeloid leukemia: Rationale, clinical evidence and perspective

Acute myeloid leukemia (AML) is a prevalent hematological malignancy that exhibits a wide array of molecular abnormalities. Although traditional treatment modalities such as chemotherapy and allogeneic stem cell transplantation (HSCT) have become standard therapeutic approaches, a considerable number of patients continue to face relapse and encounter a bleak prognosis. The emergence of immune escape, immunosuppression, minimal residual disease (MRD), and other contributing factors collectively contribute to this challenge. Recent research has increasingly highlighted the notable distinctions between AML tumor microenvironments and those of healthy individuals. In order to investigate the potential therapeutic mechanisms, this study examines the intricate transformations occurring between leukemic cells and their surrounding cells within the tumor microenvironment (TME) of AML. This review classifies immunotherapies into four distinct categories: cancer vaccines, immune checkpoint inhibitors (ICIs), antibody-based immunotherapies, and adoptive T-cell therapies. The results of numerous clinical trials strongly indicate that the identification of optimal combinations of novel agents, either in conjunction with each other or with chemotherapy, represents a crucial advancement in this field. In this review, we aim to explore the current and emerging immunotherapeutic methodologies applicable to AML patients, identify promising targets, and emphasize the crucial requirement to augment patient outcomes. The application of these strategies presents substantial therapeutic prospects within the realm of precision medicine for AML, encompassing the potential to ameliorate patient outcomes.

Rough neighborhood: Intricacies of cancer stem cells and infiltrating immune cell interaction in tumor microenvironment and potential in therapeutic targeting

Ongoing research on cellular heterogeneity of Cancer stem cells (CSCs) and its synergistic involvement with tumor milieu reveals enormous complexity, resulting in diverse hindrance in immune therapy. CSCs has captured attention for their contribution in shaping of tumor microenvironment and as target for therapeutic intervention. Recent studies have highlighted cell-extrinsic and intrinsic mechanisms of reciprocal interaction between tumor stroma constituents and CSCs. Therapeutic targeting requires an in-depth understanding of the underlying mechanisms involved with the rate limiting factors in tumor aggressiveness and pinpoint role of CSCs. Some of the major constituents of tumor microenvironment includes resident and infiltrating immune cell, both innate and adaptive. Some of these immune cells play crucial role as adjustors of tumor immune response. Tumor-adjustor immune cell interaction confer plasticity and features enabling tumor growth and metastasis in one hand and on the other hand blunts anti-tumor immunity. Detail understanding of CSC and TME resident immune cells interaction can shape new avenues for cancer immune therapy. In this review, we have tried to summarize the development of knowledge on cellular, molecular and functional interaction between CSCs and tumor microenvironment immune cells, highlighting immune-mediated therapeutic strategies aimed at CSCs. We also discussed developing a potential CSC and TME targeted therapeutic avenue.

Bibliometric analysis of global research trends on regulatory T cells in neurological diseases

This bibliometric study aimed to summarize and visualize the current research status, emerging trends, and research hotspots of regulatory T (Treg) cells in neurological diseases. Relevant documents were retrieved from the Web of Science Core Collection. Tableau Public, VOSviewer, and CiteSpace software were used to perform bibliometric analysis and network visualization. A total of 2,739 documents were included, and research on Treg cells in neurological diseases is still in a prolific period. The documents included in the research were sourced from 85 countries/regions, with the majority of them originating from the United States, and 2,811 organizations, with a significant proportion of them coming from Harvard Medical School. Howard E Gendelman was the most prolific author in this research area. Considering the number of documents and citations, impact factors, and JCR partitions, Frontiers in Immunology was the most popular journal in this research area. Keywords "multiple sclerosis," "inflammation," "regulatory T cells," "neuroinflammation," "autoimmunity," "cytokines," and "immunomodulation" were identified as high-frequency keywords. Additionally, "gut microbiota" has recently emerged as a new topic of interest. The study of Treg cells in neurological diseases continues to be a hot topic. Immunomodulation, gut microbiota, and cytokines represent the current research hotspots and frontiers in this field. Treg cell-based immunomodulatory approaches have shown immense potential in the treatment of neurological diseases. Modifying gut microbiota or regulating cytokines to boost the numbers and functions of Treg cells represents a promising therapeutic strategy for neurological diseases.

Role of tissue markers associated with tumor microenvironment in the progression and immune suppression of oral squamous cell carcinoma

Head and neck cancers (HNC) continues to dominate major cancers contributing to  mortality worldwide. Squamous cell carcinoma is the major type of HNC. Oral Squamous Cell Carcinoma grouped under HNC is a malignant tumor occurring in the oral cavity. The primary risk factors of OSCC are tobacco, alcohol consumption, etc. This review focuses on modulations, mechanisms, growth and differentiation of oral squamous cell carcinoma. Cancer cell surrounds itself with a group of elements forming a favorable environment known as tumor microenvironment (TME). It consists of numerous cells which includes immune cells, blood cells and acellular components that are responsible for the progression, immunosuppression, metastasis and angiogenesis of cancer. This review highlights the most important tissue biomarkers (mTOR, CAF, FOXp3, CD163, CD33, CD34) that are associated with TME cells. mTOR remains as the primary regulator responsible in cancer and its importance towards immune-suppression is highlighted. Tumor-associated macrophages associated with cancer development and its relationship with immunomodulatory mechanism and Tregs, which are potential blockers of immune response and its mechanism and aberrations are discussed. Cancer-associated fibroblasts that are a part of TME and their role in evading the immune response and myeloid derived suppressor cells that have slight control over the immune response and their mechanism in the tumor progression is further explained. These markers have been emphasised as therapeutic targets and are currently in different stages of clinical trials.

Cancer Stem Cell Relationship with Pro-Tumoral Inflammatory Microenvironment

Inflammatory processes and cancer stem cells (CSCs) are increasingly recognized as factors in the development of tumors. Emerging evidence indicates that CSCs are associated with cancer properties such as metastasis, treatment resistance, and disease recurrence. However, the precise interaction between CSCs and the immune microenvironment remains unexplored. Although evasion of the immune system by CSCs has been extensively studied, new research demonstrates that CSCs can also control and even profit from the immune response. This review provides an overview of the reciprocal interplay between CSCs and tumor-infiltrating immune cells, collecting pertinent data about how CSCs stimulate leukocyte reprogramming, resulting in pro-tumor immune cells that promote metastasis, chemoresistance, tumorigenicity, and even a rise in the number of CSCs. Tumor-associated macrophages, neutrophils, Th17 and regulatory T cells, mesenchymal stem cells, and cancer-associated fibroblasts, as well as the signaling pathways involved in these pro-tumor activities, are among the immune cells studied. Although cytotoxic leukocytes have the potential to eliminate CSCs, immune evasion mechanisms in CSCs and their clinical implications are also known. We intended to compile experimental findings that provide direct evidence of interactions between CSCs and the immune system and CSCs and the inflammatory milieu. In addition, we aimed to summarize key concepts in order to comprehend the cross-talk between CSCs and the tumor microenvironment as a crucial process for the effective design of anti-CSC therapies.

Paving the road to make chimeric antigen receptor-T-cell therapy effective against solid tumors

The three major standard therapies, that is, surgery, chemotherapy, and radiation therapy have conventionally been applied to the treatments for cancers and have saved many patients. In addition, for intractable, refractory, or advanced malignancies that cannot be cured by the three standard therapies, immunotherapy is an important subject of basic and clinical researches. Immune checkpoint inhibitor therapy (ICI) has shown significant therapeutic efficacies on some types of tumors in large-scale randomized clinical trials, making a major impact on clinical oncology by scientifically proving and establishing the effectiveness of an immunotherapy. In 2018, ICI was awarded the Nobel Prize in Physiology or Medicine, and immunotherapy is now becoming the "fourth" standard therapy for cancers. Recently, adoptive cell therapies, in which genetically modified T cells with enhanced reactivity against tumors are infused into the patients, have been attracting considerable attention as a hopeful immunotherapy following ICI. Particularly, chimeric antigen receptor (CAR)-T-cell therapies demonstrate marked therapeutic efficacies against some hematologic malignancies, and have been approved in many countries. However, current CAR-T-cell therapy is considered to be little effective against solid tumors, which is one of the challenging issues to be overcome in CAR-T-cell therapy. In this review, we at first introduce CAR and CAR-T cell, and then focus on the recent progress of CAR-T-cell therapy against solid tumors as well as the novel concept on a role of CAR-T cells, aiming to further understandings of the novel cancer immunotherapies.

Identification of tumor microenvironment-related signature for predicting prognosis and immunotherapy response in patients with bladder cancer

The tumor microenvironment (TME) not only provides fertile soil for tumor growth and development but also widely involves immune evasion as well as the resistance towards therapeutic response. Accumulating interest has been attracted from the biological function of TME to its effects on patient outcomes and treatment efficacy. However, the relationship between the TME-related gene expression profiles and the prognosis of bladder cancer (BLCA) remains unclear. The TME-related genes expression data of BLCA were collected from The Cancer Genome Atlas (TCGA) database. NFM algorithm was used to identify the distinct molecular pattern based on the significantly different TME-related genes. LASSO regression and Cox regression analyses were conducted to identify TME-related gene markers related to the prognosis of BLCA and to establish a prognostic model. The predictive efficacy of the risk model was verified through integrated bioinformatics analyses. Herein, 10 TME-related genes (PFKFB4, P4HB, OR2B6, OCIAD2, OAS1, KCNJ15, AHNAK, RAC3, EMP1, and PRKY) were identified to construct the prognostic model. The established risk scores were able to predict outcomes at 1, 3, and 5 years with greater accuracy than previously known models. Moreover, the risk score was closely associated with immune cell infiltration and the immunoregulatory genes including T cell exhaustion markers. Notably, the predictive power of the model in immunotherapy sensitivity was verified when it was applied to patients with metastatic urothelial carcinoma (mUC) undergoing immunotherapy. In conclusion, TME risk score can function as an independent prognostic biomarker and a predictor for evaluating immunotherapy response in BLCA patients, which provides recommendations for improving patients' response to immunotherapy and promoting personalized tumor immunotherapy in the future.

Context-Dependent Effects Explain Divergent Prognostic Roles of Tregs in Cancer

Simple Summary

Immune cells play an important role in cancer, with regard to classification, diagnostic or prognostic matters. In particular, we focused on the prognostic value of Tregs in this meta-analysis. We took into account the local context and their heterogeneity in order to solve their apparent ambiguous role. We used three proxies to recapitulate the complexity of the context: the neighboring cell, the tissue and the quantification method; and we carefully dissected the regulatory population into existing subsets. We showed that CD45RO+ Tregs had a reproducible negative prognostic value across all five cancer types studied (breast, colorectal, gastric, lung and ovarian). It suggests that Tregs from an homogeneous context have a consistent prognostic role across cancer types.

Abstract

Assessing cancer prognosis is a challenging task, given the heterogeneity of the disease. Multiple features (clinical, environmental, genetic) have been used for such assessments. The tumor immune microenvironment (TIME) is a key feature, and describing the impact of its many components on cancer prognosis is an active field of research. The complexity of the tumor microenvironment context makes it difficult to use the TIME to assess prognosis, as demonstrated by the example of regulatory T cells (Tregs). The effect of Tregs on prognosis is ambiguous, with different studies considering them to be negative, positive or neutral. We focused on five different cancer types (breast, colorectal, gastric, lung and ovarian). We clarified the definition of Tregs and their utility for assessing cancer prognosis by taking the context into account via the following parameters: the Treg subset, the anatomical location of these cells, and the neighboring cells. With a meta-analysis on these three parameters, we were able to clarify the prognostic role of Tregs. We found that CD45RO+ Tregs had a reproducible negative effect on prognosis across cancer types, and we gained insight into the contributions of the anatomical location of Tregs and of their neighboring cells on their prognostic value. Our results suggest that Tregs play a similar prognostic role in all cancer types. We also establish guidelines for improving the design of future studies addressing the pathophysiological role of Tregs in cancer.

Altered mucosal immunity in HIV-positive colon adenoma: decreased CD4+ T cell infiltration is correlated with nadir but not current CD4+ T cell blood counts

BACKGROUND

People living with HIV (PLWH) face greater risks of developing non-AIDS-defining cancers (NADCs) than the general population; however, the underlying mechanisms remain elusive. The tumor microenvironment plays a significant role in the carcinogenesis of colorectal cancer (CRC), an NADC. We studied this carcinogenesis in PLWH by determining inflammatory phenotypes and assessing PD-1/PD-L1 expression in premalignant CRC stages of colon adenomas in HIV-positive and HIV-negative patients.

METHODS

We obtained polyp specimens from 22 HIV-positive and 61 HIV-negative participants treated with colonoscopy and polyp excision. We analyzed adenomas from 33 HIV-positive and 99 HIV-negative patients by immunohistochemistry using anti-CD4, anti-CD8, anti-FoxP3, and anti-CD163 antibodies. Additionally, we analyzed the expression levels of immune checkpoint proteins. We also evaluated the correlation between cell infiltration and blood cell counts.

RESULTS

HIV-positive participants had fewer infiltrating CD4⁺ T cells than HIV-negative participants (p = 0.0016). However, no statistical differences were observed in infiltrating CD8⁺ and FoxP3⁺ T cells and CD163⁺ macrophages. Moreover, epithelial cells did not express PD-1 or PD-L1. Notably, CD4⁺ T cell infiltration correlated with nadir blood CD4⁺ T cell counts (p <  0.05) but not with current blood CD4⁺ T cell counts.

CONCLUSION

Immune surveillance dysfunction owing to decreased CD4⁺ T cell infiltration in colon adenomas might be involved in colon carcinogenesis in HIV-positive individuals. Collectively, since the nadir blood CD4⁺ T cell count is strongly correlated with CD4⁺ T cell infiltration, it could facilitate efficient follow-up and enable treatment strategies for HIV-positive patients with colon adenomas.

Head and Neck Squamous Cell Carcinoma: Risk Factors, Molecular Alterations, Immunology and Peptide Vaccines

Head and neck squamous cell carcinoma (HNSCC) arises from the epithelial lining of the oral cavity, hypopharynx, oropharynx, and larynx. There are several potential risk factors that cause the generation of HNSCC, including cigarette smoking, alcohol consumption, betel quid chewing, inadequate nutrition, poor oral hygiene, HPV and Epstein–Barr virus, and Candida albicans infections. HNSCC has causative links to both environmental factors and genetic mutations, with the latter playing a more critical role in cancer progression. These molecular changes to epithelial cells include the inactivation of cancer suppressor genes and proto-oncogenes overexpression, resulting in tumour cell proliferation and distant metastasis. HNSCC patients have impaired dendritic cell (DC) and natural killer (NK) cell functions, increased production of higher immune-suppressive molecules, loss of regulatory T cells and co-stimulatory molecules and major histocompatibility complex (MHC) class Ι molecules, lower number of lymphocyte subsets, and a poor response to antigen-presenting cells. At present, the standard treatment modalities for HNSCC patients include surgery, chemotherapy and radiotherapy, and combinatorial therapy. Despite advances in the development of novel treatment modalities over the last few decades, survival rates of HNSCC patients have not increased. To establish effective immunotherapies, a greater understanding of interactions between the immune system and HNSCC is required, and there is a particular need to develop novel therapeutic options. A therapeutic cancer vaccine has been proposed as a promising method to improve outcome by inducing a powerful adaptive immune response that leads to cancer cell elimination. Compared with other vaccines, peptide cancer vaccines are more robust and specific. In the past few years, there have been remarkable achievements in peptide-based vaccines for HNSCC patients. Here, we summarize the latest molecular alterations in HNSCC, explore the immune response to HNSCC, and discuss the latest developments in peptide-based cancer vaccine strategies. This review highlights areas for valuable future research focusing on peptide-based cancer vaccines.

Two novel human anti-CD25 antibodies with antitumor activity inversely related to their affinity and in vitro activity

High tumor regulatory T (Treg) cell infiltration is associated with poor prognosis of many cancers. CD25 is highly expressed on tumor Treg cells and is a potential target for Treg deletion. Previously characterized anti-CD25 antibodies appear to have limited efficacy in tumor inhibition. Here we identified two human anti-CD25 antibodies, BA9 and BT942, which did not prevent the activation of IL-2R signaling pathway by IL-2. BT942 had weaker binding and cytotoxic activity to human CD25-expressing cell lines than BA9. But both demonstrated significant tumor growth inhibition in early and late-stage animal cancer models. BT942 resulted in a higher expansion of CD8⁺ T cells and CD4⁺ T cells in tumor microenvironment in mouse MC38 model compared to BA9. BT942 also demonstrated significant higher tumor growth inhibition and higher expansion of CD8⁺ T cells and CD4⁺ T cells in combination with an anti-PD1 antibody. Pharmacokinetic study of BT942 in cynomolgus monkeys demonstrated a half-life of 206.97 ± 19.03 h. Structural analysis by cryo-EM revealed that BT942 recognizes an epitope on opposite side of the CD25-IL-2 binding site, consistent with no IL-2 signaling blockade in vitro. BT942 appears to be an excellent candidate for cancer immunotherapy.

Hyaluronan Functions in Wound Repair That Are Captured to Fuel Breast Cancer Progression

Signaling from an actively remodeling extracellular matrix (ECM) has emerged as a critical factor in regulating both the repair of tissue injuries and the progression of diseases such as metastatic cancer. Hyaluronan (HA) is a major component of the ECM that normally functions in tissue injury to sequentially promote then suppress inflammation and fibrosis, a duality in which is featured, and regulated in, wound repair. These essential response-to-injury functions of HA in the microenvironment are hijacked by tumor cells for invasion and avoidance of immune detection. In this review, we first discuss the numerous size-dependent functions of HA and emphasize the multifunctional nature of two of its receptors (CD44 and RHAMM) in regulating the signaling duality of HA in excisional wound healing. This is followed by a discussion of how HA metabolism is de-regulated in malignant progression and how targeting HA might be used to better manage breast cancer progression.

Distinctive CD26 Expression on CD4 T-Cell Subsets

Immune system CD4 T-cells with high cell-surface CD26 expression show anti-tumoral properties. When engineered with a chimeric antigen receptor (CAR), they incite strong responses against solid cancers. This subset was originally associated to human CD4 T helper cells bearing the CD45R0 effector/memory phenotype and later to Th17 cells. CD26 is also found in soluble form (sCD26) in several biological fluids, and its serum levels correlate with specific T cell subsets. However, the relationship between glycoprotein sCD26 and its dipeptidyl peptidase 4 (DPP4) enzymatic activity, and cell-surface CD26 expression is not well understood. We have studied ex vivo cell-surface CD26 and in vitro surface and intracellular CD26 expression and secretome's sCD26 in cultured CD4 T cells under different polarization conditions. We show that most human CD26negative CD4 T cells in circulating lymphocytes are central memory (TCM) cells while CD26high expression is present in effector Th1, Th2, Th17, and TEM (effector memory) cells. However, there are significant percentages of Th1, Th2, Th17, and Th22 CD26 negative cells. This information may help to refine the research on CAR-Ts. The cell surface CD45R0 and CD26 levels in the different T helper subsets after in vitro polarization resemble those found ex vivo. In the secretomes of these cultures there was a significant amount of sCD26. However, in all polarizations, including Th1, the levels of sCD26 were lower (although not significantly) compared to the Th0 condition (activation without polarization). These differences could have an impact on the various physiological functions proposed for sCD26/DPP4.

Identification of Immune-Related Subtypes and Characterization of Tumor Microenvironment Infiltration in Bladder Cancer

Tumors are closely related to the tumor microenvironment (TME). The complex interaction between tumor cells and the TME plays an indisputable role in tumor development. Tumor cells can affect the TME, promote tumor angiogenesis and induce immune tolerance by releasing cell signaling molecules. Immune cell infiltration (ICI) in the TME can affect the prognosis of patients with bladder cancer. However, the pattern of ICI of the TME in bladder cancer has not yet been elucidated. Herein, we identified three distinct ICI subtypes based on the TME immune infiltration pattern of 584 bladder cancer patients using the ESTIMATE and CIBERSORT algorithms. Then, we identified three gene clusters based on the differentially expressed genes (DEGs) between the three ICI subtypes. In addition, the ICI score was determined using single sample gene set enrichment analysis (ssGSEA). The results suggested that patients in the high ICI score subgroup had a favorable prognosis and higher expression of checkpoint-related and immune activity-related genes. The high ICI score subgroup was also linked to increased tumor mutation burden (TMB) and neoantigen burden. A cohort treated with anti-PD-L1 immunotherapy confirmed the therapeutic advantage and clinical benefit of patients with higher ICI scores. In the end, our study also shows that the ICI score represents an effective prognostic predictor for evaluating the response to immunotherapy. In conclusion, our study deepened the understanding of the TME, and it provides new ideas for improving patients' response to immunotherapy and promoting individualized tumor immunotherapy in the future.

The Extracellular Metabolome Stratifies Low and High Risk Potentially Premalignant Oral Keratinocytes and Identifies Citrate as a Potential Non-Invasive Marker of Tumour Progression

Simple Summary

The early detection of oral cancer is a high priority, as improvements in this area could lead to greater cure rates and reduced disability due to extensive surgery. Oral cancer is very difficult to detect in over 70% of cases as it develops unseen until quite advanced, sometimes rapidly. Therefore, the development of markers in body fluids (liquid biopsies) indicative of cancerous changes have a high priority. We show here that small molecules called metabolites can distinguish between non-diseased oral cells and two types of cells found in oral cells on the road to cancer. Although our investigation is preliminary, some of the metabolites have already been detected in the saliva (split) of oral cancer patients, and could eventually help detect oral cancer development at an earlier stage.

Abstract

Premalignant oral lesions (PPOLs) which bypass senescence (IPPOL) have a much greater probability of progressing to malignancy, but pre-cancerous fields also contain mortal PPOL keratinocytes (MPPOL) that possess tumour-promoting properties. To identify metabolites that could potentially separate IPPOL, MPPOL and normal oral keratinocytes non-invasively in vivo, we conducted an unbiased screen of their conditioned medium. MPPOL keratinocytes showed elevated levels of branch-chain amino acid, lipid, prostaglandin, and glutathione metabolites, some of which could potentially be converted into volatile compounds by oral bacteria and detected in breath analysis. Extracellular metabolites were generally depleted in IPPOL, and only six were elevated, but some metabolites distinguishing IPPOL from MPPOL have been associated with progression to oral squamous cell carcinoma (OSCC) in vivo. One of the metabolites elevated in IPPOL relative to the other groups, citrate, was confirmed by targeted metabolomics and, interestingly, has been implicated in cancer growth and metastasis. Although our investigation is preliminary, some of the metabolites described here are detectable in the saliva of oral cancer patients, albeit at a more advanced stage, and could eventually help detect oral cancer development earlier.

Identification of LIPH as an unfavorable biomarkers correlated with immune suppression or evasion in pancreatic cancer based on RNA-seq

BACKGROUND

It is widely considered that pancreatic cancer (PC) is an immunosuppressive cancer. Immune-based therapies remain promising therapeutic strategies for PC. Overexpression of lipase H (LIPH) was reported to be related to immunity in cattle and has also been demonstrated to promote tumor progression in several tumors, but its role in pancreatic carcinogenesis remains unclear. Study on LIPH in PC might provide a new insight into the immunosuppression in PC.

METHODS

The potential biological and clinical significance of LIPH was evaluated by bioinformatics analysis. We further investigated potential associations between the expression of LIPH and tumor immune infiltration using the CIBERSORT algorithm, the ESTIMAT algorithm, and single sample gene set enrichment analysis (ssGSEA).

RESULTS

LIPH was significantly overexpressed in tumor tissues compared with normal tissues. LIPH overexpression correlated with tumor recurrence, advanced histologic grade, and poorer overall survival (OS). Four of the most common somatic mutation, including KRAS, TP53, CDKN2A, and SMAD4, in PC were all correlated with high LIPH expression. And high LIPH expression was significantly correlated with KRAS activation and SMAD4 inactivation. Besides, LIPH expression was involved in various biological pathways such as negative regulation of cell-cell adhesion, actin cytoskeleton, EMT, angiogenesis, and signaling by MST1. And LIPH overexpression caused high infiltration of TAMs, Treg cells, and Th2/Th1, but reduced the infiltration of CD8⁺ T cells and Th1 cells.

CONCLUSIONS

Our findings demonstrated that LIPH correlated with immune suppression or evasion and may function as a novel unfavorable prognostic biomarker in PC.

Prognostic and immunological value of ATP6AP1 in breast cancer: implications for SARS-CoV-2

Abnormal ATPase H+ Transporting Accessory Protein 1 (ATP6AP1) expression may promote carcinogenesis. We investigated the association of ATP6AP1 with breast cancer (BC) and COVID-19. The Oncomine, Gene Expression Profiling Interactive Analysis, Human Protein Atlas and Kaplan-Meier plotter databases were used to evaluate the expression and prognostic value of ATP6AP1 in BC. ATP6AP1 was upregulated in BC tissues, and higher ATP6AP1 expression was associated with poorer outcomes. Data from the Tumor Immune Estimation Resource, Tumor-Immune System Interaction Database and Kaplan-Meier plotter indicated that ATP6AP1 expression correlated with immune infiltration, and that its prognostic effects in BC depended on tumor-infiltrating immune cell subtype levels. Multiple databases were used to evaluate the association of ATP6AP1 with clinicopathological factors, assess the mutation and methylation of ATP6AP1, and analyze gene co-expression and enrichment. The ATP6AP1 promoter was hypomethylated in BC tissues and differentially methylated between different disease stages and subtypes. Data from the Gene Expression Omnibus indicated that ATP6AP1 levels in certain cell types were reduced after SARS-CoV-2 infections. Ultimately, higher ATP6AP1 expression was associated with a poorer prognosis and with higher or lower infiltration of particular immune cells in BC. BC patients may be particularly susceptible to SARS-CoV-2 infections, which may alter their prognoses.

Prognostic Role of Tumor-Infiltrating Lymphocytes and Tumor Budding in Early Oral Tongue Carcinoma

Objectives/Hypothesis

Occult lymph metastasis is an important prognosticator for the treatment of early oral tongue squamous cell carcinoma (SCC). The objective of this study was to evaluate the prognostic significance of tumor‐infiltrating lymphocytes (TILs) in early oral tongue SCC. The combination of the TIL subtype and intermediate‐ or high‐grade budding scores was investigated as a prognostic marker for occult neck metastases.

Study Design

Retrospective study.

Methods

Specimens from 62 patients with early oral tongue SCC treated with only primary surgery were analyzed by immunohistochemistry for CD4+, CD8+, FoxP3+, and CD45RO+ T cells and CD163+ macrophages. The highest number of each TIL subtype was counted in two areas of parenchyma and stroma in the tumor (Tumor) and peripheral stroma of the invasion margin.

Results

Based on multivariate analysis, a high density of Tumor CD163+ macrophages served as the poorest prognostic factor for regional control (RC) and disease‐free survival (DFS). Patients with both a high density of Tumor CD163+ macrophages and an intermediate‐ or a high‐grade budding score had a poor prognosis for RC according to the log‐rank test.

Conclusions

In summary, each TIL subtype may use different mechanisms during early and advanced stages of oral tongue SCC. A high density of Tumor CD163+ macrophages was determined to be a risk factor for RC and DFS as well as an additional stratification factor for RC in patients with intermediate‐ or high‐grade budding scores. Therefore, identifying TIL subtypes in daily clinical practice can help determine a more successful and individualized therapeutic approach for early oral tongue SCC.

Level of Evidence

Step 4 (Level 4) Laryngoscope, 131:2512–2518, 2021

Mechanistic Targets and Nutritionally Relevant Intervention Strategies to Break Obesity-Breast Cancer Links

The worldwide prevalence of overweight and obesity has tripled since 1975. In the United States, the percentage of adults who are obese exceeds 42.5%. Individuals with obesity often display multiple metabolic perturbations, such as insulin resistance and persistent inflammation, which can suppress the immune system. These alterations in homeostatic mechanisms underlie the clinical parameters of metabolic syndrome, an established risk factor for many cancers, including breast cancer. Within the growth-promoting, proinflammatory milieu of the obese state, crosstalk between adipocytes, immune cells and breast epithelial cells occurs via obesity-associated hormones, angiogenic factors, cytokines, and other mediators that can enhance breast cancer risk and/or progression. This review synthesizes evidence on the biological mechanisms underlying obesity-breast cancer links, with emphasis on emerging mechanism-based interventions in the context of nutrition, using modifiable elements of diet alone or paired with physical activity, to reduce the burden of obesity on breast cancer.

Involvement of Cellular Prion Protein in Invasion and Metastasis of Lung Cancer by Inducing Treg Cell Development

The cellular prion protein (PrP^C) is a cell surface glycoprotein expressed in many cell types that plays an important role in normal cellular processes. However, an increase in PrP^C expression has been associated with a variety of human cancers, where it may be involved in resistance to the proliferation and metastasis of cancer cells. PrP-deficient (Prnp^0/0) and PrP-overexpressing (Tga20) mice were studied to evaluate the role of PrP^C in the invasion and metastasis of cancer. Tga20 mice, with increased PrP^C, died more quickly from lung cancer than did the Prnp^0/0 mice, and this effect was associated with increased transforming growth factor-beta (TGF-β) and programmed death ligand-1 (PD-L1), which are important for the development and function of regulatory T (Treg) cells. The number of FoxP3⁺CD25⁺ Treg cells was increased in Tga20 mice compared to Prnp^0/0 mice, but there was no significant difference in either natural killer or cytotoxic T cell numbers. In addition, mice infected with the ME7 scrapie strain had decreased numbers of Treg cells and decreased expression of TGF-β and PD-L1. These results suggest that PrP^C plays an important role in invasion and metastasis of cancer cells by inducing Treg cells through upregulation of TGF-β and PD-L1 expression.

The analysis of Treg lymphocyte blood percentage changes in patients with head and neck cancer during combined oncological treatment: a preliminary report

Introduction

In patients with cancer, Treg lymphocytes seem to play an important role in promoting tumour growth. The number of circulating Treg cells has been associated with poor survival among patients suffering from various types of cancers. The aim of the present study was to evaluate the changes in the percentage levels of Treg lymphocytes in the blood samples of patients with head and neck cancer during combined treatment with respect to the stage of the disease and the intensity of the radiation reaction as monitored using the Dische scale.

Material and methods

Peripheral blood samples were collected from 20 head and neck cancer patients prior to the combined oncological treatment, during, and then one week after the completion of the therapy.

Results

A statistically significantly higher percentage of CD3⁺/CD4⁺/CD25⁺/FoxP3⁺/CD127(^–/low) T cells within the CD3⁺/CD4⁺ T cell population was detected in patients during radiotherapy (RTH), chemotherapy (CTH), and chemoradiotherapy (CRT) than before the treatment began (p < 0.0001). A statistically significantly higher percentage of CD3⁺/CD4⁺/CD25⁺/FoxP3⁺/CD127(^–/low) T cells within the CD3⁺/CD4⁺ T cell population was detected after RTH/CRT than before treatment, with respect to the radiation reaction as evaluated using the Dische scale (p = 0.0150).

Conclusions

The increase in the percentage of Treg cells correlated with an increase in the intensity of the radiation reaction measured using the Dische scale which indicates the advance of the oral mucositis reaction to RTH. In conclusion, because the role of Treg lymphocytes in cancer patients is complex, it is necessary to monitor the percentages of these cells in patients during combined oncological therapies.

IRF4 overexpression promotes the transdifferentiation of tregs into macrophage-like cells to inhibit the development of colon cancer

Background

Interferon regulatory factor 4 (IRF4) is a transcription factor from the IRF factor family that exerts regulatory functions in the immune system and oncogenesis. However, the biological role of IRF4 in colon cancer is still unclear. The aim of this study is to investigate whether IRF4 participates in the immune response in colon cancer.

Methods

We compared the expression of IRF4, the number of regulatory T cells (Tregs) and macrophages in the colon cancer tissues and paracancerous colon tissues from colon cancer patients. Colon cancer mouse model was established by inoculation with colon cancer cells (SW480) as a xenograft tumor, and we observed tumor growth of colon cancer. Furthermore, the mechanism of action of IRF4 in transdifferentiation of Tregs into macrophage-like cells and the effect of IRF4 on colon cancer cells were investigated in vitro.

Results

IRF4 was severely down-regulated in the colon cancer tissues. Colon cancer tissues exhibited an increase in the number of regulatory T cells (Tregs) and macrophages. Furthermore, IRF4 overexpression repressed proliferation, migration and invasion of colon cancer cells (SW480 and HT116 cells). Moreover, IRF4 up-regulation ameliorated tumor growth of colon cancer by promoting the transdifferentiation of Tregs into macrophage-like cells through inhibition of BCL6 expression. Exosomes derived from colon cancer cells repressed IRF4 expression in Tregs by transmitting miR-27a-3p, miR-30a-5p and miR-320c.

Conclusions

IRF4 overexpression promoted the transdifferentiation of Tregs into macrophage-like cells to inhibit the occurrence and development of colon cancer. Thus, IRF4 may be a potential target for colon cancer treatment.

Lipid Metabolism in Tumor-Infiltrating T Cells

T cells recognize "foreign" antigens and induce durable humoral and cellular immune responses, which are indispensable for defending pathogens, as well as maintaining the integrity and homeostasis of tissues and organs. T cells are the major immune cell population in the tumor microenvironment which play a critical role in the antitumor immune response and cancer immune surveillance. Defective immune response of tumor-infiltrating T cells is the main cause of cancer immune evasion. The antitumor response of T cells is affected by multiple factors in the tumor microenvironment, including immunosuppressive cells, immune inhibitory cytokines, tumor-derived suppressive signals like PD-L1, immnuogenicity of tumor cells, as well as metabolic factors like hypoxia and nutrient deprivation. Abundant studies in past decades have proved the metabolic regulations of the immune response of T cells and the tumor-infiltrating T cells. In this chapter, we will discuss the regulations of the antitumor response of tumor-infiltrating T cells by lipid metabolism, which is one of the main components of metabolic regulation.

CCL25 Signaling in the Tumor Microenvironment

Multiple checkpoint mechanisms are overridden by cancer cells in order to develop into a tumor. Neoplastic cells, while constantly changing during the course of cancer progression, also craft their surroundings to meet their growing needs. This crafting involves changing cell surface receptors, affecting response to extracellular signals and secretion of signals that affect the nearby cells and extracellular matrix architecture. This chapter briefly comprehends the non-cancer cells facilitating the cancer growth and elaborates on the notable role of the CCR9-CCL25 chemokine axis in shaping the tumor microenvironment (TME), directly and via immune cells. Association of increased CCR9 and CCL25 levels in various tumors has demonstrated the significance of this axis as a tool commonly used by cancer to flourish. It is involved in attracting immune cells in the tumor and determining their fate via various direct and indirect mechanisms and, leaning the TME toward immunosuppressive state. Besides, elevated CCR9-CCL25 signaling allows survival and rapid proliferation of cancer cells in an otherwise repressive environment. It modulates the intra- and extracellular protein matrix to instigate tumor dissemination and creates a supportive metastatic niche at the secondary sites. Lastly, this chapter abridges the latest research efforts and challenges in using the CCR9-CCL25 axis as a cancer-specific target.

Tumor-Derived Extracellular Vesicles and the Immune System-Lessons From Immune-Competent Mouse-Tumor Models

Tumor-derived extracellular vesicles (TEVs) are important regulators of the immune response in cancer; however, most research so far has been carried out using cell culture systems. Immune-competent murine tumor models currently provide the best platform to assess proposed roles of TEVs using in vivo animal models and therefore are important for examining interactions between TEVs and the immune system. In this review, we present the current knowledge on TEVs using in vivo tumor-bearing animal models, with a focus on the role of TEVs in mediating crosstalk between tumor cells and both adaptive and innate immune cells. In particular, we address the question how animal models can clarify the reported heterogeneity of TEV effects in both anti-tumor responses and evasion of immune surveillance. The potential of TEVs in mediating direct antigen-presenting functions supports their potential as cancer vaccine therapeutics, therefore, we provide an overview of key findings of TEV trials that have the potential as novel immunotherapies, and shed light on challenges in the path toward the first in-human trials. We also highlight the important updates on the methods that continue to enhance the rigor and reproducibility of EV studies, particularly in functional animal models.

Stress and coping in women with breast cancer:unravelling the mechanisms to improve resilience

Breast cancer diagnosis, surgery, adjuvant therapies and survivorship can all be extremely stressful. In women, concerns about body image are common as a result of the disease and can affect interpersonal relationships, possibly leading to social isolation, increasing the likelihood for mood disorders. This is particularly relevant as women are at greater risk to develop anxiety and depressive symptoms in response to highly stressful situations. Here we address the mechanisms and the pathways activated as a result of stress and contributing to changes in the pathophysiology of breast cancer, as well as the potential of stress management factors and interventions in buffering the deleterious effects of chronic stress in a gender perspective. An improved understanding of the biological mechanisms linking stress-management resources to health-relevant biological processes in breast cancer patients could reveal novel therapeutic targets and help clarifying which psychosocial interventions can improve cancer outcomes, ultimately offering a unique opportunity to improve contemporary cancer treatments.

Microwave ablation enhances tumor-specific immune response in patients with hepatocellular carcinoma

Thermal ablative therapies are standard treatments for localized hepatocellular carcinoma (HCC). In addition to local tumor destruction, ablation leads to abscopal effects in distant lesions most likely mediated by an anti-tumor immune response. Although microwave ablation (MWA) is increasingly substituting other ablative techniques, its systemic immunostimulatory effects are poorly studied. We analyzed tumor-specific immune responses in peripheral blood of HCC patients after thermal ablation with regard to T cell responses and disease outcome. While comprehensive flow cytometric analyses in sequential samples of a prospective patient cohort (n = 23) demonstrated only moderate effects of MWA on circulating immune cell subsets, fluorospot analyses of specific T cell responses against seven tumor-associated antigens (TTAs) revealed de-novo or enhanced tumor-specific immune responses in 30% of patients. This anti-tumor immune response was related to tumor control as Interferon-y and Interleukin-5 T cell responses against TAAs were more frequent in patients with a long-time remission (> 1 year) after MWA (7/16) compared to patients suffering from an early relapse (0/13 patients) and presence of tumor-specific T cell response (IFN-y and/or IL-5) was associated to longer progression-free survival (27.5 vs. 10.0 months). Digital image analysis of immunohistochemically stained archival HCC samples (n = 18) of patients receiving combined MWA and resection revealed a superior disease-free survival of patients with high T cell abundance at the time of thermal ablation (37.4 vs. 13.1 months). Our data demonstrates remarkable immune-related effects of MWA in HCC patients and provides additional evidence for a combination of local ablation and immunotherapy in this challenging disease.

Cathepsin G and its Dichotomous Role in Modulating Levels of MHC Class I Molecules

Cathepsin G (CatG) is involved in controlling numerous processes of the innate and adaptive immune system. These features include the proteolytic activity of CatG and play a pivotal role in alteration of chemokines as well as cytokines, clearance of exogenous and internalized pathogens, platelet activation, apoptosis, and antigen processing. This is in contrast to the capability of CatG acting in a proteolytic-independent manner due to the net charge of arginine residues in the CatG sequence which interferes with bacteria. CatG is a double-edged sword; CatG is also responsible in pathophysiological conditions, such as autoimmunity, chronic pulmonary diseases, HIV infection, tumor progression and metastasis, photo-aged human skin, Papillon-Lefèvre syndrome, and chronic inflammatory pain. Here, we summarize the latest findings for functional responsibilities of CatG in immunity, including bivalent regulation of major histocompatibility complex class I molecules, which underscore an additional novel role of CatG within the immune system.

Chronic Stress Contributes to Osteosarcopenic Adiposity via Inflammation and Immune Modulation: The Case for More Precise Nutritional Investigation

Chronic stress and low-grade chronic inflammation (LGCI) are key underlying factors formany diseases, including bone and body composition impairments. Objectives of this narrativereview were to examine the mechanisms by which chronic stress and LGCI may influenceosteosarcopenic adiposity (OSA) syndrome, originally named as ostoesarcopenic obesity (OSO).We also examined the crucial nutrients presumed to be affected by or cause of stress andinflammation and compared/contrasted them to those of our prehistoric ancestors. The evidenceshows that stress (particularly chronic) and its related inflammatory processes, contribute toosteoporosis, sarcopenia, and adiposity ultimately leading to OSA as a final and most derangedstate of body composition, commencing at the mesenchymal cell lineage disturbance. Thefoods/nutrients consumed by modern humans, as well as their altered lifestyle, also contribute tostress, LGCI and subsequently to OSA. The processes can also go in opposite direction when stressand inflammation impact nutritional status, particularly some micronutrients' levels. Whilenutritional management of body composition and LGCI have been studied, the nutrients (and theirquantities) most affected by stressors and those which may act toward the alleviation of stressfulstate, ultimately leading to better body composition outcomes, need to be elucidated.

Chimeric antigen receptor T cells in solid tumors: a war against the tumor microenvironment

Chimeric antigen receptor (CAR) T cell is a novel approach, which utilizes anti-tumor immunity for cancer treatment. As compared to the traditional cell-mediated immunity, CAR-T possesses the improved specificity of tumor antigens and independent cytotoxicity from major histocompatibility complex molecules through a monoclonal antibody in addition to the T-cell receptor. CAR-T cell has proven its effectiveness, primarily in hematological malignancies, specifically where the CD 19 CAR-T cells were used to treat B-cell acute lymphoblastic leukemia and B-cell lymphomas. Nevertheless, there is little progress in the treatment of solid tumors despite the fact that many CAR agents have been created to target tumor antigens such as CEA, EGFR/EGFRvIII, GD2, HER2, MSLN, MUC1, and other antigens. The main obstruction against the progress of research in solid tumors is the tumor microenvironment, in which several elements, such as poor locating ability, immunosuppressive cells, cytokines, chemokines, immunosuppressive checkpoints, inhibitory metabolic factors, tumor antigen loss, and antigen heterogeneity, could affect the potency of CAR-T cells. To overcome these hurdles, researchers have reconstructed the CAR-T cells in various ways. The purpose of this review is to summarize the current research in this field, analyze the mechanisms of the major barriers mentioned above, outline the main solutions, and discuss the outlook of this novel immunotherapeutic modality.

Racial Differences in Immunological Landscape Modifiers Contributing to Disparity in Prostate Cancer

Prostate cancer affects African Americans disproportionately by exhibiting greater incidence, rapid disease progression, and higher mortality when compared to their Caucasian counterparts. Additionally, standard treatment interventions do not achieve similar outcome in African Americans compared to Caucasian Americans, indicating differences in host factors contributing to racial disparity. African Americans have allelic variants and hyper-expression of genes that often lead to an immunosuppressive tumor microenvironment, possibly contributing to more aggressive tumors and poorer disease and therapeutic outcomes than Caucasians. In this review, we have discussed race-specific differences in external factors impacting internal milieu, which modify immunological topography as well as contribute to disparity in prostate cancer.

Influence of demethylation on regulatory T and Th17 cells in myelodysplastic syndrome

Myelodysplastic syndrome (MDS) represents a heterogeneous hematopoietic disorder in which mature blood cells are derived from an abnormal multipotent progenitor cell. The current therapy for MDS involves repeated cycles of DNA methyltransferase (DNMT) inhibitors, particularly the demethylation drug 5-azacytidine (5-azaC) which has been shown to increase the survival of patients with high-risk MDS. The mechanisms behind the therapeutic effects of 5-azaC are not yet clear. In this study the effect of 5-azaC on the development of regulatory T cells (Tregs) and T-helper 17 (Th17) cells was investigated. The numbers of CD4⁺ T-cell subsets in 30 patients with intermediate-2/high-risk MDS were serially assessed at diagnosis and following 5-azaC treatment. The number of FoxP3⁺ Tregs was significantly higher after 3 months of therapy. However, there was no statistical difference in the number of Th17 cells following treatment. In vitro, 5-azaC enhanced the overall proportion of Tregs, but not Th17, in CD4⁺ T cells from patients with MDS. Addition of 5-azaC reduced the proliferative capacity of Tregs, suggesting that the increase in Tregs was due to conversion of conventional CD25⁻ cells, rather than proliferation of CD25⁺FoxP3⁺ cells. The FoxP3 expression in 5-azaC-treated T effectors was also increased. Interestingly, while Tbet and RORγT mRNA transcription had no obvious changes, due to the demethylation of the FoxP3 promoter, these findings are important in associating the induction of DNA hypomethylation and the clinical response to 5-azaC.

Th17/Treg cells imbalance and their related cytokines (IL-17, IL-10 and TGF-β) in children with autism spectrum disorder

We aimed in this study to investigate a possible involvement of Th17/Treg cells imbalance in autism spectrum disorders (ASD). Using flowcytometry to determine circulating Th17 and Treg cells percentages, RT- PCR and ELISA for cytokine expression, we demonstrated that Th17/Treg balance in ASD children was significantly skewed toward a Th17 response compared to their control. Th17 cells and the ratio of Th17/Treg cells had a significantly positive correlation with disease severity whereas Treg cells had a negative correlation. The imbalance of Th17, Treg cells and their related cytokines may play a vital role in the progression of the disease.

T Regulatory Cells and Priming the Suppressive Tumor Microenvironment

Treg play a central role in maintenance of self tolerance and homeostasis through suppression of self-reactive T cell populations. In addition to that role, Treg also survey cancers and suppress anti-tumor immune responses. Thus, understanding the unique attributes of Treg-tumor interactions may permit control of this pathologic suppression without interfering with homeostatic self-tolerance. This review will define the unique role of Treg in cancer growth, and the ways by which Treg inhibit a robust anti-tumor immune response. There will be specific focus placed on Treg homing to the tumor microenvironment (TME), TME formation of induced Treg (iTreg), mechanisms of suppression that underpin cancer immune escape, and trophic nonimmunologic effects of Treg on tumor cells.

The role of immune infiltrates as prognostic biomarkers in patients with breast cancer

The presence of immune infiltrates in the tumor microenvironment has been documented in many types of cancer. Moreover, the preexistent or endogenous immunity which consists of interactions between intratumoral lymphocytes and tumor cells is mostly relevant for the successful application of various anticancer therapies, including standard chemotherapy, immune checkpoint inhibition-based immunotherapy and targeted therapies. The immunoscore defines densities of intratumoral immune infiltrates which determine poor or favorable prognosis depending on their quantity and quality in the tumor compartments. Results from large clinical studies have demonstrated an association between high densities of cytotoxic and memory TILs in the tumor compartments with improved prognosis. Importantly, we have demonstrated that differential combined densities of immune infiltrates jointly analyzed in the tumor center (TC) and the invasive margin (IM) have a significant prognostic value in breast cancer patients with poor clinicopathological parameters.

Cell surface cathepsin G can be used as an additional marker to distinguish T cell subsets

The serine protease cathepsin G (CatG) is involved in numerous processes associated with the innate and adaptive immune system. During an immune response, neutrophils secrete CatG, which can bind to the cell surface of immune cells to provoke the proteolytic processing of cytokines and chemokines in order to stimulate lymphocytes. The present study analyzed peripheral blood mononuclear cells to characterize T cell populations in terms of their CatG content by flow cytometry. It was identified that CatG was exclusively present on the cell surface of a subset of T regulatory cells (Tregs), cluster of differentiation (CD) 39⁺ Tregs, which expressed CatG in contrast to CD39^- Tregs. Additionally, CatG was expressed on double positive CD4⁺CD8⁺ T cells, T helper (Th) 9 cells and Th22 cells, implicating CatG as a novel marker to distinguish certain T cell subsets.

Relationships of interleukin-10 with the regulatory T cell ratio and prognosis of cervical cancer patients

OBJECTIVE

This study investigated serum interleukin-10 (IL-10) levels, changes in peripheral blood CD4+CD25+ regulatory T cell (PBCDT) ratios, and the prognosis of cervical cancer (CC) patients.

METHODS

Seventy patients with CC composed the observation group, and 70 healthy subjects composed the control group. The PBCDT ratios in the CC patients and healthy subjects were calculated. Serum IL-10 levels were detected with a double antibody sandwich enzyme-linked immunosorbent assay (ELISA).

RESULTS

The PBCDT ratio was higher in the patients with active CC [12.16±2.41%] than in the control subjects [6.34±1.05%]. Serum IL-10 levels were higher in the patients with CC [384±106 pg/ml] than in the control subjects [104±50 pg/ml]; the differences in both PBCDT ratio and IL-10 level were statistically significant (p<0.01). Serum IL-10 levels were positively correlated with PBCDT ratios (r=0.375, p<0.05). The 5-year patient survival rate was significantly higher in the low serum IL-10 group (64.2%) than in the high serum IL-10 group (42.8%, p=0.012).

CONCLUSIONS

PBCDT ratios and serum IL-10 levels are related to CC activity. These factors are reciprocally related and influence one another, and both are involved in the development and progression of CC. Low IL-10 expression is beneficial regarding the survival of patients with CC.

SERUM CYTOKINE OF IL-2, IL-10 AND IL-12 LEVELS IN PATIENTS WITH STOMACH ADENOCARCINOMA

ABSTRACT BACKGROUND: Gastric adenocarcinoma is the fourth most common cause of cancer-associated death worldwide. OBJECTIVE: We evaluated the immunological status of patients with gastric cancer before surgery and circulating cytokines as potential diagnostic biomarkers for gastric cancer. METHODS: We included 90 healthy controls and 95 patients with distal Gastric adenocarcinoma in Mazandaran, Sari, Iran. We measured serum IL-2, IL-10 and IL-12 Levels by a sandwich enzyme-linked immunosorbent assay using the IBL international GMBH kit. RESULTS: The serum IL-10 levels in the patients with Gastric adenocarcinoma were significantly higher than those of the healthy controls (P=0.02). There were no significant differences in serum IL-2 and IL-12 levels between patients with gastric cancer and healthy controls. CONCLUSION: Increased levels of IL-10 might be useful as diagnostic biomarkers for Gastric adenocarcinoma; however, this needs to be confirmed with larger number of patients and with control groups other than blood donors, properly age paired. These results suggest that positive expression of IL-10 may be useful as a molecular marker to distinguish stage of gastric cancers which can be more readily controlled.

Eicosanoid and Specialized Proresolving Mediator Regulation of Lymphoid Cells

Eicosanoids and specialized proresolving mediators (SPMs) regulate leukocyte function and inflammation. They are ideally positioned at the interface of the innate and adaptive immune responses when lymphocytes interact with leukocytes. Receptors for leukotriene B₄ (LTB₄), prostaglandin E₂ (PGE₂), and SPMs are expressed on lymphocytes. Evidence points toward an essential role of these lipid mediators (LMs) in direct regulation of lymphocyte functions. SPMs, which include lipoxins, demonstrate comprehensive protective actions with lymphocytes. LTB₄ and PGE₂ regulation of lymphocytes is diverse and depends on the interaction of lymphocytes with other cells. Importantly, both LTB₄ and PGE₂ are essential regulators of T cell antitumor activity. These LMs are attractive therapeutic targets to control dysregulated innate and adaptive immune responses, promote lymphocyte antitumor activity, and prevent tumor immune evasion.

Potential function of CTLA-4 in the tumourigenic capacity of melanoma stem cells

Extensive clinical evidence supports that cytotoxic T lymphocyte antigen-4 (CTLA-4) is expressed in a variety of human malignant tumour cells in addition to T cells. In certain types of cancer, the overexpression of CTLA-4 is associated with poor patient prognosis. However, few studies have demonstrated the effects of tumour-intrinsic CTLA-4 in cancer stem cells, including melanoma stem cells (MSCs). In the present study, it was demonstrated that melanoma cell-intrinsic CTLA-4 induced tumour cell proliferation in vitro and suppressed tumour cell apoptosis. Furthermore, CTLA-4 was expressed in aldehyde dehydrogenase (ALDH)+ MSCs. CTLA-4 inhibited MSCs proliferation in vitro by blocking antibodies and significantly downregulated ALDH1A1, ALDH1A3 and ALDH2 mRNA expression (P<0.01). Functionally, blocking CTLA-4 in melanoma cell lines suppressed the properties of stem-like cells, including ALDH activity and significantly suppressed the ability of these cells to form spheres in vitro (P<0.05). In addition, the blocking of CTLA-4 in melanoma cells suppressed the properties of stem-like cells in vivo, including the capacity for tumourigenesis. The presence of residual ALDH+ MSCs within the tumour was observed, and the blocking CTLA-4 significantly decreased the number of residual ALDH+ MSCs in vivo (P<0.01). Altogether, these results indicate the identification of a novel mechanism underlying melanoma progression in the present study and that CTLA-4-targeted therapy may benefit candidate CTLA-4-targeted therapy by improving the long-term outcome for patients with advanced stages of melanoma.

Providence of the CD25+ KIR+ CD127- FOXP3- CD8+ T-cell subset determines the dynamics of tumor immune surveillance

CD8⁺ T-regulatory (Treg) cells are emerging as crucial components of immune system. Previous studies have reported the presence of FOXP3⁺ CD8⁺ Treg cells, similar to CD4⁺ Tregs, in cancer patients which produce high levels of the immunosuppressive cytokines, IL10 and TGFβ. At an early stage of tumor development, we have identified a subset of FOXP3^- CD8⁺ CD25⁺ KIR⁺ CD127^- Treg-like cells, which are IFNγ⁺ . However, this early-induced CD8⁺ CD25⁺ CD127^- T-cell subset is certainly distinct from the IFNγ⁺ CD8⁺ T-effector cells. These CD8⁺ CD25⁺ CD127^- T cells express other FOXP3^- CD8⁺ Treg cell signature markers, and can selectively suppress autoreactive HLA-E⁺ T_FH cells as well as tumor-induced CD4⁺ Treg cells. In contrast to FOXP3⁺ CD8⁺ Tregs, this subset does not inhibit effector T-cell proliferation or their functions as they are HLA-E^- . Adoptive transfer of this early-CD8⁺ Treg-like subset restrained tumor growth and inhibited CD4⁺ Treg generation that impedes the immune surveillance and impairs cancer immunotherapy. At the late stage of tumor development, when CD4⁺ Treg cells dominate the tumor-microenvironment, CD4⁺ Tregs mediate the clonal deletion of these tumor-suppressive FOXP3^- IFNγ⁺ CD8⁺ CD25⁺ CD127^- T cells and ensure tumor immune evasion. Our findings suggest that at an early stage of the tumor, this tumor-induced IFNγ-producing FOXP3^- CD8⁺ CD25⁺ CD127^- T-cell subset can potentiate immune surveillance by targeting HLA-E-restricted CD4⁺ Treg cells while leaving the effector T-cell population unaffected. Hence, manipulating their profile can open up a new avenue in cancer immunotherapy.

ImmTAC/Anti-PD-1 antibody combination to enhance killing of cancer cells by reversing regulatory T-cell-mediated immunosuppression

Recently, bi-functional molecules that can redirect immune effectors to tumour cells have emerged as potentially robust mediators of tumour regression in clinical trials. Two modalities in particular, bi-specific antibodies for T-cell redirection and activation (BiTe) and immune-mobilizing monoclonal T-cell receptors against cancer (ImmTAC), are being evaluated in efficacy studies as 'off-the-shelf' reagents. Optimal therapy will require an understanding and means to address regulatory mechanisms of limiting efficacy. In light of this, we evaluated the impact of induced regulatory T (iTreg) cells on the efficacy of tumour cell killing redirected by ImmTAC and demonstrated down-regulation of T-cell proliferation and expression of CD25, CD107a, Granzyme B and Perforin by ImmTAC-redirected T cells. Significant recovery of ImmTAC potency, however, could be achieved when combined with an anti-programmed cell death protein 1 monoclonal antibody. Furthermore, we found that among lung cancer patients failing to respond to ImmTAC therapy, there was a significantly higher fraction of Treg cells in the peripheral blood mononuclear cells of lung cancer patients than in healthy donors. These results provide in vitro evidence for an iTreg cell-mediated immunosuppression of ImmTAC-redirected T-cell responses. Whilst immune checkpoint blockade can reverse the Treg cell suppression, it forms a rational basis for a combination of the blockade with ImmTAC in clinical trials.

The Antitumor Effect of Xihuang Pill on Treg Cells Decreased in Tumor Microenvironment of 4T1 Breast Tumor-Bearing Mice by PI3K/AKT~AP-1 Signaling Pathway

To study the antitumor effect of Xihuang pill (XHP) on the number of Treg cells in the tumor microenvironment of 4T1 breast tumor-bearing mice by PI3K/AKT/AP-1 pathway, a mouse model was established. Flow cytometry (FCM) and immunohistochemistry (IHC) were used to detect the number of Treg cells in the tumor microenvironment; terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) was used to detect the apoptosis of Treg cells in tumor microenvironment. Quantitative real-time PCR (RT-qPCR) was used to detect the mRNA expression of PI3K, AKT, and AP-1 in Treg cells in tumor microenvironment; immunofluorescence (IF) and Western Blot (WB) were used to detect the protein expression of PI3K, AKT, and AP-1 in Treg cells in tumor microenvironment. Compared with the naive control group, the tumor weight in XHP groups decreased significantly (P < 0.05); FCM and IHC results showed that the number of Treg cells in the tumor microenvironment decreased with the dose of XHP groups (P < 0.05); TUNEL staining showed that the number of Treg cells in tumor microenvironment increased with the dose of XHP groups (P < 0.05); RT-qPCR results showed that the mRNA expression of PI3K and AKT in Treg cells decreased with the dose of XHP groups, while RNA expression of AP-1 increased with the dose of XHP groups (P < 0.05); IF and WB results showed that the protein expression of PI3K and AKT in Treg cells decreased with the dose of XHP groups and the protein expression of AP-1 increased with the dose of XHP groups (P < 0.05). The results suggested that XHP decreased the number of Treg cells via inhibiting PI3K and AKT expression and upregulating AP-1 expression in Treg cells and then promoting the apoptosis of Treg cells. Thus, XHP could improve the immunosuppressive state of tumor microenvironment and reverse the immune escape to inhibit tumor growth.

The short-term stress response - Mother nature's mechanism for enhancing protection and performance under conditions of threat, challenge, and opportunity

Our group has proposed that in contrast to chronic stress that can have harmful effects, the short-term (fight-or-flight) stress response (lasting for minutes to hours) is nature's fundamental survival mechanism that enhances protection and performance under conditions involving threat/challenge/opportunity. Short-term stress enhances innate/primary, adaptive/secondary, vaccine-induced, and anti-tumor immune responses, and post-surgical recovery. Mechanisms and mediators include stress hormones, dendritic cell, neutrophil, macrophage, and lymphocyte trafficking/function and local/systemic chemokine and cytokine production. Short-term stress may also enhance mental/cognitive and physical performance through effects on brain, musculo-skeletal, and cardiovascular function, reappraisal of threat/anxiety, and training-induced stress-optimization. Therefore, short-term stress psychology/physiology could be harnessed to enhance immuno-protection, as well as mental and physical performance. This review aims to provide a conceptual framework and targets for further investigation of mechanisms and conditions under which the protective/adaptive aspects of short-term stress/exercise can be optimized/harnessed, and for developing pharmacological/biobehavioral interventions to enhance health/healing, and mental/cognitive/physical performance.

Loss of FFAR2 promotes colon cancer by epigenetic dysregulation of inflammation suppressors

Free fatty acid receptor 2 (FFAR2, also named GPR43), is activated by short-chain fatty acids (SCFAs), such as butyrate, that are produced when gut bacteria ferment dietary fiber. FFAR2 has been suggested to regulate colonic inflammation, which is a major risk factor for the development of colon cancer and is also linked to epigenetic dysregulation in colon carcinogenesis. The current study assessed whether FFAR2, acting as an epigenetic regulator, protects against colon carcinogenesis. To mimic the mild inflammation that promotes human colon cancer, we treated mice with dextran sodium sulfate (DSS) overnight, which avoids excessive inflammation but induces mild inflammation that promotes colon carcinogenesis in the Apc^Min/+ and the azoxymethane (AOM)-treated mice. Our results showed that FFAR2 deficiency promotes the development of colon adenoma in the Apc^Min/+ /DSS mice and the progression of adenoma to adenocarcinoma in the AOM/DSS mice. FFAR2's downstream cAMP-PKA-CREB pathway was enhanced, leading to overexpression of histone deacetylases (HDACs) in the FFAR2-deficient mice. ChIP-qPCR analysis revealed differential binding of H3K27me3 and H3K4me3 histone marks onto the promoter regions of inflammation suppressors (e.g., sfrp1, dkk3, socs1), resulting in decreased expression of these genes in the FFAR2-deficient mice. Also, more neutrophils infiltrated into tumors and colon lamina propria of the FFAR2-deficient mice. Depletion of neutrophils blocked the progression of colon tumors. In addition, FFAR2 is required for butyrate to suppress HDAC expression and hypermethylation of inflammation suppressors. Therefore, our results suggest that FFAR2 is an epigenetic tumor suppressor that acts at multiple stages of colon carcinogenesis.

Immune checkpoint blockade combined with IL-6 and TGF-β inhibition improves the therapeutic outcome of mRNA-based immunotherapy

Improved understanding of cancer immunology has provided insight into the phenomenon of frequent tumor recurrence after initially successful immunotherapy. A delicate balance exists between the capacity of the immune system to control tumor growth and various resistance mechanisms that arise to avoid or even counteract the host's immune system. These resistance mechanisms include but are not limited to (i) adaptive expression of inhibitory checkpoint molecules in response to the proinflammatory environment and (ii) amplification of cancer stem cells, a small fraction of tumor cells possessing the capacity for self-renewal and mediating treatment resistance and formation of metastases after long periods of clinical remission. Several individual therapeutic agents have so far been developed to revert T-cell exhaustion or disrupt the cross-talk between cancer stem cells and the tumor-promoting microenvironment. Here, we demonstrate that a three-arm combination therapy-consisting of an mRNA-based vaccine to induce antigen-specific T-cell responses, monoclonal antibodies blocking inhibitory checkpoint molecules (PD-1, TIM-3, LAG-3), and antibodies targeting IL-6 and TGF-β-improves the therapeutic outcome in subcutaneous TC-1 tumors and significantly prolongs survival of treated mice. Our findings point to a need for a rational development of multidimensional anticancer therapies, aiming at the induction of tumor-specific immunity and simultaneously targeting multiple resistance mechanisms.

T regulatory cells mediate immunosuppresion by adenosine in peripheral blood, sentinel lymph node and TILs from melanoma patients

T regulatory cells (Tregs), involved in tumour tolerance, can generate Adenosine by CD39/CD73 surface enzymes, which identify four Tregs subsets: CD39⁺CD73^- nTregs, CD39⁺CD73⁺ iTregs, CD39^-CD73⁺ oTregs and CD39^-CD73^- xTregs. In melanoma patients, increased Tregs levels are detected in peripheral blood (PB), sentinel lymph node (SLN) and tumour infiltrating lymphocytes (TILs), but Adenosine role was not investigated yet. We examined total Tregs and Adenosine subsets in PB, SLN and TILs from melanoma patients (n = 32) and PB from healthy donors (HD; n = 10) by flow cytometry. Total Tregs significantly increased in stage III-IV patients PB, in SLN and TILs, as compared to HD/stage I-II patients. Tregs subsets analyses showed that: 1) PB nTregs significantly increased in SLN and decreased in TILs; 2) iTregs significantly increased in stage III-IV patients PB and further significantly increased in SLN and TILs; 3) PB oTregs and xTregs significantly decreased in SLN and TILs. Patients clinical features did not significantly influence total Tregs, except SLN excision order. Results confirmed Tregs role in melanoma progression and indicate Adenosine generation as a novel escape mechanism, being nTregs and iTregs increased in PB/SLN/TILs.