Role of TH17 cytokines in the control of colorectal cancer

The role of IL-22 in cancer

Interleukin-22, discovered in the year of 2000, is a pleiotropic Th17 cytokine from the IL-10 family of cytokines. IL-22 signals through the type 2 cytokine receptor complex IL-22R and predominantly activates STAT3. This pathway leads to the transcription of several different types of genes, giving IL-22 context-specific functions ranging from inducing antimicrobial peptide expression to target cell proliferation. In recent years, it has been shown that IL-22 is involved in the pathogenesis of neoplasia in some cancers through its pro-proliferative and anti-apoptotic effects. This review highlights studies with recent discoveries and conclusions drawn on IL-22 and its involvement and function in various cancers. Such a study may be helpful to better understand the role of IL-22 in cancer so that new treatment could be developed targeting IL-22.

Association between obesity and cancer risk in adults with HIV in Korea

INTRODUCTION

This study aimed to investigate the association between obesity and cancer risk as well as site-specific cancer risks in adults with HIV using a nationwide health screening database in Korea.

METHODS

Of the 16,671 adults with a new diagnosis of HIV from 2004 to 2020, 456 incident cancer cases and 1814 individually matched controls by sex, year of birth, year of HIV diagnosis, and follow-up duration (1 : 4 ratio) were included in this nested case-control study. The association between obesity (BMI ≥25 kg/m 2 ) and cancer risks was estimated and presented as odds ratios (ORs) and 95% confidence intervals (95% CIs).

RESULTS

Of the 456 cancer incident cases, there were 146 AIDS-defining cancer cases and 310 non-AIDS-defining cancer cases. Compared with nonobese adults with HIV, obese adults with HIV were at higher risk of non-AIDS-defining cancer (OR = 1.478, 95% CI = 1.118-1.955). Otherwise, the overall risk of AIDS-defining cancer (OR = 0.816, 95% CI = 0.520-1.279) and each type of AIDS-defining cancer (Kaposi sarcoma and non-Hodgkin's lymphoma) were not high in obese adults with HIV. Of the specific types of non-AIDS-defining cancers, obesity was associated with an increased risk of colorectal cancer (OR = 3.090, 95% CI = 1.110-8.604) and liver, bile duct, and pancreatic cancers (OR = 2.532, 95% CI = 1.141-5.617).

CONCLUSION

Obesity, which is one of the important health concerns in HIV management, was associated with an increased risk of non-AIDS-defining cancer but not AIDS-defining cancer.

Unveiling the immune symphony: decoding colorectal cancer metastasis through immune interactions

Colorectal cancer (CRC), known for its high metastatic potential, remains a leading cause of cancer-related death. This review emphasizes the critical role of immune responses in CRC metastasis, focusing on the interaction between immune cells and tumor microenvironment. We explore how immune cells, through cytokines, chemokines, and growth factors, contribute to the CRC metastasis cascade, underlining the tumor microenvironment's role in shaping immune responses. The review addresses CRC's immune evasion tactics, especially the upregulation of checkpoint inhibitors like PD-1 and CTLA-4, highlighting their potential as therapeutic targets. We also examine advanced immunotherapies, including checkpoint inhibitors and immune cell transplantation, to modify immune responses and enhance treatment outcomes in CRC metastasis. Overall, our analysis offers insights into the interplay between immune molecules and the tumor environment, crucial for developing new treatments to control CRC metastasis and improve patient prognosis, with a specific focus on overcoming immune evasion, a key aspect of this special issue.

New sights of immunometabolism and agent progress in colitis associated colorectal cancer

Colitis associated colorectal cancer is a disease with a high incidence and complex course that develops from chronic inflammation and deteriorates after various immune responses and inflammation-induced attacks. Colitis associated colorectal cancer has the characteristics of both immune diseases and cancer, and the similarity of treatment models contributes to the similar treatment dilemma. Immunometabolism contributes to the basis of life and is the core of many immune diseases. Manipulating metabolic signal transduction can be an effective way to control the immune process, which is expected to become a new target for colitis associated colorectal cancer therapy. Immune cells participate in the whole process of colitis associated colorectal cancer development by transforming their functional condition via changing their metabolic ways, such as glucose, lipid, and amino acid metabolism. The same immune and metabolic processes may play different roles in inflammation, dysplasia, and carcinoma, so anti-inflammation agents, immunomodulators, and agents targeting special metabolism should be used in combination to prevent and inhibit the development of colitis associated colorectal cancer.

Elevated levels of peripheral Th17 cells and Th17-related cytokines in patients with periampullary adenocarcinoma

AIM

Periampullary adenocarcinoma (PAC) is a malignant tumor originating at the ampulla of Vater, distal common bile duct, head of the pancreas, ampulla and duodenum. The levels of circulating Th17 cells and Th17-related cytokines in patients with PAC remain unreported. Therefore, the aim of this study was to determine the levels of circulating Th17 cells and Th17-related cytokines in patients with PAC.

MATERIALS AND METHODS

Flow cytometry was used to measure Th17 cell proportions in PBMCs from 60 PAC patients and 30 healthy controls. Enzyme-linked immunosorbent assay (ELISA) was used to quantify IL-17A and IL-23 levels in serum samples, while quantitative reverse transcription polymerase chain reaction (qRT-PCR) assessed IL-17A mRNA expression and Th17-related transcription factors (RORγt and STAT3) in tissue samples.

RESULTS

The findings showed a substantial increase in Th17 cell percentages, elevated concentrations of IL-17A and IL-23, and higher mRNA expression levels of IL-17A, RORγt, and STAT3 in patients with PAC when compared to healthy controls (HCs).

CONCLUSION

Th17 cells play an important role in the pathogenesis of PAC and may represent potential therapeutic targets.

A new strategy for treating colorectal cancer: Regulating the influence of intestinal flora and oncolytic virus on interferon

Colorectal cancer (CRC) has the third highest incidence and the second highest mortality in the world, which seriously affects human health, while current treatments methods for CRC, including systemic therapy, preoperative radiotherapy, and surgical local excision, still have poor survival rates for patients with metastatic disease, making it critical to develop new strategies for treating CRC. In this article, we found that the gut microbiota can modulate the signaling pathways of cancer cells through direct contact with tumor cells, generate inflammatory responses and oxidative stress through interactions between the innate and adaptive immune systems, and produce diverse metabolic combinations to trigger specific immune responses and promote the initiation of systemic type I interferon (IFN-I) and anti-viral immunity. In addition, oncolytic virus-mediated immunotherapy for regulating oncolytic virus can directly lyse tumor cells, induce the immune activity of the body, interact with interferon, inhibit the anti-viral effect of IFN-I, and enhance the anti-tumor effect of IFN-II. Interferon plays an important role in the anti-tumor process. We put forward that exploring the effects of intestinal flora and oncolytic virus on interferon to treat CRC is a promising therapeutic option.

T Cells in Colorectal Cancer: Unravelling the Function of Different T Cell Subsets in the Tumor Microenvironment

Therapeutic options for metastatic colorectal cancer (mCRC) are very limited, and the prognosis using combination therapy with a chemotherapeutic drug and a targeted agent, e.g., epidermal growth factor receptor or tyrosine kinase, remains poor. Therefore, mCRC is associated with a poor median overall survival (mOS) of only 25-30 months. Current immunotherapies with checkpoint inhibitor blockade (ICB) have led to a substantial change in the treatment of several cancers, such as melanoma and non-small cell lung cancer. In CRC, ICB has only limited effects, except in patients with microsatellite instability-high (MSI-H) or mismatch repair-deficient (dMMR) tumors, which comprise about 15% of sporadic CRC patients and about 4% of patients with metastatic CRC. The vast majority of sporadic CRCs are microsatellite-stable (MSS) tumors with low levels of infiltrating immune cells, in which immunotherapy has no clinical benefit so far. Immunotherapy with checkpoint inhibitors requires the presence of infiltrating T cells into the tumor microenvironment (TME). This makes T cells the most important effector cells in the TME, as evidenced by the establishment of the immunoscore-a method to estimate the prognosis of CRC patients. The microenvironment of a tumor contains several types of T cells that are anti-tumorigenic, such as CD8⁺ T cells or pro-tumorigenic, such as regulatory T cells (Tregs) or T helper 17 (Th17) cells. However, even CD8⁺ T cells show marked heterogeneity, e.g., they can become exhausted, enter a state of hyporesponsiveness or become dysfunctional and express high levels of checkpoint molecules, the targets for ICB. To kill cancer cells, CD8⁺ T cells need the recognition of the MHC class I, which is often downregulated on colorectal cancer cells. In this case, a population of unconventional T cells with a γδ T cell receptor can overcome the limitations of the conventional CD8⁺ T cells with an αβT cell receptor. γδ T cells recognize antigens in an MHC-independent manner, thus acting as a bridge between innate and adaptive immunity. Here, we discuss the effects of different T cell subsets in colorectal cancer with a special emphasis on γδ T cells and the possibility of using them in CAR-T cell therapy. We explain T cell exclusion in microsatellite-stable colorectal cancer and the possibilities to overcome this exclusion to enable immunotherapy even in these "cold" tumors.

Plasma protein changes reflect colorectal cancer development and associated inflammation

Introduction

Colorectal cancer (CRC) is the third most common malignancy and the second leading cause of death worldwide. Efficient non-invasive blood-based biomarkers for CRC early detection and prognosis are urgently needed.

Methods

To identify novel potential plasma biomarkers, we applied a proximity extension assay (PEA), an antibody-based proteomics strategy to quantify the abundance of plasma proteins in CRC development and cancer-associated inflammation from few μL of plasma sample.

Results

Among the 690 quantified proteins, levels of 202 plasma proteins were significantly changed in CRC patients compared to age-and-sex-matched healthy subjects. We identified novel protein changes involved in Th17 activity, oncogenic pathways, and cancer-related inflammation with potential implications in the CRC diagnosis. Moreover, the interferon γ (IFNG), interleukin (IL) 32, and IL17C were identified as associated with the early stages of CRC, whereas lysophosphatidic acid phosphatase type 6 (ACP6), Fms-related tyrosine kinase 4 (FLT4), and MANSC domain-containing protein 1 (MANSC1) were correlated with the late-stages of CRC.

Discussion

Further study to characterize the newly identified plasma protein changes from larger cohorts will facilitate the identification of potential novel diagnostic, prognostic biomarkers for CRC.

Type I and II interferon signaling in colorectal cancer liver metastasis

Metastatic colorectal cancer is one of the leading causes of cancer-related deaths worldwide. Traditional chemotherapy extended the lifespan of cancer patients by only a few months, but targeted therapies and immunotherapy prolonged survival and led to long-term remissions in some cases. Type I and II interferons have direct pro-apoptotic and anti-proliferative effects on cancer cells and stimulate anti-cancer immunity. As a result, interferon production by cells in the tumor microenvironment is in the spotlight of immunotherapies as it affects the responses of anti-cancer immune cells. However, promoting effects of interferons on colorectal cancer metastasis have also been reported. Here we summarize our knowledge about pro- and anti-metastatic effects of type I and II interferons in colorectal cancer liver metastasis and discuss possible therapeutic implications.

PARs in the inflammation-cancer transformation of CRC

Colorectal cancer (CRC) is one of the common malignancies with a global trend of increasing incidence and mortality. There is an urgent need to identify new predictive markers and therapeutic targets for the treatment of CRC. Protease-activated receptors (PARs) are a class of G-protein-coupled receptors, with currently identified subtypes including PAR1, PAR2, PAR3 and PAR4. Increasingly, studies suggest that PARs play an important role in the growth and metastasis of CRC. By targeting multiple signaling pathways may contribute to the pathogenesis of CRC. In this review, we first describe recent studies on the role of PARs in CRC inflammation-cancer transformation, focusing on the important role of PARs in signaling pathways associated with inflammation-cancer transformation, and summarize the progress of research on PARs-targeted drugs.

Exercise-induced changes to the human gut microbiota and implications for colorectal cancer: a narrative review

Physical activity is associated with reduced risks of colorectal cancer (CRC) incidence, recurrence and mortality. While these findings are consistent, the mechanism/s underlying this association remain unclear. Growing evidence supports the many ways in which differing characteristics of the gut microbiota can be tumourigenic or protective against CRC. CRC is characterised by significant dysbiosis including reduced short chain fatty acid-producing bacteria. Recent findings suggest that exercise can modify the gut microbiota, and these changes are inverse to the changes seen with CRC; however, this exercise-microbiota interaction is currently understudied in CRC. This review summarises parallel areas of research that are rapidly developing: The exercise-gut microbiota research and cancer-gut microbiota research and highlights the salient similarities. Preliminary evidence suggests that these areas are linked, with exercise mediating changes that promote the antitumorigenic characteristics of the gut microbiota. Future mechanistic and population-specific studies are warranted to confirm the physiological mechanism/s by which exercise changes the gut microbiota, and the influence of the exercise-gut interaction on cancer specific outcomes in CRC.

The Study of the Extracellular Matrix in Chronic Inflammation: A Way to Prevent Cancer Initiation?

Bidirectional communication between cells and their microenvironment has a key function in normal tissue homeostasis, and in disease initiation, progression and a patient's prognosis, at the very least. The extracellular matrix (ECM), as an element of all tissues and cellular microenvironment, is a frequently overlooked component implicated in the pathogenesis and progression of several diseases. In the inflammatory microenvironment (IME), different alterations resulting from remodeling processes can affect ECM, progressively inducing cancer initiation and the passage toward a tumor microenvironment (TME). Indeed, it has been demonstrated that altered ECM components interact with a variety of surface receptors triggering intracellular signaling that affect cellular pathways in turn. This review aims to support the notion that the ECM and its alterations actively participate in the promotion of chronic inflammation and cancer initiation. In conclusion, some data obtained in cancer research with the employment of decellularized ECM (dECM) models are described. The reported results encourage the application of dECM models to investigate the short circuits contributing to the creation of distinct IME, thus representing a potential tool to avoid the progression toward a malignant lesion.

How the Tumor Micromilieu Modulates the Recruitment and Activation of Colorectal Cancer-Infiltrating Lymphocytes

The successful treatment of advanced colorectal cancer disease still represents an insufficiently solved clinical challenge, which is further complicated by the fact that the majority of malignant colon tumors show only relatively low immunogenicity and therefore have only limited responsiveness to immunotherapeutic approaches, such as, for instance, the use of checkpoint inhibitors. As it has been well established over the past two decades that the local tumor microenvironment and, in particular, the quantity, quality, and activation status of intratumoral immune cells critically influence the clinical prognosis of patients diagnosed with colorectal cancer and their individual benefits from immunotherapy, the enhancement of the intratumoral accumulation of cytolytic effector T lymphocytes and other cellular mediators of the antitumor immune response has emerged as a targeted objective. For the future identification and clinical validation of novel therapeutic target structures, it will thus be essential to further decipher the molecular mechanisms and cellular interactions in the intestinal tumor microenvironment, which are crucially involved in immune cell recruitment and activation. In this context, our review article aims at providing an overview of the key chemokines and cytokines whose presence in the tumor micromilieu relevantly modulates the numeric composition and antitumor capacity of tumor-infiltrating lymphocytes.

Chang qing formula ameliorates colitis-associated colorectal cancer via suppressing IL-17/NF-κB/STAT3 pathway in mice as revealed by network pharmacology study

Colitis-associated colorectal cancer (CAC) is a specific type of colorectal cancer (CRC) with high mortality and morbidity, the chronic inflammation in the intestinal mucosal is the characteristic of CAC. Chang Qing formula (CQF) is a Chinese herbal formula used clinically for the treatment of CAC with remarkable clinical efficacy, but its mechanism remains unclear. In the present work, Combined network pharmacology and transcriptomics were used to analyze the potential active ingredients and elucidate molecular mechanism of CQF in treating CAC. Firstly, the constituents migrating to blood of CQF were analyzed and identified by UPLC-Q-TOF-MS/MS, and core genes and pathways were screened by network pharmacology analysis. Encyclopedia of Genes and Genomes (KEGG) analysis showed that the IL-17 signaling pathway involved in CAC may be closely associated with the potential mechanismof action of CQF. Subsequently, the results from animal studies indicated that CQF profoundly reduced tumor numbers and tumor size in AOM/DSS mice. The RNA-seq data was analysed utilizing Ingenuity Pathway Analysis (IPA), and the results supported the idea that CQF exerts a tumour-suppressive effect via the IL-17 signalling pathway. Further studies demonstrated that CQF significantly reduced IL-17A levels, which in turn inhibited NF-κB/IL-6/STAT3 signaling cascade, suppressed MMP9 expression and promoted tumor cell apoptosis. In conclusion, the current study demonstrated that CQF remarkably improved inflammatory tumor microenvironment, and hindered the transformation of inflammation into cancer. These findings may help to design future strategies for the treatment of CAC.

Cytokine- and chemokine-induced inflammatory colorectal tumor microenvironment: Emerging avenue for targeted therapy

Colorectal cancer (CRC) is a predominant life-threatening cancer, with liver and peritoneal metastases as the primary causes of death. Intestinal inflammation, a known CRC risk factor, nurtures a local inflammatory environment enriched with tumor cells, endothelial cells, immune cells, cancer-associated fibroblasts, immunosuppressive cells, and secretory growth factors. The complex interactions of aberrantly expressed cytokines, chemokines, growth factors, and matrix-remodeling enzymes promote CRC pathogenesis and evoke systemic responses that affect disease outcomes. Mounting evidence suggests that these cytokines and chemokines play a role in the progression of CRC through immunosuppression and modulation of the tumor microenvironment, which is partly achieved by the recruitment of immunosuppressive cells. These cells impart features such as cancer stem cell-like properties, drug resistance, invasion, and formation of the premetastatic niche in distant organs, promoting metastasis and aggressive CRC growth. A deeper understanding of the cytokine- and chemokine-mediated signaling networks that link tumor progression and metastasis will provide insights into the mechanistic details of disease aggressiveness and facilitate the development of novel therapeutics for CRC. Here, we summarized the current knowledge of cytokine- and chemokine-mediated crosstalk in the inflammatory tumor microenvironment, which drives immunosuppression, resistance to therapeutics, and metastasis during CRC progression. We also outlined the potential of this crosstalk as a novel therapeutic target for CRC. The major cytokine/chemokine pathways involved in cancer immunotherapy are also discussed in this review.

Interaction between microbiota and immunity and its implication in colorectal cancer

Colorectal cancer (CRC) is one of the leading causes of cancer-related death in the world. Besides genetic causes, colonic inflammation is one of the major risk factors for CRC development, which is synergistically regulated by multiple components, including innate and adaptive immune cells, cytokine signaling, and microbiota. The complex interaction between CRC and the gut microbiome has emerged as an important area of current CRC research. Metagenomic profiling has identified a number of prominent CRC-associated bacteria that are enriched in CRC patients, linking the microbiota composition to colitis and cancer development. Some microbiota species have been reported to promote colitis and CRC development in preclinical models, while a few others are identified as immune modulators to induce potent protective immunity against colitis and CRC. Mechanistically, microbiota regulates the activation of different immune cell populations, inflammation, and CRC via crosstalk between innate and adaptive immune signaling pathways, including nuclear factor kappa B (NF-κB), type I interferon, and inflammasome. In this review, we provide an overview of the potential interactions between gut microbiota and host immunity and how their crosstalk could synergistically regulate inflammation and CRC, thus highlighting the potential roles and mechanisms of gut microbiota in the development of microbiota-based therapies to prevent or alleviate colitis and CRC.

Targeting interleukin-17 enhances tumor response to immune checkpoint inhibitors in colorectal cancer

Although immune checkpoint inhibitors (ICIs) have gained much attention in managing cancer, only a minority of patients, especially those with tumors that have been classified as immunologically "cold" such as microsatellite stable (MSS) colorectal cancers (CRC), experience clinical benefit from ICIs. Surprisingly, interleukin-17 (IL-17) and its primary source Th17 are enriched in CRC and inversely associated with patient outcome. Our previous study revealed that IL-17A could upregulate programmed death-ligand 1 (PD-L1) expression and impede the efficacy of immunotherapy. IL-17, therefore, can be a possible target to sensitize tumor cells to ICIs. The detailed clinical results from our trial, which is the first to show the benefits of the combination of anti-PD-1 with anti-IL-17 therapy for MSS CRC, have also been presented. In this review, we highlight the role of IL-17 in ICIs resistance and summarize the current clinical evidence for the use of combination therapy. Directions for future strategies to warm up immunologically "cold" MSS CRCs have also been proposed.

Bulk and single-cell transcriptome profiling reveal necroptosis-based molecular classification, tumor microenvironment infiltration characterization, and prognosis prediction in colorectal cancer

Background

Necroptosis is a new form of programmed cell death that is associated with cancer initiation, progression, immunity, and chemoresistance. However, the roles of necroptosis-related genes (NRGs) in colorectal cancer (CRC) have not been explored comprehensively.

Methods

In this study, we obtained NRGs and performed consensus molecular subtyping by “ConsensusClusterPlus” to determine necroptosis-related subtypes in CRC bulk transcriptomic data. The ssGSEA and CIBERSORT algorithms were used to evaluate the relative infiltration levels of different cell types in the tumor microenvironment (TME). Single-cell transcriptomic analysis was performed to confirm classification related to NRGs. NRG_score was developed to predict patients’ survival outcomes with low-throughput validation in a patients’ cohort from Fudan University Shanghai Cancer Center.

Results

We identified three distinct necroptosis-related classifications (NRCs) with discrepant clinical outcomes and biological functions. Characterization of TME revealed that there were two stable necroptosis-related phenotypes in CRC: a phenotype characterized by few TME cells infiltration but with EMT/TGF-pathways activation, and another phenotype recognized as immune-excluded. NRG_score for predicting survival outcomes was established and its predictive capability was verified. In addition, we found NRCs and NRG_score could be used for patient or drug selection when considering immunotherapy and chemotherapy.

Conclusions

Based on comprehensive analysis, we revealed the potential roles of NRGs in the TME, and their correlations with clinicopathological parameters and patients’ prognosis in CRC. These findings could enhance our understanding of the biological functions of necroptosis, which thus may aid in prognosis prediction, drug selection, and therapeutics development.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12967-022-03431-6.

Inflammatory bowel disease and carcinogenesis

Colorectal cancer (CRC) is the third most common cancer and the fourth most common cause of cancer mortality worldwide. Colitis-associated colorectal cancer (CAC) is a subtype of CRC associated with inflammatory bowel disease (IBD). It is well known that individuals with IBD have a 2-3 times higher risk of developing CRC than those who do not, rendering CAC a major cause of death in this group. Although the etiology and pathogenesis of CAC are incompletely understood, animal models of chronic inflammation and human cohort data indicate that changes in the intestinal environment, including host response dysregulation and gut microbiota perturbations, may contribute to the development of CAC. Genomic alterations are a hallmark of CAC, with patterns that are distinct from those in sporadic CRC. The discovery of the biological changes that underlie the development of CAC is ongoing; however, current data suggest that chronic inflammation in IBD increases the risk of developing CAC. Therefore, a deeper understanding of the precise mechanisms by which inflammation triggers genetic alterations and disrupts intestinal homeostasis may provide insight into novel therapeutic strategies for the prevention of CAC.

The Regulatory Role of Neuropeptide Gene Glucagon in Colorectal Cancer: A Comprehensive Bioinformatic Analysis

Background

Colorectal cancer is highly prevalent and causes high global mortality, and glucagon axis has been implicated in colon cancer. The present study is aimed at investigating the regulating mechanisms of glucagon involvement in colorectal cancer.

Methods

Publicly available data from the TCGA database was utilized to explore the expression pattern and regulating role of glucagon (GCG) in colorectal cancer (COADREAD) including colon adenocarcinomas (COAD) and rectum adenocarcinomas (READ). Statistical analyses were performed using the R software packages and public web servers. The expression pattern and prognostic significance of GCG gene in pan-cancer and TCGA-COADREAD data were investigated by performing unpaired and paired sample analyses. The association of GCG expression with clinical characteristics was investigated using logistic regression analysis. Univariate cox regression analysis was performed to test the prognostic value of GCG expression for overall survival in COADREAD patients. GCG-significantly correlated genes were obtained. Biological functions and signaling pathways were identified by performing functional enrichment analysis and Gene Set Enrichment Analysis (GSEA). Additionally, the potential involvement of GCG in tumor immunity was researched by investigating the correlation between GCG expression and 24 tumor infiltrating immune cells.

Results

GCG was found to be significantly downregulated in COADREAD tumor samples compared with healthy control samples. GCG gene was shown to be associated with the prognostic outcomes of COADREAD, whereby its upregulation predicted improved survival outcomes. Functional enrichment analysis showed that the top 100 positively and top 100 negatively GCG-correlated genes were mainly enriched in three signaling pathways including ribosome, nitrogen metabolism, and proximal tubule bicarbonate reclamation. The GSEA showed that GCG-significantly correlated genes were mainly enriched in cell cycle-related pathways (reactome cell cycle, reactome cell cycle mitotic, reactome cell cycle checkpoints, reactome M phase, Reactome G2 M DNA damage checkpoint, and Reactome G2 M checkpoints), neuropeptide ligand receptor interaction, RHO GTPases signaling, WNT signaling, RUNX1 signaling, NOTCH signaling, ESR signaling, HCMV infection, and oxidative stress-related signaling. GCG was positively correlated with Th17 cells, pDC, macrophages, TFH cells, iDC, Tem, B cells, dendritic cells, neutrophils, mast cells, and eosinophils and was negatively associated with NK cells.

Conclusions

GCG dysregulation with high prognostic value in COADREAD was noted. Several tumor progression-related pathways and tumor immune-modulatory cells were linked to GCG expression in COADREAD. Therefore, GCG may be regarded as a potential therapeutic target for treating colorectal cancer.

Clinical and molecular assessment of an onco-immune signature with prognostic significance in patients with colorectal cancer

Understanding the complex tumor microenvironment is key to the development of personalized therapies for the treatment of cancer including colorectal cancer (CRC). In the past decade, significant advances in the field of immunotherapy have changed the paradigm of cancer treatment. Despite significant improvements, tumor heterogeneity and lack of appropriate classification tools for CRC have prevented accurate risk stratification and identification of a wider patient population that may potentially benefit from targeted therapies. To identify novel signatures for accurate prognostication of CRC, we quantified gene expression of 12 immune‐related genes using a medium‐throughput NanoString quantification platform in 93 CRC patients. Multivariate prognostic analysis identified a combined four‐gene prognostic signature (TGFB1, PTK2, RORC, and SOCS1) (HR: 1.76, 95% CI: 1.05–2.95, *p < 0.02). The survival trend was captured in an independent gene expression data set: GSE17536 (177 patients; HR: 3.31, 95% CI: 1.99–5.55, *p < 0.01) and GSE14333 (226 patients; HR: 2.47, 95% CI: 1.35–4.53, *p < 0.01). Further, gene set enrichment analysis of the TCGA data set associated higher prognostic scores with epithelial–mesenchymal transition (EMT) and inflammatory pathways. Comparatively, a lower prognostic score was correlated with oxidative phosphorylation and MYC and E2F targets. Analysis of immune parameters identified infiltration of T‐reg cells, CD8⁺ T cells, M2 macrophages, and B cells in high‐risk patient groups along with upregulation of immune exhaustion genes. This molecular study has identified a novel prognostic gene signature with clinical utility in CRC. Therefore, along with prognostic features, characterization of immune cell infiltrates and immunosuppression provides actionable information that should be considered while employing personalized medicine.

A Novel Multi-Mode Thermal Therapy for Colorectal Cancer Liver Metastasis: A Pilot Study

A novel multi-mode thermal therapy was developed for local tumor ablation and the systemic stimulation of anti-tumor immunity, consisting of a rapid liquid nitrogen freezing, and followed by the radiofrequency heating of target tumor tissue. This pilot study aimed to compare the therapeutic effects of the new therapy with conventional radiofrequency ablation (RFA) on patients with colorectal cancer liver metastasis (CRCLM). From August 2016 to September 2019, thirty-one patients with CRCLM received either multi-mode thermal therapy (n = 17) or RFA (n = 14). Triphasic contrast-enhanced magnetic resonance imaging (MRI), routine blood tests, and peripheral blood immune responses were evaluated before the treatment and in 1, 3, 6, and 12 months after. Local tumor response and progression-free survival (PFS) were assessed using the Kaplan-Meier method, and pre- and post-treatment immune cell counts were analyzed using Mann-Whitney U and Wilcoxon tests. A significantly longer PFS was observed in the multi-mode thermal therapy group in comparison to that of the conventional RFA group (median, 11.4 versus 3.4 months, p = 0.022). It was found that multi-mode therapy induced the functional maturation of dendritic cells, promoted CD4⁺ T cell-mediated antitumor responses, and decreased regulatory T cells, contributing to better therapeutic efficacy in CRCLM patients.

Keep a Little Fire Burning-The Delicate Balance of Targeting Sphingosine-1-Phosphate in Cancer Immunity

The sphingolipid sphingosine-1-phosphate (S1P) promotes tumor development through a variety of mechanisms including promoting proliferation, survival, and migration of cancer cells. Moreover, S1P emerged as an important regulator of tumor microenvironmental cell function by modulating, among other mechanisms, tumor angiogenesis. Therefore, S1P was proposed as a target for anti-tumor therapy. The clinical success of current cancer immunotherapy suggests that future anti-tumor therapy needs to consider its impact on the tumor-associated immune system. Hereby, S1P may have divergent effects. On the one hand, S1P gradients control leukocyte trafficking throughout the body, which is clinically exploited to suppress auto-immune reactions. On the other hand, S1P promotes pro-tumor activation of a diverse range of immune cells. In this review, we summarize the current literature describing the role of S1P in tumor-associated immunity, and we discuss strategies for how to target S1P for anti-tumor therapy without causing immune paralysis.

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

Simple Summary

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

Abstract

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

The Role of Kallikrein 7 in Tumorigenesis

Kallikrein 7 (KLK7) is a secreted serine protease with chymotrypsic protease activity. Abnormally high expression of KLK7 is closely related to the occurrence and development of various types of cancer. Therefore, KLK7 has been identified as a potential target for cancer drug development design in recent years. KLK7 mediates various biological and pathological processes in tumorigenesis, including cell proliferation, migration, invasion, angiogenesis, and cell metabolism, by hydrolyzing a series of substrates such as membrane proteins, extracellular matrix proteins, and cytokines. This review mainly introduces the downstream cell signaling pathways involved in the activation of KLK7 and its substrate-related proteins. This review will not only help us to better understand the mechanisms of KLK7 in regulating biological and pathological processes of cancer cells, but also lay a solid foundation for the design of inhibitors targeting KLK7.

Role of microbial dysbiosis in carcinogenesis & cancer therapies

The human body supports a heterogeneous population of microorganisms. Every microorganism has the ability to contribute to the unique microenvironment around it. The aim of this review is to discuss the changes in the microbial population and their relative abundance across different ecosystems of the human body, the interactions within the microbial communities, metabolites they secrete to their external environment, their immunomodulatory functions, their signal transduction pathways and how these respond to environmental stimuli such as various diets, alcohol and drug consumption, smoking and finally suggest new therapeutic approaches. The microbiota may leads to cancer through inflammation mediated mechanisms which modulate immune responses, or produce carcinogenic metabolites and genotoxins, or deregulate cell proliferative signalling pathways. The identification of these molecular mechanisms in carcinogenesis may lead to better treatment strategies. In this review we have tried to explore the changes in microbial composition between cancer and normal tissues and what molecular mechanisms provide a connecting link between microbial dysbiosis and cancer.

Cell-based immunotherapy approaches for colorectal cancer: main achievements and challenges

Immunotherapy is becoming as a major treatment modality for multiple types of solid tumors, including subsets of colorectal cancers (CRCs). The successes with immunotherapy alone has largely been achieved in patients with advanced-stage mismatch-repair-deficient and microsatellite instability-high (dMMR-MSI-H) CRCs. However, the benefits of immunotherapy have not been demonstrated to be effective in patients with proficient mismatch repair (pMMR) CRC, who are microsatellite-stable (MSS) or have low levels of microsatellite instability (MSI-L). Here, we provide a comprehensive review on the immune microenvironment of CRC tumors and describe the rapid pace of scientific changes. We discuss the tremendous promise of cell-based immunotherapy strategies that are under preclinical studies/clinical trials or being used in therapeutic paradigms.

Dynamic stromal cellular reaction throughout human colorectal adenoma-carcinoma sequence: A role of TH17/IL-17A

BACKGROUND

Accumulating data suggest that the tumour stroma rapidly undergoes dynamic mechanical and cellular changes by which creates a supportive milieu to promote disease progression and metastasis. Cytokines are reported to play a key role in the modulation of tumour stromal response.

METHODS

The activation of TH17/interleukin (IL)-17A network in association with tumour stromal proliferative and cellular response in samples from 50 patients with colorectal adenoma, 45 with colorectal cancer (CRCs) were elucidated with quantitative real-time PCR (q-PCR), immunohistochemistry and double immunofluorescence.

RESULTS

q-PCR results showed that retinoic acid-receptor-related orphan receptor-C, a critical transcriptional factor for TH17 cell differentiation, was significantly increased at the adenoma stage and slightly decreased at the CRC stage, but was still higher than that at normal controls. The level of TH17 signature cytokine IL-17A was shown in an increasing gradient throughout the adenoma-carcinoma sequence. Immunohistochemistry revealed an activated proliferative rate evaluated by Ki67 and population expansion of myofibroblasts in the adenoma/CRC stroma. Notably, densities of IL-17A-expressing cells were associated with populations of Ki67-positive cells and myofibroblasts in the adenoma/CRC stroma. Finally, CD146-positive stromal cells are an important participator for stroma remodelling, double immunofluorescence image demonstrated that IL-17 receptor C, one of the key elements for IL-17 receptor complex, was highly expressed in CD146-positive adenoma/CRC stromal cells.

CONCLUSIONS

An activated TH17/IL-17A network in the tumour microenvironment is significantly associated with dynamic stromal cellular response throughout the adenoma-carcinoma sequence, which might provide a supportive environment for the initiation and progression of CRC.

Genetic variations in the CTLA-4 immune checkpoint pathway are associated with colon cancer risk, prognosis, and immune infiltration via regulation of IQCB1 expression

The programmed cell death-1 (PD-1)/cytotoxic T lymphocyte-associated antigen 4 (CTLA-4) immune checkpoint pathways serve as targets of immunotherapy for colorectal cancer. However, the associations between genetic variations in these pathways and colorectal cancer risk, prognosis, and immune status remain unclear. The associations between single-nucleotide polymorphisms (SNPs) and colorectal cancer risk and survival were evaluated in a case-control study comprising 1150 cases and 1342 controls along with 287 cases with overall survival information. We found that individuals with the A allele of B7-2 rs2681416 in CTLA-4 immune checkpoint pathway had a significantly increased risk of colorectal cancer [odds ratio (OR) = 1.37, P = 3.17 × 10^-4] than those with G allele under the dominant model, which had a predominant site-specific effect in colon cancer (OR = 1.55, P = 3.11 × 10^-5). In addition, rs2681416 significantly decreased the overall survival time of patients with colon cancer [hazard ratio (HR) = 1.96, P = 1.10 × 10^-2], but not of patients with rectal cancer (P = 0.271). Moreover, rs2681416 had an expression quantitative trait locus effect on the B7-2 flanking gene IQCB1 in colon tissues, which contributed to colon cancer risk by regulating genome organization and influenced the expression of IQCB1 in an allele-specific manner. IQCB1 expression was upregulated in colorectal cancer tissues compared with normal tissues, accounting for various critical carcinogenic states in colon cancer and promoting immune infiltration of Th17 cells in the tumor microenvironment. Our study highlights the important roles of genetic variations in immune checkpoint pathways and provides new insight into potential site-specific independent biomarkers for colorectal cancer susceptibility, prognosis, and tumor immune status.

Role of Notch, IL-1 and leptin expression in colorectal cancer

An increasing number of studies have shown that angiogenesis has an important role in the progression of cancer. The growth of a new network of blood vessels is crucial for tumor growth and metastasis, which is promoted by several proangiogenic factors. Leptin, an essential adipokine that is secreted from fat tissue, is one of these pro-angiogenic factors. It has been shown that the inhibition of leptin-induced angiogenesis resulted in decreased levels of vascular endothelial growth factor (VEGF)/VEGFR2, hypoxia inducible factor (HIF) 1α, NF-κB, IL-1 and Notch and reduced the tumor growth in breast cancer. Leptin induces angiogenesis in breast cancer either by upregulating VEGFR2 in endothelial cells or by increasing VEGF/VEGFR2 expression through the Notch, IL-1 and leptin crosstalk outcome (NILCO) pathway. NILCO is a novel mechanism that interacts with proinflammatory and proangiogenic signals, which are critical for cell proliferation and angiogenesis in cancer. Several studies have shown that components of NILCO may affect human cancer incidence and progression. However, to the best of our knowledge, the interactions between Notch, IL-1 and leptin in human colorectal cancer have not been yet studied at the molecular level. The aim of the present study was to investigate the expression levels of genes related to the NILCO pathway in human colorectal cancer specimens. The current results demonstrated that leptin, leptin receptor (ObR) b, Notch-1, Notch-4, IL-1α, IL-1β, IL-1R, IL-6, JAK-2, STAT-1, STAT-3, VEGFA, VEGFR1, VEGFR2, TNF-α and NF-κB mRNA expression levels in the cancer tissue were increased compared with the normal tissue. No significant changes in the mRNA expression levels of Jagged-1, HIF-1α and TNF receptor 1 were observed. Western blotting revealed that the protein expression levels of IκB were increased in the cancer tissue compared with normal tissue, whereas HIF-1α and phosphorylated STAT-1 levels were decreased. IL-6 and VEGFA plasma concentrations were statistically raised and the leptin plasma concentration was also raised, although significantly, patients with cancer compared with control individuals. Together, the present findings indicated that Notch, IL-1 and leptin may serve a crucial role in the development of colorectal cancer.

Transcriptome of Tumor-Infiltrating T Cells in Colorectal Cancer Patients Uncovered a Unique Gene Signature in CD4+ T Cells Associated with Poor Disease-Specific Survival

Colorectal cancer (CRC) is influenced by infiltration of immune cell populations in the tumor microenvironment. While elevated levels of cytotoxic T cells are associated with improved prognosis, limited studies have reported associations between CD4⁺ T cells and disease outcomes. We recently performed transcriptomic profiling and comparative analyses of sorted CD4⁺ and CD8⁺ tumor-infiltrating lymphocytes (TILs) from bulk tumors of CRC patients with varying disease stages. In this study, we compared the transcriptomes of CD4⁺ with CD8⁺ TILs. Functional annotation pathway analyses revealed the downregulation of inflammatory response-related genes, while T cell activation and angiogenesis-related genes were upregulated in CD4⁺ TILs. The top 200 deregulated genes in CD4⁺ TILs were aligned with the cancer genome atlas (TCGA) CRC dataset to identify a unique gene signature associated with poor prognosis. Moreover, 69 upregulated and 20 downregulated genes showed similar trends of up/downregulation in the TCGA dataset and were used to calculate "poor prognosis score" (ppScore), which was significantly associated with disease-specific survival. High ppScore patients showed lower expression of Treg-, Th1-, and Th17-related genes, and higher expression of Th2-related genes. Our data highlight the significance of T cells within the TME and identify a unique candidate prognostic gene signature for CD4⁺ TILs in CRC patients.

MAIT Cells: Partners or Enemies in Cancer Immunotherapy?

Simple Summary

Unconventional T cells have recently come under intense scrutiny because of their innate-like effector functions and unique antigen specificity, suggesting their potential importance in antitumor immunity. MAIT cells, one such population of unconventional T cell, have been shown to significantly influence bacterial infections, parasitic and fungal infections, viral infections, autoimmune and other inflammatory diseases, and, as discussed thoroughly in this review, various cancers. This review aims to merge accumulating evidence, tease apart the complexities of MAIT cell biology in different malignancies, and discuss how these may impact clinical outcomes. While it is clear that MAIT cells can impact the tumor microenvironment, the nature of these interactions varies depending on the type of cancer, subset of MAIT cell, patient demographic, microbiome composition, and the type of therapy administered. This review examines the impact of these variables on MAIT cells and discusses outstanding questions within the field.

Abstract

A recent boom in mucosal-associated invariant T (MAIT) cell research has identified relationships between MAIT cell abundance, function, and clinical outcomes in various malignancies. As they express a variety of immune checkpoint receptors and ligands, and possess strong cytotoxic functions, MAIT cells are an attractive new subject in the field of tumor immunology. MAIT cells are a class of innate-like T cells that express a semi-invariant T cell antigen receptor (TCR) that recognizes microbially derived non-peptide antigens presented by the non-polymorphic MHC class-1 like molecule, MR1. In this review, we outline the current (and often contradictory) evidence exploring MAIT cell biology and how MAIT cells impact clinical outcomes in different human cancers, as well as what role they may have in cancer immunotherapy.

The Protein Secretome Is Altered in Rectal Cancer Tissue Compared to Normal Rectal Tissue, and Alterations in the Secretome Induce Enhanced Innate Immune Responses

Simple Summary

Rectal cancer occurs in the lower part of the bowel, and approximately half of all rectal cancer patients receive chemoradiotherapy before surgery. In ~22% of cases the tumour is eradicated, but the reasons for different response rates between patients are largely unknown. Inflammation and the immune system are important players in the response to cancer treatment, but we do not fully understand the role they play in this clinical setting. We examined the levels of 54 inflammatory markers in normal (non-cancerous) rectal tissue and rectal cancer tissue, and we found that rectal cancer tissue was more inflammatory, and the levels of inflammatory markers correlated with obesity status. We found that irradiating rectal cancer tissue enhanced the ability of immune cells to induce an anti-tumour immune response.

Abstract

Locally advanced rectal cancer is treated with neoadjuvant-chemoradiotherapy; however, only ~22% of patients achieve a complete response, and resistance mechanisms are poorly understood. The role of inflammation and immune cell biology in this setting is under-investigated. In this study, we profiled the inflammatory protein secretome of normal (non-cancer) (n = 8) and malignant rectal tissue (n = 12) pre- and post-radiation in human ex vivo explant models and examined the influence of these untreated and treated secretomes on dendritic cell biology (n = 8 for cancer and normal). These resultant profiles were correlated with patient clinical characteristics. Nineteen factors were secreted at significantly higher levels from the rectal cancer secretome when compared to the normal rectal secretome; Flt-1, P1GF, IFN-γ, IL-6, IL-10, CCL20, CCL26, CCL22, CCL3, CCL4, CCL17, GM-CSF, IL-12/IL-23p40, IL-17A, IL-1α, IL-17A/F, IL-1RA, TSLP and CXCL10 (p < 0.05). Radiation was found to have differential effects on normal rectal tissue and rectal cancer tissue with increased IL-15 and CCL22 secretion following radiation from normal rectal tissue explants (p < 0.05), while no significant alterations were observed in the irradiated rectal cancer tissue. Interestingly, however, the irradiated rectal cancer secretome induced the most potent effect on dendritic cell maturation via upregulation of CD80 and PD-L1. Patient’s visceral fat area correlated with secreted factors including CCL20, suggesting that obesity status may alter the tumour microenvironment (TME). These results suggest that radiation does not have a negative effect on the ability of the rectal cancer TME to induce an immune response. Understanding these responses may unveil potential therapeutic targets to enhance radiation response and mitigate normal tissue injury. Tumour irradiation in this cohort enhances innate immune responses, which may be harnessed to improve patient treatment outcome.

The role of Th17 cells in viral infections

The present review provides an overview of recent advances regarding the function of Th17 cells and their produced cytokines in the progression of viral diseases. Viral infections alone do not lead to virus-induced malignancies, as both genetic and host safety factors are also involved in the occurrence of malignancies. Acquired immune responses, through the differentiation of Th17 cells, form the novel components of the Th17 cell pathway when reacting with viral infections all the way from the beginning to its final stages. As a result, instead of inducing the right immune responses, these events lead to the suppression of the immune system. In fact, the responses from Th17 cells during persistent viral infections causes chronic inflammation through the production of IL-17 and other cytokines which provide a favorable environment for tumor growth and its development. Additionally, during the past decade, these cells have been understood to be involved in tumor progression and metastasis. However, further research is required to understand Th17 cells' immune mechanisms in the vast variety of viral diseases. This review aims to determine the roles and effects of the immune system, especially Th17 cells, in the progression of viral diseases; which can be highly beneficial for the diagnosis and treatment of these infections.

Infiltration by IL22-Producing T Cells Promotes Neutrophil Recruitment and Predicts Favorable Clinical Outcome in Human Colorectal Cancer

Immune cell infiltration in colorectal cancer effectively predicts clinical outcome. IL22, produced by immune cells, plays an important role in inflammatory bowel disease, but its relevance in colorectal cancer remains unclear. Here, we addressed the prognostic significance of IL22+ cell infiltration in colorectal cancer and its effects on the composition of tumor microenvironment. Tissue microarrays (TMA) were stained with an IL22-specific mAb, and positive immune cells were counted by expert pathologists. Results were correlated with clinicopathologic data and overall survival (OS). Phenotypes of IL22-producing cells were assessed by flow cytometry on cell suspensions from digested specimens. Chemokine production was evaluated in vitro upon colorectal cancer cell exposure to IL22, and culture supernatants were used to assess neutrophil migration in vitro Evaluation of a testing (n = 425) and a validation TMA (n = 89) revealed that high numbers of IL22 tumor-infiltrating immune cells were associated with improved OS in colorectal cancer. Ex vivo analysis indicated that IL22 was produced by CD4+ and CD8+ polyfunctional T cells, which also produced IL17 and IFNγ. Exposure of colorectal cancer cells to IL22 promoted the release of the neutrophil-recruiting chemokines CXCL1, CXCL2, and CXCL3 and enhanced neutrophil migration in vitro Combined survival analysis revealed that the favorable prognostic significance of IL22 in colorectal cancer relied on the presence of neutrophils and was enhanced by T-cell infiltration. Altogether, colorectal cancer-infiltrating IL22-producing T cells promoted a favorable clinical outcome by recruiting beneficial neutrophils capable of enhancing T-cell responses.

Differential gene expression of tumor-infiltrating CD4+ T cells in advanced versus early stage colorectal cancer and identification of a gene signature of poor prognosis

Tumor-infiltrating lymphocytes (TILs) play indispensable roles in the progression and response to treatment of solid tumors. However, the prognostic significance of CD4⁺ TILs is not fully disclosed in cancers generally and in CRC in particular, mainly due to the existence of different functional subsets of CD4⁺ T cells. We performed transcriptomic profiling of CD4⁺ TILs isolated from CRC patients in order to identify differentially expressed genes and their functional pathways in early versus advanced disease stages. We found that in advanced stages, genes related to immune and inflammatory responses, in particular Th1-mediated immune response and cytotoxicity-mediated genes, were downregulated; while epigenetic-mediated silencing genes were upregulated. Interestingly, we identified genes, which were steadily upregulated or downregulated in CD4⁺ TILs with CRC progression from stage I to IV. Additionally, of the top 200 deregulated genes, 43 upregulated and 64 downregulated genes showed similar deregulation trends in the cancer genome atlas CRC dataset. From these 97 deregulated genes, we identified a “poor prognosis CD4 gene signature (ppCD4sig)”. Patients with high ppCD4sig score showed shorter disease-specific survival (DSS) and progression-free interval (PFI). The ppCD4sig was an independent prognostic indicator for DSS (HR = 1.73, 95% CI 1.32–2.27, P = 0.0001) and PFI (HR = 1.75, 95% CI 1.3–2.35, P = 0.0016). Additionally, patients at advanced stages and at a younger age (<55 years) were more likely to have a high ppCD4sig score. Altogether, our data provide novel insights and a unique prognostic gene signature of CD4⁺ TILs in the CRC microenvironment.

The Wnt-β-Catenin-IL-10 Signaling Axis in Intestinal APCs Protects Mice from Colitis-Associated Colon Cancer in Response to Gut Microbiota

Loss of immune tolerance to gut microflora is inextricably linked to chronic intestinal inflammation and colitis-associated colorectal cancer (CAC). The LRP5/6 signaling cascade in APCs contributes to immune homeostasis in the gut, but whether this pathway in APCs protects against CAC is not known. In the current study, using a mouse model of CAC, we show that the LRP5/6-β-catenin-IL-10 signaling axis in intestinal CD11c⁺ APCs protects mice from CAC by regulating the expression of tumor-promoting inflammatory factors in response to commensal flora. Genetic deletion of LRP5/6 in CD11c⁺ APCs in mice (LRP5/6^ΔCD11c) resulted in enhanced susceptibility to CAC. This is due to a microbiota-dependent increased expression of proinflammatory factors and decreased expression of the immunosuppressive cytokine IL-10. This condition could be improved in LRP5/6^ΔCD11c mice by depleting the gut flora, indicating the importance of LRP5/6 in mediating immune tolerance to the gut flora. Moreover, mechanistic studies show that LRP5/6 suppresses the expression of tumor-promoting inflammatory factors in CD11c⁺ APCs via the β-catenin-IL-10 axis. Accordingly, conditional activation of β-catenin specifically in CD11c⁺ APCs or in vivo administration of IL-10 protected LRP5/6^ΔCD11c mice from CAC by suppressing the expression of inflammatory factors. In summary, in this study, we identify a key role for the LRP5/6-β-catenin-IL-10 signaling pathway in intestinal APCs in resolving chronic intestinal inflammation and protecting against CAC in response to the commensal flora.

Gut microbiota alterations are distinct for primary colorectal cancer and hepatocellular carcinoma

Colorectal cancer (CRC) and hepatocellular carcinoma (HCC) are the second and third most common causes of death by cancer, respectively. The etiologies of the two cancers are either infectious insult or due to chronic use of alcohol, smoking, diet, obesity and diabetes. Pathological changes in the composition of the gut microbiota that lead to intestinal inflammation are a common factor for both HCC and CRC. However, the gut microbiota of the cancer patient evolves with disease pathogenesis in unique ways that are affected by etiologies and environmental factors. In this review, we examine the changes that occur in the composition of the gut microbiota across the stages of the HCC and CRC. Based on the idea that the gut microbiota are an additional "lifeline" and contribute to the tumor microenvironment, we can observe from previously published literature how the microbiota can cause a shift in the balance from normal → inflammation → diminished inflammation from early to later disease stages. This pattern leads to the hypothesis that tumor survival depends on a less pro-inflammatory tumor microenvironment. The differences observed in the gut microbiota composition between different disease etiologies as well as between HCC and CRC suggest that the tumor microenvironment is unique for each case.

Alcohol-Induced Immune Dysregulation in the Colon Is Diurnally Variable

Introduction

Alcohol increases the risk of colon cancer. Colonic inflammation mediates the effects of alcohol on colon carcinogenesis. Circadian rhythm disruption enhances the alcohol's effect on colonic inflammation and cancer.

Objective

Here, we investigate the diurnal variation of lymphocyte infiltration in the colonic mucosa in response to alcohol.

Methods

Sixty C57BL6/J mice were fed a chow diet, and gavaged with alcohol at a specific time once per day for 3 consecutive days. Immunohistochemistry and immunofluorescence staining were used to quantify total, effector, and regulatory T cells in the colon. Student's t test, one-way ANOVA, and two-way ANOVA were used to determine significance.

Results

Following the alcohol binge, the composition of immune T cell subsets in the mouse colon was time-dependent. Alcohol did not alter the total number of CD3⁺ T cells. However, upon alcohol treatment, T-bet⁺ T helper 1 (Th1) cells appeared to dominate the T cell population following a reduction in Foxp3⁺ regulatory T cell (Treg) numbers. Depletion of Tregs was time-dependent, and their numbers were dramatically reduced when alcohol was administered during the rest phase. A reduction in Tregs significantly increased the Th1/Treg ratio, resulting in a more proinflammatory milieu.

Conclusions

Alcohol enhanced the proinflammatory profile in the colon mucosa, as demonstrated by a higher T-bet⁺/Foxp3⁺ ratio, especially during the rest phase. These findings may partly account for the interaction of circadian rhythm disruption with alcohol in colon inflammation and cancer.

MAP3K2 augments Th1 cell differentiation via IL-18 to promote T cell-mediated colitis

T cell-mediated immunity in the intestine is stringently controlled to ensure proper immunity against pathogenic microbes and to prevent autoimmunity, a known cause of inflammatory bowel disease. However, precisely how T cells regulate intestine immunity remains to be fully understood. In this study, we found that mitogen-activated protein kinase kinase kinase 2 (MAP3K2) is required for the CD4⁺ T cell-mediated inflammation in the intestine. Using a T cell transfer colitis model, we found that MAP3K2-deficient naïve CD4 T cells had a dramatically reduced ability to induce colitis compared to wild type T cells. In addition, significantly fewer IFN-γ- but more IL-17A-producing CD4⁺ T cells in the intestines of mice receiving MAP3K2-deficient T cells than in those from mice receiving wild type T cells was observed. Interestingly, under well-defined in vitro differentiation conditions, MAP3K2-deficient naïve T cells were not impaired in their ability to differentiate into Th1, Th17 and Treg. Furthermore, the MAP3K2-regulated colitis severity was mediated by Th1 but not Th17 cells in the intestine. At the molecular level, we showed that MAP3K2-mediated Th1 cell differentiation in the intestine was regulated by IL-18 and required specific JNK activation. Together, our study reveals a novel regulatory role of MAP3K2 in intestinal T cell immunity via the IL-18-MAP3K2-JNK axis and may provide a novel target for intervention in T cell-mediated colitis.

Role of Inflammation in Pathophysiology of Colonic Disease: An Update

Diseases of the colon are a big health burden in both men and women worldwide ranging from acute infection to cancer. Environmental and genetic factors influence disease onset and outcome in multiple colonic pathologies. The importance of inflammation in the onset, progression and outcome of multiple colonic pathologies is gaining more traction as the evidence from recent research is considered. In this review, we provide an update on the literature to understand how genetics, diet, and the gut microbiota influence the crosstalk between immune and non‑immune cells resulting in inflammation observed in multiple colonic pathologies. Specifically, we focus on four colonic diseases two of which have a more established association with inflammation (inflammatory bowel disease and colorectal cancer) while the other two have a less understood relationship with inflammation (diverticular disease and irritable bowel syndrome).

The Role of Interleukins in Colorectal Cancer

Despite great progress has been made in treatment strategies, colorectal cancer (CRC) remains the predominant life-threatening malignancy with the feature of high morbidity and mortality. It has been widely acknowledged that the dysfunction of immune system, including aberrantly expressed cytokines, is strongly correlated with the pathogenesis and progression of colorectal cancer. As one of the most well-known cytokines that were discovered centuries ago, interleukins are now uncovering new insights into colorectal cancer therapy. Herein, we divide currently known interleukins into 6 families, including IL-1 family, IL-2 family, IL-6 family, IL-8 family, IL-10 family and IL-17 family. In addition, we comprehensively reviewed the oncogenic or antitumour function of each interleukin involved in CRC pathogenesis and progression by elucidating the underlying mechanisms. Furthermore, by providing interleukins-associated clinical trials, we have further driven the profound prospect of interleukins in the treatment of colorectal cancer.

Glycogen Synthase Kinase 3β in Cancer Biology and Treatment

Glycogen synthase kinase (GSK)3β is a multifunctional serine/threonine protein kinase with more than 100 substrates and interacting molecules. GSK3β is normally active in cells and negative regulation of GSK3β activity via phosphorylation of its serine 9 residue is required for most normal cells to maintain homeostasis. Aberrant expression and activity of GSK3β contributes to the pathogenesis and progression of common recalcitrant diseases such as glucose intolerance, neurodegenerative disorders and cancer. Despite recognized roles against several proto-oncoproteins and mediators of the epithelial–mesenchymal transition, deregulated GSK3β also participates in tumor cell survival, evasion of apoptosis, proliferation and invasion, as well as sustaining cancer stemness and inducing therapy resistance. A therapeutic effect from GSK3β inhibition has been demonstrated in 25 different cancer types. Moreover, there is increasing evidence that GSK3β inhibition protects normal cells and tissues from the harmful effects associated with conventional cancer therapies. Here, we review the evidence supporting aberrant GSK3β as a hallmark property of cancer and highlight the beneficial effects of GSK3β inhibition on normal cells and tissues during cancer therapy. The biological rationale for targeting GSK3β in the treatment of cancer is also discussed at length.

Expression Levels of IL-17A, IL-17F, IL-17RA, and IL-17RC in Prostate Cancer with Taking into Account the Histological Grade according to Gleason Scale in Comparison to Benign Prostatic Hyperplasia: In Search of New Therapeutic Options

Prostate cancer (PCa) is the second most commonly diagnosed malignant tumor and the fifth leading cause of cancer death in men in the world. The most common types of tumors are adenocarcinomas. Prostate cancer is a slow-growing cancer. The incidence increases with age. Evaluation of proinflammatory factors such as IL-17A, IL-17F, IL-17RA, and IL-17RC expression makes it possible to assess the impact of inflammatory process on progression of PCa. The aim of the study was to retrospectively assess the histological material of PCa divided into few groups using the Gleason score. Studies were carried out on archival tissue material in the form of paraffin blocks of 40 men with PCa after radical prostatectomy. The control group was composed of 10 men with benign prostatic hyperplasia (BPH). The material was obtained by the transurethral resection of the prostate (TURP). Immunohistochemistry was performed on prepared material using specific primary antibodies against IL-17A, IL-17F, IL-17RA, and IL-17RC. Expression of the antibody to be examined using light microscopy and the Remmele-Stegner score (IRS) in cancer staining was then evaluated. Expression of IL-17 RA was not shown in a group of patients with PCa and in the control group. In the group of patients with Gleason score 8 and 9 PCa, the expression of IL-17A was higher compared to that of IL-17F. In addition, in PCa with an increased grade of Gleason scale, a decrease in the expression of the study inflammatory parameters was found. The inflammatory process has an impact on PCa. A study on IL-17 may become a starting point for further research on an attempt to use, for example, immunotherapy in PCa.

Wnt Signaling Cascade in Dendritic Cells and Regulation of Anti-tumor Immunity

Dendritic cells (DCs) control the strength and quality of antigen-specific adaptive immune responses. This is critical for launching a robust immunity against invading pathogens while maintaining a state of tolerance to self-antigens. However, this also represents a fundamental barrier to anti-tumor immune responses and cancer immunotherapy. DCs in the tumor microenvironment (TME) play a key role in this process. The factors in the TME and signaling networks that program DCs to a regulatory state are not fully understood. Recent advances point to novel mechanisms by which the canonical Wnt signaling cascade in DCs regulates immune suppression, and the same pathway in tumors is associated with the evasion of anti-tumor immunity. Here, we review these recent advances in the context of the pleiotropic effects of the Wnts in shaping anti-tumor immune responses by modulating DC functions. In addition, we will discuss how Wnt/β-catenin pathway in DCs can be targeted for successful cancer immunotherapy.

Dietary probiotic and metabolites improve intestinal homeostasis and prevent colorectal cancer

Metabolites from Lactobacillus casei display substantial antioxidant and anti-inflammatory activities, inhibit colorectal cancer cell proliferation and growth, and modulate gut microfloral composition, specifically reducing sulfidogenic bacteria.

Abnormal Eating Patterns Cause Circadian Disruption and Promote Alcohol-Associated Colon Carcinogenesis

BACKGROUND & AIMS

Alcohol intake with circadian rhythm disruption (CRD) increases colon cancer risk. We hypothesized that eating during or around physiologic rest time, a common habit in modern society, causes CRD and investigated the mechanisms by which it promotes alcohol-associated colon carcinogenesis.

METHODS

The effect of feeding time on CRD was assessed using B6 mice expressing a fusion protein of PERIOD2 and LUCIFERASE (PER2::LUC) were used to model colon polyposis and to assess the effects of feeding schedules, alcohol consumption, and prebiotic treatment on microbiota composition, short-chain fatty acid levels, colon inflammation, and cancer risk. The relationship between butyrate signaling and a proinflammatory profile was assessed by inactivating the butyrate receptor GPR109A.

RESULTS

Eating at rest (wrong-time eating [WTE]) shifted the phase of the colon rhythm in PER2::LUC mice. In TS4Cre × APClox468 mice, a combination of WTE and alcohol exposure (WTE + alcohol) decreased the levels of short-chain fatty acid-producing bacteria and of butyrate, reduced colonic densities of regulatory T cells, induced a proinflammatory profile characterized by hyperpermeability and an increased mucosal T-helper cell 17/regulatory T cell ratio, and promoted colorectal cancer. Prebiotic treatment improved the mucosal inflammatory profile and attenuated inflammation and cancer. WTE + alcohol-induced polyposis was associated with increased signal transducer and activator of transcription 3 expression. Decreased butyrate signaling activated the epithelial signal transducer and activator of transcription 3 in vitro. The relationship between butyrate signaling and a proinflammatory profile was confirmed in human colorectal cancers using The Cancer Genome Atlas.

CONCLUSIONS

Abnormal timing of food intake caused CRD and interacts with alcohol consumption to promote colon carcinogenesis by inducing a protumorigenic inflammatory profile driven by changes in the colon microbiota and butyrate signaling. Accession number of repository for microbiota sequence data: raw FASTQ data were deposited in the NCBI Sequence Read Archive under project PRJNA523141.