Cytokine-Induced Modulation of Colorectal Cancer

Molecular Mechanisms of Alcohol-Induced Colorectal Carcinogenesis

The etiology of colorectal cancer (CRC) is complex. Approximately, 10% of individuals with CRC have predisposing germline mutations that lead to familial cancer syndromes, whereas most CRC patients have sporadic cancer resulting from a combination of environmental and genetic risk factors. It has become increasingly clear that chronic alcohol consumption is associated with the development of sporadic CRC; however, the exact mechanisms by which alcohol contributes to colorectal carcinogenesis are largely unknown. Several proposed mechanisms from studies in CRC models suggest that alcohol metabolites and/or enzymes associated with alcohol metabolism alter cellular redox balance, cause DNA damage, and epigenetic dysregulation. In addition, alcohol metabolites can cause a dysbiotic colorectal microbiome and intestinal permeability, resulting in bacterial translocation, inflammation, and immunosuppression. All of these effects can increase the risk of developing CRC. This review aims to outline some of the most significant and recent findings on the mechanisms of alcohol in colorectal carcinogenesis. We examine the effect of alcohol on the generation of reactive oxygen species, the development of genotoxic stress, modulation of one-carbon metabolism, disruption of the microbiome, and immunosuppression.

Association of gene and protein expression and genetic polymorphism of CC chemokine ligand 4 in colorectal cancer

BACKGROUND

Leukocytes, such as T cells and macrophages, play an important role in tumorigenesis. CC chemokine ligand (CCL) 4, which is produced by lymphocytes and macrophages, has been found to be expressed in the mucosa of the gastrointestinal tract and is a potent chemoattractant for various leukocytes.

AIM

To examine CCL4 expression and its genetic polymorphism rs10491121 in patients with colorectal cancer (CRC) and evaluate their prognostic significance.

METHODS

Luminex technology was used to determine CCL4 Levels in CRC tissue (n = 98), compared with paired normal tissue, and in plasma from patients with CRC (n = 103), compared with healthy controls (n = 97). Included patients had undergone surgical resection for primary colorectal adenocarcinomas between 1996 and 2019 at the Department of Surgery, Ryhov County Hospital, Jönköping, Sweden. Reverse transcription quantitative PCR was used to investigate the CCL4 gene expression in CRC tissue (n = 101). Paired normal tissue and TaqMan single nucleotide polymorphism assays were used for the CCL4 rs10491121 polymorphism in 610 CRC patients and 409 healthy controls.

RESULTS

The CCL4 protein and messenger RNA expression levels were higher in CRC tissue than in normal paired tissue (90%, P < 0.001 and 45%, P < 0.05, respectively). CRC tissue from patients with localized disease had 2.8-fold higher protein expression levels than that from patients with disseminated disease. Low CCL4 protein expression levels in CRC tissue were associated with a 30% lower cancer-specific survival rate in patients (P < 0.01). The level of plasma CCL4 was 11% higher in CRC patients than in healthy controls (P < 0.05) and was positively correlated (r = 0.56, P < 0.01) with the CCL4 protein level in CRC tissue. The analysis of CCL4 gene polymorphism rs10491121 showed a difference (P < 0.05) between localized disease and disseminated disease in the right colon, with a dominance of allele A in localized disease. Moreover, the rate of the A allele was higher among CRC patients with mucinous cancer than among those with non-mucinous cancer.

CONCLUSION

The present study indicates that the CRC tissue levels of CCL4 and CCL4 gene polymorphism rs10491121, particularly in the right colon, are associated with clinical outcome in CRC patients.

The Genes Encoding Small Leucine-Rich Proteoglycans Undergo Differential Expression Alterations in Colorectal Cancer, Depending on Tumor Location

Small leucine-rich proteoglycans (SLRPs) regulate different processes and undergo significant alterations in various diseases. Colon carcinomas (CCs) are heterogeneous pathologies with important clinical and molecular differences depending on their location, which makes it interesting to analyze the alterations in SLRPs in right- and left-sided tumors (RS- and LSCCs). SLRP transcription levels were studied in 32 CCs using qPCR compared to healthy colon mucosae samples from the same patients, 20 of them from LSCCs and the remaining 12 from RSCCs. Protein expression of genes with significant differences in their transcriptions was analyzed by immunohistochemistry. The alterations observed were related to survival data. The arrangement of transcription of SLRPs was quite similar in ascending and descending colon, but RS- and LSCCs displayed different patterns of alteration, with a greater number of deregulations occurring in the latter. The analysis of protein expression also indicated changes in the location of these molecules, largely moving to the cell interior. While podocan underexpression showed a trend toward better outcomes, no differences were observed in terms of overall survival. In vitro studies using the HT29 tumor cell line suggest that deregulation of SLRPs could affect cell proliferation. SLRPs constitute new differential markers of RS- and LSCCs, showing differences dependent on the anatomical location of the tumor.

Proton pump inhibitor omeprazole suppresses carcinogen induced colonic adenoma progression to adenocarcinoma in F344 rat

Colorectal cancer (CRC) causes over 53,000 deaths annually in the United States. Its rising incidences worldwide and particularly in young adults is a major concern. Here, we evaluated the efficacy of omeprazole (OME) that is clinically approved for treating acid-reflux, to enable its repurposing for CRC prevention. In the azoxymethane (AOM)-induced rat CRC model, dietary OME (250 and 500 ppm) was administered at early adenoma stage (8 weeks after AOM) to assess the progression of early lesions to adenocarcinoma. Administration of OME at 250 ppm or 500 ppm doses led to suppression of total colon adenocarcinoma incidence by 15.7% and 32% (p<0.01), respectively. Importantly, invasive carcinoma incidence was reduced by 59% (p<0.0005) and 90% (p<0.0001) in OME administered rats in a dose-dependent manner. There was also a strong and dose-dependent inhibition in the adenocarcinoma multiplicity in rats exposed to OME. Administration of 250 and 500 ppm OME inhibited total colon adenocarcinoma multiplicity by ~49% and ~65% (p<0.0001), respectively. While non-invasive adenocarcinomas multiplicity was suppressed by ~34% to ~48% (p<0.02), the invasive carcinomas multiplicity was reduced by ~74% to ~94% (p<0.0001) in OME exposed rats in comparison to the untreated rats. Biomarker analysis results showed a decrease in cell proliferation and anti-apoptotic/pro-survival proteins with an increase in apoptosis. Transcriptome analysis of treated tumors revealed a significant increase in adenocarcinoma inhibitory genes (Olmf4; Spink4) expression and down regulation of progression promoting genes (SerpinA1, MMP21, IL6). In summary, OME showed significant protection against the progression of adenoma to adenocarcinoma.

Recent advancements in the exploitation of the gut microbiome in the diagnosis and treatment of colorectal cancer

Over the last few decades it has been established that the complex interaction between the host and the multitude of organisms that compose the intestinal microbiota plays an important role in human metabolic health and disease. Whilst there is no defined consensus on the composition of a healthy microbiome due to confounding factors such as ethnicity, geographical locations, age and sex, there are undoubtably populations of microbes that are consistently dysregulated in gut diseases including colorectal cancer (CRC). In this review, we discuss the most recent advances in the application of the gut microbiota, not just bacteria, and derived microbial compounds in the diagnosis of CRC and the potential to exploit microbes as novel agents in the management and treatment of CRC. We highlight examples of the microbiota, and their derivatives, that have the potential to become standalone diagnostic tools or be used in combination with current screening techniques to improve sensitivity and specificity for earlier CRC diagnoses and provide a perspective on their potential as biotherapeutics with translatability to clinical trials.

Immunomodulatory Effect of Lactobacillus casei in a Murine Model of Colon Carcinogenesis

We previously reported beneficial effects of the probiotic strain Lactobacillus casei 393 in hindering colon carcinogenesis in a 1,2-dimethylhydrazine (DMH)-induced BALB/c mouse model of colon cancer. In the present study, we investigated the effect of preventive administration of L. casei 393 on the levels of selected pro- and anti-inflammatory circulating cytokines, as well as subpopulations of splenic T cells. The resulting experimental data on IFNγ, TNFα, IL-10, and colon histological features demonstrated that administration of L. casei 2 weeks before DMH treatment impaired the pro-inflammatory effect of DMH, while maintaining the levels of the three cytokines as well as colon histology; it also modulated splenic CD4⁺, CD8⁺, and NK T cell subpopulations. The preventive administration of L. casei to DMH-treated mice increased IL-17A synthesis and Treg percentages, further indicating a tumor-protecting role. Together, the results suggest that the colon-cancer-protective properties of L. casei 393 involve the dampening of inflammation through cytokine homeostasis and the maintenance of a healthy T cell subpopulation dynamic. For these reasons, probiotics such as L. casei may contribute to the health of the host as they promote optimal control of the immune response. Further, they may be used as prophylactic agents in combination with standard therapies against colon cancer.

Cytotoxic T-lymphocyte Antigen-4 (CTLA-4) Gene Polymorphism (rs3087243) Is Related to Risk and Survival in Patients With Colorectal Cancer

BACKGROUND/AIM

Cytotoxic T-lymphocyte antigen-4 (CTLA-4), transiently expressed on T cells, plays a pivotal role in the negative feedback regulation of T-cell activation and proliferation. The aim of the present study was to examine the influence of CTLA-4 gene polymorphism rs3087243 on CRC susceptibility and long-term survival in Swedish patients with CRC.

PATIENTS AND METHODS

Genotypes of 491 patients and 433 healthy controls were determined, using TaqMan single nucleotide polymorphism (SNP) assays based on polymerase chain reaction.

RESULTS

Patients carrying allele A were found to be at a higher risk of CRC and this allele was found to be more common in patients with disseminated disease compared to localized disease in the right colon. Kaplan-Meier analysis of cancer-specific survival showed that carriers of allele A had the highest risk of CRC-related death.

CONCLUSION

The SNP rs3087243 of the CTLA-4 gene was associated with CRC risk and, therefore, it could be a prognostic marker for Swedish patients with CRC.

Familial adenomatous polyposis and changes in the gut microbiota: New insights into colorectal cancer carcinogenesis

Patients with familial adenomatous polyposis (FAP), an autosomal dominant hereditary colorectal cancer syndrome, have a lifetime risk of developing cancer of nearly 100%. Recent studies have pointed out that the gut microbiota could play a crucial role in the development of colorectal adenomas and the consequent progression to colorectal cancer. Some gut bacteria, such as Fusobacterium nucleatum, Escherichia coli, Clostridium difficile, Peptostreptococcus, and enterotoxigenic Bacteroides fragilis, could be implicated in colorectal carcinogenesis through different mechanisms, including the maintenance of a chronic inflammatory state, production of bioactive tumorigenic metabolites, and DNA damage. Studies using the adenomatous polyposis coliMin/+ mouse model, which resembles FAP in most respects, have shown that specific changes in the intestinal microbial community could influence a multistep progression, the intestinal "adenoma-carcinoma sequence", which involves mucosal barrier injury, low-grade inflammation, activation of the Wnt pathway. Therefore, modulation of gut microbiota might represent a novel therapeutic target for patients with FAP. Administration of probiotics, prebiotics, antibiotics, and nonsteroidal anti-inflammatory drugs could potentially prevent the progression of the adenoma-carcinoma sequence in FAP. The aim of this review was to summarize the best available knowledge on the role of gut microbiota in colorectal carcinogenesis in patients with FAP.

Accumulation of CD45RO+CD8+ T cells is a diagnostic and prognostic biomarker for clear cell renal cell carcinoma

Renal cell carcinoma is characterized by high immunogenicity and infiltration of immune cells. CD45RO+CD8+ T cells are well known as a critical role in host defense of the immune environment. However, their role in clear cell renal carcinoma (ccRCC) remains unknown. To elucidate the clinical importance of CD45RO+CD8+ T cells in ccRCC as well as its underlying mechanism, we analyzed several types of peripheral immune cells from 274 patients with ccRCC who have received radical or partial nephrectomy and 350 healthy people. Flow cytomety assays showed there was no significant difference in the proportions of CD8+ T cells and its subtypes other than CD45RO+/CD45RA+CD8+ cells. Both gene and protein expression levels of CD45RO in ccRCC tissues were decreased. CD45RO+CD8+ T cells showed increased proliferative abilities but decreased apoptotic abilities through MAPK signaling activation in ccRCC. High expression level of CD45RO+CD8+ T cells inhibited ccRCC progression, including proliferation, invasion, as well as autophagy of ccRCC through many signaling pathways. Bioinformatics and immunohistochemical chip analysis measured gene and protein levels of CD45RO and other related proteins. The combination of UCHL1, HMGB3, and CD36 has diagnostic value in ccRCC and is able to predict prognosis. Collectively, CD45RO+CD8+ T cells play a critical role in ccRCC progression and may be regarded as clinical indicators.

Heterogeneity of Colorectal Cancer Progression: Molecular Gas and Brakes

The review begins with molecular genetics, which hit the field unveiling the involvement of oncogenes and tumor suppressor genes in the pathogenesis of colorectal cancer (CRC) and uncovering genetic predispositions. Then the notion of molecular phenotypes with different clinical behaviors was introduced and translated in the clinical arena, paving the way to next-generation sequencing that captured previously unrecognized heterogeneity. Among other molecular regulators of CRC progression, the extent of host immune response within the tumor micro-environment has a critical position. Translational sciences deeply investigated the field, accelerating the pace toward clinical transition, due to its strong association with outcomes. While the perturbation of gut homeostasis occurring in inflammatory bowel diseases can fuel carcinogenesis, micronutrients like vitamin D and calcium can act as brakes, and we discuss underlying molecular mechanisms. Among the components of gut microbiota, Fusobacterium nucleatum is over-represented in CRC, and may worsen patient outcome. However, any translational knowledge tracing the multifaceted evolution of CRC should be interpreted according to the prognostic and predictive frame of the TNM-staging system in a perspective of clinical actionability. Eventually, we examine challenges and promises of pharmacological interventions aimed to restrain disease progression at different disease stages.

Iron deficiency, immunology, and colorectal cancer

Excessive gut luminal iron contributes to the initiation and progression of colorectal cancer. However, emerging evidence suggests that reduced iron intake and low systemic iron levels are also associated with the pathogenesis of colorectal cancer. This is important because patients with colorectal cancer often present with iron deficiency. Iron is necessary for appropriate immunological functions; hence, iron deficiency may hinder cancer immunosurveillance and potentially modify the tumor immune microenvironment, both of which may assist cancer development. This is supported by studies showing that patients with colorectal cancer with iron deficiency have inferior outcomes and reduced response to therapy. Here, we provide an overview of the immunological consequences of iron deficiency and suggest ensuring adequate iron therapy to limit these outcomes.

Role of Gut Microbiota and Probiotics in Colorectal Cancer: Onset and Progression

The gut microbiota plays an important role in maintaining homeostasis in the human body, and the disruption of these communities can lead to compromised host health and the onset of disease. Current research on probiotics is quite promising and, in particular, these microorganisms have demonstrated their potential for use as adjuvants for the treatment of colorectal cancer. This review addresses the possible applications of probiotics, postbiotics, synbiotics, and next-generation probiotics in colorectal cancer research.

In vivo evidence: Repression of mucosal immune responses in mice with colon cancer following sustained administration of Streptococcus thermophiles

Probiotics have attracted considerable attention because of their ability to ameliorate disease and prevent cancer. In this study, we examined the immunomodulatory effects of a Streptococcus thermophilus probiotic on the intestinal mucosa azoxymethane-induced colon cancer. Sixty female mice were divided into four groups (n = 15 each). One group of untreated mice was used as a control (C group). Another mouse group was injected with azoxymethane once weekly for 8 weeks to induce colon cancer (CC group). Finally, two groups of mice were continuously treated twice per week from week 2 to 16 with either the Lactobacillus plantarum (Lac CC group) or S. thermophilus (Strep CC group) bacterial strain pre-and post-treatment as performed for the CC group. Remarkably, Tlr2, Ifng, Il4, Il13, Il10, and Tp53 transcription were significantly downregulated in the Strep CC intestinal mucosa group. Additionally, IL2 expression was decreased significantly in the Strep CC mouse serum, whereas TNFα was remarkably elevated compared to that in the CC, Lac CC, and untreated groups. This study suggested that Streptococcus thermophilus did not interrupt or hinder colon cancer development in mice when administered as a prophylactic.

Tumour necrosis factor-α (TNF-α) enhances dietary carcinogen-induced DNA damage in colorectal cancer epithelial cells through activation of JNK signaling pathway

Colorectal cancer (CRC) is the third most common cancer worldwide and the second leading cause of cancer death. Benzo[a]pyrene (BaP) and 2-amino-1-methyl-6-phenylimidazol [4,5-b] pyridine (PhIP) present in cooked meat are pro-carcinogens and considered to be potential risk factors for CRC. Their carcinogenic and mutagenic effects require metabolic activation primarily by cytochrome P450 1 family enzymes (CYPs); the expression of these enzymes can be modulated by aryl hydrocarbon receptor (AhR) activation and the tumour microenvironment, involving mediators of inflammation. In this study, we hypothesized that tumour necrosis factor-α (TNF-α), a key mediator of inflammation, modulates BaP- and PhIP-induced DNA damage in colon cancer epithelial cells. Importantly, we observed that TNF-α alone (0.1-100 pg/ml) induced DNA damage (micronuclei formation) in HCT-116 cells and co-treatment of TNF-α with BaP or PhIP showed higher levels of DNA damage compared to the individual single treatments. TNF-α alone or in combination with BaP or PhIP did not affect the expression levels of CYP1A1 and CYP1B1 (target genes of AhR signaling pathways). The DNA damage induced by TNF-α was elevated in p53 null HTC-116 cells compared to wild type cells, suggesting that TNF-α-induced DNA damage is suppressed by functional p53. In contrast, p53 status failed to affect BaP and PhIP induced micronucleus frequency. Furthermore, JNK and NF-κB signaling pathway were activated by TNF-α treatment but only inhibition of JNK significantly reduced TNF-α-induced DNA damage. Collectively, these findings suggest that TNF-α induced DNA damage involves JNK signaling pathway rather than AhR and NF-κB pathways in colon cancer epithelial cells.

Role of microbiota-derived short-chain fatty acids in cancer development and prevention

Following cancer, cells in a particular tissue can no longer respond to the factors involved in controlling cell survival, differentiation, proliferation, and death. In recent years, it has been indicated that alterations in the gut microbiota components, intestinal epithelium, and host immune system are associated with cancer incidence. Also, it has been demonstrated that the short-chain fatty acids (SCFAs) generated by gut microbiota are vitally crucial in cell homeostasis as they contribute to the modulation of histone deacetylases (HDACs), resulting effected cell attachment, immune cell immigration, cytokine production, chemotaxis, and the programmed cell death. Therefore, the manipulation of SCFA levels in the intestinal tract by alterations in the microbiota structure can be potentially taken into consideration for cancer treatment/prevention. In the current study, we will explain the most recent findings on the detrimental or protective roles of SFCA (particularly butyrate, propionate, and acetate) in several cancers, including bladder, colon, breast, stomach, liver, lung, pancreas, and prostate cancers.

A Potential Role of IL-6/IL-6R in the Development and Management of Colon Cancer

Colorectal cancer (CRC) is the third most frequent cancer worldwide and the second greatest cause of cancer deaths. About 75% of all CRCs are sporadic cancers and arise following somatic mutations, while about 10% are hereditary cancers caused by germline mutations in specific genes. Several factors, such as growth factors, cytokines, and genetic or epigenetic alterations in specific oncogenes or tumor-suppressor genes, play a role during the adenoma-carcinoma sequence. Recent studies have reported an increase in interleukin-6 (IL-6) and soluble interleukin-6 receptor (sIL-6R) levels in the sera of patients affected by colon cancer that correlate with the tumor size, suggesting a potential role for IL-6 in colon cancer progression. IL-6 is a pleiotropic cytokine showing both pro- and anti-inflammatory roles. Two different types of IL-6 signaling are known. Classic IL-6 signaling involves the binding of IL-6 to its membrane receptor on the surfaces of target cells; alternatively, IL-6 binds to sIL-6R in a process called IL-6 trans-signaling. The activation of IL-6 trans-signaling by metalloproteinases has been described during colon cancer progression and metastasis, involving a shift from membrane-bound interleukin-6 receptor (IL-6R) expression on the tumor cell surface toward the release of soluble IL-6R. In this review, we aim to shed light on the role of IL-6 signaling pathway alterations in sporadic colorectal cancer and the development of familial polyposis syndrome. Furthermore, we evaluate the possible roles of IL-6 and IL-6R as biomarkers useful in disease follow-up and as potential targets for therapy, such as monoclonal antibodies against IL-6 or IL-6R, or a food-based approach against IL-6.

Fluoropyrimdine therapy induced alterations in interleukins expression in colorectal cancer patients

This study monitored the changes in the expression of inflammatory IL-6 and IL-1β during the treatment period of Fluoropyrimidine (FP) based therapy. RNA was extracted from the peripheral blood of 102 CRC patients before treatment with FP therapy, and from 48 and 32 patients after 3 and 6 months of treatment, respectively. The genetic transcription of IL-6 and IL-1β was determined by real time PCR. Patients were stratified according to their levels of IL-6 and IL-1β genes expression for subgroup and survival analyses. Baseline CRC patients showed overexpression of IL-6 and IL-1β compared to healthy control. FP therapy significantly induced IL-6 and IL-1β expression. Subgroup analysis showed that patients with right colon tumors had significant elevation in both IL-6 and IL-1β with FP therapy. FP therapy significantly induced IL-1β expression in patients ⩽45 years, smokers, with high baseline level of CA19.9, right colon tumors, low grade pathology, T3 tumors and positive lymph nodes. Survival analysis showed that baseline levels of interleukins expression had insignificant effect on overall survival and event free survival. FP therapy has an impact on the level of interleukins expression declared in certain clinicopathological subgroups of CRC patients, but without a prognostic significance on patients' survival.

A molecular subtype of colorectal cancers initiates independently of epidermal growth factor receptor and has an accelerated growth rate mediated by IL10-dependent anergy

Although epidermal growth factor receptor (EGFR)-targeted therapies are approved for colorectal cancer (CRC) treatment, only 15% of CRC patients respond to EGFR inhibition. Here, we show that colorectal cancers (CRC) can initiate and grow faster through an EGFR-independent mechanism, irrespective of the presence of EGFR, in two different mouse models using tissue-specific ablation of Egfr. The growth benefit in the absence of EGFR is also independent of Kras status. An EGFR-independent gene expression signature, also observed in human CRCs, revealed that anergy-inducing genes are overexpressed in EGFR-independent polyps, suggesting increased infiltration of anergic lymphocytes promotes an accelerated growth rate that is partially caused by escape from cell-mediated immune responses. Many genes in the EGFR-independent gene expression signature are downstream targets of interleukin 10 receptor alpha (IL10RA). We further show that IL10 is detectable in serum from mice with EGFR-independent colon polyps. Using organoids in vitro and Src ablation in vivo, we show that IL10 contributes to growth of EGFR-independent CRCs, potentially mediated by the well-documented role of SRC in IL10 signaling. Based on these data, we show that the combination of an EGFR inhibitor with an anti-IL10 neutralizing antibody results in decreased cell proliferation in organoids and in decreased polyp size in pre-clinical models harboring EGFR-independent CRCs, providing a new therapeutic intervention for CRCs resistant to EGFR inhibitor therapies.

The Protection of Crocin Against Ulcerative Colitis and Colorectal Cancer via Suppression of NF-κB-Mediated Inflammation

Background: In China, the incidence of ulcerative colitis (UC) is increasing every year, but the etiology of UC remains unclear. UC is known to increase the risk of colorectal cancer (CRC). The aim of this study was to investigate the protective effects of crocin against UC and CRC in mouse models.

Methods: Crocin was used to treat the dextran sodium sulfate (DSS)-induced UC mice for 3 weeks, and Apc^MinC/Gpt mice with colorectal cancer for 8 weeks. Proteomics screening was used to detect changes in the protein profiles of colon tissues of UC mice. Enzyme-linked immunosorbent assays and western blot were used to verify these changes.

Results: Crocin strongly reduced the disease activity index scores of UC mice, and improved the pathological symptoms of the colonic epithelium. The anti-inflammatory effects of crocin were indicated by its regulation of the activity of various cytokines, such as interleukins, via the modulation of nuclear factor kappa-B (NF-κB) signaling. Crocin significantly suppressed tumor growth in Apc^MinC/Gpt mice and ameliorated pathological alterations in the colon and liver, but had no effects on spleen and kidney. Additionally, crocin significantly decreased the concentrations of interleukins and tumor necrosis factor-α in the sera and colon tissues, suggesting its anti-inflammatory effects related to NF-κB signaling. Finally, 12-h incubation of SW480 cells with crocin caused cell cycle arrest, enhanced the apoptotic rate, promoted the dissipation of mitochondrial membrane potential, and the over-accumulation of reactive oxygen species. From the theoretical analyses, phosphorylated residues on S536 may enhance the protein-protein interactions which may influence the conformational changes in the secondary structure of NF-κB.

Conclusion: The protective effects of crocin on UC and CRC were due to its suppression of NF-κB-mediated inflammation.

Signaling pathways in intestinal homeostasis and colorectal cancer: KRAS at centre stage

The intestinal epithelium acts as a physical barrier that separates the intestinal microbiota from the host and is critical for preserving intestinal homeostasis. The barrier is formed by tightly linked intestinal epithelial cells (IECs) (i.e. enterocytes, goblet cells, neuroendocrine cells, tuft cells, Paneth cells, and M cells), which constantly self-renew and shed. IECs also communicate with microbiota, coordinate innate and adaptive effector cell functions. In this review, we summarize the signaling pathways contributing to intestinal cell fates and homeostasis functions. We focus especially on intestinal stem cell proliferation, cell junction formation, remodelling, hypoxia, the impact of intestinal microbiota, the immune system, inflammation, and metabolism. Recognizing the critical role of KRAS mutants in colorectal cancer, we highlight the connections of KRAS signaling pathways in coordinating these functions. Furthermore, we review the impact of KRAS colorectal cancer mutants on pathway rewiring associated with disruption and dysfunction of the normal intestinal homeostasis. Given that KRAS is still considered undruggable and the development of treatments that directly target KRAS are unlikely, we discuss the suitability of targeting pathways downstream of KRAS as well as alterations of cell extrinsic/microenvironmental factors as possible targets for modulating signaling pathways in colorectal cancer.

Interplay between the Gut Microbiota and Inflammatory Mediators in the Development of Colorectal Cancer

Inflammatory mediators modulate inflammatory pathways during the development of colorectal cancer. Inflammatory mediators secreted by both immune and tumor cells can influence carcinogenesis, progression, and tumor metastasis. The gut microbiota, which colonize the entire intestinal tract, especially the colon, are closely linked to colorectal cancer through an association with inflammatory mediators such as tumor necrosis factor, nuclear factor kappa B, interleukins, and interferons. This association may be a potential therapeutic target, since therapeutic interventions targeting the gut microbiota have been actively investigated in both the laboratory and in clinics and include fecal microbiota transplantation and probiotics.

Cytokine-Mediated Crosstalk between Immune Cells and Epithelial Cells in the Gut

Cytokines are small proteins that are secreted by a vast majority of cell types in the gut. They not only establish cell-to-cell interactions and facilitate cellular signaling, but also regulate both innate and adaptive immune responses, thereby playing a central role in genetic, inflammatory, and infectious diseases of the gut. Both, immune cells and gut epithelial cells, play important roles in intestinal disease development. The epithelium is located in between the mucosal immune system and the gut microbiome. It not only establishes an efficient barrier against gut microbes, but it also signals information from the gut lumen and its composition to the immune cell compartment. Communication across the epithelial cell layer also occurs in the other direction. Intestinal epithelial cells respond to immune cell cytokines and their response influences and shapes the microbial community within the gut lumen. Thus, the epithelium should be seen as a translator or a moderator between the microbiota and the mucosal immune system. Proper communication across the epithelium seems to be a key to gut homeostasis. Indeed, current genome-wide association studies for intestinal disorders have identified several disease susceptibility loci, which map cytokine signatures and their related signaling genes. A thorough understanding of this tightly regulated cytokine signaling network is crucial. The main objective of this review was to shed light on how cytokines can orchestrate epithelial functions such as proliferation, cell death, permeability, microbe interaction, and barrier maintenance, thereby safeguarding host health. In addition, cytokine-mediated therapy for inflammation and cancer are discussed.

Significant and Conflicting Correlation of IL-9 With Prevotella and Bacteroides in Human Colorectal Cancer

Background and aim

Gut microbiota (GM) can support colorectal cancer (CRC) progression by modulating immune responses through the production of both immunostimulatory and/or immunosuppressive cytokines. The role of IL-9 is paradigmatic because it can either promote tumor progression in hematological malignancies or inhibit tumorigenesis in solid cancers. Therefore, we investigate the microbiota–immunity axis in healthy and tumor mucosa, focusing on the correlation between cytokine profile and GM signature.

Methods

In this observational study, we collected tumor (CRC) and healthy (CRC-S) mucosa samples from 45 CRC patients, who were undergoing surgery in 2018 at the Careggi University Hospital (Florence, Italy). First, we characterized the tissue infiltrating lymphocyte subset profile and the GM composition. Subsequently, we evaluated the CRC and CRC-S molecular inflammatory response and correlated this profile with GM composition, using Dirichlet multinomial regression.

Results

CRC samples displayed higher percentages of Th17, Th2, and Tregs. Moreover, CRC tissues showed significantly higher levels of MIP-1α, IL-1α, IL-1β, IL-2, IP-10, IL-6, IL-8, IL-17A, IFN-γ, TNF-α, MCP-1, P-selectin, and IL-9. Compared to CRC-S, CRC samples also showed significantly higher levels of the following genera: Fusobacteria, Proteobacteria, Fusobacterium, Ruminococcus2, and Ruminococcus. Finally, the abundance of Prevotella spp. in CRC samples negatively correlated with IL-17A and positively with IL-9. On the contrary, Bacteroides spp. presence negatively correlated with IL-9.

Conclusions

Our data consolidate antitumor immunity impairment and the presence of a distinct microbiota profile in the tumor microenvironment compared with the healthy mucosa counterpart. Relating the CRC cytokine profile with GM composition, we confirm the presence of bidirectional crosstalk between the immune response and the host’s commensal microorganisms. Indeed, we document, for the first time, that Prevotella spp. and Bacteroides spp. are, respectively, positively and negatively correlated with IL-9, whose role in CRC development is still under debate.

The Prognostic Significance of 5-Fluorouracil Induced Inflammation and Immuno-Modulation in Colorectal Cancer Patients

Aim

The change in the levels of peripheral inflammatory markers together with EGFR in relation to 5- fluorouracil (5-FU) therapy was evaluated for their prognostic significance in colorectal cancer (CRC) patients.

Patients and Methods

Expression levels of COX2, IL6, IL1β, EGFR, IL10, and TNFα were determined with quantitative real-time PCR (qPCR) in the peripheral blood of 90 CRC patients. The inflammatory response was correlated with patients’ clinical features, disease-free survival (DFS), and overall survival (OS).

Results

After 6 months of 5-FU therapy, increased inflammatory response was found to be associated with smoking, T3 or T4 tumors, performance status (PS) III, positive lymph nodes, distant metastasis, and gastrointestinal (GIT) toxicity. The combination of COX2 with interleukins in a predictive equation for DFS was significant in patients with over-expression of EGFR. DFS and OS rates were reduced in patients with increased COX2, IL6, IL10, and TNFα expression with 5-FU therapy. Significant hazard of disease progression was associated with smoking (HR=1.27, P=0.004), 5-FU induction of COX2, and IL6 expression (HR=1.35, P=0.001 and HR=1.27, P=0.004, respectively). Moreover, smoking, 5-FU induction of IL6, TNFα, and IL10 expression are found to be independent prognostic factors for OS (P=0.003, 0.003, 0.002, and 0.002, respectively).

Conclusion

The peripheral effects of 5-FU therapy have shown a significant impact on the treatment outcome of CRC patients.

The Regulation of Intestinal Inflammation and Cancer Development by Type 2 Immune Responses

The gut is among the most complex organs of the human body. It has to exert several functions including food and water absorption while setting up an efficient barrier to the outside world. Dysfunction of the gut can be life-threatening. Diseases of the gastrointestinal tract such as inflammatory bowel disease, infections, or colorectal cancer, therefore, pose substantial challenges to clinical care. The intestinal epithelium plays an important role in intestinal disease development. It not only establishes an important barrier against the gut lumen but also constantly signals information about the gut lumen and its composition to immune cells in the bowel wall. Such signaling across the epithelial barrier also occurs in the other direction. Intestinal epithelial cells respond to cytokines and other mediators of immune cells in the lamina propria and shape the microbial community within the gut by producing various antimicrobial peptides. Thus, the epithelium can be considered as an interpreter between the microbiota and the mucosal immune system, safeguarding and moderating communication to the benefit of the host. Type 2 immune responses play important roles in immune-epithelial communication. They contribute to gut tissue homeostasis and protect the host against infections with helminths. However, they are also involved in pathogenic pathways in inflammatory bowel disease and colorectal cancer. The current review provides an overview of current concepts regarding type 2 immune responses in intestinal physiology and pathophysiology.

A preliminary study of cytokine gene polymorphism effects on Saudi patients with colorectal cancer

OBJECTIVE

 To determine the possible associations of polymorphisms in interleukin (IL)-8 (rs4073 T/A), IL-10 (rs1800896 A/G), IL-22 (rs1179251 C/G and rs2227485 C/T), IL-27 (rs17855750 T/G), and transforming growth factor beta 1 (TGFß1) (rs1800469 C/T) with colorectal cancer (CRC) susceptibility in Saudi patients.

METHODS

The case-control study was carried out between July 2019 and January 2020 in King Khaled University Hospital, Riyadh, Saudi Arabia. A total of 70 patients with CRC and 70 healthy controls were included  in  the  study.  Single nucleotide polymorphisms of promoter regions were determined using TaqMan genotyping assays.

RESULTS

 A statistically significant reduction in CRC risk was identified for carriers of the IL-10 (rs1800896 A/G) AG genotype, IL-22 (rs1179251 C/G) G allele, IL-27 (rs17855750 T/G) G allele and TGFß1 (rs1800469 C/T) CT and TT genotype. While IL-10 (rs1800896 A/G) AA genotype and TGFß1 (rs1800469 C/T) CC genotype were significantly associated with increased susceptibility to CRC. No significant associations were identified between the cytokine polymorphisms of IL-8 (rs4073 T/A) and IL-22 (rs2227485 C/T), and CRC risk. Conclusion: Our findings indicate a significant impact of IL-10 (rs1800896 A/G), IL-22 (rs1179251 C/G), IL-27 (rs17855750 T/G) and TGF-ß1 (rs1800469 C/T) polymorphisms on risk of CRC; while the IL-8 (rs4073 T/A) and IL-22 (rs2227485 C/T) and polymorphisms were not associated with CRC risk.

Targeting mitochondrial dysfunction in MAIT cells: Potential immunotherapeutic treatment for colorectal cancer

Mucosal associated invariant T (MAIT) cells have captured the attention of immunologists and clinicians in recent years due to their abundance in humans, especially in human liver and mucosal tissue. Colorectal cancer is one of the most common forms of cancer in mucosal tissue. Recent evidence reveal activated MAIT cells within the microenvironment of colorectal tumors. The increased tumor infiltration with MAIT cells correlates with poor survival in the colorectal cancer patients, suggesting MAIT cells are promising immunotherapeutic targets in colorectal cancer. Besides well-known role in anti-microbial immunity, MAIT cells have been associated with various forms of cancer. The Th1-biased MAIT cells are proposed to mediate anti-tumor immunity, while IL-17-producing subsets have been implicated in promoting malignancy. Reduced IFN-γ production and elevated IL-17 production of MAIT cells have been found in colorectal tumor tissue and shown to promote tumor growth and metastases. Although the mechanism(s) driving the increase in Th17-biased MAIT cells with reduced IFN-γ production in tumor is not fully understood, recent studies have linked IL-17 response to dysfunctional mitochondria and reactive oxygen species (ROS) from the mitochondria. Therefore, we hypothesize that mitochondrial dysfunction contributes to Th17-skewed MAIT cell responses with decreased IFN-γ production. Mitochondrial targeted antioxidants are supposed to be beneficial for recovering Th1-baised antitumor immunity and inhibiting IL-17 production of MAIT by improving mitochondrial function.

Tumor mutation burden in blood predicts benefit from neoadjuvant chemo/radiotherapy in locally advanced rectal cancer

Distant metastasis has been the major concern of prognosis in patients with locally advanced rectal cancer (LARC). The purpose of this study was to investigate the prognostic value of TMB in blood (bTMB) in LARC patients after receiving neoadjuvant chemoradiotherapy (nCRT) and surgery. Using targeted ctDNA sequencing, we revealed that bTMB level at baseline was positively correlated with recurrence-free survival (RFS). Following nCRT, the patients with decreasing TMB tends to have a longer median RFS. bTMB level after surgery was negatively correlated with RFS. The serum cytokines including IFNγ, IFNα2, IL-1β, IL-2 and MIP-1β were significantly higher in pre-nCRT serum with higher bTMB group than that of lower bTMB group. Clonal evolution analysis showed that the pre- and post-nCRT ctDNAs of most cases had shared mutations. In conclusion, we presume that bTMB could potentially improve pre- and post-treatment risk assessment and facilitate individualized therapy for patients with LARC.

Reduction of colitis-associated colon carcinogenesis by a black lentil water extract through inhibition of inflammatory and immunomodulatory cytokines

The objective was to compare the impact of black lentil (BL) water and delphinidin 3-O-(2-O-β-d-glucopyranosyl-α-l-arabinopyranoside) (D3G)-rich lentil extracts on tumor development, inflammation and immune response in an azoxymethane (AOM)/dextran sodium sulfate (DSS) model. C57BL/6 mice were randomly separated into four groups: healthy control (n = 6), AOM/DSS control (n = 14), AOM/DSS + BL (600 mg/kg body wt, n = 12) and AOM/DSS + D3G (41 mg/kg body wt, equivalent to D3G concentration in BL, n = 12). Mice were given treatments for 11 weeks using a voluntary jelly administration. AOM/DSS + BL presented a lower (P < 0.05) disease activity index, throughout and at the end (2.4) compared with AOM/DSS (6.3). AOM/DSS + BL mice had an average of 7.8 neoplasms versus 12.8 for the AOM/DSS (P < 0.05). Proinflammatory cytokines were downregulated in the colon mucosa: interleukin (IL)-1β (-77.5%, -70.7%) and IL-6 (-44.4%, -44.9%) by AOM/DSS + BL and AOM/DSS + D3G, respectively, compared with AOM/DSS. IL-6 protein expression was decreased by BL in plasma (-72.6%) and gene expression in colon polyps (fold change: -4.0) compared with AOM/DSS. AOM/DSS + D3G non-polyp tissue gene expression clustered with the healthy control tissue with only four genes modified (secreted phosphoprotein 1 and CXC motif chemokine ligands 2, 5 and 10). AOM/DSS + BL downregulated programmed death-ligand 1 protein expression in colon tissue (-54.7%) and gene expression by 2.8-fold compared with the AOM/DSS control. In fecal samples, gallic and protocatechuic acids and epicatechin were found, and concentration of most amino acids was lower and unsaturated fatty acids were higher for AOM/DSS + BL and AOM/DSS + D3G. BL and D3G-rich extracts showed anti-inflammatory and proimmune response effects while BL additionally prevented growth of neoplasia.

Imatinib exhibit synergistic pleiotropy in the prevention of colorectal cancer by suppressing proinflammatory, cell survival and angiogenic signaling

Recent global incidences and mortality rates have placed colorectal cancer (CRC) at third and second positions, respectively, among both sexes of all ages. Resistance during chemotherapy is a big problem in the treatment and disease-free survival of CRC patients. Discovery of new anticancer drug(s) is a time taking process and therefore, invites studies for repurposing the known therapeutics. The present study was conceived to analyze the anticancer role of Imatinib in experimental CRC at early stages. Different experimental procedures e.g. tumor incidences or histoarchitectural changes, gene and protein expression analysis, estimations of intracellular calcium, ROS, mitochondrial membrane potential, apoptotic index and molecular docking was performed to support the hypothesis. It was observed that Imatinib could function as an immunomodulator by breaking the feed-back loop between the proinflammatory cytokines (IL-1β and TNF-α) and transcription factors (NF-κB, Jak3/Stat3) knowingly involved in increased cell proliferation during tumorigenesis via activating different intracellular signaling. Also, Imatinib could independently deregulate the other cell survival and proliferation signaling e.g. PI3-K/Akt/mTOR, Wnt/β-catenin and MAPK. Proinflammatory cytokines orchestrated intracellular signaling also involve angiogenic factors to be upregulated during CRC which were also seemed to be independently suppressed by Imatinib. Restoration of physiological apoptosis by increasing the release of intracellular calcium to generate ROS thereby reducing the mitochondrial membrane potential for the release of cytochrome c and activation of caspase-3 was also reported with Imatinib administration. Thus, it may be suggested that Imatinib show synergistic pleiotropy in suppressing the interlinked tumorigenic signaling pathways independently.

Multi-omics Analysis Reveals Adipose-tumor Crosstalk in Patients with Colorectal Cancer

Obesity and obesity-driven cancer rates are continuing to rise worldwide. We hypothesize that adipocyte-colonocyte interactions are a key driver of obesity-associated cancers. To understand the clinical relevance of visceral adipose tissue in advancing tumor growth, we analyzed paired tumor-adjacent visceral adipose, normal mucosa, and colorectal tumor tissues as well as presurgery blood samples from patients with sporadic colorectal cancer. We report that high peroxisome proliferator-activated receptor gamma (PPARG) visceral adipose tissue expression is associated with glycoprotein VI (GPVI) signaling-the major signaling receptor for collagen-as well as fibrosis and adipogenesis pathway signaling in colorectal tumors. These associations were supported by correlations between PPARG visceral adipose tissue expression and circulating levels of plasma 4-hydroxyproline and serum intercellular adhesion molecule 1 (ICAM1), as well as gene set enrichment analysis and joint gene-metabolite pathway results integration that yielded significant enrichment of genes defining epithelial-to-mesenchymal transition-as in fibrosis and metastasis-and genes involved in glycolytic metabolism, confirmed this association. We also reveal that elevated prostaglandin-endoperoxide synthase 2 (PTGS2) colorectal tumor expression is associated with a fibrotic signature in adipose-tumor crosstalk via GPVI signaling and dendritic cell maturation in visceral adipose tissue. Systemic metabolite and biomarker profiling confirmed that high PTGS2 expression in colorectal tumors is significantly associated with higher concentrations of serum amyloid A and glycine, and lower concentrations of sphingomyelin, in patients with colorectal cancer. This multi-omics study suggests that adipose-tumor crosstalk in patients with colorectal cancer is a critical microenvironment interaction that could be therapeutically targeted.See related spotlight by Colacino et al., p. 803.

Gut Microbiota-Mediated Inflammation and Gut Permeability in Patients with Obesity and Colorectal Cancer

Obesity is considered an important factor that increases the risk of colorectal cancer (CRC). So far, the association of gut microbiota with both obesity and cancer has been described independently. Nevertheless, a specific obesity-related microbial profile linked to CRC development has not been identified. The aim of this study was to determine the gut microbiota composition in fecal samples from CRC patients with (OB-CRC) and without obesity (L-CRC) compared to the microbiota profile present in non-obese healthy controls (L-HC), in order to unravel the possible relationship between gut microbiota and microbial-derived metabolite trimethylamine N-oxide (TMAO), the inflammatory status, and the intestinal permeability in the context of obesity-associated CRC. The presence of obesity does not induce significant changes in the diversity and richness of intestinal bacteria of CRC patients. Nevertheless, OB-CRC patients display a specific gut microbiota profile characterized by a reduction in butyrate-producing bacteria and an overabundance of opportunistic pathogens, which in turn could be responsible, at least in part, for the higher levels of proinflammatory cytokine IL-1β, the deleterious bacterial metabolite TMAO, and gut permeability found in these patients. These results suggest a possible role of obesity-related gut microbiota in the development of CRC, which could give new clues for the design of new diagnostic tools for CRC prevention.

Serum cytokine profile as a potential prognostic tool in colorectal cancer patients - one center study

Aim

Comparison of 14 cytokines levels between a control group and prospectively enrolled CRC patients to confirm their significance in CRC development. We tested if a model based on 14 cytokines levels could predict prognosis in Caucasian CRC patients treated with 5-FU based chemotherapy.

Background

Novel prognostic tools in colorectal cancer (CRC) are necessary to optimize treatment, reduce toxicity and chemotherapy (CHT) costs.

Materials and Methods

We assessed prognostic significance of 14 cytokines: IL-1 beta, IL-1RA, IL-2, IL-4, IL-5, IL-6, IL-7, IL-8, IL-9, IL-10, IL12p70, IL-13, IL-17A in 75 prospectively enrolled CRC patients before initiation of palliative or adjuvant CHT and in 22 control subjects. Readings were taken using the Bio-Plex 200 System. Response to treatment was assessed after 6 months from initiation of CHT. The treated group was divided depending on the response into a progressors (death, progression of disease) and non-progressors group (stable disease, partial response, complete response).

Results

We found that increased concentration of IL-8 was a negative prognostic factor in the whole group and palliative subgroup, whereas increased level of IL-10, IL-7, and IL-12p70 was a negative predictor in the adjuvant group CHT.

Conclusions

We proposed a statistical model based on circulating cytokine levels, showing a good prognostic value in prediction of the response to CHT (AUC = 0.956). The model, including combined IL-2, IL-8, IL-10 and IL-13 levels, established in the whole treated group, should be validated in larger trials.

An overview of the role of interleukin-8 in colorectal cancer

Colorectal Cancer (CRC), a common malignancy, is developing globally among people. Mutagenic insults activate peripheral nucleated cells to secrete chemokines in order to cause an inflammatory state. Despite the presence of multi-retrieving factors, elevated production of minor cytokines may speed-up the sever stages of the baseline inflammation targeting normal compensatory mechanism. IL-8 is a pro-inflammatory cytokine that is believed to be up-regulated in CRC to proceed primary condition into tumor behavior via induction of proliferation, angiogenesis and metastasis. Here, we assess the role of IL-8 in every step of CRC from signaling pathway and formation to invasion and discuss around new perspective therapy that targets IL-8 to manage CRC worldwide incidence and survival rate, more precisely.

Combinatorial Immunotherapies for Metastatic Colorectal Cancer

Colorectal cancer (CRC) is one of the most frequent and deadly forms of cancer. About half of patients are affected by metastasis, with the cancer spreading to e.g., liver, lungs or the peritoneum. The majority of these patients cannot be cured despite steady advances in treatment options. Immunotherapies are currently not widely applicable for this disease, yet show potential in preclinical models and clinical translation. The tumour microenvironment (TME) has emerged as a key factor in CRC metastasis, including by means of immune evasion-forming a major barrier to effective immuno-oncology. Several approaches are in development that aim to overcome the immunosuppressive environment and boost anti-tumour immunity. Among them are vaccination strategies, cellular transplantation therapies, and targeted treatments. Given the complexity of the system, we argue for rational design of combinatorial therapies and consider the implications of precision medicine in this context.

IL-34, IL-36 and IL-38 in colorectal cancer-key immunoregulators of carcinogenesis

Colorectal cancer (CRC) is still a big killer nowadays, but the precise underlying mechanism remains to be explored. It is believed that imbalance of host immunity in the local microenvironment plays a critical role in the tumorigenesis of CRC. IL-34 is inversely correlated with overall survival in CRC patients, perhaps via regulating terminal differentiation of a subset of macrophages (M2). It is believed that the recruitment/differentiation of M2 macrophages within the cancer simply represents an increase in number, but the function of these M2 macrophages may be compromised. IL-36s (IL-36α, β and γ) are constitutively expressed in non-cancer colon tissue, but colonic IL-36α, IL-36β and IL-36γ are substantially reduced in the CRC tissues (~ 80%). IL-36α is an independent factor affecting the survival of CRC patients. The level of IL-36α and/or IL-36γ in CRC tissue could potentially be used as biomarkers for predicting the prognosis of CRC at both the later or early stages of CRC. IL-38 is also an anti-inflammatory cytokine. Colonic IL-38 is ~ 95% lower in CRC compared to non-CRC colonic tissue, consistent with the positive correlation between differentiation of CRC, and colonic tumour expression of IL-38. IL-38 is a reliable/sensitive biomarker for distinguishing between CRC and non-cancer colonic tissue. There is a positive correlation between colonic IL-38 in CRC and prognosis and/or overall survival, particularly in advanced CRC, supporting IL-38 probably being a reliable and consistent independent factor in predicting the prognosis of CRC. The findings above may be useful in exploring therapeutic targeting for precision medicine.

The chemopreventive effect of 5-demethylnobiletin, a unique citrus flavonoid, on colitis-driven colorectal carcinogenesis in mice is associated with its colonic metabolites

5-Demethylnobiletin (5DN) is a unique flavonoid mainly found in citrus fruits. In this study, we determined the chemopreventive effects of 5DN and its major colonic metabolites on both a colitis-driven colon carcinogenesis mouse model and a human colon cancer cell model. In azoxymethane/dextran sulfate sodium-treated mice, dietary 5DN (0.05% w/w in the diet) significantly decreased the tumor incidence, multiplicity and burden, and showed potent anti-proliferative, proapoptotic, and anti-inflammatory activities in mouse colon tissue. Three major metabolites of 5DN, named 5,3'-didemethylnobiletin (M1), 5,4'-didemethylnobiletin (M2) and 5,3',4'-tridemethylnobiletin (M3), were found in the colonic mucosa of 5DN-treated mice, and the combined level of these metabolites in mouse colonic mucosa was 1.56-fold higher than that of 5DN. Cell culture studies revealed that 5DN and its colonic metabolites profoundly inhibited the growth of human colon cancer cells by inducing cell cycle arrest, triggering apoptosis and modulating key signaling proteins related to cell proliferation and apoptosis. Importantly, the colonic metabolites, especially M1, showed much stronger effects than those produced by 5DN itself. Overall, our results demonstrated that dietary 5DN significantly inhibited colitis-driven colon carcinogenesis in mice, and this chemopreventive effect was associated with its metabolites in the colon.

The relationships between systemic cytokine profiles and inflammatory markers in colorectal cancer and the prognostic significance of these parameters

BACKGROUND

Immunomodulatory cytokines and systemic inflammatory markers are important during cancer development and progression. This study investigated the association and prognostic impact of systemic cytokine profiles and inflammatory markers in colorectal cancer (CRC).

METHODS

Interleukin (IL)-1β, IL-6, IL-8, IL-9, IL-10, tumour necrosis factor (TNF)-α and vascular endothelial growth factor (VEGF) serum levels were measured using multiplex bead assays in CRC patients. Data on systemic inflammatory markers, such as the modified Glasgow prognostic score (mGPS), the neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), lymphocyte-to-monocyte ratio (LMR), prognostic nutritional index (PNI) and fibrinogen, were collected. Survival analysis was performed to identify factors associated with progression-free survival (PFS) and overall survival (OS).

RESULTS

There were moderate-to-strong correlations within serum cytokines, as well as within systemic inflammatory markers, whereas the associations between serum cytokines and systemic inflammatory markers were generally weak. IL-8 and the LMR were independent significant prognostic factors for PFS and OS. The low IL-8 and high LMR group had the best survival (both PFS and OS) of all groups.

CONCLUSIONS

Systemic cytokine profiles and inflammatory markers have relatively weak intergroup correlations. A composite classification of systemic cytokine profiles and inflammatory markers has an enhanced prognostic value in CRC.

A Role for MAIT Cells in Colorectal Cancer

MAIT cells are MR1-restricted T cells that are well-known for their anti-microbial properties, but they have recently been associated with different forms of cancer. Several studies have reported activated MAIT cells within the microenvironment of colorectal tumors, but there is conjecture about the nature of their response and whether they are contributing to anti-tumor immunity, or to the progression of the disease. We have reviewed the current state of knowledge about the role of MAIT cells in colorectal cancer, including their likely influence when activated and potential sources of stimulation in the tumor microenvironment. The prospects for MAIT cells being used in clinical settings as biomarkers or as targets of new immunotherapies designed to harness their function are discussed.

Immunogenetic markers in IL17F predict the risk of metastases spread and overall survival in rectal cancer patients treated with neoadjuvant chemoradiotherapy

BACKGROUND AND PURPOSE

The role of the immune system in tumor response to chemo-radiotherapy (CRT) is an emerging issue. This work aimed at identifying predictive and prognostic immunogenetic variants in LARC patients after preoperative (po)-CRT and surgery.

MATERIALS AND METHODS

A set of 192 polymorphisms in 34 candidate genes involved in the regulation of the immune response signalling network, was selected and analyzed in 370 LARC patients treated with po-CRT and surgery, split into a Test Set (n = 233) and a Validation Set (n = 137). Immunogenetic markers were selected based on a concordant significant effect on 2-year relapse-free survival (2-yrRFS) (bootstrapped P < 0.05) in both patients Sets. The effect of the selected immunogenetic variants on 5-year metastases-free (5yrMFS), 5-year disease-free (5yrDFS), and 10-year overall (10yrOS) survival was tested in the entire Set of 370 patients.

RESULTS

Two immunogenetic IL17F (IL17F-rs641701 and IL17F-rs9463772) markers predictive of 2yrRFS, 5yrDFS, 5yrMFS, and 10yrOS were identified. The combination of tumor regression grade (TRG) and patients genotype for IL17F-rs641701 and IL17F-rs9463772 allowed the identification of subgroups of patients with differential prognosis in term of both 5yrDFS (HR 11.29, P-value <0.001, and HR 5.86, P-value = 0.001, respectively) and 10yrOS (HR 7.07, P-value = 0.005, and HR 6.05, P-value = 0.002, respectively).

CONCLUSION

IL17F-rs641701 and IL17F-rs9463772 were highlighted as promising immunogenetic markers significantly associated with the prognosis of LARC patients. After a prospective validation of the herein reported findings, the combination of TRG and patients genotype should be considered to provide additional stratification criteria for the selection of a personalized multimodality treatment.

Immune battle at the premalignant stage of colorectal cancer: focus on immune cell compositions, functions and cytokine products

It is now widely accepted that most human cancers, including colorectal cancers (CRCs), develop from premalignant lesions through a long-term multistep process. Host immunity is a key determinant that maintains most premalignant lesions in a stable state via immunosurveillance. However, premalignant cells use diverse strategies to escape host immunosurveillance. A switch in the immune function from immunosurveillance to immunosuppression facilitates the progression of premalignant lesions to established CRCs. This review summarizes the recent progress in understanding alterations in the immune landscape, including immune cell compositions, functions and cytokine products, in the premalignant stage of CRC and provides an updated discussion on its translational significance along the colorectal adenoma-carcinoma sequence.

Cytokines regulate the antigen-presenting characteristics of human circulating and tissue-resident intestinal ILCs

ILCs and T helper cells have been shown to exert bi-directional regulation in mice. However, how crosstalk between ILCs and CD4⁺ T cells influences immune function in humans is unknown. Here we show that human intestinal ILCs co-localize with T cells in healthy and colorectal cancer tissue and display elevated HLA-DR expression in tumor and tumor-adjacent areas. Although mostly lacking co-stimulatory molecules ex vivo, intestinal and peripheral blood (PB) ILCs acquire antigen-presenting characteristics triggered by inflammasome-associated cytokines IL-1β and IL-18. IL-1β drives the expression of HLA-DR and co-stimulatory molecules on PB ILCs in an NF-κB-dependent manner, priming them as efficient inducers of cytomegalovirus-specific memory CD4⁺ T-cell responses. This effect is strongly inhibited by the anti-inflammatory cytokine TGF-β. Our results suggest that circulating and tissue-resident ILCs have the intrinsic capacity to respond to the immediate cytokine milieu and regulate local CD4⁺ T-cell responses, with potential implications for anti-tumor immunity and inflammation.

Murine ILCs can modulate T cell responses in MHCII-dependent manner. Here the authors show that human ILCs process and present antigens and induce T-cell responses upon exposure to IL-1-family cytokines; along with the article by Lehmann et al, this work elucidates how cytokines set context specificity of ILC-T cell crosstalk by regulating ILC antigen presentation.

Topical Anti-Inflammatory Activity of Essential Oils of Alpinia calcarata Rosc., Its Main Constituents, and Possible Mechanism of Action

This study aimed at investigating the anti-inflammatory potential of essential oil from rhizome and leaf of Alpinia calcarata Rosc. (ACEO) with the focus of its topical anti-inflammatory activity along with its dominant compounds 1,8-cineole and α-terpineol using mouse ear edema model. ACEOs were analyzed by GC-MS. The anti-inflammatory activity was determined by studying the inhibition of overproduction of proinflammatory mediators-nitric oxide, reactive oxygen species, prostaglandins, cyclooxygenases, and cytokines induced by lipopolysaccharides in murine macrophages. Topical anti-inflammatory and antinociceptive activity was studied by 12-O-tetradecanoylphorbol-13-acetate (TPA) induced skin inflammation and formalin-induced pain model in mice, respectively. Rhizome oil has 1,8-cineole (31.08%), α-terpineol (10.31%), and fenchyl acetate (10.73%) as major compounds whereas the ACEO from leaves has 1,8-cineole (38.45%), a-terpineol (11.62%), and camphor (10%). ACEOs reduced the production of inflammatory mediators in vitro in a concentration-dependent manner. Further, ACEO and its major compounds reduced ear thickness, weight, myeloperoxidase, and cytokines significantly (p < 0.01) in mouse ear. Dose-dependent reduction in flinching and licking in both the phases of pain sensation concludes the topical analgesic effect. Our findings suggest the potency of topical use of ACEOs for inflammatory disease conditions.

Targeted MIP-3β plasmid nanoparticles induce dendritic cell maturation and inhibit M2 macrophage polarisation to suppress cancer growth

In recent decades, cancer immunotherapy has demonstrated considerable clinical advantages in cancer therapy. Particularly, the use of immunological gene therapy continues to grow in this field. Macrophage Inflammatory Protein 3 Beta (MIP-3β) has emerged as a potential immunomodulator for anti-cancer treatments by enhancing the interaction among immune responses. In this study, we demonstrate an innovative targeted gene delivery system based on a self-assembly technique with 1,2-Dioleoyl-3-trimethylammonium-propane (DOTAP), Methoxy poly(ethylene glycol)-poly(lactide) (MPEG-PLA), and folic acid modified poly(ethylene glycol)-poly(ε-caprolactone) (FA-PEG-PCL) (FDMCA). Results showed that the expression of MIP-3β was up-regulated in cancer cells following the transfection with FDMCA-pMIP-3β, in comparison with cells transfected with DMCA-pMIP-3β. The supernatants collected from cancer cells transfected with FDMCA-pMIP-3β and DMCA-pMIP-3β both instigate dendritic cell maturation, M1 polarisation of macrophages, activation and presentation of cytotoxicity in lymphocytes. Moreover, tumor growth and metastasis were markedly inhibited following the administration of the FDMCA-pMIP-3β complex in both subcutaneous and pulmonary metastasis mice models, which is attributed to reduced angiogenesis, enhanced cancer cell apoptosis, and suppressed proliferation by activation of the immune system. Our study suggests that the MIP-3β plasmid and FDMCA complex provide a new approach for the treatment of breast cancer.

Gut Microbiota Modulate CD8 T Cell Responses to Influence Colitis-Associated Tumorigenesis

There is increasing evidence that gut microbiome perturbations, also known as dysbiosis, can influence colorectal cancer development. To understand the mechanisms by which the gut microbiome modulates cancer susceptibility, we examine two wild-type mouse colonies with distinct gut microbial communities that develop significantly different tumor numbers using a mouse model of inflammation-associated tumorigenesis. We demonstrate that adaptive immune cells contribute to the different tumor susceptibilities associated with the two microbial communities. Mice that develop more tumors have increased colon lamina propria CD8+ IFNγ+ T cells before tumorigenesis but reduced CD8+ IFNγ+ T cells in tumors and adjacent tissues compared with mice that develop fewer tumors. Notably, intratumoral T cells in mice that develop more tumors exhibit increased exhaustion. Thus, these studies suggest that microbial dysbiosis can contribute to colon tumor susceptibility by hyperstimulating CD8 T cells to promote chronic inflammation and early T cell exhaustion, which can reduce anti-tumor immunity.

ST2 and regulatory T cells in the colorectal adenoma/carcinoma microenvironment: implications for diseases progression and prognosis

ST2 (also known as IL1RL1) is the critical functional receptor for interleukin (IL)-33 in stimulating regulatory T cell (Treg) expansion and function in physiological and pathological conditions. We examined the correlation between ST2 cell expression and FoxP3 positive Tregs in both colorectal adenoma and cancer (CRC) microenvironment by real-time PCR, immunohistochemistry (IHC) and double immunofluorescences. The clinicopathological and prognostic significance of cellular ST2-positive cells and FoxP3-positive Tregs in patients with adenoma and CRC were evaluated. Real-time PCR results revealed increased expression levels of ST2 and FoxP3 mRNAs in both adenoma and CRC tissues as compared with control tissues. IHC analysis confirmed increased densities of ST2-positive cells in both the adenoma/CRC epithelium and stroma, which show a close positive linear association with the densities of FoxP3-positive Tregs in respective compartments. Pathological feature analysis showed that densities of ST2-positive cells in the tumor stroma were notably associated with degree of dysplastic grading in patients with adenoma, and disease stages and lymph node metastasis in patients with CRC. Kaplan-Meier survival curves suggested that CRC patients with high densities of ST2-positive cells in the stroma tend to have a shorter overall survival. We therefore concluded that increased densities of ST2-postive cells relate to Treg accumulation within the adenoma/CRC microenvironment, suggesting the IL-33/ST2 pathway as a potential contributor for immunosuppressive milieu formation that impact disease stage and prognosis in patients with CRC.

A Nine-Gene Signature for Predicting the Response to Preoperative Chemoradiotherapy in Patients with Locally Advanced Rectal Cancer

Preoperative chemoradiotherapy (PCRT) and subsequent surgery is the standard multimodal treatment for locally advanced rectal cancer (LARC), albeit PCRT response varies among the individuals. This creates a dire necessity to identify a predictive model to forecast treatment response outcomes and identify patients who would benefit from PCRT. In this study, we performed a gene expression study using formalin-fixed paraffin-embedded (FFPE) tumor biopsy samples from 156 LARC patients (training cohort n = 60; validation cohort n = 96); we identified the nine-gene signature (FGFR3, GNA11, H3F3A, IL12A, IL1R1, IL2RB, NKD1, SGK2, and SPRY2) that distinctively differentiated responders from non-responders in the training cohort (accuracy = 86.9%, specificity = 84.8%, sensitivity = 81.5%) as well as in an independent validation cohort (accuracy = 81.0%, specificity = 79.4%, sensitivity = 82.3%). The signature was independent of all pathological and clinical features and was robust in predicting PCRT response. It is readily applicable to the clinical setting using FFPE samples and Food and Drug Administration (FDA) approved hardware and reagents. Predicting the response to PCRT may aid in tailored therapies for respective responders to PCRT and improve the oncologic outcomes for LARC patients.