Model Of Colitis-associated Colorectal Cancer Research Articles

Exposure to microcystin-LR promotes the progression of colitis-associated colorectal cancer by inducing barrier disruption and gut microbiota dysbiosis

Microcystins (MCs) are secondary metabolites generated by cyanobacterial blooms, among which microcystin-LR (MC-LR) stands out as the most widely distributed variant in aquatic environments. However, the effects of MC-LR on the colorectum and its role in promoting colorectal tumor progression remain unclear. Therefore, this study aims to scrutinize the impact of MC-LR on a mice model of colitis-associated colorectal cancer and elucidate the potential underlying molecular mechanisms. In this study, we used AOM/DSS mice and orally administered MC-LR at doses of 40 µg/kg or 200 µg/kg. Exposure to MC-LR increased tumor burden, promoted tumor growth, shortened colon size, and decreased goblet cell numbers and tight junction protein levels in intestinal tissues. Additionally, exposure to MC-LR induced alterations in the structure of gut microbiota in the mouse colon, characterized by an increase in the relative abundance of Escherichia_coli and Shigella_sonnei, and a decline in the relative abundance of Akkermansia_muciniphila. Transcriptomic analysis revealed that MC-LR exposure activated the IL-17 signaling pathway in mouse colorectal tissues and participated in inflammation regulation and immune response. Immunofluorescence results demonstrated an increase in T-helper 17 (Th17) cell levels in mouse colorectal tumors following MC-LR exposure. The results from RT-qPCR revealed that MC-LR induced the upregulation of IL-6, IL-1β, IL-10, IL-17A, TNF-α, CXCL1, CXCL2, CXCL5 and CCL20. The novelty of this study lies in its comprehensive approach to understanding the mechanisms by which MC-LR may contribute to CRC progression, offering new perspectives and valuable reference points for establishing guidance standards regarding MC-LR in drinking water. Our findings suggest that even at guideline value, MC-LR can have profound effects on susceptible mice, emphasizing the need for a reevaluation of guideline value and a deeper understanding of the role of environmental toxins in cancer progression.

Tong-Xie-Yao-Fang induces mitophagy in colonic epithelial cells to inhibit colitis-associated colorectal cancer

Ethnopharmacological relevanceBased on the core pathogenesis of hepatosplenic disorder and qi transformation disorder in ulcerative colitis, Tong-Xie-Yao-Fang (TXYF) is a classical traditional Chinese medicine commonly used to treat ulcerative colitis. Our study revealed that it has the potential to prevent colitis-associated colorectal cancer, which embodies the academic concept in traditional Chinese medicine of treating the disease before it develops. Aim of the studyThis study was aimed at evaluating the therapeutic role of TXYF in treating colitis-associated colorectal cancer and exploring its possible underlying mechanisms. Materials and methodsA colitis-associated colorectal cancer model was established in mice using azoxymethane and dextran sulfate sodium salt to examine the therapeutic effect of TXYF. The mouse body weights were observed. Hematoxylin-eosin staining was used to evaluate mouse colon histopathology. Colon cancer cells and colon epithelial cells were used to explore the potential molecular mechanisms. The proliferation and apoptosis of cells were detected by CCK8 and cell colony assays, flow cytometry and western blotting. The epithelial–mesenchymal transition (EMT) and mitophagy markers were examined by immunohistochemistry, western blotting, quantitative real-time PCR and immunofluorescence staining. ResultsTXYF inhibited the tumorigenesis of mice with colitis-associated colorectal cancer and the growth of inflammatory colon cells. TXYF induced mitophagy in colon cancer cells through the PTEN-induced putative kinase 1 (PINK1)/Parkin pathway to reverse EMT, which was consistent with the results in mice with colitis-associated colorectal cancer. ConclusionsThe results of the present study demonstrated that TXYF effectively inhibited the progression of colitis-associated colorectal cancer through the PINK1/Parkin pathway, which provides new evidence for prevention strategies for this disease.

The role of bidirectional communication between the adipokines and the endogenous opioid system in an experimental mouse model of colitis-associated colorectal cancer.

Colorectal cancer (CRC) is one of the leading causes of death globally. Multiple factors may contribute to the pathogenesis of CRC, including the abnormalities in the functioning of the endogenous opioid system (EOS) or adiponectin-related signaling. The aim of our study was to evaluate if differences in the expression of opioid receptors (ORs) influence the development of CRC and if modulation of adiponectin receptors using AdipoRon, a selective AdipoR1 receptor agonist, affects colorectal carcinogenesis. Naltrexone, an opioid receptor antagonist, was injected intraperitoneally every second day for 2weeks, at the dose of 1mg/kg in healthy Balb/C mice to induce changes in ORs expression. CRC was induced by a single intraperitoneal injection of azoxymethane (AOM) and the addition of dextran sodium sulfate (DSS) into drinking water in three-week cycles. The development of CRC was assessed using macro- and microscopic scoring and molecular analysis (RT qPCR, ELISA)after 14 weeks. Naltrexone significantly increased the mRNA expression of Oprm1, Oprd1, and Oprk1 in the mouse colon and in the brain (non-significantly). The pretreatment of mice with naltrexone aggravated the course of CRC (as indicated by tumor area, colon thickness, and spleen weight). The level of circulatory adiponectin was lowered in mice with CRC and increased in the colon as compared with healthy mice. The β-endorphin level was increased in the plasma of mice with CRC and decreased in the colon as compared to healthy mice. AdipoRon, AdipoR1 agonist, worsened the CRC development, and pretreatment with naltrexone enhanced this negative effect in mice. CRC did not affect the expression of the Adipor1 gene, but the Adipor1 level was increased in mice pretreated with naltrexone (AOM/DSS and healthy mice). AdipoRon did not influence the expression of opioid receptors at the mRNA level in the colon of mice with CRC. The mRNA expression of Ptgs2, Il6, Nos2, Il1b, Il18, Gsdmd, and Rela was increased in mice with CRC as compared to the healthy colon. AdipoRon significantly decreased mRNA expression of Ptgs2, Il6, Il1b, and Il18 as compared to CRC mice. EOS and adiponectin-related signaling may play a role in the pathogenesis of CRC and these systems may present some additivity during carcinogenesis.

SCF and IL-33 regulate mouse mast cell phenotypic and functional plasticity supporting a pro-inflammatory microenvironment

Mast cells (MCs) are multifaceted innate immune cells often present in the tumor microenvironment (TME). Several recent findings support their contribution to the transition from chronic inflammation to cancer. However, MC-derived mediators can either favor tumor progression, inducing the spread of the tumor, or exert anti-tumorigenic functions, limiting tumor growth. This apparent controversial role likely depends on the plastic nature of MCs that under different microenvironmental stimuli can rapidly change their phenotype and functions. Thus, the exact effect of unique MC subset(s) during tumor progression is far from being understood. Using a murine model of colitis-associated colorectal cancer, we initially characterized the MC population within the TME and in non-lesional colonic areas, by multicolor flow cytometry and confocal microscopy. Our results demonstrated that tumor-associated MCs harbor a main connective tissue phenotype and release high amounts of Interleukin (IL)-6 and Tumor Necrosis Factor (TNF)-α. This MC phenotype correlates with the presence of high levels of Stem Cell Factor (SCF) and IL-33 inside the tumor. Thus, we investigated the effect of SCF and IL-33 on primary MC cultures and underscored their ability to shape MC phenotype eliciting the production of pro-inflammatory cytokines. Our findings support the conclusion that during colonic transformation a sustained stimulation by SCF and IL-33 promotes the accumulation of a prevalent connective tissue-like MC subset that through the secretion of IL-6 and TNF-α maintains a pro-inflammatory microenvironment.

A Short-Term Model of Colitis-Associated Colorectal Cancer That Suggests Initial Tumor Development and the Characteristics of Cancer Stem Cells.

The mechanisms underlying the transition from colitis-associated inflammation to carcinogenesis and the cell origin of cancer formation are still unclear. The azoxymethane (AOM)/dextran sodium sulfate (DSS) mouse model reproduces human colitis-associated colorectal cancer. To elucidate the mechanisms of cancer development and dynamics of the linker threonine-phosphorylated Smad2/3 (pSmad2/3L-Thr)-positive cells, we explored the early stages of colitis-associated colorectal cancer in AOM/DSS mice. The AOM/DSS mice were sacrificed at 4 to 6 weeks following AOM administration. To analyze the initial lesions, immunofluorescence staining for the following markers was performed: β-catenin, Ki67, CDK4, Sox9, Bmi1, cyclin D1, and pSmad2/3L-Thr. Micro-neoplastic lesions were flat and unrecognizable, and the uni-cryptal ones were either open to the surfaces or hidden within the mucosae. These neoplastic cells overexpressed β-catenin, Sox9, Ki67, and Cyclin D1 and had large basophilic nuclei in the immature atypical cells. In both the lesions, pSmad2/3L-Thr-positive cells were scattered and showed immunohistochemical co-localization with β-catenin, CDK4, and Bmi1 but never with Ki67. More β-catenin-positive neoplastic cells of both lesions were detected at the top compared to the base or center of the mucosae. We confirmed initial lesions in the colitis-associated colorectal cancer model mice and observed results that suggest that pSmad2/3L-Thr is a biomarker for tissue stem cells and cancer stem cells.

Overexpression of Mitochondrial Catalase in Adipose Tissue Improves Survival and Cardiac Cachexia in AOM-DSS Model of Colitis-associated Colorectal Cancer

Overexpression of Mitochondrial Catalase in Adipose Tissue Improves Survival and Cardiac Cachexia in AOM-DSS Model of Colitis-associated Colorectal Cancer

Ginsenoside Rb1 Suppresses AOM/DSS-induced Colon Carcinogenesis.

Colorectal cancer (CRC) is the third most common cancer worldwide. Current treatments, including surgery, radiotherapy, and chemotherapy, are limited by severe side effects and the development of resistance. Therefore, it is important to find additional therapies to combat the problem. Ginsenoside Rb1 is the main active ingredient of ginseng, which is a well-known herb in traditional Chinese medicine. Ginsenoside is reported to play an important role in the prevention and treatment of cancer. We established Azoxymethane (AOM)/Dextran sodium sulfate (DSS) colon cancer model based on inflammation, observed the beneficial effect of ginsenoside Rb1, and detected the changes in gut microbiota. Our experimental results showed that ginsenoside Rb1 significantly reduced the levels of TNF-α, IL-6, IL- 17A, IL-33, IL-1β, and IL-22, increased the level of IL-10, and also changed the gut microbiota composition. These results suggested that ginsenoside Rb1 can be used to prevent inflammation-associated CRC development and may provide an effective therapeutic strategy for CRC by relieving chronic inflammation and restoring the gut microenvironment in the AOM/DSS-induced model of colitis-associated colorectal cancer in mice. Ginsenoside Rb1 significantly attenuated AOM/DSS-induced colon carcinogenesis.

Ligature-Induced Periodontitis Drives Colorectal Cancer: An Experimental Model in Mice

Periodontitis is a prevalent inflammatory oral disease associated with an increased risk of colorectal cancer. Experimental animal models are critical tools to investigate the effects and mechanisms of periodontitis on colorectal cancer. Several murine periodontitis models have been used in research, including oral gavage, periodontal pathogen injection, and ligature models. The role of experimental periodontitis caused by silk ligation in colorectal cancer remains unclear. In this study, we used an experimental periodontitis model on a colitis-associated colorectal cancer model and a spontaneous model, respectively. We observed the promotion of colorectal cancer in ligature-induced periodontitis mice compared to those control mice in 2 different models, as assessed by tumor number, tumor size, and tumor load. Since bacterial dysbiosis is an important feature of periodontitis, we next analyzed the oral and gut microbiomes using 16S ribosomal RNA gene sequencing. We found that the experimental periodontitis model reshaped the microbial community in the oral cavity and gut. In addition, we found a higher extent of programmed death 1 (PD-1)–positive CD8+ T-cell infiltration in tumor samples of the periodontitis group than in controls by immunofluorescence staining. Regarding the potential molecular mechanism, we transplanted the fecal microbiota of the periodontitis patient into mice and observed a tumor-promoting effect in the periodontitis group, assessed by tumor volume and tumor weight, together with a low level of INF-γ+ CD8+ T-cell infiltration in subcutaneous tumor mice. Taken together, we show that ligature-induced periodontitis model promotes colorectal cancer by microbiota remodeling and suppression of the immune response.

Adeno-Associated Virus-Mediated Knockdown of Agmatinase Attenuates Inflammation and Tumorigenesis in a Mouse Model of Colitis-Associated Colorectal Cancer.

Agmatinase (AGMAT) is an enzyme that hydrolyzes agmatine to putrescine and urea. Here, we explored the functions of AGMAT in colorectal cancer (CRC). By performing gain-of-function and loss-of-function experiments, we investigated the roles of AGMAT in proliferation, cell cycle progression, and apoptosis of CRC cells. We also established a colitis-associated colorectal cancer (CAC) model by challenging mice with azoxymethane (AOM) and dextran sodium sulfate (DSS), and we subsequently silenced AGMAT expression in mice by adeno-associated virus 9 (AAV9)-mediated delivery of short hairpin RNA (shRNA). In vitro experiments showed that overexpression of AGAMT accelerated the proliferation and inhibited the apoptosis of CRC cells, and AGMAT knockdown exhibited the opposite effects. Interestingly, the oncogenic transcription factor c-Myc could bind to the AGMAT promoter and transcriptionally increase AGMAT expression in CRC cells. Additionally, c-Myc and AGMAT were upregulated in the colon of AOM/DSS-treated mice, and AGMAT silencing significantly mitigated colitis in AOM/DSS-treated mice, as evidenced by the increased colon length, attenuated crypt damage, and reduced levels of inflammatory indicators (myeloperoxidase, interleukin-6, tumor necrosis factor-α, inducible nitric oxide synthase, and phosphorylated p65) in colon tissues. Notably, AGMAT silencing decreased both the number and size of tumors, reduced expression of proliferating cell nuclear antigen (PCNA), and inhibited the phosphorylation of protein kinase B (AKT) and extracellular signal-regulated kinase (ERK) in the colon of AOM/DSS-treated mice. Overall, we determined that AGMAT facilitates tumor progression in CRC. Our findings will be helpful in the search for potential therapeutic targets for CRC.

The Anti-Tumorigenic Role of Cannabinoid Receptor 2 in Colon Cancer: A Study in Mice and Humans.

The endocannabinoid system, particularly cannabinoid receptor 2 (CB2 in mice and CNR2 in humans), has controversial pathophysiological implications in colon cancer. Here, we investigate the role of CB2 in potentiating the immune response in colon cancer in mice and determine the influence of CNR2 variants in humans. Comparing wild-type (WT) mice to CB2 knockout (CB2-/-) mice, we performed a spontaneous cancer study in aging mice and subsequently used the AOM/DSS model of colitis-associated colorectal cancer and a model for hereditary colon cancer (ApcMin/+). Additionally, we analyzed genomic data in a large human population to determine the relationship between CNR2 variants and colon cancer incidence. Aging CB2-/- mice exhibited a higher incidence of spontaneous precancerous lesions in the colon compared to WT controls. The AOM/DSS-treated CB2-/- and ApcMin/+CB2-/- mice experienced aggravated tumorigenesis and enhanced splenic populations of immunosuppressive myeloid-derived suppressor cells along with abated anti-tumor CD8+ T cells. Importantly, corroborative genomic data reveal a significant association between non-synonymous variants of CNR2 and the incidence of colon cancer in humans. Taken together, the results suggest that endogenous CB2 activation suppresses colon tumorigenesis by shifting the balance towards anti-tumor immune cells in mice and thus portray the prognostic value of CNR2 variants for colon cancer patients.

CSN6 mediates nucleotide metabolism to promote tumor development and chemoresistance in colorectal cancer.

Metabolic reprogramming can contribute to colorectal cancer (CRC) progression and therapy resistance. Identification of key regulators of CRC metabolism could provide new approaches to improve treatment and reduce recurrence. Here, we demonstrate a critical role for the COP9 signalosome subunit CSN6 in rewiring nucleotide metabolism in CRC. Transcriptomic analysis of CRC patient samples revealed a correlation between CSN6 expression and purine and pyrimidine metabolism. A colitis-associated colorectal cancer model established that Csn6 intestinal conditional deletion decreased tumor development and altered nucleotide metabolism. CSN6 knockdown increased the chemosensitivity of CRC cells in vitro and in vivo, which could be partially reversed with nucleoside supplementation. Isotope metabolite tracing showed that CSN6 loss reduced de novo nucleotide synthesis. Mechanistically, CSN6 upregulated purine and pyrimidine biosynthesis by increasing expression of PHGDH, a key enzyme in the serine synthesis pathway. CSN6 inhibited β-Trcp-mediated DDX5 polyubiquitination and degradation, which in turn promoted DDX5-mediated PHGDH mRNA stabilization, leading to metabolic reprogramming and CRC progression. Butyrate treatment decreased CSN6 expression and improved chemotherapy efficacy. These findings unravel the oncogenic role of CSN6 in regulating nucleotide metabolism and chemosensitivity in CRC.

Dietary Supplementation with Black Raspberries Altered the Gut Microbiome Composition in a Mouse Model of Colitis-Associated Colorectal Cancer, although with Differing Effects for a Healthy versus a Western Basal Diet.

Black raspberries (BRB) are rich in anthocyanins with purported anti-inflammatory properties. However, it is not known whether dietary supplementation would ameliorate Western-diet enhanced gut inflammation and colon tumorigenesis. We employed a mouse model of colitis-associated colorectal cancer (CAC) to determine the effects of dietary supplementation with 5 to 10% (w/w) whole, freeze-dried BRB in male C57BL/6J mice fed either a standard healthy diet (AIN93G) or the total Western diet (TWD). In a pilot study, BRB suppressed colitis and colon tumorigenesis while also shifting the composition of the fecal microbiome in favor of taxa with purported health benefits, including Bifidobacterium pseudolongum. In a follow-up experiment using a 2 × 2 factorial design with AIN and TWD basal diets with and without 10% (w/w) BRB, supplementation with BRB reduced tumor multiplicity and increased colon length, irrespective of the basal diet, but it did not apparently affect colitis symptoms, colon inflammation or mucosal injury based on histopathological findings. However, BRB intake increased alpha diversity, altered beta diversity and changed the relative abundance of Erysipelotrichaceae, Bifidobacteriaceae, Streptococcaceae, Rikenellaceae, Ruminococcaceae and Akkermansiaceae, among others, of the fecal microbiome. Notably, changes in microbiome profiles were inconsistent with respect to the basal diet consumed. Overall, these studies provide equivocal evidence for in vivo anti-inflammatory effects of BRB on colitis and colon tumorigenesis; yet, BRB supplementation led to dynamic changes in the fecal microbiome composition over the course of disease development.

De novo engineering of both an omega-3 fatty acid-derived nanocarrier host and a prodrug guest to potentiate drug efficacy against colorectal malignancies

Drug-carrier compatibility impacts drug delivery efficiency and resulting therapeutic efficacy and tolerability. Although numerous biodegradable carrier materials have been pursued over the past decades, chemical strategies that are sought to tailor therapeutic structures and their carriers together in a concerted effort remain rare yet may be powerful. Based on the principle of improving the structural similarity between these central components, we developed an omega-3 fatty acid-conjugated poly(ethylene glycol) (PEG) nanocarrier host that is capable of supramolecular assembly of a cytotoxic prodrug guest. To demonstrate the proof of concept, we ligated two docosahexaenoic acid (DHA) molecules and one PEG chain via a d-lysine linkage to produce an amphiphilic matrix DHA2-PEG, which is suited for the encapsulation of active compounds, including a DHA monoconjugated camptothecin prodrug. The resulting DHA2-PEG-cloaked nanoassemblies show superior stability and rapid cellular uptake compared with those formulated in clinically approved materials. In a chemically induced mouse model of colitis-associated colorectal cancer, administration of the camptothecin nanoassemblies demonstrated notable inhibition of colon tumor growth. Furthermore, this new delivery platform has low systemic toxicity and immunotoxicity in animals and is appealing for further investigation and clinical translation. Thus, through rational engineering of the carrier biomaterials and drug derivatization, the in vivo performance of drug delivery systems can be improved. This approach also establishes a methodology for leveraging synthetic chemistry tools to optimize delivery systems for a broad range of drug classes.

PFKFB3 Increases IL-1β and TNF-α in Intestinal Epithelial Cells to Promote Tumorigenesis in Colitis-Associated Colorectal Cancer.

Colorectal cancer (CRC) is significantly correlated with inflammatory bowel disease, which usually manifests as chronic relapsing-remitting colitis. Phosphofructo-2-kinase/fructose-2,6-biophosphatase 3 (PFKFB3) can catalyze to produce fructose-2,6-bisphosphate and function as an oncogene. In this study, we revealed the function of PFKFB3 in colitis-associated CRC (CAC) and the potential mechanism. RT-qPCR and Western blot were utilized to detect the level of PFKFB3 expression. Increased PFKFB3 expression was observed in the mouse CAC model and CAC patient samples. We identified that overexpression of PFKFB3 in intestinal epithelial cells (IECs) could increase the proliferation, migration, and invasion of CRC cells by the coculture system. Mechanistically, overexpression of PFKFB3 induced phospho-p65 and promoted the expression of IL-1β and tumor necrosis factor alpha (TNF-α) in the development of colitis and CAC. In addition, PFK158, the PFKFB3 inhibitor, could reduce the CRC cell viability, migration, and invasion caused by PFKFB3 overexpression. In conclusion, overexpression of PFKFB3 promoted tumorigenesis in CAC by inducing phospho-p65 and expression of IL-1β and TNF-α. Our study suggested that PFKFB3 acted as a potential treatment target for CAC.

Ojeok-san ameliorates visceral and somatic nociception in a mouse model of colitis induced colorectal cancer.

Cancer patients can develop visceral, somatic, and neuropathic pain, largely due to the malignancy itself and its treatments. Often cancer patients and survivors turn to the use of complementary and alternative medicine (CAM) to alleviate pain and fatigue. Thus, it is necessary to investigate how CAM therapies work as novel analgesics to treat cancer pain. Ojeok-san (OJS) is an herbal formula consisting of seventeen herbs. This herbal formula has been shown to possess anti-inflammatory, immunoregulatory, and analgesic properties. In this study, we examined the potential beneficial effects and mechanism of action of OJS in a preclinical model of colitis-associated colorectal cancer. Male and female C57BL/6J mice were exposed to the carcinogen, azoxymethane (AOM, 10 mg/kg) and a chemical inflammatory driver, dextran sulfate sodium (DSS1-2%), to promote tumorigenesis in the colorectum. OJS was given orally (500, 1000, and 2000 mg/kg) to determine its influence on disease activity, tumor burden, nociception, sedation, Erk signaling, and behavioral and metabolic outcomes. In addition, in vitro studies were performed to assess CT-26 cell viability, dorsal root ganglia (DRG) activation, and bone-marrow-derived macrophage (BMDM) inflammatory response to lipopolysaccharide stimulation after OJS treatment. We found that administration of 2000 mg/kg of OJS was able to mitigate mechanical somatic and visceral nociception via Erk signaling without affecting symptom score and polyp number. Moreover, we discovered that OJS has sedative properties and elicits prolonged total sleeping time in AOM/DSS mice. Our in vitro experiments showed that OJS has the capacity to reduce TNFα gene expression in LPS-stimulated BMDM, but no changes were observed in DRG spike number and CT-26 cell proliferation. Taken together, these data suggest that OJS ameliorates nociception in mice and warrants further examination as a potential CAM therapy to promote analgesia.

Chemically Induced Colitis-Associated Cancer Models in Rodents for Pharmacological Modulation: A Systematic Review.

Animal models for colitis-associated colorectal cancer (CACC) represent an important tool to explore the mechanistic basis of cancer-related inflammation, providing important evidence that several inflammatory mediators play specific roles in the initiation and perpetuation of colitis and CACC. Although several original articles have been published describing the CACC model in rodents, there is no consensus about the induction method. This review aims to identify, summarize, compare, and discuss the chemical methods for the induction of CACC through the PRISMA methodology. Methods: We searched MEDLINE via the Pubmed platform for studies published through March 2021, using a highly sensitive search expression. The inclusion criteria were only original articles, articles where a chemically-induced animal model of CACC is described, preclinical studies in vivo with rodents, and articles published in English. Results: Chemically inducible models typically begin with the administration of a carcinogenic compound (as azoxymethane (AOM) or 1,2-dimethylhydrazine (DMH)), and inflammation is caused by repeated cycles of colitis-inducing agents (such as 2,4,6-trinitrobenzenesulfonic acid (TNBS) or dextran sulfate sodium (DSS)). The strains mostly used are C57BL/6 and Balb/c with 5–6 weeks. To characterize the preclinical model, the parameters more used include body weight, stool consistency and morbidity, inflammatory biomarkers such as tumor necrosis factor (TNF)-α, interleukin (IL)-6 and IL-1β, angiogenesis markers such as proliferating cell nuclear antigen (PCNA), marker of proliferation Ki-67, and caspase 3, the presence of ulcers, thickness or hyperemia in the colon, and histological evaluation of inflammation. Conclusion: The AOM administration seems to be important to the CACC induction method, since the carcinogenic effect is achieved with just one administration. DSS has been the more used inflammatory agent; however, the TNBS contribution should be more studied, since it allows a reliable, robust, and a highly reproducible animal model of intestinal inflammation.

MiR-126 downregulates CXCL12 expression in intestinal epithelial cells to suppress the recruitment and function of macrophages and tumorigenesis in a murine model of colitis-associated colorectal cancer.

Inflammatory bowel disease, characterised by chronic relapsing‐remitting colitis, is a significant risk factor for colorectal cancer (CRC). Previously, we showed that miR‐126 functions as a tumour suppressor in CRC and is inversely correlated with tumour proliferation, metastasis and patient prognosis. In the current study, we documented a protective role for miR‐126 in colitis‐associated CRC (CAC) and its underlying mechanism. We detected downregulated miR‐126 expression during colorectal tumorigenesis in the mouse CAC model and in specimens from patients with CRC. The deficiency of miR‐126 in intestinal epithelial cells (IECs) exacerbated tumorigenesis in mice. We identified CXCL12 as a direct target of miR‐126 in inhibiting the development of colitis and CAC. Moreover, miR‐126 regulated the recruitment of macrophages via CXCL12 and decreased the levels of proinflammatory cytokines (IL‐6, IL‐12 and IL‐23). In addition, IL‐6 secreted by macrophages, which were regulated by cocultured transfected CRC cells, altered the proliferation and migration of colon cells. Our data suggest that miR‐126 exerts an antitumour effect on CAC by regulating the crosstalk between IECs and macrophages via CXCL12‐IL‐6 signalling. Our study contributes to the understanding of cancer progression and suggests miR‐126 as a potential therapy for CRC.

Huangqin Tang Interference With Colitis Associated Colorectal Cancer Through Regulation of Epithelial Mesenchymal Transition and Cell Cycle.

Background: Although the exact molecular mechanisms of colitis-associated colorectal cancer are not fully understood, the chronic inflammation was positively correlated with tumorigenesis. The traditional Chinese medicine botanical formulation Huangqin Tang has significant anti-inflammatory effects. We investigated whether HQT can ameliorate the progression of inflammation to cancer through its anti-inflammatory effects by using relevant predictions and experiments. Methods: We used the azoxymethane/dextran sodium sulfate method to induce the mice colitis-associated colorectal cancer model. After preventive administration of Huangqin Tang to the mice model, colonic tissues were taken for quantitative proteomic analysis of tandem mass tags, and the proteomic results were then experimentally validated using the molecular biology approach. Results: Proteomic screening revealed that the effect of the mechanism of Huangqin-Tang on the colitis-associated colorectal cancer mice model may be related to infinite replication which demonstrated abnormal G1/S checkpoint and epithelial mesenchymal transition acceleration. The levels of inflammatory factors such as interleukin-1α, interleukin-1β, interleukin-6, and tumor necrosis factor-α were significantly reduced in colitis-associated colorectal cancer mice treated with Huangqin Tang; the aberrant expression of G1/S checkpoint-associated sites of cell cycle protein-dependent kinase 4, D1-type cyclins, and dysregulation of related sites of the WNT pathway which are most related to the acceleration of the epithelial mesenchymal transition process including WNT3A, β-catenin, E-cadherin, and glycogen synthase kinase 3β has been improved. Conclusion: Reducing inflammation and thus inhibiting the progression of colitis-associated colorectal cancer by using Huangqin-Tang is effective, and the mechanism of action may be related to the inhibition of uncontrolled proliferation during tumorigenesis. In the follow-up, we will conduct a more in-depth study on the relevant mechanism of action.

Neferine Suppresses Experimental Colitis-Associated Colorectal Cancer by Inhibition of NF-[Formula: see text]B p65 and STAT3.

Colitis is an important risk factor for the development of colorectal cancer (CRC). The inhibitory effect and the underlying mechanism of neferine on colitis-associated colorectal cancer (CA-CRC) were investigated using an azoxymethane (AOM)/dextran sulfate sodium (DSS) triggered mice model. Compared with the CA-CRC model, oral treatment of neferine (2.5 and 5.0 mg/kg) significantly inhibited the DAI scores, decreased the tumor number, and reduced the tumor size. Neferine decreased inflammatory cell infiltration and epithelial hyperplasia in colon tissues. The levels of tumor necrosis factor-[Formula: see text] (TNF-[Formula: see text], interleukin-1beta (IL-1[Formula: see text], and interleukin 6 (IL-6) in colon tissues were decreased by neferine. Furthermore, neferine significantly decreased protein expressions of cyclooxygenase-2 (COX-2), inducible nitric oxide synthase (iNOS), p-p65, and p-STAT3 in both tumor and non-tumor tissues. In addition, neferine inhibited LPS and IL-6-induced phosphorylation of both NF-[Formula: see text]B p65 and STAT3. Molecular docking demonstrated the interactions of neferine with both NF-[Formula: see text]B p65 and STAT3. In conclusion, these results suggested that neferine inhibited CA-CRC carcinogenesis possibly by regulating NF-[Formula: see text]B and STAT3. Neferine might be a lead compound for the chemoprevention of CA-CRC.

Emu Oil Attenuates Disease Severity and Results in Fewer Large Colonic Tumors in a Mouse Model of Colitis-Associated Colorectal Cancer

Ulcerative colitis patients have an increased risk of developing colorectal cancer (CRC). The aim of the current study was to determine whether Emu Oil (EO) could reduce the severity of colitis, thereby inhibiting colitis-associated CRC (CA-CRC) development. Female C57BL/6 mice (n = 8/group) were injected (i.p.) with saline or azoxymethane (AOM) (7.4 mg/kg). Mice underwent three dextran sulfate sodium (DSS)/water cycles. Mice were orally-administered either water (160 µL) or EO (80 µL or 160 µL) thrice weekly and euthanized after 12 weeks. AOM/DSS decreased bodyweight compared with normal controls (max. 20%; p < 0.05). In AOM/DSS mice, EO (160 µL) increased bodyweight compared with untreated and 80 µL EO-treated mice (max. 10%; p < 0.05). Both volumes of EO reduced disease activity index (DAI) scores on day 49, 56–63 (max. 40%; p < 0.05), compared with AOM/DSS controls. Histological damage was increased in the distal colon of AOM/DSS mice, and reduced by EO (160 µL; p < 0.05). Mucin-secreting goblet cells were increased by AOM/DSS compared to normal, with no effect observed following EO treatment (p > 0.05). Large tumor numbers were decreased in EO-treated mice (160 µL; 2 ± 0.6) compared with AOM/DSS controls (5 ± 0.7; p < 0.05). EO did not impact overall tumor number (p > 0.05). Other analyses remained unchanged across groups (p > 0.05). EO demonstrates promise as an adjunct to conventional treatment options for colitis management.