[Banxia Xiexin Decoction inhibiting colitis-associated colorectal cancer infected with Fusobacterium nucleatum by regulating Wnt/ß-catenin pathway].

This paper investigates the intervention effect and mechanism of Banxia Xiexin Decoction(BXD) on colitis-associated colorectal cancer(CAC) infected with Fusobacterium nucleatum(Fn). C57BL/6 mice were randomly divided into a control group, Fn group, CAC group [azoxymethane(AOM)/dextran sulfate sodium salt(DSS)](AOM/DSS), model group, and BXD group. Except for the control and AOM/DSS groups, the mice in the other groups were orally administered with Fn suspension twice a week. The AOM/DSS group, model group, and BXD group were also injected with a single dose of 10 mg·kg~(-1) AOM combined with three cycles of 2.5% DSS taken intragastrically. The BXD group received oral administration of BXD starting from the second cycle until the end of the experiment. The general condition and weight changes of the mice were monitored during the experiment, and the disease activity index(DAI) was calculated. At the end of the experiment, the colon length and weight of the mice in each group were compared. Hematoxylin-eosin(HE) staining was used to observe the pathological changes in the colon tissue. Enzyme-linked immunosorbent assay(ELISA) was used to detect the levels of interleukin(IL)-2, IL-4, and IL-6 inflammatory factors in the serum. Immunohistochemistry(IHC) was used to detect the expression of Ki67, E-cadherin, and ß-catenin in the colon tissue. Western blot was used to detect the protein content of Wnt3a, ß-catenin, E-cadherin, annexin A1, cyclin D1, and glycogen synthase kinase-3ß(GSK-3ß) in the colon tissue. The results showed that compared with the control group, the Fn group had no significant lesions. The mice in the AOM/DSS group and model group had decreased body weight, increased DAI scores, significantly increased colon weight, and significantly shortened colon length, with more significant lesions in the model group. At the same time, the colon histology of the model group showed more severe adenomas, inflammatory infiltration, and cellular dysplasia. The levels of IL-4 and IL-6 in the serum were significantly increased, while the IL-2 content was significantly decreased. The IHC results showed low expression of E-cadherin and high expression of Ki67 and ß-catenin in the model group, with a decreased protein content of E-cadherin and GSK-3ß and an increased protein content of Wnt3a, ß-catenin, annexin A1, and cyclin D1. After intervention with BXD, the body weight of the mice increased; the DAI score decreased; the colon length increased, and the tumor decreased. The histopathology showed reduced tumor proliferation and reduced inflammatory infiltration. The levels of IL-6 and IL-4 in the serum were significantly decreased, while the IL-2 content was increased. Meanwhile, the expression of E-cadherin was upregulated, and that of Ki67 and ß-catenin was downregulated. The protein content of E-cadherin and GSK-3ß increased, while that of Wnt3a, ß-catenin, annexin A1, and cyclin D1 decreased. In conclusion, BXD can inhibit CAC infected with Fn, and its potential mechanism may be related to the inhibition of Fn binding to E-cadherin, the decrease in annexin A1 protein level, and the regulation of the Wnt/ß-catenin pathway.

Genetic and microbial determinants of azoxymethane-induced colorectal tumor susceptibility in Collaborative Cross mice and their implication in human cancer.

The insights into interactions between host genetics and gut microbiome (GM) in colorectal tumor susceptibility (CTS) remains lacking. We used Collaborative Cross mouse population model to identify genetic and microbial determinants of Azoxymethane-induced CTS. We identified 4417 CTS-associated single nucleotide polymorphisms (SNPs) containing 334 genes that were transcriptionally altered in human colorectal cancers (CRCs) and consistently clustered independent human CRC cohorts into two subgroups with different prognosis. We discovered a set of genera in early-life associated with CTS and defined a 16-genus signature that accurately predicted CTS, the majority of which were correlated with human CRCs. We identified 547 SNPs associated with abundances of these genera. Mediation analysis revealed GM as mediators partially exerting the effect of SNP UNC3869242 within Duox2 on CTS. Intestine cell-specific depletion of Duox2 altered GM composition and contribution of Duox2 depletion to CTS was significantly influenced by GM. Our findings provide potential novel targets for personalized CRC prevention and treatment.

Isolation and high-dimensional flow cytometric analysis of tumor-infiltrating leukocytes in a mouse model of colorectal cancer.

Colorectal cancer (CRC) is a complex and heterogeneous disease characterized by dysregulated interactions between tumor cells and the immune system. The tumor microenvironment plays a pivotal role in cancer initiation as well as progression, with myeloid immune cells such as dendritic cell and macrophage subsets playing diverse roles in cancer immunity. On one hand, they exert anti-tumor effects, but they can also contribute to tumor growth. The AOM/DSS colitis-associated cancer mouse model has emerged as a valuable tool to investigate inflammation-driven CRC. To understand the role of different leukocyte populations in tumor development, the preparation of single cell suspensions from tumors has become standard procedure for many types of cancer in recent years. However, in the case of AOM/DSS-induced colorectal tumors, this is still challenging and rarely described. For one, to be able to properly distinguish tumor-associated immune cells, separate processing of cancerous and surrounding colon tissue is essential. In addition, cell yield, due to the low tumor mass, viability, as well as preservation of cell surface epitopes are important for successful flow cytometric profiling of tumor-infiltrating leukocytes. Here we present a fast, simple, and economical step-by-step protocol for isolating colorectal tumor-associated leukocytes from AOM/DSS-treated mice. Furthermore, we demonstrate the feasibility of this protocol for high-dimensional flow cytometric identification of the different tumor-infiltrating leukocyte populations, with a specific focus on myeloid cell subsets.

EARLY STAGES OF COLORECTAL CANCER CHARACTERIZATION BY AUTOFLUORESCENCE 3D MICROSCOPY: A PRELIMINARY STUDY.

BACKGROUND: Colorectal cancer is one of the most prevalent pathologies worldwide whose prognosis is linked to early detection. Colonoscopy is the gold standard for screening, and diagnosis is usually made histologically from biopsies. Aiming to reduce the inspection and diagnostic time as well as the biopsies and resources involved, other techniques are being promoted to conduct accurate in vivo colonoscopy assessments. Optical biopsy aims to detect normal and neoplastic tissues analysing the autofluorescence spectrum based on the changes in the distribution and concentration of autofluorescent molecules caused by colorectal cancer. Therefore, the autofluorescence contribution analysed by image processing techniques could be an approach to a faster characterization of the target tissue. OBJECTIVE: Quantify intensity parameters through digital processing of two data sets of three-dimensional widefield autofluorescence microscopy images, acquired by fresh colon tissue samples from a colorectal cancer murine model. Additionally, analyse the autofluorescence data to provide a characterization over a volume of approximately 50 µm of the colon mucosa for each image, at second (2nd), fourth (4th) and eighth (8th) weeks after colorectal cancer induction. METHODS: Development of a colorectal cancer murine model using azoxymethane/dextran sodium sulphate induction, and data sets acquisition of Z-stack images by widefield autofluorescence microscopy, from control and colorectal cancer induced animals. Pre-processing steps of intensity value adjustments followed by quantification and characterization procedures using image processing workflow automation by Fiji's macros, and statistical data analysis. RESULTS: The effectiveness of the colorectal cancer induction model was corroborated by a histological assessment to correlate and validate the link between histological and autofluorescence changes. The image digital processing methodology proposed was then performed on the three-dimensional images from control mice and from the 2nd, 4th, and 8th weeks after colorectal cancer chemical induction, for each data set. Statistical analyses found significant differences in the mean, standard deviation, and minimum parameters between control samples and those of the 2nd week after induction with respect to the 4th week of the first experimental study. This suggests that the characteristics of colorectal cancer can be detected after the 2nd week post-induction. CONCLUSION: The use of autofluorescence still exhibits levels of variability that prevent greater systematization of the data obtained during the progression of colorectal cancer. However, these preliminary outcomes could be considered an approach to the three-dimensional characterization of the autofluorescence of colorectal tissue, describing the autofluorescence features of samples coming from dysplasia to colorectal cancer. BACKGROUND: • A new digital image processing method was developed to measure intensity in 3D autofluorescence images of colorectal samples using a CRC mouse model. BACKGROUND: • This method showed that autofluorescence intensity in colon mucosa is similar in healthy tissue but changes significantly in tumor development. BACKGROUND: • Statistical analysis revealed CRC traits detectable from the second week post-induction, aiding in early CRC detection. BACKGROUND: • The study provides a basis for 3D autofluorescence characterization in colorectal tissue from dysplasia to cancer, although variability in autofluorescence limits data systematization during cancer progression.

Mitotic Spindle Positioning (MISP) Facilitates Colorectal Cancer Progression by Forming a Complex with Opa Interacting Protein 5 (OIP5) and Activating the JAK2-STAT3 Signaling Pathway.

Patients with inflammatory bowel disease (IBD) who experience long-term chronic inflammation of the colon are at an increased risk of developing colorectal cancer (CRC). Mitotic spindle positioning (MISP), an actin-binding protein, plays a role in mitosis and spindle positioning. MISP is found on the apical membrane of the intestinal mucosa and helps stabilize and elongate microvilli, offering protection against colitis. This study explored the role of MISP in colorectal tumorigenesis using a database, human CRC cells, and a mouse model for colitis-induced colorectal tumors triggered by azoxymethane (AOM)/dextran sodium sulfate (DSS) treatment. We found that MISP was highly expressed in colon cancer patient tissues and that reduced MISP expression inhibited cell proliferation. Notably, MISP-deficient mice showed reduced colon tumor formation in the AOM/DSS-induced colitis model. Furthermore, MISP was found to form a complex with Opa interacting protein 5 (OIP5) in the cytoplasm, influencing the expression of OIP5 in a unidirectional manner. We also observed that MISP increased the levels of phosphorylated STAT3 in the JAK2-STAT3 signaling pathway, which is linked to tumorigenesis. These findings indicate that MISP could be a risk factor for CRC, and targeting MISP might provide insights into the mechanisms of colitis-induced colorectal tumorigenesis.

Anchang Yuyang Decoction inhibits experimental colitis-related carcinogenesis by regulating PPAR signaling pathway and affecting metabolic homeostasis of host and microbiota.

ETHNOPHARMACOLOGICAL RELEVANCE: Inflammatory bowel disease (IBD) presents a risk of carcinogenesis, which escalates with the duration of IBD. Persistent histological inflammation is considered to be the driving factor of colitis carcinogenesis. Effective control of inflammation is helpful to prevent and treat colitis-related colorectal cancer (CAC). Anchang Yuyang Decoction (AYD), a traditional Chinese medicine (TCM) formula, is originated from the ancient prescription of TCM for treating colitis and colorectal cancer. AYD has demonstrated efficacy in treating IBD and potential anti-carcinogenic properties. AIM OF THE STUDY: This research aims to assess the therapeutic efficacy of AYD in ameliorating experimental colitis-related carcinogenesis induced by AOM/DSS. It further seeks to elucidate its potential mechanisms by integrating multiple omics sequencing approaches. MATERIALS AND METHODS: A rat model for colitis-related carcinogenesis was developed using azoxymethane (AOM)/dextran sulfate sodium (DSS). UPLC-MS identified AYD's chemical constituents. Rats were administered varying doses of AYD (18.37, 9.19 and 4.59 g/kg) orally for 53 days, with mesalazine as a positive control. The study evaluated anti-carcinogenic effects by examining adenoma number, adenoma load, abnormal crypt foci (ACF), histopathological damage, and tumor-related protein expression. Anti-inflammatory and reparative effects were assessed through body weight, disease activity index (DAI), colon length, spleen index, inflammatory cytokine levels, and tight junction protein expression. The effects on intestinal microbiota and host metabolism were explored through 16S rRNA sequencing, targeted short-chain fatty acid (SCFA) metabonomics, and non-targeted colon metabolomics. Potential AYD targets were identified through transcriptomic sequencing and validated by qRT-PCR and western blotting. RESULTS: AYD significantly reduced adenoma number, adenoma load, neoplasm-associated lesions, ACF, and tumor-related protein expression (e.g., p53, PCNA) in AOM/DSS-induced rats, thus impeding colitis-related carcinogenesis progression. AYD also alleviated histopathological damage and inflammation, promoting intestinal mucosal barrier repair. Furthermore, AYD modulated intestinal flora structure, enhanced SCFA production, and regulated colon metabolites. Transcriptomic sequencing revealed a significant impact on the peroxisome proliferator-activated receptor (PPAR) signaling pathway. Subsequent qRT-PCR and western blotting experiments indicated AYD's influence in up-regulating PPAR-γ and down-regulating PPAR-α, PPAR-ß/δ, and related proteins (thrombomodulin [Thbd], fatty acid binding protein 5 [Fabp5], stearoyl-CoA desaturase 2 [Scd2], phospholipid transfer protein [Pltp]). CONCLUSIONS: This study demonstrates AYD's ability to inhibit experimental colitis-related carcinogenesis induced by AOM/DSS. Its mechanism likely involves modulation of the PPAR signaling pathway, impacting intestinal microbiota and host metabolic equilibrium.

Roseburia intestinalis sensitizes colorectal cancer to radiotherapy through the butyrate/OR51E1/RALB axis.

The radioresistant signature of colorectal cancer (CRC) hampers the clinical utility of radiotherapy. Here, we find that fecal microbiota transplantation (FMT) potentiates the tumoricidal effects of radiation and degrades the intertwined adverse events in azoxymethane (AOM)/dextran sodium sulfate (DSS)-induced CRC mice. FMT cumulates Roseburia intestinalis (R. intestinalis) in the gastrointestinal tract. Oral gavage of R. intestinalis assembles at the CRC site and synthetizes butyrate, sensitizing CRC to radiation and alleviating intestinal toxicity in primary and CRC hepatic metastasis mouse models. R. intestinalis-derived butyrate activates OR51E1, a G-protein-coupled receptor overexpressing in patients with rectal cancer, facilitating radiogenic autophagy in CRC cells. OR51E1 shows a positive correlation with RALB in clinical rectal cancer tissues and CRC mouse model. Blockage of OR51E1/RALB signaling restrains butyrate-elicited autophagy in irradiated CRC cells. Our findings highlight that the gut commensal bacteria R. intestinalis motivates radiation-induced autophagy to accelerate CRC cell death through the butyrate/OR51E1/RALB axis and provide a promising radiosensitizer for CRC in a pre-clinical setting.

Osthole impairs mitochondrial metabolism and the autophagic flux in colorectal cancer.

BACKGROUND: Osthole is active constituent of Cnidium monnieri (L.) Cuss. with various physiological functions including anti-inflammation and anti-lipedemic effects. However, the regulatory activity of osthole in colorectal cancer development, focusing on mitochondrial metabolism, is not well known. HYPOTHESIS/PURPOSE: We hypothesized that osthole may suppress progression of colorectal cancer and aimed to determine the underlying mitochondrial metabolism and the autophagic flux. STUDY DESIGN: In this study, we elucidated the mechanism of action of osthole in colorectal cancer using an in vivo azoxymethane/dextran sodium sulfate (AOM/DSS) mouse model and an in vitro cell culture system. METHODS: AOM/DSS mouse model was established and analyzed the effects of osthole on survival rate, diseases activity index, number of tumor and histopathology. Then, cell based assays including viability, cell cycle, reactive oxygen species (ROS), apoptosis, calcium efflux, and mitochondrial function were analyzed. Moreover, osthole-mediated signaling was demonstrated by western blot analyses. RESULTS: Osthole effectively suppressed the growth of colorectal tumors and alleviated AOM/DSS-induced intestinal injury. Osthole restored the function of goblet cells and impaired the expression of Claudin1 and Axin1 impaired by AOM/DSS. In addition, osthole specifically showed cytotoxicity in colorectal carcinoma cells, but not in normal colon cells. Osthole decreased the ASC/caspase-1/IL-1ß inflammasome pathway and induced mitochondrial dysfunction in redox homeostasis, calcium homeostasis. Furthermore, osthole inhibited both oxidative phosphorylation (OXPHOS) and glycolysis, leading to the suppression of ATP production. Moreover, via combination treatment with chloroquine (CQ), we demonstrated that osthole impaired autophagic flux, leading to apoptosis of HCT116 and HT29 cells. Finally, we elucidated that the functional role of tiRNAHisGTG regulated by osthole directly affects the cellular fate of colon cancer cells. CONCLUSION: These results suggest that osthole has the potential to manage progression of colorectal cancer by regulating autophagy- and mitochondria-mediated signal transduction.

Mangiferin (mango) attenuates AOM-induced colorectal cancer in rat's colon by augmentation of apoptotic proteins and antioxidant mechanisms.

Mangiferin (MF) is a natural C-glucosylxantone compound that has many substantial curative potentials against numerous illnesses including cancers. The present study's goal is to appraise the chemo preventive possessions of MF on azoxymethane (AOM)-mediated colonic aberrant crypt foci (ACF) in rats. Rats clustered into 5 groups, negative control (A), inoculated subcutaneously with normal saline twice and nourished on 0.5% CMC; groups B-E injected twice with 15 mg/kg azoxymethane followed by ingestion of 0.5% CMC (B, cancer control); intraperitoneal inoculation of 35 mg/kg 5-fluorouracil (C, reference rats) or nourished on 30 mg/kg (D) and 60 mg/kg (E) of MF. Results of gross morphology of colorectal specimens showed significantly lower total colonic ACF incidence in MF-treated rats than that of cancer controls. The colon tissue examination of cancer control rats showed increased ACF availability with bizarrely elongated nuclei, stratified cells, and higher depletion of the submucosal glands compared to MF-treated rats. Mangiferin treatment caused increased regulation of pro-apoptotic (increased Bax) proteins and reduced the ß-catenin) proteins expression. Moreover, rats fed on MF had significantly higher glutathione peroxidase (GPx), superoxide dismutase (SOD), catalase (CAT), and lower malondialdehyde (MDA) concentrations in their colonic tissue homogenates. Mangiferin supplementation significantly down-shifted pro-inflammatory cytokines (transforming growth factor-α and interleukine-6) and up-shifted anti-inflammatory cytokines (interleukine-10) based on serum analysis. The chemo-protective mechanistic of MF against AOM-induced ACF, shown by lower ACF values and colon tissue penetration, could be correlated with its positive modulation of apoptotic cascade, antioxidant enzymes, and inflammatory cytokines originating from AOM oxidative stress insults.

Azoxymethane/Dextran Sodium Sulfate (AOM/DSS) Model of Colorectal Cancer.

Recent progress in developing new vaccination strategies against cancer requires the production of complex and reliable animal models reflecting the complexity of the tumors with their microenvironment. Mice can be considered a good source due to low cost and ease of being genetically modified, inoculated with tumor cell lines or treated by chemicals to induce different cancers. Despite significant limitations in modeling human cancer complexity, preclinical trials conducted in mice can efficiently contribute to understand molecular mechanisms of cancer, to closely resemble and follow carcinogenesis steps impossible to study into humans, and to test new anticancer therapies. In this chapter, we generally describe the different mouse models developed for cancer vaccines' preclinical trials. A particular focus is dedicated to a chemically-induced colorectal cancer model in use in our laboratories.

Deletion of IL-27p28 induces CD8 T cell immunity against colorectal tumorigenesis.

Colorectal cancer (CRC) is a leading cause of cancer-related deaths worldwide, characterized by molecular and clinical heterogeneity. Interleukin (IL)-27, a heterodimeric cytokine composed of p28 and EBI3 subunits, has been reported to exert potent antitumor activity in several cancer models. However, the precise role of IL-27 in the pathogenesis of CRC remains unclear. Here, we show that during the azoxymethane (AOM)/dextran sodium sulfate (DSS)-induced CRC development, IL-27p28 levels are dramatically increased in peripheral blood and tumor tissues, and the cytokine is mainly produced by tumor-infiltrating myeloid cells. IL-27p28 deficient mice display tumor resistances in both inflammation-associated CRC model and syngeneic MC38 colon cancer model. Administration with IL-27p28 neutralizing antibody also reduces the tumor formation in AOM/DSS-treated mice. Mechanically, CD8+ T cells in IL-27p28-/- mice exhibit enhanced tumor infiltration and cytotoxicity, which can be largely attributed to activation of the Akt/mTOR signaling pathway. Furthermore, selective depletion of CD8+ T cells in IL-27p28-/- mice markedly accelerate tumor growth and almost abrogate the protective effects of IL-27p28 deficiency. Most interestingly, the expression of IL-27p28 is also upregulated in tumor tissues of CRC patients and those with high expression of IL-27p28 tend to have a poorer overall survival. Our results suggest that loss of IL-27p28 suppresses colorectal tumorigenesis by augmenting CD8+ T cell-mediated anti-tumor immunity. Targeting IL-27p28 could be developed as a novel strategy for the treatment of colorectal cancers.

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

BACKGROUND: 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. METHODS: Naltrexone, an opioid receptor antagonist, was injected intraperitoneally every second day for 2 weeks, at the dose of 1 mg/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. RESULTS: 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 ß-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. CONCLUSION: EOS and adiponectin-related signaling may play a role in the pathogenesis of CRC and these systems may present some additivity during carcinogenesis.

High Soluble Fiber Promotes Colorectal Tumorigenesis Through Modulating Gut Microbiota and Metabolites in Mice.

BACKGROUND & AIMS: Dietary fibers are mainly fermented by the gut microbiota, but their roles in colorectal cancer (CRC) are largely unclear. Here, we investigated the associations of different fibers with colorectal tumorigenesis in mice. METHODS: Apcmin/+ mice and C57BL/6 mice with azoxymethane (AOM) injection were used as CRC mouse models. Mice were fed with mixed high-fiber diet (20% soluble fiber and 20% insoluble fiber), high-inulin diet, high-guar gum diet, high-cellulose diet, or diets with different inulin dose. Germ-free mice were used for validation. Fecal microbiota and metabolites were profiled by shotgun metagenomic sequencing and liquid chromatography-mass spectrometry, respectively. RESULTS: Mixed high-fiber diet promoted colorectal tumorigenesis with increased tumor number and tumor load in AOM-treated and Apcmin/+ mice. Antibiotics use abolished the pro-tumorigenic effect of mixed high-fiber diet, while transplanting stools from mice fed with mixed high-fiber diet accelerated tumor growth in AOM-treated germ-free mice. We therefore characterized the contribution of soluble and insoluble fiber in CRC separately. Our results revealed that soluble fiber inulin or guar gum, but not insoluble fiber cellulose, promoted colorectal tumorigenesis in AOM-treated and Apcmin/+ mice. Soluble fiber induced gut dysbiosis with Bacteroides uniformis enrichment and Bifidobacterium pseudolongum depletion, accompanied by increased fecal butyrate and serum bile acids and decreased inosine. We also identified a positive correlation between inulin dosage and colorectal tumorigenesis. Moreover, transplanting stools from mice fed with high-inulin diet increased colonic cell proliferation and oncogene expressions in germ-free mice. CONCLUSION: High-dose soluble but not insoluble fiber potentiates colorectal tumorigenesis in a dose-dependent manner by dysregulating gut microbiota and metabolites in mice.

Sulforaphane Attenuates AOM/DSS-Induced Colorectal Tumorigenesis in Mice via Inhibition of Intestinal Inflammation.

Sulforaphane (SFN) is a compound derived from cruciferous plants. It has received considerable attention in recent years due to its effectiveness in cancer prevention and anti-inflammatory properties. The purpose of this study was to evaluate the antitumor potential of sulforaphane on colitis-associated carcinogenesis (CAC) through the establishment of a mouse model with AOM/DSS. First, AOM/DSS and DSS-induced model were established and administered SFN for 10 wk, and then the severity of colitis-associated colon cancer was examined macroscopically and histologically. Subsequently, immune cells and cytokines in the tumor microenvironment (TME) were quantified. Finally, the influence of sulforaphane was also investigated using different colon cell lines. We found that sulforaphane treatment decreased tumor volume, myeloid-derived suppressor cells (MDSC) expansion, the expression of the proinflammatory cytokine IL-1ß, and the level of IL-10 in serum. Also, it enhanced the antitumor activities of CD8+ T cells and significantly reduced tumorigenesis as induced by AOM/DSS. SFN also attenuated intestinal inflammation in DSS-induced chronic colitis by reshaping the inflammatory microenvironment. This work demonstrates that sulforaphane suppresses carcinogenesis-associated intestinal inflammation and prevents AOM/DSS-induced intestinal tumorigenesis and progression.

Deficiency of BCAT2-mediated branched-chain amino acid catabolism promotes colorectal cancer development.

OBJECTIVE: Branched-chain amino acid (BCAA) metabolism is involved in the development of colorectal cancer (CRC); however, the underlying mechanism remains unclear. Therefore, this study investigates the role of BCAA metabolism in CRC progression. METHODS: Dietary BCAA was administered to both azoxymethane-induced and azoxymethane/dextran sodium sulfate-induced CRC mouse models. The expression of genes related to BCAA metabolism was determined using RNA sequencing. Adjacent tissue samples, obtained from 58 patients with CRC, were subjected to quantitative real-time PCR and immunohistochemical analysis. Moreover, the suppressive role of branched-chain aminotransferase 2 (BCAT2) in cell proliferation, apoptosis, and xenograft mouse models was investigated. Alterations in BCAAs and activation of downstream pathways were also assessed using metabolic analysis and western blotting. RESULTS: High levels of dietary BCAA intake promoted CRC tumorigenesis in chemical-induced CRC and xenograft mouse models. Both the mRNA and protein levels of BCAT2 were decreased in tumor tissues of patients with CRC compared to those in normal tissues. Proliferation assays and xenograft models confirmed the suppressive role of BCAT2 in CRC progression. Furthermore, the accumulation of BCAAs caused by BCAT2 deficiency facilitated the chronic activation of mTORC1, thereby mediating the oncogenic effect of BCAAs. CONCLUSION: BCAT2 deficiency promotes CRC progression through inhibition of BCAAs metabolism and chronic activation of mTORC1.

Huangqin Decoction Delays Progress of Colitis-Associated Carcinogenesis by Regulating Nrf2/HO-1 Antioxidant Signal Pathway in Mice.

OBJECTIVE: To investigate the effect of Huangqin Decoction (HQD) on nuclear factor erythroid 2 related-factor 2 (Nrf2)/heme oxygenase (HO-1) signaling pathway by inducing the colitis-associated carcinogenesis (CAC) model mice with azoxymethane (AOM)/dextran sodium sulfate (DSS). METHODS: The chemical components of HQD were analyzed by liquid chromatography-quadrupole-time-of-flight mass spectrometry (LC-Q-TOF-MS/MS) to determine the molecular constituents of HQD. Totally 48 C57BL/6J mice were randomly divided into 6 groups by a random number table, including control, model (AOM/DSS), mesalazine (MS), low-, medium-, and high-dose HQD (HQD-L, HQD-M, and HQD-H) groups, 8 mice in each group. Except for the control group, the mice in the other groups were intraperitoneally injected with AOM (10 mg/kg) and administrated with 2.5% DSS orally for 1 week every two weeks (totally 3 rounds of DSS) to construct a colitis-associated carcinogenesis mouse model. The mice in the HQD-L, HQD-M and HQD-H groups were given HQD by gavage at doses of 2.925, 5.85, and 11.7 g/kg, respectively; the mice in the MS group was given a suspension of MS at a dose of 0.043 g/kg (totally 11 weeks). The serum levels of malondialdehyde (MDA) and superoxide dismutase (SOD) were measured by enzyme-linked immunosorbent assay. The mRNA and protein expression levels of Nrf2, HO-1, and inhibitory KELCH like ECH-related protein 1 (Keap1) in colon tissue were detected by quantitative real-time PCR, immunohistochemistry, and Western blot, respectively. RESULTS: LC-Q-TOF-MS/MS analysis revealed that the chemical constituents of HQD include baicalin, paeoniflorin, and glycyrrhizic acid. Compared to the control group, significantly higher MDA levels and lower SOD levels were observed in the model group (P<0.05), whereas the expressions of Nrf2 and HO-1 were significantly decreased, and the expression of Keap1 increased (P<0.01). Compared with the model group, serum MDA level was decreased and SOD level was increased in the HQD-M, HQD-H and MS groups (P<0.05). Higher expressions of Nrf2 and HO-1 were observed in the HQD groups. CONCLUSION: HQD may regulate the expression of Nrf2 and HO-1 in colon tissue, reduce the expression of MDA and increase the expression of SOD in serum, thus delaying the progress of CAC in AOM/DSS mice.

Gliclazide Reduces Colitis-Associated Colorectal Cancer Formation by Deceasing Colonic Inflammation and Regulating AMPK-NF-κB Signaling Pathway.

BACKGROUND: Gliclazide is a potential anti-cancer drug candidate for preventing carcinogenesis. However, the effect of gliclazide on colitis-associated colorectal cancer remains unknown. AIMS: We aimed to evaluate whether gliclazide plays a protective role in colitis-associated colorectal cancer and the underlying molecular mechanism. METHODS: The administration of azoxymethane (AOM) followed by dextran sulfate sodium (DSS) aimed to induce colitis-associated colorectal cancer in mice. C57BL mice were gavaged with gliclazide (6 mg/kg by gavage 5 days a week) for 12 weeks immediately following AOM administration. After sacrificing the mice, colon tissues were measured for tumor number and tumor burden. The proliferation- and inflammation-related molecular mechanisms were explored. RESULTS: The administration of gliclazide significantly reduced the tumor number and tumor burden in mice. Cell proliferation decreased in the gliclazide group compared with the control group, as indicated by reduced Ki-67 expression. Furthermore, gliclazide alleviated colonic inflammation, significantly decreased pro-inflammatory factor TNF-α levels and increased anti-inflammatory factor IL-10 levels in vivo. In vivo and vitro, it was shown that gliclazide increased the level of phospho-AMPK (p-AMPK) and inhibited NF-κB activity. Further studies demonstrated that the inhibition of NF-κB activity induced by gliclazide was mediated by p-AMPK in vitro. CONCLUSIONS: Gliclazide effectively alleviated colonic inflammation and prevented colonic carcinogenesis in an AOM-DSS mouse model by modulating the AMPK-NF-κB signaling pathway. Thus, gliclazide holds potential as a chemopreventive agent for colitis-associated colorectal cancer.

Anise (Pimpinella anisum L.) attenuates azoxymethane-induced colorectal cancer by antioxidant, anti-inflammatory, and anti-apoptotic pathways in rats.

Herbal medicine is one of the most common fields explored for combating colon cancers, and Pimpinella anisum L. seeds (PAS) have been utilized widely as medicinal agents because of their increased essential oil (trans-anethole) contents. In this essence, our study investigates the toxic effect and chemoprotective potentials of PAS against azoxymethane (AOM)-induced colon cancer in rats. The toxicity trial for PAS conducted by clustering fifteen rats into three groups (five rats each): A, normal control had 10% Tween 20; B, ingested with 2 g/kg PAS; and C, supplemented with 4 g/kg PAS. The in vivo cancer trial was performed by using 30 rats (Sprague-Dawley) that were randomly adapted in five steel cages (six rats each): group A, normal controls received two subcutaneous injections of normal saline 0.09% and ingested orally 10% Tween 20; groups B-E, rats received two injections of 15 mg/kg of azoxymethane (AOM) subcutaneously in 2 weeks and treated orally with 10% Tween 20 (group B) or intraperitoneal injection of 5-fluorouracil (35 mg/kg) (group C), or orally given 200 mg/kg PAS (group D) and 400 mg/kg PAS (group E) for 8 weeks. After the scarification of rats, the colon tissues were dissected for gross and histopathological evaluations. The acute toxicity trial showed the absence of any toxic signs in rats even after 14 days of ingesting 4 g/kg of PAS. The chemoprotective experiment revealed significant inhibitory potentials (65.93%) of PAS (400 mg/kg) against aberrant crypto foci incidence that could be correlated with its positive modulation of the immunohistochemically proteins represented by a significant up-regulation of the Bax protein and a decrease of the Bcl-2 protein expressions in colon tissues. Furthermore, PAS-treated rats had notably lower oxidative stress in colon tissues evidenced by decreased MDA levels and increased antiradical defense enzymes (SOD, CAT, and GPx). The outcomes suggest 400 mg/kg PAS as a viable additive for the development of potential pharmaceuticals against colorectal cancer.

Klebsiella aerogenes exacerbates colon tumorigenesis in the AOM/DSS-induced C57BL/6J mouse.

Klebsiella aerogenes (K. aerogenes, KA) is a gram-negative opportunistic pathogen from the Klebsiella species and the Enterobacteriaceae family. However, the impact of K. aerogenes on colorectal cancer (CRC) remains uncertain. A colitis-associated tumorigenesis animal model was established by administering azoxymethane (AOM) and dextran sulfate sodium (DSS) to C57BL/6J mice. The concentration of K. aerogenes gavage in mice was 109 cfu. The study measured the following parameters: tumor formation (number and size), intestinal permeability (MUC2, ZO-1, and Occludin), colonic inflammation (TNF-α, IL-1ß, IL-6, and IL-10), proliferation and the fluctuation of the intestinal flora. Under the AOM/DSS-treated setting, K. aerogenes colonization worsened colitis by exacerbating intestinal inflammatory reaction and destroying the mucosal barrier. The intervention markedly augmented the quantity and dimensions of neoplasm in the AOM/DSS mice, stimulated cellular growth, and impeded cellular programmed cell death. In addition, K. aerogenes exacerbated the imbalance of the intestinal microbiota by elevating the abundance of Pseudomonas, Erysipelatoclostridium, Turicibacter, Rikenella, and Muribaculum and leading to a reduction in the abundance of Odoribacter, Alloprevotella, Roseburia, and Lachnospiraceae_NK4A136_group. The presence of K. aerogenes in AOM/DSS-treated mice promoted tumorigenesis, worsened intestinal inflammation, disrupted the intestinal barrier, and caused disturbance to the gut microbiota.

Ephrin B3 exacerbates colitis and colitis-associated colorectal cancer.

Ephrin B3, a member of Eph/ephrin family, contributes to embryogenesis and carcinogenesis, but few studies have suggested whether this ligand has regulatory effect on colitis. This study was to determine whether ephrin B3 played a role in colitis and colonic carcinogenesis. Dextran sodium sulfate (DSS)-induced colitis and azoxymethane (AOM)/DSS-induced colitis-associated carcinogenesis model was established in Efnb3-deficient (Efnb3-/-) mice. Label-free quantitative proteomics were performed to identify the Efnb3-regulated proteins. Our results showed that Efnb3 knock out reduced the symptoms of DSS-induced colitis, such as disease activity index (DAI), inflammatory factors release, and dysfunction of the intestinal barrier. Quantitative proteomics revealed that Efnb3 regulated 95 proteins which clustered in the platelet degranulation, response to elevated platelet cytosolic Ca2+, MAPK signaling for integrins such as ITGB4. Furthermore, ephrin B3 inactived ITGB4/AKT signal pathway and then promoted epithelial barrier dysfunction. Simultaneously, ephrin B3 promoted Gremlin-1/NF-κB signal pathway and thereby increased inflammatory factors release. In addition, the higher level of Efnb3 in colon cancer patients is correlated with worse survival. Efnb3-/- mice exhibited susceptibility to AOM/DSS-induced colorectal cancer. Our finding discovered that Efnb3 played an important role in the development of colitis and colitis-associated colorectal cancer. Efnb3 deficiency improved the intestinal barrier by ITGB4 and suppressed inflammation via Gremlin-1/NF-κB signal pathway, which may provide a novel therapeutic strategy for the treatment of colitis and colitis-associated colorectal cancer.