An inducible mouse model of colon carcinogenesis for the analysis of sporadic and inflammation-driven tumor progression

To explore the potential combined treatment strategy for colorectal cancer: Inhibition of cancer stem cells and enhancement of intestinal immune microenvironment

BACKGROUND

The antibiotic salinomycin, a well-known cancer stem cell inhibitor, may impact the diversity of the intestinal microbiota in colorectal cancer (CRC) mice, which plays a pivotal role in shaping the immune system. This study explores the anti-cancer effects and mechanisms of combining salinomycin and fecal microbiota transplantation (FMT) in treating CRC.

METHODS

FMT was given via enema, while salinomycin was injected intraperitoneally into the CRC mouse model induced by azoxymethane/dextran sodium sulfate.

RESULTS

In CRC mice, a large number of LGR5-labeled cancer stem cells and severe disturbances in the intestinal microbiota were observed. Interestingly, salinomycin inhibited the proliferation of cancer stem cells without exacerbating the microbial disorder as expected. In comparison to salinomycin treatment, the combination of salinomycin and FMT significantly improved pathological damage and restored intestinal microbial diversity, which is responsible for shaping the anti-cancer immune microenvironment. The supplementation of FMT significantly increased the levels of propionic acid and butyric acid while also promoting the infiltration of CD8+ T cells and Ly6G+ neutrophils, as well as reducing F4/80+ macrophage recruitment. Notably, cytokines that were not impacted by salinomycin exhibited robust reactions to alterations in the gut microbiota. These included pro-inflammatory factors (IL6, IL12b, IL17, and IL22), chemokine-like protein OPN, and immunosuppressive factor PD-L1.

CONCLUSIONS

Salinomycin plays the role of "eliminating pathogenic qi," targeting cancer stem cells; FMT plays the role of "strengthening vital qi," reversing the intestinal microbiota disorder and enhancing anti-cancer immunity. They have a synergistic effect on the development of CRC.

Experimental toolkit to study the oncogenic role of WNT signaling in colorectal cancer

Colorectal cancer (CRC) is linked to the WNT/β-catenin signaling as its primary driver. Aberrant activation of WNT/β-catenin signaling is closely correlated with increased incidence, malignancy, poorer prognosis, and even higher cancer-related death. Research over the years has postulated various experimental models that have facilitated an understanding of the complex mechanisms underlying WNT signaling in CRC. In the present review, we have comprehensively summarized the in vitro, in vivo, patient-derived, and computational models used to study the role of WNT signaling in CRC. We discuss the use of CRC cell lines and organoids in capturing the molecular intricacies of WNT signaling and implementing xenograft and genetically engineered mouse models to mimic the tumor microenvironment. Patient-derived models, including xenografts and organoids, provide valuable insights into personalized medicine approaches. Additionally, we elaborated on the role of computational models in simulating WNT signaling dynamics and predicting therapeutic outcomes. By evaluating the advantages and limitations of each model, this review highlights the critical contributions of these systems to our understanding of WNT signaling in CRC. We emphasize the need to integrate diverse model systems to enhance translational research and clinical applications, which is the primary goal of this review.

Loss of proton-sensing GPR4 reduces tumor progression in mouse models of colon cancer

We aimed to understand the role of G protein-coupled receptor 4 (GPR4) in tumorigenesis. GPR4 is a pH-sensing receptor that is activated by acidic extracellular pH. GPR4 is expressed primarily in vascular endothelial cells (ECs). Intestinal tissue from patients with inflammatory bowel disease (IBD) shows increased expression of GPR4. Patients with IBD have a significantly increased risk of developing colorectal cancer (CRC). In the MC38 model, Gpr4-deficient mice showed significantly reduced tumor size and weight compared to wild-type (WT) mice. This effect correlated with a significant increase in IL2 protein and natural killer (NK)1.1+ cells in tumor tissue in Gpr4-/- compared to WT. In the azoxymethane (AOM)/dextran sodium sulfate (DSS) model of CRC, Gpr4-deficient mice showed significantly reduced tumor progression and number of apurinic/apyrimidinic (AP) sites. Gpr4-deficient mice showed a significantly increased number of NKp46+ cells in tumor tissue, and increased numbers of NK cells were confirmed by qPCR and flow cytometry. The absence of GPR4 significantly attenuated tumor progression in the colon of mice, and this result correlated with increased cytotoxic cell activity and reduced presence of tumor-associated macrophages and neutrophils. GPR4 represents a potential new target for therapeutic intervention.

Gut commensal bacteria influence colorectal cancer development by modulating immune response in AOM/DSS-treated mice

The gut microbiota has been closely associated with the pathogenesis of colorectal cancer (CRC). However, precise identification of particular microorganisms promoting CRC carcinogenesis, and more importantly those blocking tumor development, has been challenging based on human gut microbiota profiling studies. With a well-established azoxymethane/dextran sodium sulfate induction murine CRC model, we found a subset of mice consistently failed to develop CRC. This genetically homogeneous but cancer-refractory population gave us a unique opportunity to reveal that the microbial compositions between mice with and without CRC formation are indeed distinct, indicating key different gut microbiota between those groups are responsible for the differential susceptibility of the animals to CRC development. Our analysis revealed that Ruminococcus flavefaciens (R.f) and Fibrobacter succinogenes (F.s) were significantly enriched in CRC-free mice, while the presence of Eubacterium dolichum (E.d) was dramatically reduced. The correlative evidence was further substantiated as important causal factors, with subsequent bacteria intragastric administration experiments demonstrating independent, protective roles of R.f and F.s and a correspondingly detrimental role of E.d in inflammation-induced CRC initiation. Notably, E.d strongly activates NF-κB and promotes the local accumulation of myeloid-derived suppressor cells and macrophages. Significant disturbance of gut immune homeostasis, therefore, might be a critical trigger leading to subsequent CRC development. These findings indicate a clear direction for precise and rational gut microbiota-mediated CRC prevention.IMPORTANCEThere is a complex ecosystem of different microbes residing within the gut, which is highly relevant to health and diseases. The causal linkage between specific gut microbes and the development of colorectal cancer has been established with a mouse model, pinpointing specific bacteria species either promoting or preventing colorectal cancer development. A key aspect of these gut residual bacteria in colorectal cancer development is through exaggerating or easing gut inflammation. Therefore, by taking probiotics composed of corresponding cancer-preventing bacteria from human microbiota, it can be an effective and economic way to reduce human colorectal cancer risks.

Dipeptidase-1-knockout mice develop invasive tumors with features of microsatellite-unstable colorectal cancer

Dipeptidase-1 (DPEP1) is highly upregulated in colorectal cancer (CRC), with its enzymatic function linked to invasion and metastasis. More recently, DPEP1 was found to serve as a receptor for neutrophils when expressed by activated endothelial cells. It is unknown whether neutrophils bind to DPEP1-expressing CRC cells and whether this impacts features of CRC. Neutrophils have been shown to be tumor promoting in cancers including CRC, where they act to exclude CD8+ T cells. Herein, we show that neutrophils bind DPEP1-expressing CRC cells. In addition, DPEP1 is preferentially expressed in microsatellite-stable (MSS) CRCs, in which there are a paucity of CD8+ T cells, whereas DPEP1 is negatively correlated with microsatellite-unstable (MSI-H) CRCs, which are T cell rich and are more responsive to immunotherapy. Remarkably, carcinogen-treated Dpep1-null mice develop multiple, large, plaque-like, locally invasive adenocarcinomas and squamous cell cancers in the distal colon. These adenocarcinomas exhibit a marked reduction in neutrophils and an influx CD8+ T cells, along with reduced expression of mismatch repair proteins, consistent with features of MSI-H CRC. These results establish DPEP1's importance in maintaining MSS CRC and its ability to shape the tumor microenvironment.

The macrophage galactose-type C-type lectin 1 receptor plays a major role in mediating colitis-associated colorectal cancer malignancy

Cancer-associated aberrant glycosylation can be detected by the macrophage galactose-type C-type lectin (MGL) receptor; however, whether this interaction enhances or deadens cancer development along with the associated immune response has not been well established. To determine the role of mouse MGL1 in colitis-associated colon cancer (CAC), azoxymethane (AOM)/dextran sodium sulfate (DSS)-induced tumor development was compared between Mgl1 knockout (Mgl1-/-) mice and their wild-type (WT) littermates. At 75 days post-CAC induction, colon tumor tissue contained more highly glycosylated proteins, representing potential ligands for the mMGL1 receptor, than did healthy colon tissue. The Mgl1-/- CAC mice scored lower in disease activity indices and had fewer colonic tumors. In addition, the colonic crypt architecture was less damaged, and mucin production was more significant than in the WT CAC mice. Furthermore, Mgl1-/- CAC mice displayed higher percentages of CD4+ and CD8+ T cells in the peripheral blood, and colonic lamina propria; and lower percentages of myeloid-derived suppressor cells (MDSCs). Additionally, less macrophage (Mφ) and natural killer (NK) cell infiltration and lower levels of iNOS and arginase were found in the tumor microenvironment of Mgl1-/- CAC mice compared with WT mice. These results suggest that the mMGL1 receptor may recognize aberrant glycosylation in colon cancer, which may trigger an inflammatory microenvironment and favor colon tumorigenesis.

Fecal Microbiota Transplantation Using Donor Stool Obtained from Exercised Mice Suppresses Colonic Tumor Development Induced by Azoxymethane in High-Fat Diet-Induced Obese Mice

The gut microbiota plays an important role in the development of colorectal tumors. However, the underlying mechanisms remain unclear. In this study, we examined the effects of fecal microbiota transplantation (FMT) on azoxymethane (AOM)-induced colorectal tumors in obese mice. We divided the study subjects into the following five groups: high-fat diet (HFD), normal diet (ND), ND+exercise (Ex), HFD+FMT from ND-alone donor (HFD+FMT(ND alone)), and HFD+FMT from ND+Ex donor (HFD+FMT(ND+Ex)). The Ex group performed treadmill exercise for 15 weeks. Thereafter, fecal and colonic mucus samples were extracted for microbiome analysis. The deoxyribonucleic acid sample was collected from the feces and colonic mucosa, and V3-V4 amplicon sequencing analysis of the 16S rRNA gene was performed using MiSeq. The number of polyps was significantly lower in the ND (6.0 ± 1.6) and ND+Ex (1.8 ± 1.3) groups than in the HFD group (11.4 ± 1.5). The ND+Ex group had significantly fewer polyps than the ND group. The HFD+FMT(ND alone) (5.2 ± 0.8) and HFD+FMT(ND+Ex) (2.8 ± 2.6) groups also had significantly fewer polyps than the HFD group. The IL-15 mRNA levels in the colonic tissues were significantly higher in the HFD+FMT(ND alone) group than in the ND group. Fecal ω-muricholic acid concentrations were significantly higher in the HFD+FMT(ND alone) group than in the ND group and in the HFD+FMT(ND+Ex) group than in the ND+Ex group. The ND, ND+Ex, HFD+FMT(ND alone), and HFD+FMT(ND+Ex) groups had a significantly higher abundance of Lacyobacillaceae than the HFD group. In the FMT group, Erysipelotrichaceae and Tannerellaceae were significantly less abundant. Compared with the HFD group, the ND, ND+Ex, HFD+FMT(ND alone), and HFD+FMT(ND+Ex) groups had a significantly higher abundance of Muribaculaceae and a significantly higher abundance of Lactobacillaceae and Rikenellaceae in common among the ND and ND+Ex groups. The common and significantly less common species were Bacteroidaceae in the FMT group and Lactobacillaceae and Rikenellaceae in the ND alone and ND+Ex groups. Bacteroidaceae and Lachnospiraceae were significantly less common in the FMT group. We found that FMT inhibited AOM-induced colorectal tumorigenesis in obese mice. Furthermore, the fecal concentrations of short-chain fatty acids, bile acids, microbiota, and mucosa-associated microbiota differed between the FMT and diet/EX groups, suggesting that the inhibitory effect of FMT on colorectal tumorigenesis may be due to mechanisms different from those of ND alone and ND+Ex.

Rap2B drives tumorigenesis and progression of colorectal cancer through intestinal cytoskeleton remodeling

Ras family protein plays a key role in transducing signals involved in cytoskeletal remodeling and cell adhesion, which are particularly important in the development of colorectal cancer (CRC). While Rap2B, a member of the Ras superfamily, has been linked to cancer malignancy in vitro, its exact role in tumorigenesis remains unclear. In this study, we demonstrated that intestine-specific knockout of Rap2B suppresses the initiation and progression of CRC. Mechanistically, Rap2B interacts with plectin and enhances its expression, which in turn inhibits plectin-mediated F-actin assembly. Deletion of Rap2B resulted in a remodeling of the intestinal cytoskeleton, leading to reduced tumorigenesis and diminished metastatic potential. Clinically, there is a positive correlation between the expression levels of Rap2B and plectin in human CRC tissues, and higher levels of Rap2B and plectin predicting poorer clinical outcome in CRC patients. These findings underscore a critical role of Rap2B in CRC progression and highlight its potential as a therapeutic target.

Standardization of a Preclinical Colon Cancer Model in Male and Female BALB/c Mice: Macroscopic and Microscopic Characterization from Pre-Neoplastic to Tumoral Lesions

Background/Objetives: This study standardized a chemically induced colorectal cancer (CRC) model using azoxymethane (AOM) and dextran sodium sulfate (DSS) in BALB/c mice, replicating the progression from preneoplastic lesions to adenocarcinoma observed in human colorectal carcinogenesis. Methods: The CCR-AOM/DSS model was standardized in male and female BALB/c mice. Two protocols were tested. Subsequently, the positive control group was established with nine evaluation points. Tumor progression was characterized histopathologically and corroborated by methylene blue staining and scanning electron microscopy. Results: Two cycles of 2% DSS combined with a single injection of AOM (10 mg/kg) were necessary to induce adenocarcinoma in 100% of the mice, with no significant sex-based differences in tumor development. Females showed earlier tumor susceptibility under certain protocols. Inflammatory processes played a critical role in tumorigenesis, with neutrophil infiltration and fibrosis observed. Conclusions: The findings align with previous reports, emphasizing the influence of DSS cycles, molecular weight, and mouse strain on model outcomes. This standardized model provides a reliable platform for the preclinical evaluation of novel preventive and therapeutic strategies for CRC.

Targeting the Adenosine-Mediated Metabolic Immune Checkpoint with Engineered Probiotic for Enhanced Chemo-Immunotherapy

Immunotherapy has revolutionized cancer treatment by leveraging the patient's immune system, yet its efficacy is often hampered by the immunosuppressive tumor microenvironment (TME). Adenosine, a key player in this milieu, suppresses immune cell activity via cAMP signaling. Here, an innovative strategy to remodel the TME using a genetically engineered strain of Escherichia coli Nissle 1917 that expresses adenosine deaminase on its surface under hypoxic conditions is presented. This engineered probiotic targets tumors, converts immunosuppressive adenosine to inosine, and enhances anti-tumor immune responses. In vivo, the engineered probiotic significantly improved immune cell infiltration and demonstrated synergistic effects with low-dose doxorubicin in both subcutaneous and orthotopic mouse colorectal cancer model. Furthermore, the engineered probiotic modulated the TME, promoting a shift from M2-like to M1-like macrophages and increasing effector T cell populations. These findings highlight the potential of using engineered probiotics for metabolic modulation of the TME, offering a novel approach for enhancing cancer immunotherapy.

Mechanism of Qingjie Fuzheng Granules in inhibiting colitis associated colorectal cancer by regulating TLR4 and IL-4R mediated macrophage polarization

ETHNOPHARMACOLOGICAL RELEVANCE

Qingjie Fuzheng Granules (QFG), a herbal formula, has been employed as an adjuvant therapy for colitis-associated colorectal cancer (CAC), yet the underlying mechanisms by which QFG operates remain unclear.

AIMS OF THE STUDY

The aim of this study is to investigate whether the potential mechanism of QFG against CAC is associated with macrophage polarization.

MATERIALS AND METHODS

Non-targeted metabolomics and molecular docking assessed potential compounds of QFG to interact with targets associated with macrophage polarization. A model of AOM/DSS-induced CAC mice was established to analyze the effects of QFG on macrophage polarization using flow cytometry and immunohistochemical staining. In vitro experiments involved models of Ana-1 macrophages, either induced by varying QFG concentrations or with MD2 knockdown, to analyze M1-like phenotype. Meanwhile, M2-like macrophages models induced by IL-4 or culture supernatant of CT26 cells were utilized to assess the effects of QFG on M2-like macrophages. Finally, the mRNA expression of M1-like phenotype related to TLR4 pathways and the protein expression in IL-4R-mediated pathways were analyzed using RT-qPCR and Western blot, respectively.

RESULTS

Molecular docking confirmed the presence of binding sites between the ingredients of QFG and IL-4R or TLR4/MD2 receptor complex. QFG could induce a shift in macrophages towards an M1-like phenotype while inhibiting an M2-like phenotype in the colon with CAC mice and Ana-1 macrophages. QFG resulted in the upregulation of iNOS, IL-6, IL-1β, and TNF-α mRNA expression, which could be counteracted by TAK242, SR11302, INH14, PDTC, and LY294002, or by the knockdown of MD2. Meanwhile, QFG inhibited IL-4R-induced phosphorylation of STAT 6 and Akt.

CONCLUSION

Various monomer components within QFG can bind to MD2 or IL-4R, respectively, thereby inducing macrophages towards an M1-like phenotype through TLR4-mediated NF-κB, MAPK, and PI3K/Akt pathway activation, or inhibiting macrophages towards an M2-like phenotype via IL-4R-mediated JAKs pathway inhibition, ultimately exerting an inhibitory effect on the occurrence and development of CAC.

Enrichment of Porphyromonas gingivalis in colonic mucosa-associated microbiota and its enhanced adhesion to epithelium in colorectal carcinogenesis: Insights from in vivo and clinical studies

OBJECTIVES

The oral-gut axis is believed to play a role in the pathogenesis of colorectal cancer (CRC). Previous studies have demonstrated the transmission of oral microbiota to the gut, disrupting gut microbial balance and creating a protumorigenic microenvironment conducive to CRC progression. Fusobacterium nucleatum is a putative periodontal pathogen recognized as a specific bacterium that promotes CRC development. However, the possible involvement of other periodontal pathogens in CRC is poorly understood. This study aimed to explore the effects of ingested periodontal pathogens on experimental CRC in mice and elucidate the underlying mechanisms.

METHODS

In this study, experimental colitis-induced CRC mouse models were used. The mice were orally administered periodontal pathogens (Porphyromonas gingivalis and Prevotella intermedia) three times a week during the experimental period. The CRC severity between the P. gingivalis-treated and P. intermedia-treated groups was compared. Lumen-associated microbiota (LAM) and mucosa-associated microbiota (MAM) were analyzed in both mouse and human samples. In vitro studies were conducted using intestinal epithelial cells to explore the possible mechanisms by which the periodontal pathogens affect the CRC development.

RESULTS

The P. gingivalis-treated group exhibited significantly increased CRC severity compared to the other groups among azoxymethane/dextran sodium sulfate (AOM/DSS)-induced mouse models. The LAM and MAM exhibited distinct bacterial compositions, and P. gingivalis was enriched more in MAM than in LAM. In vitro adhesion assays revealed that P. gingivalis had higher adhesive capacity to intestinal epithelial cells than P. intermedia and indicated the possible involvement of gingipains in such a capacity.

CONCLUSION

P. gingivalis is enriched in MAM, and its subsequent adhesion to intestinal epithelial cells is potentially involved in the progression of CRC.

Mediterranean diet improves liver health but does not protect against azoxymethane-induced colon tumorigenesis compared to Western diet in A/J mice

INTRODUCTION

Abundant evidence indicates that the Mediterranean (MED) diet pattern is beneficial for health, especially cardiovascular health. Epidemiological evidence indicates that the MED diet also affords protection against colorectal cancer (CRC). To date, preclinical models have only evaluated specific MED diet components and therefore, although supportive, fall short of confirming the chemoprotective capacity of this complex dietary pattern. We sought to address this gap.

METHOD

A/J mice were randomized to receive Western (WRN) or MED diets differing in their fat, protein, and carbohydrate sources. Azoxymethane (AOM) was used to initiate colon tumorigenesis and mice were maintained for 19 weeks after the final dose.

RESULT

Unexpectedly high mortality was observed amongst male mice following the second AOM dose. At the end of the study hepatic Cyp2E1, an enzyme that metabolize AOM, was lower in males than females. Livers from MED diet mice were significantly lighter, had lower histologic Non-Alcoholic Fatty Liver Disease (NAFLD) scores, and contained less triglycerides than WRN mice. Amongst females, serum alanine transaminase (ALT) was also lower in MED than WRN mice. Amongst male mice, those fed MED diet presented with significantly more colonic tumors than those on the WRN diet.

CONCLUSION

In this study male mice displayed elevated sensitivity to AOM-induced hepatotoxicity and mortality than females. In agreement with human and preclinical data, livers of MED-diet-fed mice were healthier than those fed WRN diets. We could not confirm the chemoprotective capacity of the MED diet. Additional studies are required to evaluate the purported anticancer effect of the MED diet.

Intestinal crypt microbiota modulates intestinal stem cell turnover and tumorigenesis via indole acetic acid

Intestinal crypts harbour a specific microbiota but whether and how these bacteria regulate intestinal stem cells (ISCs) or influence colorectal cancer (CRC) development is unclear. Here we screened crypt-resident bacteria in organoids and found that indole acetic acid (IAA) secreted by Acinetobacter radioresistens inhibits ISC turnover. A. radioresistens inhibited cellular proliferation in tumour slices from CRC patients and inhibited intestinal tumorigenesis and spheroid initiation in APCMin/+ mice. Targeted clearance of A. radioresistens from colonic crypts using bacteriophage increased EphB2 expression and consequently promoted cellular proliferation, ISC turnover and tumorigenesis in mouse models of CRC. The protective effects of A. radioresistens were abrogated upon deletion of trpC to prevent IAA production, or upon intestine-specific aryl hydrocarbon receptor (AhR) knockout, identifying an IAA-AhR-Wnt-β-catenin signalling axis that promotes ISC homeostasis. Our findings reveal a protective role for an intestinal crypt-resident microbiota member in tumorigenesis.

Gegen Qinlian Decoction Attenuates Colitis-Associated Colorectal Cancer via Suppressing TLR4 Signaling Pathway Based on Network Pharmacology and In Vivo/In Vitro Experimental Validation

Background: Gegen Qinlian Decoction (GQD), is used for intestinal disorders like ulcerative colitis, irritable bowel syndrome, and colorectal cancer. But the precise mechanisms underlying its anti-inflammatory and anti-tumor effects are not fully elucidated. Methods: Use network pharmacology to identify targets and pathways of GQD. In vivo (azoxymethane/dextran sodium sulfate (AOM/DSS)-induced colitis-associated colorectal cancer (CAC) mouse model) and in vitro (lipopolysaccharide (LPS)-stimulated RAW264.7 macrophages) experiments were conducted to explore GQD's anti-inflammatory and anti-tumor effects. We monitored mouse body weight and disease activity index (DAI), and evaluated colon cancer tissues using hematoxylin and eosin staining. Expression of Ki67 and F4/80 was determined by immunohistochemistry analysis. The protein levels of TLR4 signaling pathway were assessed by western blotting analysis. Enzyme-linked immunosorbent assay measured IL-1β, IL-6, and TNF-α levels. Immunofluorescence (IF) staining visualized NF-κB and IRF3 translocation. Results: There were 18, 9, 24 and 77 active ingredients in the four herbs of GQD, respectively, targeting 435, 156, 485 and 691 genes. Through data platform analysis, it was concluded that there were 1104 target genes of GQD and 2022 target genes of CAC. Moreover, there were 99 intersecting genes between GQD and CAC. The core targets of GQD contained NFKB1, IL1B, IL6, TLR4, and TNF, and GQD reduced inflammation by inhibiting the TLR4 signaling pathway. In vivo experiment, GQD increased mouse body weight, lowered DAI scores, while also alleviating histopathological changes in the colon and decreasing the expressions of Ki67 and F4/80 in the AOM/DSS-induced mice. GQD reduced IL-1β, IL-6, and TNF-α levels in the serum and downregulated TLR4, MyD88, and phosphorylation of IκBα, P65, and IRF3 in the colon tissue from AOM/DSS-induced mice. In vitro, GQD suppressed pro-inflammatory cytokines and TLR4 signaling pathway in the LPS-induced RAW264.7 cells, and combined with TAK242, it further reduced the phosphorylation of IκBα, P65. Conclusions: GQD mitigated CAC by inhibiting the TLR4 signaling pathway, offering a potential therapeutic approach for CAC management.

Active fraction of ground cherry (Physalis angulata L.) calyces attenuates azoxymethane dextran sulfate sodium‑induced colon carcinogenesis in mice

Physalis angulata L., commonly known as wild tomato or ground cherry, is widely used in tropical and subtropical areas to treat health disorders including inflammation, hepatitis, dermatitis, cancer and diabetes. In Colombia, anti-cancer and anti-inflammatory activity are the most common ethnopharmacological applications of P. angulata calyces. P. angulata dichloromethane fraction (PADF) has significant anti-inflammatory activity. The present study assessed the pharmacological effect of PADF on colorectal cancer (CRC) using cancer and normal human cells and an azoxymethane (AOM)/dextran sulfate sodium (DSS) murine model. MTT and clonogenic assay, cell cycle and apoptosis analysis and mitochondrial membrane potential measurement were employed to evaluate in vitro activity of PADF. PADF selectively induced a cytotoxic effect against CRC cells via apoptosis and G2/M arrest. In the AOM/DSS model, treatment with PADF diminished tumor number and size, affected area and expression of proliferating cell nuclear antigen and promoted colon tissue repair. These effects might be related to the increased expression of p38 pro-apoptotic protein in addition to anti-inflammatory activity of PADF demonstrated by decreased levels of TNF-α, IL-6, and IL-1β. PADF may serve as a potential treatment for CRC. Further investigation is warranted to identify the bioactive components in PADF.

DUSP6 regulates Notch1 signalling in colorectal cancer

Notch1 plays various roles in cancer development, and Notch1-induced transactivation is controlled by phosphorylation of its cleaved intracellular domain. However, it is unclear whether there are phosphatases capable of dephosphorylating the cleaved Notch1 transmembrane/intracellular region (NTM) to regulate its function. Here, we show that DUSP6 can function as a phosphatase for Notch1, thereby regulating NTM stability and transcriptional activity, thus influencing colorectal cancer (CRC) development. In human CRC cells, elevated DUSP6 expression correlates with increased NTM levels, leading to enhanced CRC cell proliferation both in vitro and in vivo. High tumoral DUSP6 protein expression is associated with poorer overall CRC patient survival. In mice, DUSP6 deficiency results in reduced CRC development. Mechanistically, DUSP6 dephosphorylates phospho-Y2116, which in turn reduces NTM ubiquitination, leading to increased NTM stability and transcriptional activity. As a result, the expression of Notch1-targeted proliferation genes is increased to promote tumour cell growth.

Altered gut metabolites and metabolic reprogramming involved in the pathogenesis of colitis-associated colorectal cancer and the transition of colon "inflammation to cancer"

Colitis-associated colorectal cancer (CAC) is fatal and can develop spontaneously or as a complication of inflammatory bowel diseases. Although co-administration of azoxymethane/dextran sulfate sodium (AOM/DSS) is a classic method for CAC modeling, its limitations need to be addressed. Accordingly, we aimed to optimize the AOM/DSS model to study CAC extensively and further investigate its pathogenic mechanisms relative to microbiota and metabolism. We optimized the CAC model via a single or enhanced injection of AOM combined with different administration modes and varying DSS concentrations. Subsequently, the fecal-microbiota composition was examined using 16S RNA sequencing, and fecal-colon-metabolome profiles were evaluated via ultra-high performance liquid chromatography-mass spectrometry. Two interval injections of AOM combined with 1.5 % DSS-free drinking resulted in a high tumor formation rate, uniform tumor formation, and low mortality. Based on this model, we innovatively divided the pathogenesis of CAC into three stages, namely inflammation induction, proliferation initiation, and tumorigenesis, and examined the pathological characteristics in each stage. Gut microbial dysbiosis and metabolic alteration drove colorectal tumorigenesis by aggravating inflammation while promoting cell proliferation and carcinogenesis in mice. For the first time, we dynamically demonstrated the process of colon "inflammation to cancer" transformation and provided novel insights to clarify the role of amino acid metabolism in the formation of CAC.

Veratridine, a plant-derived alkaloid, suppresses the hyperactive Rictor-mTORC2 pathway: a new targeted therapy for primary and metastatic colorectal cancer

Despite considerable advances to improve colorectal cancer (CRC) survival over the last decade, therapeutic challenges remain due to the rapid metastatic dissemination of primary tumors and screening limitations. Meanwhile, the rise of CRC in younger adults (Early-onset CRC), commonly diagnosed with a metastatic form of the disease, shows the pressing need to develop more effective targeted therapies to decrease the high mortality rates associated with metastatic disease. Hyperactivation of the Rictor-mTORC2-AKT signaling pathway drives key metastatic players in diverse malignant tumors, including early- and late-onset colorectal cancer. Selective mTORC2 inhibitors are becoming a potential treatment strategy for CRC due to the therapeutic limitations of mTORC1 inhibitors. Veratridine (VTD), a lipid-soluble alkaloid extracted from Liliaceae plants, can transcriptionally increase UBXN2A, which induces 26S proteasomal degradation of the Rictor protein, a key member in the mTORC2 complex. Destabilization of Rictor protein by VTD decreases Akt phosphorylation on Ser473, which is responsible for metastatic signaling downstream of the mTORC2 pathway in diverse malignant tumors. VTD decreases the population of metastatic colon cancer stem cells and functions as an angiogenesis inhibitor. VTD effectively reduces the spheroid growth rate and restricts cell migration. Live cell migration and invasion assays alongside biomechanical-force-based experiments revealed that VTD suppresses colon cancer cell invasiveness and the ensuing risk of tumor metastasis. A CRC mouse model that mimics the natural stages of human sporadic CRC revealed that VTD treatment significantly decreases tumor growth in a UBXN2A-dependent manner. This study showed a novel mechanistic connection between a ubiquitin-like protein and mTORC2-dependent migration and invasion in CRC tumors. This study revealed the therapeutic benefit of selective inhibition of Rictor in CRC, particularly in tumors with a hyperactive Rictor-mTORC2 signaling pathway. Finally, this study opened a new platform for repurposing VTD, a supplemental anti-hypertension molecule, into an effective targeted therapy in CRC tumors.

PD-L1 restrains PD-1+Nrp1lo Treg cells to suppress inflammation-driven colorectal tumorigenesis

T cells function not only as an essential component of host cancer immunosurveillance but also as a regulator of colonic inflammation, a process that promotes colorectal cancer. Programmed death-ligand 1 (PD-L1) is a T cell-negative regulator, but its role in regulation of T cell functions in the context of colorectal cancer is unknown. We report that global deletion of Cd274 results in increased colonic inflammation, PD-1+ T cells, and inflammation-driven colorectal tumorigenesis in mice. Single-cell RNA sequencing (scRNA-seq) analysis revealed that PD-L1 suppresses subpopulations of programmed cell death protein 1 (PD-1)+Nrp1lo regulatory T (Treg) cells and interleukin (IL) 6+ neutrophils in colorectal tumor. Treg cells produce transforming growth factor (TGF) β to recruit IL6+ neutrophils. Neutrophils produce IL6 to inhibit activation of tumor-specific cytotoxic T lymphocytes (CTLs) and primary CTLs. Accordingly, IL6 blockade immunotherapy increases CTL activation and suppresses colon tumor growth in vivo. Our findings determine that PD-L1 restrains PD-1+Nrp1loTGFβ+ Treg cells to suppress IL6+ neutrophil tumor recruitment to sustain CTL activation to control inflammation-driven colorectal tumorigenesis.

Tocotrienol suppresses colitis-associated cancer progression through TLR4 signaling in a mouse model of colorectal cancer

This study aimed to evaluate the preventive efficacy of tocotrienol in inhibiting the nuclear factor-kappa B (NF-κB) mediated inflammation pathways in colorectal cancer. We utilized the azoxymethane (AOM) and dextran sulfate sodium salt (DSS) to induce colitis-associated colorectal cancer (CAC) mice model. In generating a CAC model, mice were intraperitoneally injected with AOM at a concentration of 10 mg/kg body weight. Seven days after the AOM injection, mice drinking water containing 3 % DSS for 1 week, followed by a 2-week period of regular water. This cycle of DSS treatment (1-week 3 % DSS+2-week water) was repeated for two additional cycles. Mice were randomly divided into five groups (n = 20/group), including Blank group, Model group, three different dosages tocotrienol groups (Low dose group [50 mg/kg], Medium dose group [75 mg/kg], and High dose group [100 mg/kg]). The protective effects of tocotrienol were assessed using histological, flow cytometry, western blot and mouse Luminex assay. Compared with the blank group, expressions of toll-like receptor 4 (TLR4), myeloid differentiation protein 88 (MyD88), tumor necrosis factor receptor-associated factor 6 (TRAF-6), NF-κB, Interleukin (IL)-6 and tumor necrosis factor (TNF) -α were increased in model group, while IL-4 and IL-10 were decreased in model group (P<0.05). Tocotrienol prevented carcinogenesis and decreased the IL-6, TNF-α, MyD88, TLR4, TRAF-6 and NF-κB expression levels, compared with the model group (P<0.05). Compared with the model group, the expression of IL-10 was increased in medium dose group and high dose group (P<0.05). The protective effects of tocotrienol may be related to the inhibition of TLR4 /MyD88 /NF-κB mediated inflammatory signaling pathways. Therefore, the use of tocotrienol can improve the abnormal expression of cytokines in a mouse model of colorectal cancer and inhibit the occurrence and development of colorectal cancer.

Fusobacterium nucleatum extracellular vesicles are enriched in colorectal cancer and facilitate bacterial adhesion

Fusobacterium nucleatum in colorectal cancer (CRC) tissue is implicated at multiple stages of the disease, while the mechanisms underlying bacterial translocation and colonization remain incompletely understood. Herein, we investigated whether extracellular vesicles derived from F. nucleatum (FnEVs) have impacts on bacterial colonization. In mice with colitis-related CRC, a notable enrichment of FnEVs was observed, leading to a significant increase in intratumor colonization by F. nucleatum and accelerated progression of CRC. The enrichment of FnEVs in clinical CRC tissues was demonstrated. Subsequently, we revealed that FnEVs undergo membrane fusion with CRC cells, leading to the transfer and retention of FomA on recipient cell surfaces. Given its ability to facilitate F. nucleatum autoaggregation through interaction with FN1441, the presence of FomA on CRC cell surfaces presents a target for bacterial adhesion. Collectively, the findings unveil a mechanism used by EVs to prepare a niche conducive for bacterial colonization in distal organs.

The association of appendectomy with prognosis and tumor-associated macrophages in patients with colorectal cancer

The vermiform appendix plays an important role in colorectal immunity and the homeostasis of the gut microbiome. We aimed to evaluate the prognostic value of prior appendectomy for patients with colorectal cancer (CRC). This study revealed that prior appendectomy is an independent risk factor for the prognosis of patients with CRC, based on a multicentral CRC cohort. We further demonstrated that appendectomy induced a poor prognosis of CRC through the depletion of M1 macrophage cells in AOM-induced mice, which was confirmed in age-, sex-, and location-matched patients' cohorts and orthotopic model models with the CT26 cell line. Poor responses to anti-PD-1 immunotherapy were detected in patients with CRC with appendectomy, and cetuximab is an effective treatment for patients with appendectomy-associated colorectal cancer (APD-CRC) to improve their prognosis. Our study will provide a reference for developing treatment plans for a considerable number of patients with APD-CRC, which is of great clinical significance.

Cyclophilin J limits linear ubiquitin signaling and controls colorectal cancer progression

Exorbitant sustained inflammation is closely linked to inflammation-associated disorders, including cancer. The initiation of gastrointestinal cancers such as colorectal cancer is frequently accelerated by uncontrollable chronic inflammation which is triggered by excessive activation of nuclear factor kappa-B (NF-κB) signaling. Linear ubiquitin chains play an important role in activating canonical NF-κB pathway. The only known E3 complex, linear ubiquitin chain assembly complex is responsible for the synthesis of linear ubiquitin chains, thus leading to the activation of NF-κB axis and promoting the development of inflammation and inflammation-associated cancers. We report here cyclophilin J (CYPJ) which is a negative regulator of the linear ubiquitin chain assembly complex. The N terminus of CYPJ binds to the second Npl4 zinc finger (NZF) domain of HOIL-1-interacting protein and the ubiquitin-like domain of Shank-associated RH domain-interacting protein to disrupt the interaction between HOIL-1-interacting protein and Shank-associated RH domain-interacting protein and thus restrains linear ubiquitin chain synthesis and NF-κB activation. Cypj-deficient mice are highly susceptible to dextran sulfate sodium-induced colitis and dextran sulfate sodium plus azoxymethane-induced colon cancer. Moreover, CYPJ expression is induced by hypoxia. Patients with high expression of both CYPJ and hypoxia-inducible factor-1α have longer overall survival and progression-free survival. These results implicate CYPJ as an unexpected robust attenuator of inflammation-driven tumorigenesis that exerts its effects by controlling linear ubiquitin chain synthesis in NF-κB signal pathway.

Comparison of cell delivery and cell membrane camouflaged PLGA nanoparticles in the delivery of shikonin for colorectal cancer treatment

Inspired by the "natural camouflage" strategy, cell-based biomimetic drug delivery systems (BDDS) have shown great potential in cancer therapy. Red blood cell (RBC) delivery vehicles and red blood cell membrane (RBCm)-camouflaged vehicles were commonly used strategies for drug delivery. We prepared shikonin-encapsulated PLGA nanoparticles (PLGA/SK) with different surface charges to obtain both RBC delivery and RBCm-camouflaged PLGA NPs. The physicochemical properties, in vivo circulation and antitumor effects of these biomimetic preparations were studied. Since the positive PLGA NPs may affect the morphology and function of RBCs, the biomimetic preparations prepared by the negative PLGA NPs showed better in vitro stability. However, positive PLGA NP-based biomimetic preparations exhibited longer circulation time and higher tumor region accumulation, leading to stronger anti-tumor effects. Meanwhile, the RBC delivery PLGA(+) NPs possessed better in vitro cytotoxicity, longer circulation time and higher tumor accumulation than RBCm-camouflaged PLGA(+) NPs. Collectively, RBC delivery vehicles possessed more potential than RBCm-camouflaged vehicles on drug delivery for tumor treatment, especially with positive NPs-loaded.

Antitumorigenic potential of Lactobacillus-derived extracellular vesicles: p53 succinylation and glycolytic reprogramming in intestinal epithelial cells via SIRT5 modulation

OBJECTIVE

Colorectal cancer progression involves complex cellular mechanisms. This study examines the effects of Lactobacillus plantarum-derived extracellular vesicles (LEVs) on the SIRT5/p53 axis, focusing on glycolytic metabolic reprogramming and abnormal proliferation in intestinal epithelial cells.

METHODS

LEVs were isolated from Lactobacillus plantarum and incubated with Caco-2 cells. Differential gene expression was analyzed through RNA sequencing and compared with TCGA-COAD data. Key target genes and pathways were identified using PPI network and pathway enrichment analysis. Various assays, including RT-qPCR, EdU staining, colony formation, flow cytometry, and Western blotting, were used to assess gene expression, cell proliferation, and metabolic changes. Co-immunoprecipitation confirmed the interaction between SIRT5 and p53, and animal models were employed to validate in vivo effects.

RESULTS

Bioinformatics analysis indicated the SIRT5/p53 axis as a critical pathway in LEVs' modulation of colorectal cancer. LEVs were found to inhibit colorectal cancer cell proliferation and glycolytic metabolism by downregulating SIRT5, influencing p53 desuccinylation. In vivo, LEVs regulated this axis, reducing tumor formation in mice. Clinical sample analysis showed that SIRT5 and p53 succinylation levels correlated with patient prognosis.

CONCLUSION

Lactobacillus-derived extracellular vesicles play a pivotal role in suppressing colonic tumor formation by modulating the SIRT5/p53 axis. This results in decreased glycolytic metabolic reprogramming and reduced proliferation in intestinal epithelial cells.

ZEB1-mediated fibroblast polarization controls inflammation and sensitivity to immunotherapy in colorectal cancer

The EMT-transcription factor ZEB1 is heterogeneously expressed in tumor cells and in cancer-associated fibroblasts (CAFs) in colorectal cancer (CRC). While ZEB1 in tumor cells regulates metastasis and therapy resistance, its role in CAFs is largely unknown. Combining fibroblast-specific Zeb1 deletion with immunocompetent mouse models of CRC, we observe that inflammation-driven tumorigenesis is accelerated, whereas invasion and metastasis in sporadic cancers are reduced. Single-cell transcriptomics, histological characterization, and in vitro modeling reveal a crucial role of ZEB1 in CAF polarization, promoting myofibroblastic features by restricting inflammatory activation. Zeb1 deficiency impairs collagen deposition and CAF barrier function but increases NFκB-mediated cytokine production, jointly promoting lymphocyte recruitment and immune checkpoint activation. Strikingly, the Zeb1-deficient CAF repertoire sensitizes to immune checkpoint inhibition, offering a therapeutic opportunity of targeting ZEB1 in CAFs and its usage as a prognostic biomarker. Collectively, we demonstrate that ZEB1-dependent plasticity of CAFs suppresses anti-tumor immunity and promotes metastasis.

Hypoxia-Mediated Upregulation of Xanthine Oxidoreductase Causes DNA Damage of Colonic Epithelial Cells in Colitis

Xanthine oxidoreductase (XOR) serves as the primary source of hydrogen peroxide and superoxide anions in the intestinal mucosa. However, its specific contribution to the progression of colonic disease remains unclear. In this study, we investigated the role of XOR in ulcerative colitis (UC) and attempted to identify the underlying mechanisms. We used the dextran sulfate sodium (DSS)-induced mouse model to mimic UC and observed that XOR inhibitors, allopurinol and diphenyleneiodonium sulfate (DPI), significantly alleviated UC in mice. In addition, treatment with cobalt chloride (CoCl2) and 1% O2 increased the expression of XOR and induced DNA oxidative damage in colonic epithelial cells. Furthermore, we identified that XOR accumulation in the nucleus may directly cause DNA oxidative damage and regulates HIF1α protein levels. In addition, allopurinol effectively protected colon epithelial cells from CoCl2-induced DNA damage. Altogether, our data provided evidence that XOR could induce DNA damage under hypoxic conditions, indicating a significant role of XOR in the initiation and early development of colitis-associated colorectal cancer (CAC).

The receptor protein tyrosine phosphatase PTPRK promotes intestinal repair and catalysis-independent tumour suppression

PTPRK is a receptor tyrosine phosphatase that is linked to the regulation of growth factor signalling and tumour suppression. It is stabilized at the plasma membrane by trans homophilic interactions upon cell-cell contact. PTPRK regulates cell-cell adhesion but is also reported to regulate numerous cancer-associated signalling pathways. However, the signalling mechanism of PTPRK remains to be determined. Here, we find that PTPRK regulates cell adhesion signalling, suppresses invasion and promotes collective, directed migration in colorectal cancer cells. In vivo, PTPRK supports recovery from inflammation-induced colitis. In addition, we confirm that PTPRK functions as a tumour suppressor in the mouse colon and in colorectal cancer xenografts. PTPRK regulates growth factor and adhesion signalling, and suppresses epithelial to mesenchymal transition (EMT). Contrary to the prevailing notion that PTPRK directly dephosphorylates EGFR, we find that PTPRK regulation of both EGFR and EMT is independent of its catalytic function. This suggests that additional adaptor and scaffold functions are important features of PTPRK signalling.

AMPK Deficiency Increases DNA Methylation and Aggravates Colorectal Tumorigenesis in AOM/DSS Mice

The incidence of colorectal cancer (CRC) is closely linked to metabolic diseases. Accumulating evidence suggests the regulatory role of AMP-activated protein kinase (AMPK) in cancer metabolic reprogramming. In this study, wild-type and AMPK knockout mice were subjected to azoxymethane-induced and dextran sulfate sodium (AOM/DSS)-promoted colitis-associated CRC induction. A stable AMPK-deficient Caco-2 cell line was also established for the mechanistic studies. The data showed that AMPK deficiency accelerated CRC development, characterized by increased tumor number, tumor size, and hyperplasia in AOM/DSS-treated mice. The aggravated colorectal tumorigenesis resulting from AMPK ablation was associated with reduced α-ketoglutarate production and ten-eleven translocation hydroxylase 2 (TET2) transcription, correlated with the reduced mismatch repair protein mutL homolog 1 (MLH1) protein. Furthermore, in AMPK-deficient Caco-2 cells, the mRNA expression of mismatch repair and tumor suppressor genes, intracellular α-ketoglutarate, and the protein level of TET2 were also downregulated. AMPK deficiency also increased hypermethylation in the CpG islands of Mlh1 in both colonic tissues and Caco-2 cells. In conclusion, AMPK deficiency leads to reduced α-ketoglutarate concentration and elevates the suppressive epigenetic modifications of tumor suppressor genes in gut epithelial cells, thereby increasing the risk of colorectal tumorigenesis. Given the modifiable nature of AMPK activity, it holds promise as a prospective molecular target for the prevention and treatment of CRC.

Loss of cytidine deaminase expression as a potential attempt to counteract the process of carcinogenesis by reducing basal PARP-1 activity and increasing tau levels

Cytidine deaminase (CDA) is a pyrimidine salvage pathway enzyme that catalyzes the hydrolytic deamination of free cytidine and deoxycytidine to uridine and deoxyuridine, respectively. Our team discovered that CDA deficiency is associated with several aspects of genetic instability, such as increased sister chromatid exchange and ultrafine anaphase bridge frequencies. Based on these results, we sought (1) to determine how CDA deficiency contributes to genetic instability, (2) to explore the possible relationships between CDA deficiency and carcinogenesis, and (3) to develop a new anticancer treatment targeting CDA-deficient tumors. This review summarizes our major findings indicating that CDA deficiency is associated with a genetic instability that does not confer an increased cancer risk. In light of our results and published data, I propose a novel hypothesis that loss of CDA, by reducing basal PARP-1 activity and increasing Tau levels, may reflect an attempt to prevent, slow or reverse the process of carcinogenesis.

Studies on the mechanism of local and extra-intestinal tissue manifestations in AOM-DSS-induced carcinogenesis in BALB/c mice: role of PARP-1, NLRP3, and autophagy

Colitis-associated colorectal cancer (CACC) is one of the devastating complications of long-term inflammatory bowel disease and is associated with substantial morbidity and mortality. Combination of azoxymethane (AOM) and dextran sulfate sodium (DSS) has been extensively used for inflammation-mediated colon tumor development due to its reproducibility, potency, histological and molecular changes, and resemblance to human CACC. In the tumor microenvironment and extra-intestinal tissues, PARP-1, NLRP3 inflammasome, and autophagy's biological functions are complicated and encompass intricate interactions between these molecular components. The focus of the present investigation is to determine the colonic and extra-intestinal tissue damage induced by AOM-DSS and related molecular mechanisms. Azoxymethane (10 mg/kg, i.p.; single injection) followed by DSS (3 cycles, 7 days per cycle) over a period of 10 weeks induced colitis-associated colon cancer in male BALB/c mice. By initiating carcinogenesis with a single injection of azoxymethane (AOM) and then establishing inflammation with dextran sulfate sodium (DSS), a two-stage murine model for CACC was developed. Biochemical parameters, ELISA, histopathological and immunohistochemical analysis, and western blotting have been performed to evaluate the colonic, hepatic, testicular and pancreatic damage. In addition, the AOM/DSS-induced damage has been assessed by analyzing the expression of a variety of molecular targets, including proliferating cell nuclear antigen (PCNA), interleukin-10 (IL-10), AMP-activated protein kinase (AMPK), poly (ADP-ribose) polymerase-1 (PARP-1), cysteine-associated protein kinase-1 (caspase-1), NLR family pyrin domain containing 3 (NLRP3), beclin-1, and interleukin-1β (IL-1β). Present findings revealed that AOM/DSS developed tumors in colon tissue followed by extra-intestinal hepatic, testicular, and pancreatic damages.

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-β/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.

NF-κB Inducing Kinase Attenuates Colorectal Cancer by Regulating Noncanonical NF-κB Mediated Colonic Epithelial Cell Regeneration

BACKGROUND & AIMS

Dysregulated colonic epithelial cell (CEC) proliferation is a critical feature in the development of colorectal cancer. We show that NF-κB-inducing kinase (NIK) attenuates colorectal cancer through coordinating CEC regeneration/differentiation via noncanonical NF-κB signaling that is unique from canonical NF-kB signaling.

METHODS

Initial studies evaluated crypt morphology/functionality, organoid generation, transcriptome profiles, and the microbiome. Inflammation and inflammation-induced tumorigenesis were initiated in whole-body NIK knockout mice (Nik-/-) and conditional-knockout mice following administration of azoxymethane and dextran sulfate sodium.

RESULTS

Human transcriptomic data revealed dysregulated noncanonical NF-kB signaling. In vitro studies evaluating Nik-/- crypts and organoids derived from mature, nondividing CECs, and colonic stem cells exhibited increased accumulation and stunted growth, respectively. Transcriptomic analysis of Nik-/- cells revealed gene expression signatures associated with altered differentiation-regeneration. When assessed in vivo, Nik-/- mice exhibited more severe colitis with dextran sulfate sodium administration and an altered microbiome characterized by increased colitogenic microbiota. In the inflammation-induced tumorigenesis model, we observed both increased tumor burdens and inflammation in mice where NIK is knocked out in CECs (NikΔCEC). Interestingly, this was not recapitulated when NIK was conditionally knocked out in myeloid cells (NikΔMYE). Surprisingly, conditional knockout of the canonical pathway in myeloid cells (RelAΔMYE) revealed decreased tumor burden and inflammation and no significant changes when conditionally knocked out in CECs (RelAΔCEC).

CONCLUSIONS

Dysregulated noncanonical NF-κB signaling is associated with the development of colorectal cancer in a tissue-dependent manner and defines a critical role for NIK in regulating gastrointestinal inflammation and regeneration associated with colorectal cancer.

Review of Animal Models of Colorectal Cancer in Different Carcinogenesis Pathways

Colorectal cancer (CRC) is a common malignant tumor of the gastrointestinal tract with increasing morbidity and mortality. Exploring the factors affecting colorectal carcinogenesis and controlling its occurrence at its root is as important as studying post-cancer treatment and management. Establishing ideal animal models of CRC is crucial, which can occur through various pathways, such as adenoma-carcinoma sequence, inflammation-induced carcinogenesis, serrated polyp pathway and de-novo pathway. This article aims to categorize the existing well-established CRC animal models based on different carcinogenesis pathways, and to describe their mechanisms, methods, advantages and limitations using domestic and international literature sources. This will provide suggestions for the selection of animal models in early-stage CRC research.

Mitochondrial genome transfer drives metabolic reprogramming in adjacent colonic epithelial cells promoting TGFβ1-mediated tumor progression

Although nontumor components play an essential role in colon cancer (CC) progression, the intercellular communication between CC cells and adjacent colonic epithelial cells (CECs) remains poorly understood. Here, we show that intact mitochondrial genome (mitochondrial DNA, mtDNA) is enriched in serum extracellular vesicles (EVs) from CC patients and positively correlated with tumor stage. Intriguingly, circular mtDNA transferred via tumor cell-derived EVs (EV-mtDNA) enhances mitochondrial respiration and reactive oxygen species (ROS) production in CECs. Moreover, the EV-mtDNA increases TGFβ1 expression in CECs, which in turn promotes tumor progression. Mechanistically, the intercellular mtDNA transfer activates the mitochondrial respiratory chain to induce the ROS-driven RelA nuclear translocation in CECs, thereby transcriptionally regulating TGFβ1 expression and promoting tumor progression via the TGFβ/Smad pathway. Hence, this study highlights EV-mtDNA as a major driver of paracrine metabolic crosstalk between CC cells and adjacent CECs, possibly identifying it as a potential biomarker and therapeutic target for CC.

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.

LRRK2 G2019S Promotes Colon Cancer Potentially via LRRK2-GSDMD Axis-Mediated Gut Inflammation

Leucine-rich repeat kinase 2 (LRRK2) is a serine-threonine protein kinase belonging to the ROCO protein family. Within the kinase domain of LRRK2, a point mutation known as LRRK2 G2019S has emerged as the most prevalent variant associated with Parkinson's disease. Recent clinical studies have indicated that G2019S carriers have an elevated risk of cancers, including colon cancer. Despite this observation, the underlying mechanisms linking LRRK2 G2019S to colon cancer remain elusive. In this study, employing a colitis-associated cancer (CAC) model and LRRK2 G2019S knock-in (KI) mouse model, we demonstrate that LRRK2 G2019S promotes the pathogenesis of colon cancer, characterized by increased tumor number and size in KI mice. Furthermore, LRRK2 G2019S enhances intestinal epithelial cell proliferation and inflammation within the tumor microenvironment. Mechanistically, KI mice exhibit heightened susceptibility to DSS-induced colitis, with inhibition of LRRK2 kinase activity ameliorating colitis severity and CAC progression. Our investigation also reveals that LRRK2 G2019S promotes inflammasome activation and exacerbates gut epithelium necrosis in the colitis model. Notably, GSDMD inhibitors attenuate colitis in LRRK2 G2019S KI mice. Taken together, our findings offer experimental evidence indicating that the gain-of-kinase activity in LRRK2 promotes colorectal tumorigenesis, suggesting LRRK2 as a potential therapeutic target in colon cancer patients exhibiting hyper LRRK2 kinase activity.

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.

Gamabufotalin inhibits colitis-associated colorectal cancer by suppressing transcription factor STAT3

Constitutive activation of STAT3 plays important role in the pathogenesis of colorectal cancer (CRC). Inhibition of STAT3 has been proposed as a reasonable strategy to suppress CRC. Gamabufotalin (Gam), an effective bioactive compound of ChanChu, has been used for cancer therapy due to its desirable metabolic stability and less adverse effect. However, its effect on CRC is still unclear. In this study, we found that Gam significantly inhibited the CRC in vitro and vivo. Furthermore, Gam induced apoptosis to inhibit the viability of HCT-116 and HT-29 cell lines in dose-dependent manner by suppressing the transcription factor STAT3. In addition, Gam was also found to inhibit carcinogenesis of colitis-associated cancer (CAC) in AOM/DSS mice model by inhibiting STAT3. Our findings suggest that Gam may be an effective way to prevent occurrence and development of CRC and CAC.

TRAF4-Mediated LAMTOR1 Ubiquitination Promotes mTORC1 Activation and Inhibits the Inflammation-Induced Colorectal Cancer Progression

Mechanistic target of rapamycin complex 1 (mTORC1) is a conserved serine/threonine kinase that integrates various environmental signals to regulate cell growth and metabolism. mTORC1 activation requires tethering to lysosomes by the Ragulator-Rag complex. However, the dynamic regulation of the interaction between Ragulator and Rag guanosine triphosphatase (GTPase) remains unclear. In this study, that LAMTOR1, an essential component of Ragulator, is dynamically ubiquitinated depending on amino acid abundance is reported. It is found that the E3 ligase TRAF4 directly interacts with LAMTOR1 and catalyzes the K63-linked polyubiquitination of LAMTOR1 at K151. Ubiquitination of LAMTOR1 by TRAF4 promoted its binding to Rag GTPases and enhanced mTORC1 activation, K151R knock-in or TRAF4 knock-out blocks amino acid-induced mTORC1 activation and accelerates the development of inflammation-induced colon cancer. This study revealed that TRAF4-mediated LAMTOR1 ubiquitination is a regulatory mechanism for mTORC1 activation and provides a therapeutic target for diseases involving mTORC1 dysregulation.

The generation and use of animal models of osteosarcoma in cancer research

Osteosarcoma is the most common malignant bone tumor affecting children and adolescents. Currently, the most common treatment is surgery combined with neoadjuvant chemotherapy. Although the survival rate of patients with osteosarcoma has improved in recent years, it remains poor when the tumor(s) progress and distant metastases develop. Therefore, better animal models that more accurately replicate the natural progression of the disease are needed to develop improved prognostic and diagnostic markers, as well as targeted therapies for both primary and metastatic osteosarcoma. The present review described animal models currently being used in research investigating osteosarcoma, and their characteristics, advantages, and disadvantages. These models may help elucidate the pathogenic mechanism(s) of osteosarcoma and provide evidence to support and develop clinical treatment strategies.

Delivery of Interferon β-Encoding Plasmid via Lipid Nanoparticle Restores Interferon β Expression to Enhance Antitumor Immunity in Colon Cancer

Type I interferon (IFN-I) plays a critical role in host cancer immunosurveillance, but its expression is often impaired in the tumor microenvironment. We aimed at testing the hypothesis that cationic lipid nanoparticle delivery of interferon β (IFNβ)-encoding plasmid to tumors is effective in restoring IFNβ expression to suppress tumor immune evasion. We determined that IFN-I function in tumor suppression depends on the host immune cells. IFN-I activates the expression of Cxcl9 and Cxcl10 to enhance T cell tumor infiltration. RNA-Seq detected a low level of IFNα13 and IFNβ in colon tumor tissue. scRNA-Seq revealed that IFNβ is expressed in immune cell subsets in non-neoplastic human tissues and to a lesser degree in human colon tumor tissues. Forced expression of IFNα13 and IFNβ in colon tumor cells up-regulates major histocompatibility complex I (MHC I) expression and suppresses colon tumor growth in vivo. In human cancer patients, IFNβ expression is positively correlated with human leukocyte antigen (HLA) expression, and IFN-I signaling activation correlates with the patient response to PD-1 blockade immunotherapy. To translate this finding to colon cancer immunotherapy, we formulated a 1,2-dioleoyl-3-trimethylammonium propane (DOTAP)-cholesterol-encapsulated IFNβ-encoding plasmid (IFNBCOL01). IFNBCOL01 transfects colon tumor cells to express IFNβ to increase the level of MHC I expression. IFNBCOL01 therapy transfects tumor cells and tumor-infiltrating immune cells to produce IFNβ to activate MHC I and granzyme B expression and inhibits colon tumor growth in mice. Our data determine that lipid nanoparticle delivery of IFNβ-encoding plasmid DNA enhances tumor immunogenicity and T cell effector function to suppress colon tumor growth in vivo.

p21 Prevents the Exhaustion of CD4+ T Cells Within the Antitumor Immune Response Against Colorectal Cancer

BACKGROUND & AIMS

T cells are crucial for the antitumor response against colorectal cancer (CRC). T-cell reactivity to CRC is nevertheless limited by T-cell exhaustion. However, molecular mechanisms regulating T-cell exhaustion are only poorly understood.

METHODS

We investigated the functional role of cyclin-dependent kinase 1a (Cdkn1a or p21) in cluster of differentiation (CD) 4+ T cells using murine CRC models. Furthermore, we evaluated the expression of p21 in patients with stage I to IV CRC. In vitro coculture models were used to understand the effector function of p21-deficient CD4+ T cells.

RESULTS

We observed that the activation of cell cycle regulator p21 is crucial for CD4+ T-cell cytotoxic function and that p21 deficiency in type 1 helper T cells (Th1) leads to increased tumor growth in murine CRC. Similarly, low p21 expression in CD4+ T cells infiltrated into tumors of CRC patients is associated with reduced cancer-related survival. In mouse models of CRC, p21-deficient Th1 cells show signs of exhaustion, where an accumulation of effector/effector memory T cells and CD27/CD28 loss are predominant. Immune reconstitution of tumor-bearing Rag1-/- mice using ex vivo-treated p21-deficient T cells with palbociclib, an inhibitor of cyclin-dependent kinase 4/6, restored cytotoxic function and prevented exhaustion of p21-deficient CD4+ T cells as a possible concept for future immunotherapy of human disease.

CONCLUSIONS

Our data reveal the importance of p21 in controlling the cell cycle and preventing exhaustion of Th1 cells. Furthermore, we unveil the therapeutic potential of cyclin-dependent kinase inhibitors such as palbociclib to reduce T-cell exhaustion for future treatment of patients with colorectal cancer.

Gut Bacteria-derived Membrane Vesicles Induce Colonic Dysplasia by Inducing DNA Damage in Colon Epithelial Cells

BACKGROUND & AIMS

Colorectal cancer (CRC) is the third most common cancer in the world. Gut microbiota has recently been implicated in the development of CRC. Actinomyces odontolyticus is one of the most abundant bacteria in the gut of patients with very early stages of CRC. A odontolyticus is an anaerobic bacterium existing principally in the oral cavity, similar to Fusobacterium nucleatum, which is known as a colon carcinogenic bacterium. Here we newly determined the biological functions of A odontolyticus on colonic oncogenesis.

METHODS

We examined the induction of intracellular signaling by A odontolyticus in human colonic epithelial cells (CECs). DNA damage levels in CECs were confirmed using the human induced pluripotent stem cell-derived gut organoid model and mouse colon tissues in vivo.

RESULTS

A odontolyticus secretes membrane vesicles (MVs), which induce nuclear factor kappa B signaling and also produce excessive reactive oxygen species (ROS) in colon epithelial cells. We found that A odontolyticus secretes lipoteichoic acid-rich MVs, promoting inflammatory signaling via TLR2. Simultaneously, those MVs are internalized into the colon epithelial cells, co-localize with the mitochondria, and cause mitochondrial dysfunction, resulting in excessive ROS production and DNA damage. Induction of excessive DNA damage in colonic cells by A odontolyticus-derived MVs was confirmed in the gut organoid model and also in mouse colon tissues.

CONCLUSIONS

A odontolyticus secretes MVs, which cause chronic inflammation and ROS production in colonic epithelial cells, leading to the initiation of CRC.

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.

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.

Endogenous Coriobacteriaceae enriched by a high-fat diet promotes colorectal tumorigenesis through the CPT1A-ERK axis

A high-fat diet (HFD) may be linked to an increased colorectal cancer (CRC) risk. Stem cell proliferation and adipokine release under inflammatory and obese conditions are the main factors regulating CRC progression. Furthermore, alterations in intestinal flora have been linked to tumorigenesis and tumour progression. However, whether a HFD can promote CRC occurrence by altering intestinal flora remains unclear. The objective of this study was to identify bacterial strains enriched by a HFD and investigate the association and mechanism by which a HFD and bacterial enrichment promote CRC occurrence and development. In this study, the intestinal microbiota of mice was assessed using 16S rRNA and metagenomic sequencing. Serum metabolites of HFD-fed mice were assessed using tandem liquid chromatography-mass spectrometry. CRC cell lines and organoids were co-cultured with Coriobacteriaceae to evaluate the effect of these bacteria on the CPT1A-ERK signalling pathway. We found that Coriobacteriaceae were enriched in the colons of HFD-fed mice. An endogenous Coriobacteriaceae strain, designated as Cori.ST1911, was successfully isolated and cultured from the stools of HFD-fed mice, and the tumorigenic potential of Cori.ST1911 in CRC was validated in several CRC mouse models. Furthermore, Cori.ST1911 increased acylcarnitine levels by activating CPT1A, demonstrating the involvement of the CPT1A-ERK axis. We also found that the endogenous Lactobacillus strain La.mu730 can interfere with Cori.ST1911 colonisation and restore gut barrier function. In conclusion, we identified a novel endogenous intestinal Coriobacteriaceae, Cori.ST1911, which might lead to a new gut microbiota intervention strategy for the prevention and treatment of CRC.

CXADR-Like Membrane Protein Regulates Colonic Epithelial Cell Proliferation and Prevents Tumor Growth

BACKGROUND & AIMS

CXADR-like membrane protein (CLMP) is structurally related to coxsackie and adenovirus receptor. Pathogenic variants in CLMP gene have been associated with congenital short bowel syndrome, implying a role for CLMP in intestinal development. However, the contribution of CLMP to regulating gut development and homeostasis is unknown.

METHODS

In this study, we investigated CLMP function in the colonic epithelium using complementary in vivo and in vitro approaches, including mice with inducible intestinal epithelial cell (IEC)-specific deletion of CLMP (ClmpΔIEC), intestinal organoids, IECs with overexpression, or loss of CLMP and RNA sequencing data from individuals with colorectal cancer.

RESULTS

Loss of CLMP enhanced IEC proliferation and, conversely, CLMP overexpression reduced proliferation. Xenograft experiments revealed increased tumor growth in mice implanted with CLMP-deficient colonic tumor cells, and poor engraftment was observed with CLMP-overexpressing cells. ClmpΔIEC mice showed exacerbated tumor burden in an azoxymethane and dextran sulfate sodium-induced colonic tumorigenesis model, and CLMP expression was reduced in human colorectal cancer samples. Mechanistic studies revealed that CLMP-dependent regulation of IEC proliferation is linked to signaling through mTOR-Akt-β-catenin pathways.

CONCLUSIONS

These results reveal novel insights into CLMP function in the colonic epithelium, highlighting an important role in regulating IEC proliferation, suggesting tumor suppressive function in colon cancer.

Inhibition of FABP5 attenuates inflammatory bowel disease by modulating macrophage alternative activation

Fatty acid binding protein 5 (FABP5) is an intracellular chaperone of fatty acid molecules that regulates lipid metabolism and cell growth. However, its role in intestinal inflammation remains enigmatic. Through examination of human tissue samples and single-cell data, we observed a significant upregulation of FABP5 within the mucosa of patients afflicted with ulcerative colitis (UC) and Crohn's disease (CD), predominantly localized in intestinal macrophages. Herein, we investigate the regulation of FABP5-IN-1, a FABP5 inhibitor, on various cells of the gut in an inflammatory environment. Our investigations confirmed that FABP5 ameliorates DSS-induced colitis in mice by impeding the differentiation of macrophages into M1 macrophages in vitro and in vivo. Furthermore, following FABP5-IN-1 intervention, we observed a notable restoration of intestinal goblet cells and tuft cells, even under inflammatory conditions. Additionally, FABP5-IN-1 exhibits a protective effect against DSS-induced colitis by promoting the polarization of macrophages towards the M2 phenotype in vivo. In summary, FABP5-IN-1 confers protection against DSS-induced acute colitis through a multifaceted approach, encompassing the reduction of inflammatory macrophage infiltration, macrophage polarization, regulating Th17/Treg cells to play an anti-inflammatory role in IBD. The implications for IBD are underscored by the comprehensive in vivo and in vitro experiments presented in this article, thereby positioning FABP5 as a promising and novel therapeutic target for the treatment of IBD.