Colitis-associated Colon Cancer Research Articles

Helminth-derived molecules improve 5-fluorouracil treatment on experimental colon tumorigenesis

Colorectal cancer (CRC) is one of the most prevalent fatal neoplasias worldwide. Despite efforts to improve the early diagnosis of CRC, the mortality rate of patients is still nearly 50%. The primary treatment strategy for CRC is surgery, which may be accompanied by chemotherapy and radiotherapy. The conventional and first-line chemotherapeutic agent utilized is 5-fluorouracil (5FU). However, it has low efficiency. Combination treatment with leucovorin and oxaliplatin or irinotecan improves the effectiveness of 5FU therapy. Unfortunately, most patients develop drug resistance, leading to disease progression. Here, we evaluated the effect of a potential alternative adjuvant treatment for 5FU, helminth-derived Taenia crassiceps (TcES) molecules, on treating advanced colitis-associated colon cancer. The use of TcES enhanced the effects of 5FU on established colonic tumors by downregulating the expression of the immunoregulatory cytokines, Il-10 and Tgf-β, and proinflammatory cytokines, Tnf-α and Il-17a, and reducing the levels of molecular markers associated with malignancy, cyclin D1, and Ki67, both involved in apoptosis inhibition and the signaling pathway of β-catenin. TcES+5FU therapy promoted NK cell recruitment and the release of Granzyme B1 at the tumor site, consequently inducing tumor cell death. Additionally, it restored P53 activity which relates to decreased Mdm2 expression. In vitro assays with human colon cancer cell lines showed that therapy with TcES+5FU significantly reduced cell proliferation and migration by modulating the P53 and P21 signaling pathways. Our findings demonstrate, for the first time in vivo, that helminth-derived excreted/secreted products may potentiate the effect of 5FU on established colon tumors.

Role of CRH in colitis and colitis-associated cancer: a combinative result of central and peripheral effects?

Corticotropin-releasing factor family peptides (CRF peptides) comprise corticotropin releasing hormone (CRH), urocortin (UCN1), UCN2 and UCN3. CRH is first isolated in the brain and later with UCNs found in many peripheral cells/tissues including the colon. CRH and UCNs function via the two types of receptors, CRF1 and CRF2, with CRH mainly acting on CRF1, UCN1 on both CRF1 &CRF2 and UCN2-3 on CRF2. Compiling evidence shows that CRH participates in inflammation and cancers via both indirect central effects related to stress response and direct peripheral influence. CRH, as a stress-response mediator, plays a significant central role in promoting the development of colitis involving colon motility, immunity and gut flora, while a few anti-colitis results of central CRH are also reported. Moreover, CRH is found to directly influence the motility and immune/inflammatory cells in the colon. Likewise, CRH is believed to be greatly related to tumorigenesis of many kinds of cancers including colon cancer via the central action during chronic stress while the peripheral effects on colitis-associated-colon cancer (CAC) are also proved. We and others observe that CRH/CRF1 plays a significant peripheral role in the development of colitis and CAC in that CRF1 deficiency dramatically suppresses the colon inflammation and CAC. However, up to date, there still exist not many relevant experimental data on this topic, and there seems to be no absolute clearcut between the central and direct peripheral effects of CRH in colitis and colon cancer. Taken together, CRH, as a critical factor in stress and immunity, may participate in colitis and CAC as a centrally active molecule; meanwhile, CRH has direct peripheral effects regulating the development of colitis and CAC, both of which will be summarized in this review.

Abstract 6885: Investigating a novel role of DCLK1 isoforms in colitis and colitis associated colon cancer

Abstract Chronic intestinal inflammation in patients diagnosed with inflammatory bowel disease (IBD) significantly increases their risk of colorectal cancer (CRC). Despite the rising global frequency of IBD, the precise mechanisms that regulate the transition from IBD to colon cancer are poorly understood. Doublecortin-like kinase 1 (DCLK1) is a protein with two major isoforms, DCLK1-L and DCLK1-S. Previous studies have shown that hypermethylation of the DCLK-1α promoter encoding DCLK1-L, particularly in colorectal cancer, allows switching to the DCLK1-S isoform that confers an invasive tumor phenotype. The DCLK1-L is a tuft cell marker that protects against colitis by sensing and eliminating gut pathogenic infection through various mechanisms. On the contrary, the role of DCLK1-S in colitis and colitis-associated cancer has not been thoroughly investigated. Studies from our lab have identified a marked elevation of DCLK1-S in tissue samples of IBD patients. We also recently discovered that DCLK1-S is predominantly expressed in Ly6G+; MHCII- neutrophils, which coincide with elevated levels of inflammation and tissue damage in the colon. To further understand the role of DCLK1 isoforms in driving the progression of colitis to colon cancer, we bred Dclk1fl/fl mice with MRP8-Cre-ires/GFP mice to generate Dclk1fl/fl;MRP8-Cre+/- that eliminates DCLK1-L upon tamoxifen injection resulting in sustained expression of DCLK1-S in the granulocytes especially neutrophils. When infected with Citrobacter rodentium (CR), MRP8;Dclk1−/− mice compared to MRP8;Dclk1+/− or WT mice developed more severe colitis. We have also discovered a novel interaction between DCLK1-S and MMP13 in an unbiased docking study that correlated with significant co-localization of DCLK1-S with MMP13 in the colons of CR-infected mice. Employing a knock-in mice over-expressing the DCLK1-S +19 under the CAG promoter, the DCLK1-MMP13 co-localization correlated with severe ulceration and colitis with loss of crypts and immune cell infiltration including Ly6G+ neutrophils. Studies are underway to see if the severity of colitis in MRP8;Dclk1−/− mice translates into enhanced tumorigenesis and to see if potential interaction between DCLK1-S and MMP13 could provide a plausible mechanism of colitis progression to colon cancer through ECM remodeling and tissue damage. Citation Format: Kafayat Aderonke Yusuf, Badal C. Roy, Shrikant Anant, Shahid Umar. Investigating a novel role of DCLK1 isoforms in colitis and colitis associated colon cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 6885.

Sophora japonica Extract Inhibits Ulcerative Colitis and Colitis-Associated Colon Cancer via Regulation of Lipid Metabolism

Inflammation is a well-known risk factor for tumor development. Intervening in chronic inflammation may be an effective approach to inhibit the progression of ulcerative colitis (UC) to colitis-associated colon cancer (CAC). Sophora japonica is a medicinal and food plant commonly used to treat hemorrhoids, bleeding, and inflammation, symptoms that coincide with those of patients with CAC. However, studies on using Sophora japonica to treat CAC are scarce. Therefore, this study aimed to investigate the anti-inflammatory and antitumor effects of Sophora japonica extract (SJE) using dextran sodium sulfate (DSS)-induced UC and azoxymethane (AOM)/DSS-induced CAC models. Furthermore, we employed ultraperformance liquid chromatography–quadrupole time-of-flight–tandem mass spectrometry (UPLC–QTOF–MS/MS) technology to explore the metabolomics mechanism through which SJE inhibited the progression of UC to CAC. The results demonstrated that SJE significantly inhibited UC and CAC and alleviated symptoms such as bloody stools, colon shortening, inflammation, and intestinal tissue damage in model mice. Further, 57 differential metabolites were identified by UPLC–QTOF–MS/MS, which were composed mainly of lipids (fatty acids, glycerophospholipids, sterol lipids, pregnenolone lipids, etc.) and peptides (amino acids). Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis suggested that SJE might inhibit the progression of UC to CAC by regulating lipid metabolic pathways such as arachidonic acid metabolism, primary bile acid biosynthesis, and linoleic acid metabolism. This study, for the first time, substantiated the inhibitory effect of SJE on CAC. Employing metabolomics techniques, the research delved into the potential pathways through which SJE may exert its inhibitory effects on CAC by suppressing the progression of UC. These findings contribute scientific evidence to the application of Sophora japonica in functional foods and the development of natural drugs for the prevention and treatment of UC and CAC.

Enterohemorrhagic Escherichia coli effector EspF triggers oxidative DNA lesions in intestinal epithelial cells.

Attaching/effacing (A/E) pathogens induce DNA damage and colorectal cancer by injecting effector proteins into host cells via the type III secretion system (T3SS). EspF is one of the T3SS-dependent effector proteins exclusive to A/E pathogens, which include enterohemorrhagic Escherichia coli. The role of EspF in the induction of double-strand breaks (DSBs) and the phosphorylation of the repair protein SMC1 has been demonstrated previously. However, the process of damage accumulation and DSB formation has remained enigmatic, and the damage response is not well understood. Here, we first showed a compensatory increase in the mismatch repair proteins MutS homolog 2 (MSH2) and MSH6, as well as poly(ADP-ribose) polymerase 1, followed by a dramatic decrease, threatening cell survival in the presence of EspF. Flow cytometry revealed that EspF arrested the cell cycle at the G2/M phase to facilitate DNA repair. Subsequently, 8-oxoguanine (8-oxoG) lesions, a marker of oxidative damage, were assayed by ELISA and immunofluorescence, which revealed the accumulation of 8-oxoG from the cytosol to the nucleus. Furthermore, the status of single-stranded DNA (ssDNA) and DSBs was confirmed. We observed that EspF accelerated the course of DNA lesions, including 8-oxoG and unrepaired ssDNA, which were converted into DSBs; this was accompanied by the phosphorylation of replication protein A 32 in repair-defective cells. Collectively, these findings reveal that EspF triggers various types of oxidative DNA lesions with impairment of the DNA damage response and may result in genomic instability and cell death, offering novel insight into the tumorigenic potential of EspF.IMPORTANCEOxidative DNA lesions play causative roles in colitis-associated colon cancer. Accumulating evidence shows strong links between attaching/effacing (A/E) pathogens and colorectal cancer (CRC). EspF is one of many effector proteins exclusive to A/E pathogens with defined roles in the induction of oxidative stress, double-strand breaks (DSBs), and repair dysregulation. Here, we found that EspF promotes reactive oxygen species generation and 8-oxoguanine (8-oxoG) lesions when the repair system is activated, contributing to sustained cell survival. However, infected cells exposed to EspF presented 8-oxoG, which results in DSBs and ssDNA accumulation when the cell cycle is arrested at the G2/M phase and the repair system is defective or saturated by DNA lesions. In addition, we found that EspF could intensify the accumulation of nuclear DNA lesions through oxidative and replication stress. Overall, our work highlights the involvement of EspF in DNA lesions and DNA damage response, providing a novel avenue by which A/E pathogens may contribute to CRC.

Musashi-2 potentiates colorectal cancer immune infiltration by regulating the post-translational modifications of HMGB1 to promote DCs maturation and migration

Post-translational modifications (PTMs) of the non-histone protein high-mobility group protein B1 (HMGB1) are involved in modulating inflammation and immune responses. Recent studies have implicated that the RNA-binding protein (RBP) Musashi-2 (MSI2) regulates multiple critical biological metabolic and immunoregulatory functions. However, the precise role of MSI2 in regulating PTMs and tumor immunity in colorectal cancer (CRC) remains unclear. Here, we present data indicating that MSI2 potentiates CRC immunopathology in colitis-associated colon cancer (CAC) mouse models, cell lines and clinical specimens, specifically via HMGB1-mediated dendritic cell (DC) maturation and migration, further contributes to the infiltration of CD4+ and CD8+ T cells and inflammatory responses. Under stress conditions, MSI2 can exacerbate the production, nucleocytoplasmic transport and extracellular release of damage-associated molecular patterns (DAMPs)-HMGB1 in CRC cells. Mechanistically, MSI2 mainly enhances the disulfide HMGB1 production and protein translation via direct binding to nucleotides 1403–1409 in the HMGB1 3′ UTR, and interacts with the cytoplasmic acetyltransferase P300 to upregulate its expression, further promoting the acetylation of K29 residue in HMGB1, thus leading to K29-HMGB1 nucleocytoplasmic translocation and extracellular release. Furthermore, blocking HMGB1 activity with glycyrrhizic acid (Gly) attenuates MSI2-mediated immunopathology and immune infiltration in CRC in vitro and in vivo. Collectively, this study suggests that MSI2 may improve the prognosis of CRC patients by reprogramming the tumor immune microenvironment (TIME) through HMGB1-mediated PTMs, which might be a novel therapeutic option for CRC immunotherapy.

Jiedu Xiaozheng Yin Inhibits the Progression of Colitis Associated Colorectal Cancer by Stimulating Macrophage Polarization Towards an M1 Phenotype via the TLR4 Pathway.

To investigate the effect of Jiedu Xiaozheng Yin (JXY) on the polarization of macrophages in colitis-associated colon cancer (CAC). An orthotopic model of CAC was established to monitor changes in the pathological state of mice. Colon length, number of colon tumors were recorded, and indices for liver, spleen, and thymus were calculated. Hematoxylin and eosin (H&E) staining was employed to observe intestinal mucosal injury and tumor formation. Immunohistochemistry (IHC) staining was utilized to investigate the effect of JXY on M1 and M2 polarization of macrophages in the colonic mucosa of CAC mice. For in vitro experiments, RT-qPCR (Reverse Transcription-quantitative PCR) and flow cytometry were used to observe the effect of JXY on various M1-related molecules such as IL-1β, TNF-α, iNOS, CD80, CD86, and its phagocytic function as well as M2-related molecules including Arg-1, CD206, and IL-10. Subsequently, after antagonizing the TLR4 pathway with antagonists (TAK242, PDTC, KG501, SR11302, LY294002), the expression of IL-6, TNF-α, iNOS, and IL-1β mRNA were detected by RT-qPCR. In vivo experiments, the results showed that JXY improved the pathological condition of mice in general. And JXY treatment decreased the shortening of colon length and number of tumors as compared to non-treated CAC mice. Additionally, JXY treatment improved the lesions in the colonic tissue and induced a polarization of intestinal mucosal macrophages towards the M1 phenotype, while inhibiting polarization towards the M2 phenotype. In vitro experiments further confirmed that JXY treatment promoted the activation of macrophages towards the M1 phenotype, leading to increased expression of IL-1β, TNF-α, iNOS, CD80, CD86, as well as enhanced phagocytic function. JXY treatment concomitantly inhibited the expression of M2-phenotype related molecules Arginase-1 (Arg-1), CD206, and IL-10. Furthermore, JXY inhibited M1-related molecules such as IL-6, TNF-α, iNOS, and IL-1β after antagonizing the TLR4 pathway. Obviously, JXY could exhibit inhibitory effects on the development of colon tumors in mice with CAC by promoting M1 polarization through TLR4-mediated signaling and impeding M2 polarization of macrophages.

OP24 SPP1 in colitis-associated colon cancer

Abstract Background Patients with ulcerative colitis (UC) and Crohn’s disease (CD) face a lifelong risk of developing colitis-associated carcinoma (CAC). Current insights into CAC development originate from murine CAC models, while human CAC studies primarily focus on mutational analyses. Although the mutational landscape reveals distinct patterns and frequencies compared to colorectal cancer, it falls short in elucidating the inflammatory mechanisms of CAC development. Consequently, we adopted a multi-omics approach to unravel CAC carcinogenesis, utilizing human samples from patients with CD, CD-associated CAC (CD-CAC), UC, and UC-associated CAC (UC-CAC). Findings were further validated in vitro using human colon organoids. Methods A Nanostring Immunology v2 panel was employed on RNA (archival FFPE sections) from 40 patients suffering from either IBD or CAC, alongside inflammation-free healthy controls (n=10 per group). Our data revealed a robust upregulation of the SPP1 (Secreted Phosphoprotein 1) gene encoding osteopontin (OPN) in CAC patients. Prospectively, we extended our methodology to an unbiased imaging-based spatial RNA in situ sequencing (ISS) approach (477 genes, Xenium, 10X Genomics) using FFPE sections from CAC and UC patients (n=3 per group). This provided insights into the spatial expression of SPP1 and its target receptors at a subcellular resolution. Findings were validated using whole FFPE section confocal microscopy. In addition, in vitro models, including human UC organoids, were analyzed by bulk RNA-Seq, RT-qPCR, and downstream functional assays. Results Nanostring Immunology v2 gene expression data revealed upregulation of the SPP1 gene encoding OPN (Fig 1A) and EMT transcription factors FN1 and ZEB1 in CAC patients. Xenium RNA in situ sequencing (ISS) unveiled the spatial heterogeneity of SPP1 expression in CAC (Fig 1B). Unsupervised graph-based clustering identified an SPP1+CD68+ macrophage cluster exclusively in CAC (Fig 1C), validated through OPN/CD68 immunostainings (Fig 1D). In vitro OPN stimulation across multiple human and mice colon organoid models excluded OPN as the trigger of EMT. Interestingly, Xenium ISS and immunostainings revealed a mutually exclusive spatial location of SPP1/OPN+ macrophages and CD8+ T cells (Fig 1E, F and G). Conclusion SPP1 is significantly upregulated in CAC (RNA and protein), expressed by CD68+ macrophages. In vitro OPN stimulation demonstrated no direct effect on intestinal epithelial organoids. The mutually exclusive spatial locations of SPP1/OPN+ macrophages and CD8+ T cells suggests a crucial role of SPP1/OPN in modulating the immunosurveillance of CAC cells by CD8+ tumour lymphocytes.

Self-assembled fructo-oligosaccharide conjugated ferulic acid microparticle: Anticancer, anti-inflammatory and immunomodulatory effects

Fructo-oligosaccharide ferulic acid conjugate was synthesized, which self-assembles into disc shaped amorphous microparticles (FA FOS I), that could be used for targeted delivery to the colon. It is accessed for its ability to ameliorate colorectal cancer and inflammation. The microparticle exhibited selective cytotoxicity and apoptosis induction in colon cancer cells. The microparticle arrested the cell cycle in the G0-G1 phase. In-vivo anti-colorectal cancer activity were evaluated in colitis associated colon cancer mice model. There was a reduction in 60.83% of tumour lesions and 48.27% reduction in the malignant cells. The immunohistochemistry (IHC) revealed the suppression of inflammation and related inflammatory cytokines in the colon. The inhibition of cell proliferation, up-regulation of tumour suppressor protein and induction of apoptosis in the malignant cells were observed. The evaluation of immune modulation by FA FOS I microparticle revealed a 9% increase in WBC count and an increase in the infiltration of T-helper cells and cytotoxic T-cells into the tumour microenvironment. There was a considerable decrease in the expression of immune suppressing PD-L1 by the tumour cells on treatment with FA FOS I microparticle. All these data implicate better efficacy of the FA FOS I microparticle delivery to colon and amelioration of colitis associated colorectal cancer through multimodal route of inflammation reduction, apoptosis induction and positive modulation of immune system in the tumour microenvironment. FA FOS I was proposed to be a candidate drug which is physiologically and metabolically stable under gastro-intestinal condition and potentiating its effect in the target site large intestine; without being absorbed or transported to other tissue nor causing any adverse cytotoxicity to the neighbouring normal tissue.

Clofazimine attenuates colitis-associated colon cancer through β-catenin signaling pathway in the AOM/DSS mice models

Clofazimine attenuates colitis-associated colon cancer through β-catenin signaling pathway in the AOM/DSS mice models

GPR15 in colon cancer development and anti-tumor immune responses

IntroductionThe chemoattractant receptor, G protein-coupled receptor 15 (GPR15), promotes colon homing of T cells in health and colitis. GPR15 function in colon cancer is largely unexplored, motivating our current studies.MethodsIn human study, immune cells were isolated from tumor tissues and healthy surgical tumor margins (STM), and their proportions as well as expression of GPR15 was analyzed by flow cytometry. In mouse studies, colon cancer was induced in GPR15-deficient (KO) and GPR15-suficient (Het) mice using azoxymethane (AOM) and dextran sulfate sodium (DSS) solution in drinking water. Serial endoscopy was performed in mice to monitor and visualize the distal region of colon. Mice were euthanized 10 weeks after the initial DSS administration, and the colon length and the number of polyps were recorded. Next, we identified the effects of GPR15L on established tumors in the MC38-colorectal cancer (CRC) mouse model. Immune cells were isolated from the mice colons or tumors and assessed by flow cytometry.ResultsOur analysis of human CRC tissue revealed a significant reduction in GPR15+ immune cell frequencies in tumors compared to ‘tumor-free’ surgical margins. Similarly, our data analysis using The Cancer Genome Atlas (TCGA) indicated that lower GPR15 expression is associated with poor survival in human colon cancer. In the AOM/DSS colitis-associated colon cancer model, we observed increased colonic polyps and lower survival in Gpr15+-KO compared to Gpr15-Het mice. Analysis of immune cell infiltrates in the colonic polyps showed significantly decreased CD8+ T cells and increased IL-17+ CD4+ and IL-17+ CD8+ T cells in Gpr15-KO than in Het mice. Consistent with a protective role of GPR15, administration of GPR15L to established tumors in the MC38-CRC model increased CD45+ cell infiltration, enhanced TNFa expression on CD4+ and CD8+ T cells at the tumor site and dramatically reduced tumor burden.DiscussionOur findings highlight an important, unidentified role of the GPR15-GPR15L axis in promoting a tumor-suppressive immune microenvironment and unveils a novel, colon-specific therapeutic target for CRC.

Disruption of hypoxia-inducible factor-2α in neutrophils decreases colitis-associated colon cancer.

Neutrophils are abundant immune cells in the colon tumor microenvironment. Studies have shown that neutrophils are recruited into hypoxic foci in colon cancer. However, the impact of hypoxia signaling on neutrophil function and its involvement in colon tumorigenesis remain unclear. To address this, we generated mice with a deletion of hypoxia-inducible factor (HIF)-1α or HIF-2α in neutrophils driven by the MRP8Cre (HIF-1αΔNeu) or (HIF-2αΔNeu) and littermate controls. In an azoxymethane (AOM)/dextran sulfate sodium (DSS) model of colon cancer, the disruption of neutrophils-HIF-1α did not result in any significant changes in body weight, colon length, tumor size, proliferation, or burden. However, the disruption of HIF-2α in neutrophils led to a slight increase in body weight, a significant decrease in the number of tumors, and a reduction in tumor size and volume compared with their littermate controls. Histological analysis of colon tissue from mice with HIF-2α-deficient neutrophils revealed notable reductions in proliferation as compared with control mice. In addition, we observed reduced levels of proinflammatory cytokines, such as TNF-α and IL-1β, in neutrophil-specific HIF-2α-deficient mice in both the tumor tissue as well as the neutrophils. Importantly, it is worth noting that the reduced tumorigenesis associated with HIF-2α deficiency in neutrophils was not evident in already established syngeneic tumors or a DSS-induced inflammation model, indicating a potential role of HIF-2α specifically in colon tumorigenesis. In conclusion, we found that the loss of neutrophil-specific HIF-2α slows colon tumor growth and progression by reducing the levels of inflammatory mediators.NEW & NOTEWORTHY Despite the importance of hypoxia and neutrophils in colorectal cancer (CRC), the contribution of neutrophil-specific HIFs to colon tumorigenesis is not known. We describe that neutrophil HIF-1α has no impact on colon cancer, whereas neutrophil HIF-2α loss reduces CRC growth by decreasing proinflammatory and immunosuppressive cytokines. Furthermore, neutrophil HIF-2α does not reduce preestablished tumor growth or inflammation-induced colitis. The present study offers novel potential of neutrophil HIF-2α as a therapeutic target in CRC.

Kinase Signaling in Colitis-Associated Colon Cancer and Inflammatory Bowel Disease.

Colorectal cancer is a known complication of chronic inflammation of the colon ("colitis-associated colon cancer"). Inflammatory bowel disease (IBD) is a chronic inflammatory disorder of the gastrointestinal tract. Patients with IBD are at increased risk of colon cancer compared to the general population. Kinase signaling pathways play critical roles in both the inflammation and regulating cellular processes such as proliferation and survival that contribute to cancer development. Here we review the interplay of kinase signaling pathways (mitogen-activated protein kinases, cyclin-dependent kinases, autophagy-activated kinases, JAK-STAT, and other kinases) and their effects on colitis-associated colon cancer. We also discuss the role of JAK-STAT signaling in the pathogenesis of IBD and the therapeutic landscape of JAK inhibitors for the treatment of IBD.

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-1β, 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.

Loss of NOD2 in macrophages improves colitis and tumorigenesis in a lysozyme-dependent manner.

Crohn's disease (CD) is a complex and poorly understood myeloid-mediated disorder. Genetic variants with loss of function in the NOD2 gene confer an increased susceptibility to ileal CD. While Nod2 in myeloid cells may confer protection against T-cell mediated ileopathy, it remains unclear whether it may promote resolution of the inflamed colon. In this study, we evaluated the function of Nod2 in myeloid cells in a model of acute colitis and colitis-associated colon cancer (CAC). To ablate Nod2 specifically within the myeloid compartment, we generated LysMCre/+;Nod2fl/fl mice. The role of NOD2 was studied in a setting of Dextran Sodium Sulfate (DSS)-induced colitis and in azoxymethane (AOM)/DSS model. Clinical parameters were quantified by colonoscopy, histological, flow cytometry, and qRT-PCR analysis. Upon DSS colitis model, LysMCre/+;Nod2fl/fl mice lost less weight than control littermates and had less severe damage to the colonic epithelium. In the AOM/DSS model, endoscopic monitoring of tumor progression revealed a lowered number of adenomas within the colon of LysMCre/+;Nod2fl/fl mice, associated with less expression of Tgfb. Mechanistically, lysozyme M was required for the improved disease severity in mice with a defect of NOD2 in myeloid cells. Our results indicate that loss of Nod2 signaling in myeloid cells aids in the tissue repair of the inflamed large intestine through lysozyme secretion by myeloid cells. These results may pave the way to design new therapeutics to limit the inflammatory and tumorigenic functions of NOD2.

Hematopoietic-specific heterozygous loss of Dnmt3a exacerbates colitis-associated colon cancer.

Clonal hematopoiesis (CH) is defined as clonal expansion of mutant hematopoietic stem cells absent diagnosis of a hematologic malignancy. Presence of CH in solid tumor patients, including colon cancer, correlates with shorter survival. We hypothesized that bone marrow-derived cells with heterozygous loss-of-function mutations of DNMT3A, the most common genetic alteration in CH, contribute to the pathogenesis of colon cancer. In a mouse model that combines colitis-associated colon cancer (CAC) with experimental CH driven by Dnmt3a+/Δ, we found higher tumor penetrance and increased tumor burden compared with controls. Histopathological analysis revealed accentuated colonic epithelium injury, dysplasia, and adenocarcinoma formation. Transcriptome profiling of colon tumors identified enrichment of gene signatures associated with carcinogenesis, including angiogenesis. Treatment with the angiogenesis inhibitor axitinib eliminated the colon tumor-promoting effect of experimental CH driven by Dnmt3a haploinsufficiency and rebalanced hematopoiesis. This study provides conceptually novel insights into non-tumor-cell-autonomous effects of hematopoietic alterations on colon carcinogenesis and identifies potential therapeutic strategies.

Biglycan regulated colorectal cancer progress by modulating enteric neuron-derived IL-10 and abundance of Bacteroides thetaiotaomicron

Biglycan (BGN) is a proteoglycan with branch chains and highly expressed in enteric neurons in the tumor tissue of colorectal cancer (CRC), which is negatively associated with survival rates in patients with CRC. However, how the proteoglycan promotes the progress of CRC through interacting with bacteria and regulating the immune response of enteric neurons remains largely unknown. In the present study, we found that biglycan deficiency changed tumor distribution in a colitis-associated colon cancer model. Furthermore, we revealed that BGN deficiency inhibits tumor growth in an allograft tumor model and the migration of cancer cell by upregulating interleukin-10 expression in enteric neurons. Significantly, we demonstrated that biglycan deficiency enriched the abundance of Bacteroides thetaiotaomicron through competing with it for chondroitin sulfate to inhibit CRC progress. Our work provided new insights into the interaction between host proteoglycan and gut microbiota as well as the role of enteric neurons in the tumor microenvironment.

Beneficial effects of alpha-1 antitrypsin therapy in a mouse model of colitis-associated colon cancer

BackgroundIt is widely accepted that chronic inflammatory bowel diseases significantly higher a risk for colorectal cancer development. Among different types of treatments for patients with colon cancer, novel protein-based therapeutic strategies are considered.AIMTo explore the effect of human plasma alpha-1 antitrypsin (AAT) protein in the chemically induced mouse model of colorectal cancer.MethodsBALB/c mice with azoxymethane/dextran sodium sulfate (AOM/DSS)-induced colitis-associated colorectal cancer (CAC), we intraperitoneally treated with commercial preparation of human plasma AAT (4 mg per mouse). Effects of this therapy were evaluated histologically, and by immunohistochemical and gene expression assays.ResultsWhen compared with non-treated controls, AOM/DSS mice receiving AAT therapy exhibited significantly longer colons, and less anal bleeding. Concurrently, AAT-treated mice had significantly fewer polyps, and lower numbers of large colon tumors. Immunohistochemical examinations of colon tissues showed significantly lower neutrophil counts, more granzyme B-positive but fewer MMP9 (gelatinase B)-positive cancer cells and lower numbers of apoptotic cells in mice receiving AAT therapy. The expression levels of IL4 were significantly higher while TNFA was slightly reduced in tumor tissues of AOM/DSS mice treated with AAT than in AOM/DSS mice.ConclusionHuman AAT is an acute phase protein with a broad-protease inhibitory and immunomodulatory activities used as a therapeutic for emphysema patients with inherited AAT deficiency. Our results are consistent with previous findings and support an idea that AAT alone and/or in combination with available anti-cancer therapies may represent a new personalized approach for patients with colitis-induced colon cancer.

Animal models of inflammatory bowel disease: novel experiments for revealing pathogenesis of colitis, fibrosis, and colitis-associated colon cancer.

Inflammatory bowel disease (IBD), comprising Crohn's disease and ulcerative colitis, is a lifelong disease that manifests with chronic intestinal inflammation, sequential fibrosis, and an increased risk of colitis-associated colon cancer (CAC). The combined effects of genetic, immunological, environmental, and microbial factors render it difficult to determine the specific mechanism underlying the induction and perpetuation of IBD. Various animal models of IBD have contributed enormously to the understanding of IBD pathogenesis in terms of genomics, transcriptomics, proteomics, microbiome, and drug development of novel therapeutics. Although comprehensive research on IBD has been enabled by advanced technologies, such as genetically engineered models, there is a great need to develop relevant in vivo models of colitis and fibrosis. Here, we review 4 categories of animal models of acute and chronic intestinal inflammation, fibrosis, and CAC: chemically induced, genetically engineered, T cell transfer, and spontaneous gene mutation models.

Investigation of artificial intelligence integrated fluorescence endoscopy image analysis with indocyanine green for interpretation of precancerous lesions in colon cancer.

Indocyanine green (ICG) has been used in clinical practice for more than 40 years and its safety and preferential accumulation in tumors has been reported for various tumor types, including colon cancer. However, reports on clinical assessments of ICG-based molecular endoscopy imaging for precancerous lesions are scarce. We determined visualization ability of ICG fluorescence endoscopy in colitis-associated colon cancer using 30 lesions from an azoxymethane/dextran sulfate sodium (AOM/DSS) mouse model and 16 colon cancer patient tissue-samples. With a total of 60 images (optical, fluorescence) obtained during endoscopy observation of mouse colon cancer, we used deep learning network to predict four classes (Normal, Dysplasia, Adenoma, and Carcinoma) of colorectal cancer development. ICG could detect 100% of carcinoma, 90% of adenoma, and 57% of dysplasia, with little background signal at 30 min after injection via real-time fluorescence endoscopy. Correlation analysis with immunohistochemistry revealed a positive correlation of ICG with inducible nitric oxide synthase (iNOS; r > 0.5). Increased expression of iNOS resulted in increased levels of cellular nitric oxide in cancer cells compared to that in normal cells, which was related to the inhibition of drug efflux via the ABCB1 transporter down-regulation resulting in delayed retention of intracellular ICG. With artificial intelligence training, the accuracy of image classification into four classes using data sets, such as fluorescence, optical, and fluorescence/optical images was assessed. Fluorescence images obtained the highest accuracy (AUC of 0.8125) than optical and fluorescence/optical images (AUC of 0.75 and 0.6667, respectively). These findings highlight the clinical feasibility of ICG as a detector of precancerous lesions in real-time fluorescence endoscopy with artificial intelligence training and suggest that the mechanism of ICG retention in cancer cells is related to intracellular nitric oxide concentration.