Colonic Cell Proliferation Research Articles

Nano-TiO2 regulates the MAPK (ERK, P38) pathway to promote apoptosis and inhibit proliferation of human colon cells

BackgroundNano titanium dioxides (TiO2) are widely used in drug development, food additives and packaging materials. Although several studies have demonstrated the poisonousness of TiO2 in vivo and in vitro, the underlying molecular mechanisms have not been fully revealed. MethodsCharacterization of TiO2 by FTIR, XRD, TEM and DLS. The NCM460 cell line, representing normal colon epithelial cells, was utilized as a model to assess the impact of TiO2 nanoparticles (TiO2-NPs) on cell proliferation and apoptosis. The potential molecular mechanisms underlying its toxic effects were investigated through transcriptome analysis, RT-qPCR, and western blot experiments. ResultsThe particle size of the TiO2-NPs used is about 25 nm, which has typical characteristics of anatase. TiO2-NPs at a concentration of 30–60 μg/mL will cause changes in colon cell morphology, decreased proliferation ability, and increased number of apoptotic cells. TiO2-NPs at a concentration of 6 μg/mL did not significantly modify the transcriptome expression profile of colon cells; while 30 μg/mL had a significant effect, leading to up-regulation of gene expression. The differentially expressed genes predominantly modulate the MAPK signaling pathway, TNF signaling pathway, cytokine-cytokine receptor interaction, and other related pathways. Further, western blot analysis revealed that higher concentrations of TiO2-NPs (30–60 μg/mL) could up-regulate the expression of P53, P21 and Bax, while down-regulating the expression of Bcl2 by regulating the MAPK (ERK, P38) signaling pathway. Simultaneously, it also promoted the decreased in Fos protein expression and inhibited the phosphorylation of Jun and Fos. ConclusionThis study demonstrates that TiO2-NPs may exert potential toxic effects on colon cells, and therefore the intake of TiO2-NPs should be strictly regulated in practical applications.

Rutin Ameliorates Inflammation and Oxidative Stress in Ulcerative Colitis by Inhibiting NLRP3 Inflammasome Signaling Pathway.

Ulcerative colitis (UC) is an idiopathic inflammatory disease. We intend to explore the mechanism of Rutin in the therapy of UC. Disease activity index (DAI) and hematoxylin-eosin staining were employed to assess therapeutic effect of Rutin on dextran sulfate sodium-stimulated mice. The proliferation was detected by 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyl tetrazolium bromide assay. Oxidative stress (OS) was assessed by measuring reactive oxygen species (ROS), malondialdehyde (MDA), and superoxide dismutase (SOD). Inflammatory factors were detected using enzyme-linked immunosorbent assay and immunofluorescence staining. mRNA and protein expressions were detected by real-time quantitative polymerase chain reaction and immunoblotting assay. Rutin decreased DAI scores and ameliorated pathological damage in UC mice with decreased levels of inflammatory factors. Rutin recovered the inhibited proliferation of fetal human colon cells caused by lipopolysaccharide. Rutin inhibited OS by reducing ROS and MDA, while enhancing SOD activity in LPS-induced fetal human colon cells. Rutin inhibited NLRP3 inflammasome in UC mice and cell model. Silencing NLRP3 enhanced the inhibitory effect of Rutin on OS in lipopolysaccharide-induced fetal human colon cells. Conversely, NLRP3 overexpression reversed the restraining role of Rutin in OS. Rutin ameliorates UC by inhibiting inflammation and OS through suppressing NLRP3 inflammasome.

Class A1 scavenger receptor antibody improves murine colitis by influencing macrophage and gut microbiota

This study aimed to investigate whether class A1 scavenger receptor (SR-A1) regulated macrophage polarization and gut microbial alteration during intestinal inflammation of colitis. A murine colitis model was established by feeding with dextran sulfate sodium (DSS), and treatment groups were injected intravenously with SR-A1 antibody. Results showed a preventive effect on colitis symptoms and fewer inflammatory cell infiltrates in treatment groups. Down-regulation of inflammatory cytokines and up-regulation of anti-inflammatory cytokine related to macrophages were seen in murine PBMC and LPMC after injected with SR-A1 antibody. The percentage of M2 macrophages was also elevated in treatment groups. In addition, SR-A1 antibody treatment resulted in the decreased apoptosis and increased proliferation of colonic epithelial cells. Other findings indicated that SR-A1 antibody injection could mediate its anti-inflammatory effect via inhibiting TLR4-MyD88-NF-kB signaling pathway and alterating the gut microbiota composition. Our research identified SR-A1 as a potential therapeutic target in inflammatory bowel disease (IBD).

Modified Gegen Qinlian Decoction modulated the gut microbiome and bile acid metabolism and restored the function of goblet cells in a mouse model of ulcerative colitis.

Modified Gegen Qinlian Decoction (MGQD) has been shown to effectively relieve ulcerative colitis (UC) without a known pharmacological mechanism. In this study, the anti-colitis efficaciousness of MGQD and its underlying mechanisms in UC were evaluated. Mice with colitis were administered MGQD for 7 days. Following the evaluation of clinical symptoms, gut microbiota in the feces of UC mice was examined using 16S rRNA sequencing and bile acids (BAs) were examined using LC/MS. Gut microbiota consumption and fecal microbiota transplantation (FMT) were used to explore the involvement of gut microbiota in the anti-UC action of MGQD. MGQD relieved colitis as shown by weight loss protection, a lower disease activity index (DAI), restoration of intestinal length reduction, and lower histopathologic scores. MGQD also restored crypt stem cell proliferation and function of colonic goblet cells, and promoted MUC2 protein secretion. Interestingly, investigations using gut bacterial depletion and FMT showed that MGQD attenuated colonic damage in a gut-dependent way. The modulation of the gut microbiota by MGQD might be attributed to a decrease in Odoribacter and an increase in norank_f_Muribaculaceae. In addition, MGQD modulated the metabolism of BAs while restoring the structure of the gut microbiota. MGQD significantly alleviated colitis in mice, which may be associated with the modulation of gut microbiota and BA metabolism and restoration of function of goblet cells. However, factors other than the gut microbiota may also be involved in the amelioration of UC by MGQD.

BCAA-producing Clostridium symbiosum promotes colorectal tumorigenesis through the modulation of host cholesterol metabolism

Identification of potential bacterial players in colorectal tumorigenesis has been a focus of intense research. Herein, we find that Clostridium symbiosum (C.symbiosum) is selectively enriched in tumor tissues of patients with colorectal cancer (CRC) and associated with higher colorectal adenoma recurrence after endoscopic polypectomy. The tumorigenic effect of C.symbiosum is observed in multiple murine models. Single-cell transcriptome profiling along with functional assays demonstrates that C.symbiosum promotes the proliferation of colonic stem cells and enhances cancer stemness. Mechanistically, C.symbiosum intensifies cellular cholesterol synthesis by producing branched-chain amino acids (BCAAs), which sequentially activates Sonic hedgehog signaling. Low dietary BCAA intake or blockade of cholesterol synthesis by statins could partially abrogate the C.symbiosum-induced cell proliferation invivo and invitro. Collectively, we reveal C.symbiosum as a bacterial driver of colorectal tumorigenesis, thus identifying a potential target in CRC prediction, prevention, and treatment.

Chronic Exposure to Both Electronic and Conventional Cigarettes Alters Ileum and Colon Turnover, Immune Function, and Barrier Integrity in Mice.

Although the effects of cigarette smoke (CS) on the development of several intestinal diseases is well documented, the impact of e-cigarette aerosol (e-cig) on digestive health is largely unknown. To compare the effects of e-cig and CS on mouse ileum and colon, animals were chronically exposed for 6 months by nose-only inhalation to e-cig at 18 or 30 W power, or to 3R4F CS. Results showed that e-cig exposure decreased colon cell proliferation. Several other proliferative defects were observed in response to both e-cig and CS exposure, including up- and down-regulation of cyclin D1 protein levels in the ileum and colon, respectively. E-cig and CS exposure reduced myeloperoxidase activity in the ileum. In the colon, both exposures disrupted gene expression of cytokines and T cell transcription factors. For tight junction genes, ZO-1- and occludin-protein expression levels were reduced in the ileum and colon, respectively, by e-cig and CS exposure. The 16S sequencing of microbiota showed specific mild dysbiosis, according to the type of exposure. Overall, e-cig exposure led to altered proliferation, inflammation, and barrier function in both the ileum and colon, and therefore may be a gut hazard on par with conventional CS.

Aggravated Ulcerative Colitis via circNlgn-Mediated Suppression of Nuclear Actin Polymerization.

Colitis is a chronic bowel disease characterized by damage to the lining of the large intestine, with its precise underlying causes remaining incompletely understood. In this study, we provide evidence that circular RNA circNlgn plays a pivotal role in promoting the development of colitis. Colitis patients produce significant higher levels of circNlgn. Transgenic mice expressing circNlgn exhibit heightened susceptibility to colitis development and progression, primarily attributed to the presence of the protein isoform Nlgn173 encoded by circNlgn. Nlgn173 undergoes translocation into cell nuclei, where it interacts with actin, impeding the binding of actin-related protein 2 and 3 (Arp2/3) complex to actin molecules. Consequently, this leads to a reduction in actin polymerization. Mechanistically, Nlgn173 enhances tyrosine-53 phosphorylation of nuclear actin, diminishing its capacity to interact with the Arp2/3 complex and causing a decrease in filamentous actin levels. These alterations in actin dynamics result in inhibited cell cycle progression, increased apoptosis, and decreased proliferation of colonic epithelial cells, thereby exacerbating colitis development and progression. In contrast, the silencing of circNlgn or the targeted inhibition of Nlgn173 translation and nuclear translocation leads to the promotion of nuclear actin polymerization, enhanced cell survival, and reduced apoptosis and ultimately improves the outcome of colitis invivo. Interestingly, nuclear actin polymerization is highly related with expression of PIAS3, which modulates signal transducer and activator of transcription 3 and NF-κB activity in colitis. Strategies such as circNlgn knockdown and targeting nuclear actin polymerization of the colonic epithelium may explore a novel avenue for acute ulcerative colitis clinical intervention.

Underlying Mechanism of Fluoride Inhibits Colonic Gland Cells Proliferation by Inducing an Inflammation Response.

The integrity of colonic gland cells is a prerequisite for normal colonic function and maintenance. To evaluate the underlying injury mechanisms in colonic gland cells induced by excessive fluoride (F), forty-eight female Kunming mice were randomly allocated into four groups and treated with different concentrations of NaF (0, 25, 50, and 100 mg F-/L) for 70 days. As a result, the integrity of the colonic mucosa and the cell layer was seriously damaged after F treatment, as manifested by atrophy of the colonic glands, colonic cell surface collapse, breakage of microvilli, and mitochondrial vacuolization. Alcian blue and periodic acid Schiff staining revealed that F decreased the number of goblet cells and glycoprotein secretion. Furthermore, F increased the protein expression of TLR4, NF-κB, and ERK1/2 and decreased IL-6, interfered with NF-κB signaling, following induced colonic gland cells inflammation. The accumulation of F inhibited proliferation via the JAK/STAT signaling pathway, as characterized by decreased mRNA and protein expression of JAK, STAT3, STAT5, PCNA, and Ki67 in colon tissue. Additionally, the expression of CDK4 was up-regulated by increased F concentration. In conclusion, excessive F triggered colonic inflammation and inhibited colonic gland cell proliferation via regulation of the NF-κB and JAK/STAT signaling pathways, leading to histopathology and barrier damage in the colon. The results explain the damaging effect of the F-induced inflammatory response on the colon from the perspective of cell proliferation and provide a new idea for explaining the potential mechanism of F-induced intestinal damage.

Toll-like receptor 13-mediated signaling protects against the development of colon cancer.

Appropriate host-microbiota interactions are essential for maintaining intestinal homeostasis; hence, an imbalance in these interactions leads to inflammation-associated intestinal diseases. Toll-like receptors (TLRs) recognize microbial ligands and play a key role in host-microbe interactions in health and disease. TLR13 has a well-established function in enhancing host defenses against pathogenic bacteria. However, its role in maintaining intestinal homeostasis and controlling colitis-associated colon cancer (CAC) is largely unknown. This study aimed to investigate the involvement of TLR13-mediated signaling in intestinal homeostasis and colonic tumorigenesis using ex vivo cell and in vivo CAC animal model. Tlr13-deficient mice were prone to dextran sodium sulfate (DSS)-induced colitis. During the early stages of the CAC regimen (AOM/DSS-treated), Tlr13 deficiency led to severe ulcerative colitis. Moreover, Tlr13-deficient mice exhibited increased intestinal permeability, as evidenced by elevated levels of fluorescein isothiocyanate (FITC)-dextran, endotoxins, and bacterial translocation. Enhanced cell survival and proliferation of colonic intestinal cells were observed in Tlr13-deficient mice. A transcriptome analysis revealed that Tlr13 deficiency is associated with substantial changes in gene expression profile of colonic tumor tissue. Tlr13-deficient mice were more susceptible to CAC, with increased production of interleukin (IL)-6, IL-12, and TNF-α cytokines and enhanced STAT3, NF-κB, and MAPK signaling in colon tissues. These findings suggest that TLR13 plays a protective role in maintaining intestinal homeostasis and controlling CAC. Our study provides a novel perspective on intestinal health via TLR13-mediated signaling, which is crucial for deciphering the role of host-microbiota interactions in health and disease.

Polyphenol- and Glucuronoxylan-Rich Fiber Extract from Birch (Betula sp.) Wood Regulates Colonic Barrier Function and Cell Proliferation in Healthy Rats.

Birch wood-derived fiber extracts containing glucuronoxylans (GX) and polyphenols show potential for various food technological applications. This study investigated the effect of two extracts, GXpoly and pureGX, differing in lignin content on colonic barrier function. Healthy rats were fed diets containing 10% GXpoly, pureGX, or cellulose for 4 weeks. Colon crypt depth was lower in the GX groups than in the control group, but in the proximal colon, the result was significant only in GXpoly. An artificial intelligence approach was established to measure the mucus content and goblet cells. In the distal colon, their amounts were higher in the control group than in the GX groups. All diets had a similar effect on the expression of the tight junction proteins occludin, claudin-1, and claudin-7. GXpoly enhanced the fecal IgA production. Our results suggest that GX-rich extracts could support the colonic barrier and work as functional food ingredients in the future.

Black rice diet alleviates colorectal cancer development through modulating tryptophan metabolism and activating AHR pathway.

Consumption of dietary fiber and anthocyanin has been linked to a lower incidence of colorectal cancer (CRC). This study scrutinizes the potential antitumorigenic attributes of a black rice diet (BRD), abundantly rich in dietary fiber and anthocyanin. Our results demonstrate notable antitumorigenic effects in mice on BRD, indicated by a reduction in both the size and number of intestinal tumors and a consequent extension in life span, compared to control diet-fed counterparts. Furthermore, fecal transplants from BRD-fed mice to germ-free mice led to a decrease in colonic cell proliferation, coupled with maintained integrity of the intestinal barrier. The BRD was associated with significant shifts in gut microbiota composition, specifically an augmentation in probiotic strains Bacteroides uniformis and Lactobacillus. Noteworthy changes in gut metabolites were also documented, including the upregulation of indole-3-lactic acid and indole. These metabolites have been identified to stimulate the intestinal aryl hydrocarbon receptor pathway, inhibiting CRC cell proliferation and colorectal tumorigenesis. In summary, these findings propose that a BRD may modulate the progression of intestinal tumors by fostering protective gut microbiota and metabolite profiles. The study accentuates the potential health advantages of whole-grain foods, emphasizing the potential utility of black rice in promoting health.

Performance of Azolla pinnata fern protein hydrolysates as an emulsifier and nutraceutical ingredient in an O/W emulsion system and their effect on human gut microbiota and mammalian cells.

This study investigated the dual potential of Azolla pinnata fern protein hydrolysates (AFPHs) as functional and nutraceutical ingredients in an oil/water emulsion system. The AFPH-stabilised emulsion (AFPH-E) displayed a small and uniform droplet distribution and was stable to aggregation and creaming over a wide range of pH (5-8), salt concentrations ≤ 100 mM, and heat treatment ≤ 70 °C. Besides, the AFPH-E possessed and maintained strong biological activities, including antihypertensive, antidiabetic, and antioxidant, under different food processing conditions (pH 5-8; NaCl: 50-150 mM, and heat treatment: 30-100 °C). Following in vitro gastrointestinal digestion, the antihypertensive and antioxidant activities were unchanged, while a notable increase of 8% was observed for DPPH. However, the antidiabetic activities were partially reduced in the range of 5-11%. Notably, AFPH-E modulated the gut microbiota and short-chain fatty acids (SCFAs), promoting the growth of beneficial bacteria, particularly Bifidobacteria and Lactobacilli, along with increased SCFA acetate, propionate, and butyrate. Also, AFPH-E up to 10 mg mL-1 did not affect the proliferation of the normal colon cells. In the current work, AFPH demonstrated dual functionality as a plant-based emulsifier with strong biological activities in an oil/water emulsion system and promoted healthy changes in the human gut microbiota.

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

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. 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. Human transcriptomic data revealed dysregulated noncanonical NF-kB signaling. Invitro 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 invivo, 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). 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.

INDIAN MILLETS (FINGER MILLET, KODO, SORGHUM AND PEARL MILLET): POTENT FUNCTIONAL FOODS AND PROCESSING SCOPES

Millets, a group of small-seeded grasses, are emerging as functional foods with numerous health benefits. With the world facing challenges in agriculture and nutrition, millets offer a promising solution due to their resilience in marginal growing conditions and high nutritional value. Millets are an abundant source of essential macronutrients and micronutrients, branched-chain amino acids (BCAAs) that are essential for muscle growth and repair. The phytochemicals present in millets, such as phytosterols, polyphenols, and phytoestrogens, act as antioxidants, immunomodulators, and detoxifying agents, potentially preventing age-related diseases like cardiovascular conditions, type-2 diabetes, and cancer. Different millets contain diverse phenolic groups with potent antioxidant capacity. The nutritional characteristics and processing techniques of four common Indian millets - Finger millet, Kodo, Sorghum and Pearl millets are discussed in view of their potential as functional foods for promoting good health. Millets contain resistant starch, that acts as prebiotic, promoting the growth of beneficial bacteria in the gut and reducing inflammation, helps in the production of desirable metabolites such as short-chain fatty acids in the colon, especially butyrate, which helps to stabilize colonic cell proliferation and thus contributing to overall health. Although millets contain higher levels of antinutrients, some of these compounds also offer antioxidant properties. The use of processing techniques like debranning, soaking, germination, fermentation, and autoclaving can reduce antinutrient content and enhance the bioavailability of essential nutrients and proteins. Future research in the realm of Indian millets could focus on optimizing processing techniques, exploring health impacts, and transforming antinutrients for potential benefits in combating malnutrition and food security

Tuft cells utilize taste signaling molecules to respond to the pathobiont microbe Ruminococcus gnavus in the proximal colon

Tuft cells are a type of rare epithelial cells that have been recently found to utilize taste signal transduction pathways to detect and respond to various noxious stimuli and pathogens, including allergens, bacteria, protists and parasitic helminths. It is, however, not fully understood how many different types of pathogens they can sense or what exact molecular mechanisms they employ to initiate targeted responses. In this study, we found that an anaerobic pathobiont microbe, Ruminococcus gnavus (R. gnavus), can induce tuft cell proliferation in the proximal colon whereas the microbe’s lysate can stimulate these proximal colonic tuft cells to release interleukin-25 (IL-25). Nullification of the Gng13 and Trpm5 genes that encode the G protein subunit Gγ13 and transient receptor potential ion channel Trpm5, respectively, or application of the Tas2r inhibitor allyl isothiocyanate (AITC), G protein Gβγ subunit inhibitor Gallein or the phospholipase Cβ2 (PLCβ2) inhibitor U73122 reduces R. gnavus-elicited tuft cell proliferation or IL-25 release or both. Furthermore, Gng13 conditional knockout or Trpm5 knockout diminishes the expression of gasdermins C2, C3 and C4, and concomitantly increases the activated forms of caspases 3, 8 and 9 as well as the number of TUNEL-positive apoptotic cells in the proximal colon. Together, our data suggest that taste signal transduction pathways are not only involved in the detection of R. gnavus infection, but also contribute to helping maintain gasdermin expression and prevent apoptotic cell death in the proximal colon, and these findings provide another strategy to combat R. gnavus infection and sheds light on new roles of taste signaling proteins along with gasdermins in protecting the integrity of the proximal colonic epithelium.

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

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

Hungatella hathewayi impairs the sensitivity of colorectal cancer cells to 5-FU through decreasing CDX2 expression.

Hungatella hathewayi (H. hathewayi), also known as Clostridium hathewayi, has been reported to be accumulated in the colorectal cancer (CRC) samples. In addition, evidence has demonstrated that inoculation with H. hathewayi promotes the proliferation of colonic epithelial cells in mice. Herein, we explored H. hathewayi role in regulating the 5-fluorouracil (5-FU) resistance in CRC cells, and investigated the underlying mechanisms. H. hathewayi abundance in CRC tissues and the corresponding adjacent normal tissues was tested using qRT-PCR. Both parental and 5-FU resistance CRC cell lines were used to assess H. hathewayi role in regulating the 5-FU resistance of CRC cells using CCK-8, flow cytometry and animal experiments. H. hathewayi abundance was significantly increased in CRC tissues, and the high level of H. hathewayi was linked to lower overall survival rate. H. hathewayi treatment significantly weakened 5-FU effects on inhibiting cell growth and inducing cell apoptosis in CRC HCT116 and HT29 cells. In addition, H. hathewayi enhanced the 5-FU resistance of HCT116/5-FU and HT29/5-FU cells (the 5-FU resistance cell lines). In mechanism, H. hathewayi decreased the expression of CDX2, and increased the expression of nuclear accumulation of β-catenin. Overexpression of CDX2 abolished H. hathewayi-mediated enhancement in cell growth and inhibition in cell apoptosis in HCT116/5-FU and HT29/5-FU cells, as well as inhibited the expression and nuclear accumulation of β-catenin. In conclusion, H. hathewayi abundance was increased in CRC tissues, and the high level of H. hathewayi was linked to lower overall survival rate. In mechanisam, H. hathewayi treatment enhanced the 5-FU resistance of CRC cells through modulating CDX2/β-catenin signaling.

Altered gut microbiota of obesity subjects promotes colorectal carcinogenesis in mice.

Obesity is a risk factor for colorectal cancer (CRC). The role of gut microbiota in mediating the cancer-promoting effect of obesity is unknown. Azoxymethane (AOM)-treated, ApcMin/+ and germ-free mice were gavaged with feces from obese individuals and control subjects respectively. The colonic tumor load and number were recorded at the endpoint in two carcinogenic models. The gut microbiota composition and colonic transcriptome were assessed by metagenomic sequencing and RNA sequencing, respectively. The anticancer effects of bacteria depleted in fecal samples of obese individuals were validated. Conventional AOM-treated and ApcMin/+ mice receiving feces from obese individuals showed significantly increased colon tumor formation compared with those receiving feces from control subjects. AOM-treated mice receiving feces from obese individuals showed impaired intestinal barrier function and significant upregulation of pro-inflammatory cytokines and activation of oncogenic Wnt signaling pathway. Consistently, transferring feces from obese individuals to germ-free mice led to increased colonic cell proliferation, intestinal barrier function impairment, and induction of oncogenic and proinflammatory gene expression. Moreover, germ-free mice transplanted with feces from obese human donors had increased abundance of potential pathobiont Alistipes finegoldii, and reduced abundance of commensals Bacteroides vulgatus and Akkermansia muciniphila compared with those receiving feces from human donors with normal body mass index (BMI). Validation experiments showed that B.vulgatus and A.muciniphila demonstrated anti-proliferative effects in CRC, while A.finegoldii promoted CRC tumor growth. Our results supported the role of obesity-associated microbiota in colorectal carcinogenesis and identified putative bacterial candidates that may mediate its mechanisms. Microbiota modulation in obese individuals may provide new approaches to prevent or treat obesity-related cancers including CRC. This work was funded by National Key Research and Development Program of China (2020YFA0509200/2020YFA0509203), National Natural Science Foundation of China (81922082), RGC Theme-based Research Scheme Hong Kong (T21-705/20-N), RGC Research Impact Fund Hong Kong (R4632-21F), RGC-CRF Hong Kong (C4039-19GF and C7065-18GF), RGC-GRF Hong Kong (14110819, 14111621), and NTU Start-Up Grant (021337-00001).

Elucidating the Mechanism of Agrimonolide in Treating Colon Cancer Based on Network Pharmacology.

This study reported the efficacy and underlying mechanism of agrimonolide (AM) in treating colon cancer. Colon cancer-AM-related targets were screened from online database. AM targets for colon cancer were identified by Venn diagram. Main molecular function, biological process, cellular component and pathways associated with AM targets for colon cancer were analyzed by GO and KEGG enrichment analysis. Relationship of the 10 core targets of AM for colon cancer with the top 15 BP and KEGG pathways was analyzed by Cytoscape software. A "component-target-pathway" network was constructed to select the hub genes of AM for colon cancer. AM effects on colon cancer cell viability, proliferation, invasion, migration and apoptosis were researched by CCK-8, colony formation, Transwell invasion, wound healing and flow cytometry assays. Tumor-bearing nude mice models were constructed and given AM treatment. Hub gene expression in cells/tissues was detected by Western blot. A total of 107 targets were selected as AM targets for colon cancer. The 10 core targets were related to the top 15 biological process terms and KEGG pathways. PI3K, AKT and mTOR were selected as the hub genes of AM for colon cancer. AM weakened colon cell proliferation, invasion, migration and apoptosis inhibition, and suppressed colon cell in vivo growth. AM up-regulated Caspase-3 and BAX proteins, down-regulated C-Myc, Cyclin D1 and BCL-2 proteins, and inactivated the PI3K/AKT/mTOR pathway both in vitro and in vivo. AM suppressed colon cancer progression through inactivating the PI3K/AKT/mTOR pathway. It may be useful for colon cancer treatment.

FGF21 Depletion Attenuates Colitis through Intestinal Epithelial IL-22-STAT3 Activation in Mice.

Fibroblast growth factor 21 (FGF21) is a glucose and lipid metabolic regulator. Recent research revealed that FGF21 was also induced by inflammatory stimuli. Its role in inflammatory bowel disease (IBD) has not been investigated. In this study, an experimental IBD model was established in FGF21 knockout (KO) and wild-type (WT) mice by adding 2.5% (wt/vol) dextran sodium sulfate (DSS) to their drinking water for 7 days. The severity of the colitis and the inflammation of the mouse colon tissues were analyzed. In WT mice, acute DSS treatment induced an elevation in plasma FGF21 and a significant loss of body weight in a time-dependent manner. Surprisingly, the loss of body weight and the severity of the colitis induced by DSS treatment in WT mice were significantly attenuated in FGF21 KO mice. Colon and circulating pro-inflammatory factors were significantly lower in the FGF21 KO mice compared to the WT mice. As shown by BrdU staining, the FGF21 KO mice demonstrated increased colonic epithelial cell proliferation. DSS treatment reduced intestinal Paneth cell and goblet cell numbers in the WT mice, and this effect was attenuated in the FGF21 KO mice. Mechanistically, FGF21 deficiency significantly increased the signal transducer and activator of transcription (STAT)-3 activation in intestinal epithelial cells and increased the expression of IL-22. Further study showed that the expression of suppressor of cytokine signaling-2/3 (SOCS 2/3), a known feedback inhibitor of STAT3, was significantly inhibited in the DSS-treated FGF2 KO mice compared to the WT mice. We conclude that FGF21 deficiency attenuated the severity of DSS-induced acute colitis, which is likely mediated by enhancing the activation of the IL-22-STAT3 signaling pathway in intestinal epithelial cells.