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Cancer Research Communications Jun 2024Escherichia coli that harbor the polyketide synthase (pks) genomic island produce colibactin and are associated with sporadic colorectal cancer development (CRC). Given...
Escherichia coli that harbor the polyketide synthase (pks) genomic island produce colibactin and are associated with sporadic colorectal cancer development (CRC). Given the considerable prevalence of pks+ bacteria in healthy individuals, we sought to identify strategies to limit the growth and expansion of pks+ E. coli. We found that culture supernatants of the probiotic strain E. coli Nissle 1917 were able to inhibit the growth of the murine pathogenic strain pks+ E. coli NC101 (EcNC101). We performed a non-targeted analysis of the metabolome in supernatants from several E. coli strains and identified putrescine as a potential postbiotic capable of suppressing EcNC101 growth in vitro. The effect of putrescine supplementation was then evaluated in the azoxymethane (AOM)/dextran sulfate sodium (DSS) mouse model of CRC in mice colonized with EcNC101. Putrescine supplementation inhibited the growth of pks+ E. coli; reduced the number and size of colonic tumors; and downmodulated the release of inflammatory cytokines in the colonic lumen. Additionally, putrescine supplementation led to shifts in the composition and function of gut microbiota, characterized by an increase of the Firmicutes/Bacteroidetes ratio and enhanced acetate production. The effect of putrescine was further confirmed in vitro using a pks+ E. coli strain isolated from a CRC patient. These results suggest that probiotic-derived metabolites can be used as an alternative to live bacteria in individuals at risk of developing CRC due to the presence of pks+ bacteria in their colon.
PubMed: 38934090
DOI: 10.1158/2767-9764.CRC-23-0355 -
Journal of Cancer 2024Colorectal cancer (CRC) ranks third in terms of cancer incidence and fourth in terms of cancer-related deaths worldwide. Identifying potential biomarkers of CRC is...
Colorectal cancer (CRC) ranks third in terms of cancer incidence and fourth in terms of cancer-related deaths worldwide. Identifying potential biomarkers of CRC is crucial for treatment and drug development. In this study, we established a C57B/6N mouse model of colon carcinogenesis using azoxymethane-dextran sodium sulfate (AOM-DSS) treatment for 14 weeks to identify proteins associated with colon cancer. An isobaric tag for relative and absolute quantitation (iTRAQ)-based proteomic analysis was conducted on the cell membrane components enriched in the colonic mucosa. Additionally, tumor tissues and adjacent normal colon tissues were collected from patients with colon cancer for comparative protein and metabolite analyses. In total, 74 differentially expressed proteins were identified in the tumor tissue samples from AOM/DSS-treated mice compared to both the adjacent tissue samples from AOM/DSS-treated mice and tissue samples from saline-treated control mice. Bioinformatics analysis revealed eight downregulated proteins enriched in the branched-chain amino acids pathway (valine, leucine, and isoleucine degradation). Moreover, these proteins are already known to be associated with the survival rate of patients with cancer. Targeted metabolomics showed increased levels of valine, leucine, and isoleucine in tumor tissues compared to those in adjacent normal tissues in patients with colon cancer. Furthermore, a real-time PCR experiment demonstrated that Aldehyde dehydrogenase, mitochondrial (short protein name ALDH2, gene name ) and Hydroxyacyl-coenzyme A dehydrogenase, mitochondrial (short protein name HCDH, gene name ) (two genes) in the pathway of branched-chain amino acids) were downregulated in patients with colon cancer (colon tumor tissues vs. their adjacent colon tissues). ALDH2 expression was further validated by western blotting in AOM/DSS-treated mouse model and in clinical samples. This study highlighted the inactivation of the branched-chain amino acid degradation pathway in colon cancer and identified ALDH2 and HCDH as potential biomarkers for diagnosing colon cancer and developing new therapeutic strategies.
PubMed: 38911385
DOI: 10.7150/jca.95454 -
Biomedicine & Pharmacotherapy =... Jul 2024The unresectable or postoperative recurrence of advanced metastatic colorectal cancer (CRC) is the difficulty of its clinical management, and pharmacological therapy is...
The unresectable or postoperative recurrence of advanced metastatic colorectal cancer (CRC) is the difficulty of its clinical management, and pharmacological therapy is the main source of benefit. Immune checkpoint inhibitors are therapeutic options but are effective in approximately 5 % of patients with deficient mismatch repair (MMR)/microsatellite instability CRC and are ineffective in patients with MMR-proficient (pMMR)/microsatellite stable (MSS) CRCs, which may be associated with the tumor microenvironment (TME). Here, we propose a new combination strategy and evaluate the efficacy of rapamycin (Rapa) combined with anti-PD-1 (αPD-1) in CT26 tumor-bearing mice, azoxymethane (AOM)/dextran sodium sulfate (DSS) inflammation-associated CRC mice, CT26-Luc tumor-bearing mice with postoperative recurrence, and CT26 liver metastasis mice. The results revealed that Rapa improved the therapeutic effect of αPD-1 and effectively inhibited colorectal carcinogenesis, postoperative recurrence, and liver metastasis. Mechanistically, Rapa improved the anticancer effect of αPD-1, associated with Rapa reprograming of the immunosuppressive TME. Rapa effectively depleted α-SMA cancer-associated fibroblasts and degraded collagen in the tumor tissue, increasing T lymphocyte infiltration into the tumor tissue. Rapa induced the downregulation of programed cell death 1 ligand 1 (PD-L1) protein and transcript levels in CT26 cells, which may be associated with the inhibition of the mTOR/P70S6K signaling axis. Furthermore, co-culture of tumor cells and CD8 T lymphocytes demonstrated that Rapa-induced PD-L1 downregulation in tumor cells increased spleen-derived CD8 T lymphocyte activation. Therefore, Rapa improves the anti-tumor effect of αPD-1 in CRCs, providing new ideas for its use to improve combinatorial strategies for anti-PD-1 immunotherapy.
Topics: Animals; Tumor Microenvironment; Colorectal Neoplasms; Sirolimus; B7-H1 Antigen; Mice; Cell Line, Tumor; Immune Checkpoint Inhibitors; Mice, Inbred BALB C; Drug Resistance, Neoplasm; Programmed Cell Death 1 Receptor; Male; Humans; Liver Neoplasms; Antineoplastic Combined Chemotherapy Protocols
PubMed: 38876047
DOI: 10.1016/j.biopha.2024.116883 -
Phytomedicine : International Journal... Aug 2024Although AMP-activated protein kinase (AMPK) has been extensively studied in cellular processes, the understanding of its substrates, downstream functions, contributions...
BACKGROUND
Although AMP-activated protein kinase (AMPK) has been extensively studied in cellular processes, the understanding of its substrates, downstream functions, contributions to cell fate and colorectal cancer (CRC) progression remains incomplete.
PURPOSE
The aim of this study was to investigate the effects and mechanisms of naringenin on CRC.
METHODS
The biological and cellular properties of naringenin and its anticancer activity were evaluated in CRC. In addition, the effect of combined treatment with naringenin and 5-fluorouracil on tumor growth in vitro and in vivo was evaluated.
RESULTS
The present study found that naringenin inhibits the proliferation of CRC and promote its apoptosis. Compared with the naringenin group, naringenin combined with 5-fluorouracil had significant effect on inhibiting cell proliferation and promoting its apoptosis. It is showed that naringenin activates AMPK phosphorylation and mitochondrial fusion in CRC. Naringenin combined with 5-fluorouracil significantly reduces cardiotoxicity and liver damage induced by 5-fluorouracil in nude mice bearing subcutaneous CRC tumors, and attenuates colorectal injuries in azoxymethane/DSS dextran sulfate (AOM/DSS)-induced CRC. The combination of these two drugs alters mitochondrial function by increasing reactive oxygen species (ROS) levels and decreasing the mitochondrial membrane potential (MMP), thereby stimulating AMPK/mTOR signaling. Mitochondrial dynamics are thereby regulated by activating the AMPK/p-AMPK pathway, and mitochondrial homeostasis is coordinated through increased mitochondrial fusion and reduced fission to activate apoptosis in cancer cells.
CONCLUSIONS
Our data suggest that naringenin is important for inhibiting CRC proliferation, possibly through the AMPK pathway, to regulate mitochondrial function and induce apoptosis in CRC.
Topics: Flavanones; Colorectal Neoplasms; Animals; AMP-Activated Protein Kinases; Humans; Mitochondria; Mice, Nude; Apoptosis; Cell Proliferation; Reactive Oxygen Species; Fluorouracil; Mice; Cell Line, Tumor; Male; Mice, Inbred BALB C; Phosphorylation; Antineoplastic Agents, Phytogenic
PubMed: 38875812
DOI: 10.1016/j.phymed.2024.155786 -
European Journal of Medical Research Jun 2024KDM6A (lysine demethylase 6A) has been reported to undergo inactivating mutations in colorectal cancer, but its function in the progression of colorectal cancer has not...
KDM6A (lysine demethylase 6A) has been reported to undergo inactivating mutations in colorectal cancer, but its function in the progression of colorectal cancer has not been evaluated using animal models of colorectal cancer. In this study, we found that knocking out KDM6A expression in mouse intestinal epithelium increased the length of villus and crypt, promoting the development of AOM (azoxymethane)/DSS (dextran sulfate sodium salt)-induced colorectal cancer. On the other hand, knocking down KDM6A expression promoted the growth of colorectal cancer cells. In molecular mechanism studies, we found that KDM6A interacts with HIF-1α; knocking down KDM6A promotes the binding of HIF-1α to the LDHA promoter, thereby promoting LDHA expression and lactate production, enhancing glycolysis. Knocking down LDHA reversed the malignant phenotype caused by KDM6A expression loss. In summary, this study using animal models revealed that KDM6A loss promotes the progression of colorectal cancer through reprogramming the metabolism of the colorectal cancer cells, suggesting that restoring the function of KDM6A is likely to be one of the strategies for colorectal cancer treatment.
Topics: Animals; Humans; Mice; Cell Proliferation; Colorectal Neoplasms; Disease Progression; Gene Expression Regulation, Neoplastic; Glycolysis; Histone Demethylases; Hypoxia-Inducible Factor 1, alpha Subunit
PubMed: 38840262
DOI: 10.1186/s40001-024-01828-1 -
Journal of Ethnopharmacology May 2024Previous studies have revealed that a high-fat diet (HFD) promotes the progression of colorectal cancer (CRC) in close association with disturbances in the intestinal...
Traditional medicine Xianglian pill suppresses high-fat diet-related colorectal cancer via inactivating TLR4/MyD88 by remodeling gut microbiota composition and bile acid metabolism.
ETHNOPHARMACOLOGICAL RELEVANCE
Previous studies have revealed that a high-fat diet (HFD) promotes the progression of colorectal cancer (CRC) in close association with disturbances in the intestinal flora and metabolic disorders. Xianglian pill (XLP) is a well-established traditional prescription with unique advantages in controlling intestinal flora imbalance and inflammation. However, its therapeutic effects on HFD-related CRC remain largely unknown.
AIM OF THE STUDY
The primary objective of this research was to investigate the anticancer mechanism of XLP in countering HFD-related CRC.
MATERIALS AND METHODS
The protective effect of XLP was evaluated using azoxymethane (AOM) and dextran sulfate sodium (DSS)-induced CRC model of mice exposed to a HFD. The degree of colorectal carcinogenesis, including body weight, colon length, and histopathology, was measured in mice treated with XLP and untreated mice. The effect of XLP on gut microbiota and its metabolites was detected using 16S rDNA and liquid chromatography/mass spectrometry analysis. Furthermore, a "pseudo-sterile" mouse model was constructed using antibiotics (Abx) to verify whether the gut microbiota and metabolites play a role in the pathogenesis of CRC.
RESULTS
XLP inhibited colorectal tumorigenesis in a dose-dependent fashion. Our findings also highlighted that XLP protected the integrity of the intestinal barrier by reducing the expression of pro-inflammatory cytokines, such as IL-6 and TNF-α, as well as the infiltration of pro-inflammatory macrophages. Mechanistically, XLP inhibited the TLR4/MyD88 pathway. Notably, the XLP treatment increased the proportion of probiotics (particularly Akkermansia) and significantly reduced fecal deoxycholic acid (DCA), a microbiota-derived metabolite of bile acids (BA) closely related to Muribaculaceae. Furthermore, after Abx treatment, XLP showed no clear antitumor effects on CRC. Simultaneously, DCA-supplemented feedings promoted colorectal tumorigenesis and provoked obvious colonic inflammation, M1 macrophage infiltration, and colonic injury. In vitro, the results of RAW-264.7 macrophages and normal intestinal epithelial cells treated with DCA corroborated our in vivo findings, demonstrating consistent patterns in inflammatory responses and intestinal barrier protein expression.
CONCLUSION
Our findings suggest that XLP inhibits colorectal cancer associated with HFD via inactivating TLR4/MyD88 by remodeling gut microbiota composition and BA metabolism.
PubMed: 38824980
DOI: 10.1016/j.jep.2024.118411 -
Molecular Biology Reports Jun 2024Tumor modeling using organoids holds potential in studies of cancer development, enlightening both the intracellular and extracellular molecular mechanisms behind...
BACKGROUND
Tumor modeling using organoids holds potential in studies of cancer development, enlightening both the intracellular and extracellular molecular mechanisms behind different cancer types, biobanking, and drug screening. Intestinal organoids can be generated in vitro using a unique type of adult stem cells which are found at the base of crypts and are characterized by their high Lgr5 expression levels.
METHODS AND RESULTS
In this study, we successfully established intestinal cancer organoid models by using both the BALB/c derived and mouse embryonic stem cells (mESCs)-derived intestinal organoids. In both cases, carcinogenesis-like model was developed by using azoxymethane (AOM) treatment. Carcinogenesis-like model was verified by H&E staining, immunostaining, relative mRNA expression analysis, and LC/MS analysis. The morphologic analysis demonstrated that the number of generated organoids, the number of crypts, and the intensity of the organoids were significantly augmented in AOM-treated intestinal organoids compared to non-AOM-treated ones. Relative mRNA expression data revealed that there was a significant increase in both Wnt signaling pathway-related genes and pluripotency transcription factors in the AOM-induced intestinal organoids.
CONCLUSION
We successfully developed simple carcinogenesis-like models using mESC-based and Lgr5 + stem cell-based intestinal organoids. Intestinal organoid based carcinogenesi models might be used for personalized cancer therapy in the future.
Topics: Animals; Organoids; Mice; Azoxymethane; Carcinogenesis; Mouse Embryonic Stem Cells; Wnt Signaling Pathway; Receptors, G-Protein-Coupled; Mice, Inbred BALB C; Intestines; Intestinal Neoplasms; Disease Models, Animal; Intestinal Mucosa
PubMed: 38824233
DOI: 10.1007/s11033-024-09660-w -
Autophagy Jun 2024strains producing the genotoxin colibactin, designated as CoPEC (colibactin-producing ), have emerged as an important player in the etiology of colorectal cancer (CRC)....
strains producing the genotoxin colibactin, designated as CoPEC (colibactin-producing ), have emerged as an important player in the etiology of colorectal cancer (CRC). Here, we investigated the role of macroautophagy/autophagy in myeloid cells, an important component of the tumor microenvironment, in the tumorigenesis of a susceptible mouse model infected with CoPEC. For that, a preclinical mouse model of CRC, the mice, with deficiency specifically in myeloid cells (/) and the corresponding control mice (), were infected with a clinical CoPEC strain 11G5 or its isogenic mutant 11G5 that does not produce colibactin. We showed that myeloid cell-specific deficiency led to an increase in the volume of colonic tumors in mice under infection with 11G5, but not with 11G5. This was accompanied by increased colonocyte proliferation, enhanced inflammasome activation and IL1B/IL-1β secretion, increased neutrophil number and decreased total T cell and cytotoxic CD8 T cell numbers in the colonic mucosa and tumors. In bone marrow-derived macrophages (BMDMs), compared to uninfected and 11G5∆-infected conditions, 11G5 infection increased inflammasome activation and IL1B secretion, and this was further enhanced by autophagy deficiency. These data indicate that ATG16L1 in myeloid cells was necessary to inhibit colonic tumor growth in CoPEC-infected mice inhibiting colibactin-induced inflammasome activation and modulating immune cell response in the tumor microenvironment. : AOM, azoxymethane; APC, APC regulator of WNT signaling pathway; ATG, autophagy related; mice, mice deficient for specifically in myeloid cells; CASP1, caspase 1; BMDM, bone marrow-derived macrophage; CFU, colony-forming unit; CoPEC, colibactin-producing ; CRC, colorectal cancer; CXCL1/KC, C-X-C motif chemokine ligand 1; ELISA, enzyme-linked immunosorbent assay; IL, interleukin; MC, myeloid cell; MOI, multiplicity of infection; PBS, phosphate-buffered saline; , polyketide synthase; qRT-PCR, quantitative real-time reverse-transcription polymerase chain reaction; siRNA, small interfering RNA; TME, tumor microenvironment; TNF/TNF-α, tumor necrosis factor.
PubMed: 38818900
DOI: 10.1080/15548627.2024.2359770 -
Acta Pharmaceutica Sinica. B May 2024Aberrant changes in the gut microbiota are implicated in many diseases, including inflammatory bowel disease (IBD). Gut microbes produce diverse metabolites that can...
Aberrant changes in the gut microbiota are implicated in many diseases, including inflammatory bowel disease (IBD). Gut microbes produce diverse metabolites that can shape the immune system and impact the intestinal barrier integrity, indicating that microbe-mediated modulation may be a promising strategy for preventing and treating IBD. Although fecal microbiota transplantation and probiotic supplementation are well-established IBD therapies, novel chemical agents that are safe and exert strong effects on the gut microbiota are urgently needed. Herein, we report the total synthesis of heudelotinone and the discovery of 5-heudelotinone (an enantiomer) as a potent agent against experimental colitis that acts by modulating the gut microbiota. 5-Heudelotinone alters the diversity and composition of the gut microbiota and increases the concentration of short-chain fatty acids (SCFAs); thus, it regulates the intestinal immune system by reducing proinflammatory immune cell numbers, and maintains intestinal mucosal integrity by modulating tight junctions (TJs). Moreover, 5-heudelotinone () ameliorates colitis-associated colorectal cancer (CAC) in an azoxymethane (AOM)/dextran sulfate sodium (DSS)-induced carcinoma model. Together, these findings reveal the potential of a novel natural product, namely, 5-heudelotinone, to control intestinal inflammation and highlight that this product is a safe and effective candidate for the treatment of IBD and CAC.
PubMed: 38799623
DOI: 10.1016/j.apsb.2024.02.020 -
Microorganisms May 2024The only reliable factor that reduces the risk of colorectal carcinogenesis is physical activity. However, the underlying mechanisms remain unclear. In this study, we...
The only reliable factor that reduces the risk of colorectal carcinogenesis is physical activity. However, the underlying mechanisms remain unclear. In this study, we examined the effects of physical activity against gut microbiota, including mucosa-associated microbiota (MAM) on azoxymethane-induced colorectal tumors in obese mice. We divided the subjects into four groups: normal diet (ND), high-fat diet (HFD), ND + exercise (Ex), and HFD + Ex groups. The Ex group performed treadmill exercise for 20 weeks. Thereafter, fecal and colonic mucus samples were extracted for microbiota analysis. DNA was collected from feces and colonic mucosa, and V3-V4 amplicon sequencing analysis of the 16SrRNA gene was performed using MiSeq. The HFD group had significantly more colonic polyps than the ND group (ND 6.5 ± 1.3, HFD 11.4 ± 1.5, < 0.001), and the addition of Ex suppressed the number of colonic polyps in ND and HFD groups (ND 6.5 ± 1.3, ND + Ex 2.8 ± 2.5, < 0.05). The HFD group showed significantly lower concentrations of succinic, acetic, butyric, and propionic acids (mg/g) in feces, compared with the ND group (succinic acid HFD 0.59, ND 0.17; acetic acid HFD 0.63, ND 2.41; propionic acid HFD 0.10, ND 0.47; and N-butyric acid HFD 0.31, ND 0.93). In the case of ND, succinic acid and butyric acid tended to decrease with Ex (succinic acid ND 0.17, ND + Ex 0.12; N-butyric acid ND 0.93, ND + Ex 0.74 0.74). Succinic acid, acetic acid, butyric acid, and propionic acid levels in feces were significantly lower in the HFD group than in the ND group; in both feces and mucus samples, and levels were significantly lower in the HFD group. was significantly increased in ND + Ex and HFD + Ex groups. Diet and exercise affected the number of colorectal tumors. Furthermore, diet and exercise alter intestinal MAM, which may be involved in colorectal tumor development.
PubMed: 38792787
DOI: 10.3390/microorganisms12050957