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2.
Commun Biol ; 7(1): 551, 2024 May 08.
Article in English | MEDLINE | ID: mdl-38720110

ABSTRACT

Fusobacterium nucleatum, a gram-negative oral bacterium, has been consistently validated as a strong contributor to the progression of several types of cancer, including colorectal (CRC) and pancreatic cancer. While previous in vitro studies have shown that intracellular F. nucleatum enhances malignant phenotypes such as cell migration, the dependence of this regulation on features of the tumor microenvironment (TME) such as oxygen levels are wholly uncharacterized. Here we examine the influence of hypoxia in facilitating F. nucleatum invasion and its effects on host responses focusing on changes in the global epigenome and transcriptome. Using a multiomic approach, we analyze epigenomic alterations of H3K27ac and global transcriptomic alterations sustained within a hypoxia and normoxia conditioned CRC cell line HCT116 at 24 h following initial infection with F. nucleatum. Our findings reveal that intracellular F. nucleatum activates signaling pathways and biological processes in host cells similar to those induced upon hypoxia conditioning in the absence of infection. Furthermore, we show that a hypoxic TME favors F. nucleatum invasion and persistence and therefore infection under hypoxia may amplify malignant transformation by exacerbating the effects induced by hypoxia alone. These results motivate future studies to investigate host-microbe interactions in tumor tissue relevant conditions that more accurately define parameters for targeted cancer therapies.


Subject(s)
Colorectal Neoplasms , Epigenome , Fusobacterium Infections , Fusobacterium nucleatum , Oxygen , Transcriptome , Humans , Fusobacterium nucleatum/genetics , Fusobacterium nucleatum/physiology , Fusobacterium nucleatum/pathogenicity , Colorectal Neoplasms/genetics , Colorectal Neoplasms/microbiology , Colorectal Neoplasms/metabolism , Colorectal Neoplasms/pathology , HCT116 Cells , Fusobacterium Infections/genetics , Fusobacterium Infections/microbiology , Fusobacterium Infections/metabolism , Oxygen/metabolism , Tumor Microenvironment/genetics , Gene Expression Regulation, Neoplastic
3.
Gut Microbes ; 16(1): 2348441, 2024.
Article in English | MEDLINE | ID: mdl-38706224

ABSTRACT

Colorectal cancer (CRC), a malignant tumor worldwide, is associated with gut microbiota. The influence of gut microbe-derived metabolites on CRC has attracted a lot of attention. However, the role of immunity mediated by commensal microbiota-derived metabolites in tumorigenesis of CRC is not intensively explored. Here we monitored the gut microbial dysbiosis in CRC mouse model (ApcMin/+ model) without dietary and pharmacological intervention, followed by characterized of metabolites enriched in CRC model mice. Profound changes of gut microbiome (bacteriome) were observed during intestinal disorders. Metabolomic profiling indicated that agmatine, derived from the gut bacteria i.e. Blautia, Odoribacter, Alistipes and Paraprevotella, could interact with Rnf128 to suppress the Rnf128-mediated ubiquitination of ß-catenin to further upregulate the downstream targets of ß-catenin including Cyclin D1, Lgr5, CD44 and C-myc, thus activating Wnt signaling. The activated Wnt signaling pathway promoted dysplasia of intestinal cells and inflammatory infiltration of lymphocytes via inducing the upregulation of pro-inflammatory cytokines (IL-6 and TNF-α) and downregulation of anti-inflammatory cytokine (IL-10), thereby contributing to colorectal carcinogenesis. Therefore, our study presented novel insights into the roles and mechanisms of gut microbiota in pathogenesis of CRC.


Subject(s)
Carcinogenesis , Colorectal Neoplasms , Gastrointestinal Microbiome , Inflammation , Wnt Signaling Pathway , Animals , Colorectal Neoplasms/microbiology , Colorectal Neoplasms/metabolism , Mice , Inflammation/metabolism , Inflammation/microbiology , Bacteria/classification , Bacteria/metabolism , Bacteria/isolation & purification , Bacteria/genetics , Mice, Inbred C57BL , beta Catenin/metabolism , Dysbiosis/microbiology , Humans , Disease Models, Animal , Cytokines/metabolism , Symbiosis , Male
4.
Clin Ter ; 175(3): 98-116, 2024.
Article in English | MEDLINE | ID: mdl-38767067

ABSTRACT

Background: The human microbiome, consisting of diverse bacte-rial, fungal, protozoan and viral species, exerts a profound influence on various physiological processes and disease susceptibility. However, the complexity of microbiome data has presented significant challenges in the analysis and interpretation of these intricate datasets, leading to the development of specialized software that employs machine learning algorithms for these aims. Methods: In this paper, we analyze raw data taken from 16S rRNA gene sequencing from three studies, including stool samples from healthy control, patients with adenoma, and patients with colorectal cancer. Firstly, we use network-based methods to reduce dimensions of the dataset and consider only the most important features. In addition, we employ supervised machine learning algorithms to make prediction. Results: Results show that graph-based techniques reduces dimen-sion from 255 up to 78 features with modularity score 0.73 based on different centrality measures. On the other hand, projection methods (non-negative matrix factorization and principal component analysis) reduce dimensions to 7 features. Furthermore, we apply supervised machine learning algorithms on the most important features obtained from centrality measures and on the ones obtained from projection methods, founding that the evaluation metrics have approximately the same scores when applying the algorithms on the entire dataset, on 78 feature and on 7 features. Conclusions: This study demonstrates the efficacy of graph-based and projection methods in the interpretation for 16S rRNA gene sequencing data. Supervised machine learning on refined features from both approaches yields comparable predictive performance, emphasizing specific microbial features-bacteroides, prevotella, fusobacterium, lysinibacillus, blautia, sphingomonas, and faecalibacterium-as key in predicting patient conditions from raw data.


Subject(s)
Microbiota , RNA, Ribosomal, 16S , Supervised Machine Learning , Unsupervised Machine Learning , Humans , Microbiota/genetics , RNA, Ribosomal, 16S/genetics , RNA, Ribosomal, 16S/analysis , Colorectal Neoplasms/microbiology , Gastrointestinal Microbiome/genetics , Algorithms , Feces/microbiology , Adenoma/microbiology
5.
Gut Microbes ; 16(1): 2350156, 2024.
Article in English | MEDLINE | ID: mdl-38726597

ABSTRACT

Extensive research has explored the role of gut microbiota in colorectal cancer (CRC). Nonetheless, metatranscriptomic studies investigating the in situ functional implications of host-microbe interactions in CRC are scarce. Therefore, we characterized the influence of CRC core pathogens and biofilms on the tumor microenvironment (TME) in 40 CRC, paired normal, and healthy tissue biopsies using fluorescence in situ hybridization (FISH) and dual-RNA sequencing. FISH revealed that Fusobacterium spp. was associated with increased bacterial biomass and inflammatory response in CRC samples. Dual-RNA sequencing demonstrated increased expression of pro-inflammatory cytokines, defensins, matrix-metalloproteases, and immunomodulatory factors in CRC samples with high bacterial activity. In addition, bacterial activity correlated with the infiltration of several immune cell subtypes, including M2 macrophages and regulatory T-cells in CRC samples. Specifically, Bacteroides fragilis and Fusobacterium nucleatum correlated with the infiltration of neutrophils and CD4+ T-cells, respectively. The collective bacterial activity/biomass appeared to exert a more significant influence on the TME than core pathogens, underscoring the intricate interplay between gut microbiota and CRC. These results emphasize how biofilms and core pathogens shape the immune phenotype and TME in CRC while highlighting the need to extend the bacterial scope beyond CRC pathogens to advance our understanding and identify treatment targets.


Subject(s)
Biofilms , Colorectal Neoplasms , Gastrointestinal Microbiome , Tumor Microenvironment , Colorectal Neoplasms/microbiology , Colorectal Neoplasms/immunology , Colorectal Neoplasms/pathology , Humans , Biofilms/growth & development , Tumor Microenvironment/immunology , Male , Female , Bacteria/classification , Bacteria/genetics , Bacteria/immunology , Middle Aged , In Situ Hybridization, Fluorescence , Aged , Fusobacterium nucleatum/immunology , Cytokines/metabolism , Macrophages/immunology , Macrophages/microbiology , Phenotype , Bacteroides fragilis/immunology , Bacteroides fragilis/physiology , Bacteroides fragilis/genetics
6.
Virulence ; 15(1): 2350904, 2024 12.
Article in English | MEDLINE | ID: mdl-38725098

ABSTRACT

Fusobacterium nucleatum (F. nucleatum) is closely correlated with tumorigenesis in colorectal cancer (CRC). We aimed to investigate the effects of host norepinephrine on the carcinogenicity of F. nucleatum in CRC and reveal the underlying mechanism. The results revealed that both norepinephrine and bacterial quorum sensing (QS) molecule auto-inducer-2 (AI-2) were positively associated with the progression of F. nucleatum related CRC (p < 0.01). In vitro studies, norepinephrine induced upregulation of QS-associated genes and promoted the virulence and proliferation of F. nucleatum. Moreover, chronic stress significantly increased the colon tumour burden of ApcMin/+ mice infected with F. nucleatum (p < 0.01), which was decreased by a catecholamine inhibitor (p < 0.001). Our findings suggest that stress-induced norepinephrine may promote the progression of F. nucleatum related CRC via bacterial QS signalling. These preliminary data provide a novel strategy for the management of pathogenic bacteria by targeting host hormones-bacterial QS inter-kingdom signalling.


Subject(s)
Colorectal Neoplasms , Fusobacterium nucleatum , Norepinephrine , Quorum Sensing , Signal Transduction , Quorum Sensing/drug effects , Fusobacterium nucleatum/pathogenicity , Fusobacterium nucleatum/drug effects , Fusobacterium nucleatum/physiology , Animals , Colorectal Neoplasms/microbiology , Norepinephrine/pharmacology , Mice , Humans , Disease Progression , Fusobacterium Infections/microbiology , Virulence , Homoserine/analogs & derivatives , Homoserine/metabolism , Mice, Inbred C57BL , Male , Lactones
7.
J Agric Food Chem ; 72(21): 12130-12145, 2024 May 29.
Article in English | MEDLINE | ID: mdl-38748495

ABSTRACT

Colorectal cancer (CRC) is a common malignant tumor that occurs in the colon. Gut microbiota is a complex ecosystem that plays an important role in the pathogenesis of CRC. Our previous studies showed that the soluble dietary fiber of foxtail millet (FMB-SDF) exhibited significant antitumor activity in vitro. The present study evaluated the anticancer potential of FMB-SDF in the azoxymethane (AOM)- and dextran sodium sulfate (DSS)-induced mouse CRC models. The results showed that FMB-SDF could significantly alleviate colon cancer symptoms in mice. Further, we found that FMB-SDF consumption significantly altered gut microbiota diversity and the overall structure and regulated the abundance of some microorganisms in CRC mice. Meanwhile, KEGG pathway enrichment showed that FMB-SDF can also alleviate the occurrence of colon cancer in mice by regulating certain cancer-related signaling pathways. In conclusion, our findings may provide a novel approach for the prevention and biotherapy of CRC.


Subject(s)
Bacteria , Colorectal Neoplasms , Dietary Fiber , Gastrointestinal Microbiome , Setaria Plant , Animals , Gastrointestinal Microbiome/drug effects , Colorectal Neoplasms/prevention & control , Colorectal Neoplasms/microbiology , Colorectal Neoplasms/metabolism , Mice , Setaria Plant/chemistry , Dietary Fiber/metabolism , Dietary Fiber/pharmacology , Humans , Bacteria/classification , Bacteria/isolation & purification , Bacteria/genetics , Bacteria/drug effects , Bacteria/metabolism , Male , Plant Extracts/administration & dosage , Plant Extracts/pharmacology , Plant Extracts/chemistry , Azoxymethane , Mice, Inbred C57BL
8.
Theranostics ; 14(7): 2719-2735, 2024.
Article in English | MEDLINE | ID: mdl-38773969

ABSTRACT

Aim: To elucidate dynamics and functions in colonic macrophage subsets, and their regulation by Bifidobacterium breve (B. breve) and its associated metabolites in the initiation of colitis-associated colorectal cancer (CAC). Methods: Azoxymethane (AOM) and dextran sodium sulfate (DSS) were used to create a CAC model. The tumor-suppressive effect of B. breve and variations of macrophage subsets were evaluated. Intestinal macrophages were ablated to determine their role in the protective effects of B. breve. Efficacious molecules produced by B. breve were identified by non-targeted and targeted liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis. The molecular mechanism was further verified in murine bone marrow-derived macrophages (BMDMs), macrophages derived from human peripheral blood mononuclear cells (hPBMCs), and demonstrated in CAC mice. Results: B. breve alleviated colitis symptoms, delayed colonic tumorigenesis, and promoted phenotypic differentiation of immature inflammatory macrophages into mature homeostatic macrophages. On the contrary, the ablation of intestinal macrophages largely annulled the protective effects of B. breve. Microbial analysis of colonic contents revealed the enrichment of probiotics and the depletion of potential pathogens following B. breve supplementation. Moreover, indole-3-lactic acid (ILA) was positively correlated with B. breve in CAC mice and highly enriched in the culture supernatant of B. breve. Also, the addition of ILA directly promoted AKT phosphorylation and restricted the pro-inflammatory response of murine BMDMs and macrophages derived from hPBMCs in vitro. The effects of ILA in murine BMDMs and macrophages derived from hPBMCs were abolished by the aryl hydrocarbon receptor (AhR) antagonist CH-223191 or the AKT inhibitor MK-2206. Furthermore, ILA could protect against tumorigenesis by regulating macrophage differentiation in CAC mice; the AhR antagonist largely abrogated the effects of B. breve and ILA in relieving colitis and tumorigenesis. Conclusion: B. breve-mediated tryptophan metabolism ameliorates the precancerous inflammatory intestinal milieu to inhibit tumorigenesis by directing the differentiation of immature colonic macrophages.


Subject(s)
Bifidobacterium breve , Cell Differentiation , Colitis , Indoles , Macrophages , Probiotics , Animals , Mice , Macrophages/metabolism , Macrophages/drug effects , Bifidobacterium breve/metabolism , Indoles/pharmacology , Indoles/metabolism , Humans , Colitis/chemically induced , Colitis/microbiology , Colitis/complications , Cell Differentiation/drug effects , Probiotics/pharmacology , Probiotics/administration & dosage , Disease Models, Animal , Carcinogenesis/drug effects , Colitis-Associated Neoplasms/pathology , Colitis-Associated Neoplasms/microbiology , Colitis-Associated Neoplasms/metabolism , Mice, Inbred C57BL , Colon/microbiology , Colon/pathology , Colon/metabolism , Dextran Sulfate , Male , Gastrointestinal Microbiome , Colorectal Neoplasms/metabolism , Colorectal Neoplasms/microbiology , Azoxymethane
9.
Nat Commun ; 15(1): 3379, 2024 Apr 20.
Article in English | MEDLINE | ID: mdl-38643180

ABSTRACT

Transition from traditional high-fiber to Western diets in urbanizing communities of Sub-Saharan Africa is associated with increased risk of non-communicable diseases (NCD), exemplified by colorectal cancer (CRC) risk. To investigate how urbanization gives rise to microbial patterns that may be amenable by dietary intervention, we analyzed diet intake, fecal 16 S bacteriome, virome, and metabolome in a cross-sectional study in healthy rural and urban Xhosa people (South Africa). Urban Xhosa individuals had higher intakes of energy (urban: 3,578 ± 455; rural: 2,185 ± 179 kcal/d), fat and animal protein. This was associated with lower fecal bacteriome diversity and a shift from genera favoring degradation of complex carbohydrates (e.g., Prevotella) to taxa previously shown to be associated with bile acid metabolism and CRC. Urban Xhosa individuals had higher fecal levels of deoxycholic acid, shown to be associated with higher CRC risk, but similar short-chain fatty acid concentrations compared with rural individuals. Fecal virome composition was associated with distinct gut bacterial communities across urbanization, characterized by different dominant host bacteria (urban: Bacteriodota; rural: unassigned taxa) and variable correlation with fecal metabolites and dietary nutrients. Food and skin microbiota samples showed compositional differences along the urbanization gradient. Rural-urban dietary transition in South Africa is linked to major changes in the gut microbiome and metabolome. Further studies are needed to prove cause and identify whether restoration of specific components of the traditional diet will arrest the accelerating rise in NCDs in Sub-Saharan Africa.


Subject(s)
Colorectal Neoplasms , Gastrointestinal Microbiome , Southern African People , Animals , Humans , Urbanization , South Africa/epidemiology , Cross-Sectional Studies , Diet , Metabolome , Diet, Western , Colorectal Neoplasms/epidemiology , Colorectal Neoplasms/microbiology , Feces/microbiology
10.
World J Gastroenterol ; 30(14): 2018-2037, 2024 Apr 14.
Article in English | MEDLINE | ID: mdl-38681125

ABSTRACT

BACKGROUND: Colorectal cancer (CRC) ranks among the most prevalent malignant tumors globally. Recent reports suggest that Fusobacterium nucleatum (F. nucleatum) contributes to the initiation, progression, and prognosis of CRC. Butyrate, a short-chain fatty acid derived from the bacterial fermentation of soluble dietary fiber, is known to inhibit various cancers. This study is designed to explore whether F. nucleatum influences the onset and progression of CRC by impacting the intestinal metabolite butyric acid. AIM: To investigate the mechanism by which F. nucleatum affects CRC occurrence and development. METHODS: Alterations in the gut microbiota of BALB/c mice were observed following the oral administration of F. nucleatum. Additionally, DLD-1 and HCT116 cell lines were exposed to sodium butyrate (NaB) and F. nucleatum in vitro to examine the effects on proliferative proteins and mitochondrial function. RESULTS: Our research indicates that the prevalence of F. nucleatum in fecal samples from CRC patients is significantly greater than in healthy counterparts, while the prevalence of butyrate-producing bacteria is notably lower. In mice colonized with F. nucleatum, the population of butyrate-producing bacteria decreased, resulting in altered levels of butyric acid, a key intestinal metabolite of butyrate. Exposure to NaB can impair mitochondrial morphology and diminish mitochondrial membrane potential in DLD-1 and HCT116 CRC cells. Consequently, this leads to modulated production of adenosine triphosphate and reactive oxygen species, thereby inhibiting cancer cell proliferation. Additionally, NaB triggers the adenosine monophosphate-activated protein kinase (AMPK) signaling pathway, blocks the cell cycle in HCT116 and DLD-1 cells, and curtails the proliferation of CRC cells. The combined presence of F. nucleatum and NaB attenuated the effects of the latter. By employing small interfering RNA to suppress AMPK, it was demonstrated that AMPK is essential for NaB's inhibition of CRC cell proliferation. CONCLUSION: F. nucleatum can promote cancer progression through its inhibitory effect on butyric acid, via the AMPK signaling pathway.


Subject(s)
Butyric Acid , Cell Proliferation , Colorectal Neoplasms , Feces , Fusobacterium nucleatum , Gastrointestinal Microbiome , Mice, Inbred BALB C , Animals , Colorectal Neoplasms/microbiology , Colorectal Neoplasms/pathology , Colorectal Neoplasms/metabolism , Gastrointestinal Microbiome/drug effects , Butyric Acid/pharmacology , Butyric Acid/metabolism , Humans , Mice , Feces/microbiology , Cell Proliferation/drug effects , HCT116 Cells , Male , Mitochondria/metabolism , Mitochondria/drug effects , Fusobacterium Infections/microbiology , Disease Models, Animal , Cell Line, Tumor , Female , Disease Progression , Dysbiosis , Membrane Potential, Mitochondrial/drug effects
11.
Gut Microbes ; 16(1): 2341647, 2024.
Article in English | MEDLINE | ID: mdl-38659246

ABSTRACT

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


Subject(s)
Azoxymethane , Collaborative Cross Mice , Colorectal Neoplasms , Gastrointestinal Microbiome , Polymorphism, Single Nucleotide , Animals , Colorectal Neoplasms/microbiology , Colorectal Neoplasms/genetics , Colorectal Neoplasms/chemically induced , Humans , Mice , Collaborative Cross Mice/genetics , Dual Oxidases/genetics , Dual Oxidases/metabolism , Genetic Predisposition to Disease , Male , Bacteria/genetics , Bacteria/classification , Bacteria/metabolism , Bacteria/isolation & purification , Disease Models, Animal , Female
12.
Talanta ; 274: 126081, 2024 Jul 01.
Article in English | MEDLINE | ID: mdl-38613947

ABSTRACT

The development of efficient, accurate, and high-throughput technology for gut microbiota sensing holds great promise in the maintenance of health and the treatment of diseases. Herein, we developed a rapid fluorescent sensor array based on surface-engineered silver nanoparticles (AgNPs) and vancomycin-modified gold nanoclusters (AuNCs@Van) for gut microbiota sensing. By controlling the surface of AgNPs, the recognition ability of the sensor can be effectively improved. The sensor array was used to successfully discriminate six gut-derived bacteria, including probiotics, neutral, and pathogenic bacteria and even their mixtures. Significantly, the sensing system has also been successfully applied to classify healthy individuals and colorectal cancer (CRC) patients rapidly and accurately within 30 min, demonstrating its clinically relevant specificity.


Subject(s)
Colorectal Neoplasms , Gastrointestinal Microbiome , Gold , Metal Nanoparticles , Silver , Colorectal Neoplasms/microbiology , Colorectal Neoplasms/diagnosis , Humans , Silver/chemistry , Metal Nanoparticles/chemistry , Gold/chemistry , Vancomycin/pharmacology , Surface Properties , Fluorescent Dyes/chemistry
13.
Pathology ; 56(4): 528-539, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38609782

ABSTRACT

This study explored the relationship between faecal microbiota distribution and local or systemic immune response in patients with colorectal cancer (CRC). The study population included 114 surgically treated CRC patients. Faeces were analysed using 16S rRNA gene sequencing. The immune score in tumour microenvironment was evaluated using CD3 and CD8 immunohistochemistry. Genetic alterations, microsatellite instability status and five systemic inflammatory markers were also analysed. Thirty of 114 (26.3%) CRC patients were categorised as the 'immune type' with a high density of T-cells. The immune type CRC cases showed lower angiolymphatic invasion and longer overall survival. Of the 123 selected bacterial species, Bacteroides fragilis and Collinsella aerofaciens were prevalent in immune CRC cases, whereas Odoribacter splanchnicus and Phascolarctobacterium succinatutens were prevalent in non-immune CRC patients. Bacteroides fragilis was associated with shorter disease free survival in univariable and multivariable survival analyses. Regarding systemic immunity, a high prevalence of C. aerofaciens was associated with a high modified Glasgow prognostic score. This study revealed a potential relationship among the gut microbiome, immune microenvironment, and disease progression in patients with CRC. Our findings suggest that abundant B. fragilis in patients with CRC is associated with a 'cold immune' tumour microenvironment.


Subject(s)
Colorectal Neoplasms , Gastrointestinal Microbiome , Tumor Microenvironment , Humans , Colorectal Neoplasms/pathology , Colorectal Neoplasms/immunology , Colorectal Neoplasms/microbiology , Colorectal Neoplasms/surgery , Tumor Microenvironment/immunology , Male , Female , Middle Aged , Aged , Feces/microbiology , Adult , Aged, 80 and over , RNA, Ribosomal, 16S/genetics , Prognosis , Bacteroides fragilis/immunology
14.
Microbiol Spectr ; 12(5): e0272023, 2024 May 02.
Article in English | MEDLINE | ID: mdl-38572984

ABSTRACT

Gut microbiota has demonstrated an increasingly important role in the onset and development of colorectal cancer (CRC). Nonetheless, the association between gut microbiota and KRAS mutation in CRC remains enigmatic. We conducted 16S rRNA sequencing on stool samples from 94 CRC patients and employed the linear discriminant analysis effect size algorithm to identify distinct gut microbiota between KRAS mutant and KRAS wild-type CRC patients. Transcriptome sequencing data from nine CRC patients were transformed into a matrix of immune infiltrating cells, which was then utilized to explore KRAS mutation-associated biological functions, including Gene Ontology items and Kyoto Encyclopedia of Genes and Genomes pathways. Subsequently, we analyzed the correlations among these KRAS mutation-associated gut microbiota, host immunity, and KRAS mutation-associated biological functions. At last, we developed a predictive random forest (RF) machine learning model to predict the KRAS mutation status in CRC patients, based on the gut microbiota associated with KRAS mutation. We identified a total of 26 differential gut microbiota between both groups. Intriguingly, a significant positive correlation was observed between Bifidobacterium spp. and mast cells, as well as between Bifidobacterium longum and chemokine receptor CX3CR1. Additionally, we also observed a notable negative correlation between Bifidobacterium and GOMF:proteasome binding. The RF model constructed using the KRAS mutation-associated gut microbiota demonstrated qualified efficacy in predicting the KRAS phenotype in CRC. Our study ascertained the presence of 26 KRAS mutation-associated gut microbiota in CRC and speculated that Bifidobacterium may exert an essential role in preventing CRC progression, which appeared to correlate with the upregulation of mast cells and CX3CR1 expression, as well as the downregulation of GOMF:proteasome binding. Furthermore, the RF model constructed on the basis of KRAS mutation-associated gut microbiota exhibited substantial potential in predicting KRAS mutation status in CRC patients.IMPORTANCEGut microbiota has emerged as an essential player in the onset and development of colorectal cancer (CRC). However, the relationship between gut microbiota and KRAS mutation in CRC remains elusive. Our study not only identified a total of 26 gut microbiota associated with KRAS mutation in CRC but also unveiled their significant correlations with tumor-infiltrating immune cells, immune-related genes, and biological pathways (Gene Ontology items and Kyoto Encyclopedia of Genes and Genomes pathways). We speculated that Bifidobacterium may play a crucial role in impeding CRC progression, potentially linked to the upregulation of mast cells and CX3CR1 expression, as well as the downregulation of GOMF:Proteasome binding. Furthermore, based on the KRAS mutation-associated gut microbiota, the RF model exhibited promising potential in the prediction of KRAS mutation status for CRC patients. Overall, the findings of our study offered fresh insights into microbiological research and clinical prediction of KRAS mutation status for CRC patients.


Subject(s)
Colorectal Neoplasms , Gastrointestinal Microbiome , Machine Learning , Mutation , Proto-Oncogene Proteins p21(ras) , Humans , Colorectal Neoplasms/microbiology , Colorectal Neoplasms/genetics , Colorectal Neoplasms/pathology , Gastrointestinal Microbiome/genetics , Proto-Oncogene Proteins p21(ras)/genetics , Male , Female , RNA, Ribosomal, 16S/genetics , Middle Aged , Aged , Feces/microbiology , Bifidobacterium/genetics , Bacteria/genetics , Bacteria/classification , Bacteria/isolation & purification , CX3C Chemokine Receptor 1/genetics , CX3C Chemokine Receptor 1/metabolism
15.
Nutrients ; 16(8)2024 Apr 13.
Article in English | MEDLINE | ID: mdl-38674851

ABSTRACT

Colorectal cancer stands as the third most prevalent form of cancer worldwide, with a notable increase in incidence in Western countries, mainly attributable to unhealthy dietary habits and other factors, such as smoking or reduced physical activity. Greater consumption of vegetables and fruits has been associated with a lower incidence of colorectal cancer, which is attributed to their high content of fiber and bioactive compounds, such as flavonoids. In this study, we have tested the flavonoids quercetin, luteolin, and xanthohumol as potential antitumor agents in an animal model of colorectal cancer induced by azoxymethane and dodecyl sodium sulphate. Forty rats were divided into four cohorts: Cohort 1 (control cohort), Cohort 2 (quercetin cohort), Cohort 3 (luteolin cohort), and Cohort 4 (xanthohumol cohort). These flavonoids were administered intraperitoneally to evaluate their antitumor potential as pharmaceutical agents. At the end of the experiment, after euthanasia, different physical parameters and the intestinal microbiota populations were analyzed. Luteolin was effective in significantly reducing the number of tumors compared to the control cohort. Furthermore, the main significant differences at the microbiota level were observed between the control cohort and the cohort treated with luteolin, which experienced a significant reduction in the abundance of genera associated with disease or inflammatory conditions, such as Clostridia UCG-014 or Turicibacter. On the other hand, genera associated with a healthy state, such as Muribaculum, showed a significant increase in the luteolin cohort. These results underline the anti-colorectal cancer potential of luteolin, manifested through a modulation of the intestinal microbiota and a reduction in the number of tumors.


Subject(s)
Colorectal Neoplasms , Flavonoids , Gastrointestinal Microbiome , Luteolin , Propiophenones , Quercetin , Animals , Luteolin/pharmacology , Colorectal Neoplasms/prevention & control , Colorectal Neoplasms/microbiology , Gastrointestinal Microbiome/drug effects , Propiophenones/pharmacology , Flavonoids/pharmacology , Quercetin/pharmacology , Rats , Male , Disease Models, Animal , Azoxymethane , Antineoplastic Agents/pharmacology , Rats, Wistar
16.
Front Biosci (Landmark Ed) ; 29(4): 152, 2024 Apr 18.
Article in English | MEDLINE | ID: mdl-38682201

ABSTRACT

Metastasis remains a leading cause of mortality for patients with solid tumors. An expanding body of literature suggests interplay between the host, gut, and tumoral microbiomes may play a role in cancer initiation and distant dissemination. These associations have been particularly well-studied in colorectal cancer, where gut dysbiosis and an endotoxin-induced inflammatory milieu foster premalignant polyp formation, setting the stage for carcinogenesis. Subsequent violation of the gut vascular barrier enables dissemination of bacterial agents to sites such as the liver, where they contribute to establishment of pre-metastatic niches, which promote tumor cell extravasation and metastatic outgrowth. Intriguingly, breakdown of this vascular barrier has been shown to be aided by the presence of tumoral bacteria. The presence of similar species, including Fusobacterium nucleatum and Escherichia Coli, in both primary and metastatic colorectal tumors, supports this hypothesis and their presence is associated with chemotherapy resistance and an overall poor prognosis. Specific gut microbial populations are also associated with differential response to immunotherapy, which has a growing role in microsatellite unstable colorectal cancers. Recent work suggests that modulation of gut microbiome using dietary modification, targeted antibiotics, or fecal microbiota transplantation may improve response to immunotherapy and oncologic outcomes. Elucidation of the precise mechanistic links between the microbiome and cancer dissemination will open the doors to additional therapeutic possibilities.


Subject(s)
Colorectal Neoplasms , Gastrointestinal Microbiome , Neoplasm Metastasis , Humans , Colorectal Neoplasms/microbiology , Colorectal Neoplasms/pathology , Colorectal Neoplasms/therapy , Gastrointestinal Microbiome/physiology , Dysbiosis/microbiology , Bacteria/classification , Bacteria/genetics , Fecal Microbiota Transplantation
18.
J Microbiol ; 62(3): 153-165, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38625645

ABSTRACT

Colorectal cancer (CRC) is the second-highest cause of cancer-associated mortality among both men and women worldwide. One of the risk factors for CRC is obesity, which is correlated with a high-fat diet prevalent in Western dietary habits. The association between an obesogenic high-fat diet and CRC has been established for several decades; however, the mechanisms by which a high-fat diet increases the risk of CRC remain unclear. Recent studies indicate that gut microbiota strongly influence the pathogenesis of both high-fat diet-induced obesity and CRC. The gut microbiota is composed of hundreds of bacterial species, some of which are implicated in CRC. In particular, the expansion of facultative anaerobic Enterobacteriaceae, which is considered a microbial signature of intestinal microbiota functional imbalance (dysbiosis), is associated with both high-fat diet-induced obesity and CRC. Here, we review the interaction between the gut microbiome and its metabolic byproducts in the context of colorectal cancer (CRC) during high-fat diet-induced obesity. In addition, we will cover how a high-fat diet can drive the expansion of genotoxin-producing Escherichia coli by altering intestinal epithelial cell metabolism during gut inflammation conditions.


Subject(s)
Colorectal Neoplasms , Diet, High-Fat , Dysbiosis , Gastrointestinal Microbiome , Obesity , Diet, High-Fat/adverse effects , Colorectal Neoplasms/microbiology , Colorectal Neoplasms/etiology , Humans , Obesity/microbiology , Animals , Dysbiosis/microbiology , Bacteria/classification , Bacteria/metabolism , Bacteria/genetics , Bacteria/isolation & purification , Intestinal Mucosa/microbiology , Intestinal Mucosa/metabolism
19.
Free Radic Biol Med ; 220: 125-138, 2024 Aug 01.
Article in English | MEDLINE | ID: mdl-38657754

ABSTRACT

Fusobacterium (F.) nucleatum is a carcinogenesis microbiota in colorectal cancer (CRC). Growing evidence shows that F. nucleatum contributes to chemoresistance. Ferroptosis is reported to restore the susceptibility of resistant cells to chemotherapy. However, the role of gut microbiota affecting ferroptosis in chemoresistance remains unclear. Here, we examined the CRC tissues of patients using 16S rRNA sequencing to investigate the possible connection between gut microbiota dysbiosis and the relapse of CRC. We found that a high abundance of F. nucleatum in CRC tissue is associated with relapse. We further demonstrated that F. nucleatum induced oxaliplatin resistance in vitro and in vivo. The transcriptome of an F. nucleatum-infected cell revealed ferroptosis was associated with F. nucleatum infection. We perform malondialdehyde, ferrous iron, and glutathione assays to verify the effect of F. nucleatum on ferroptosis under oxaliplatin treatment in vivo and in vitro. Mechanistically, F. nucleatum promoted oxaliplatin resistance by overexpressing GPX4 and then inhibiting ferroptosis. E-cadherin/ß-catenin/TCF4 pathway conducted the GPX4 overexpression effect of F. nucleatum. The chromatin immuno-precipitation quantitative PCR (CHIP-qPCR) and dual-luciferase reporter assay showed that F. nucleatum promoted TCF4 binding with GPX4. We also determined the E-cadherin/ß-catenin/TCF4/GPX4 axis related to tumor tissue F. nucleatum status and CRC relapse clinically. Here, we revealed the contribution of F. nucleatum to oxaliplatin resistance by inhibiting ferroptosis in CRC. Targeting F. nucleatum and ferroptosis will provide valuable insight into chemoresistance management and may improve outcomes for patients with CRC.


Subject(s)
Cadherins , Colorectal Neoplasms , Drug Resistance, Neoplasm , Ferroptosis , Fusobacterium nucleatum , Gastrointestinal Microbiome , Oxaliplatin , Phospholipid Hydroperoxide Glutathione Peroxidase , beta Catenin , Ferroptosis/drug effects , Ferroptosis/genetics , Humans , Colorectal Neoplasms/pathology , Colorectal Neoplasms/microbiology , Colorectal Neoplasms/drug therapy , Colorectal Neoplasms/metabolism , Colorectal Neoplasms/genetics , Cadherins/metabolism , Cadherins/genetics , Oxaliplatin/pharmacology , beta Catenin/metabolism , beta Catenin/genetics , Phospholipid Hydroperoxide Glutathione Peroxidase/metabolism , Phospholipid Hydroperoxide Glutathione Peroxidase/genetics , Animals , Fusobacterium nucleatum/pathogenicity , Mice , Gastrointestinal Microbiome/drug effects , Xenograft Model Antitumor Assays , Gene Expression Regulation, Neoplastic/drug effects , Male , Antigens, CD/metabolism , Antigens, CD/genetics , Female , Cell Line, Tumor , Fusobacterium Infections/microbiology , Fusobacterium Infections/drug therapy , Fusobacterium Infections/metabolism , Fusobacterium Infections/genetics , Fusobacterium Infections/pathology , Dysbiosis/microbiology , Transcription Factor 4/metabolism , Transcription Factor 4/genetics , Mice, Nude
20.
Surg Clin North Am ; 104(3): 647-656, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38677827

ABSTRACT

The gut microbiome is defined as the microorganisms that reside within the gastrointestinal tract and produce a variety of metabolites that impact human health. These microbes play an intricate role in human health, and an imbalance in the gut microbiome, termed gut dysbiosis, has been implicated in the development of varying diseases. The purpose of this review is to highlight what is known about the microbiome and its impact on colorectal cancer, inflammatory bowel disease, constipation, Clostridioides difficile infection, the impact of bowel prep, and anastomotic leaks.


Subject(s)
Colorectal Neoplasms , Gastrointestinal Microbiome , Humans , Gastrointestinal Microbiome/physiology , Colorectal Neoplasms/microbiology , Dysbiosis/microbiology , Inflammatory Bowel Diseases/microbiology , Clostridium Infections/therapy , Clostridium Infections/microbiology , Constipation/microbiology , Constipation/etiology , Anastomotic Leak/microbiology , Anastomotic Leak/etiology
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