Ontology highlight
ABSTRACT:
PROVIDER: PRJNA669570 | ENA |
REPOSITORIES: ENA
Dataset's files
| Action | DRS | |||
|---|---|---|---|---|
| Other | ||||
| SRR12831696_1.fastq.gz | Fastqsanger.gz | |||
| SRR12831696_2.fastq.gz | Fastqsanger.gz | |||
| SRR12831697_subreads.fastq.gz | Fastqsanger.gz |
Items per page: 5 1 - 4 of 4 |
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Project description:Various species of the intestinal microbiota have been associated with the
development of colorectal cancer (CRC), yet a direct role of bacteria in the
occurrence of oncogenic mutations has not been established. Escherichia coli can
carry the pathogenicity island pks, which encodes a set of enzymes that
synthesize colibactin. This compound alkylates DNA on adenine residues and
induces double strand breaks in cultured cells. Here, we exposed human intestinal
organoids to genotoxic pks+ Escherichia coli by repeated luminal injection over a
period of 5 months. Whole genome sequencing (WGS) of clonal organoids before
and after this exposure reveals a distinct mutational signature, absent from
organoids injected with isogenic pks-mutant bacteria. The same mutational
signature is detected in a subset of 3668 human metastatic cancer genomes,
predominantly in a subset of CRC cases. Our study describes a distinct mutational
signature in CRC and implies that the underlying mutational process directly
results from past exposure to bacteria carrying the colibactin-producing pks
pathogenicity island.
| EGAS00001003934 | EGA
Project description:The complex reservoir of metabolite-producing bacteria in the gastrointestinal tract contributes tremendously to human health and disease. Bacterial composition, and by extension gut metabolomic composition, is undoubtably influenced by the use of modern antibiotics. Herein, we demonstrate that polymyxin B, a last resort antibiotic used for chronic multidrug resistant infections infections, influences the production of the genotoxic metabolite colibactin from adherent-invasive Escherichia coli (AIEC) NC101. Colibactin can augment colorectal cancer (CRC) through DNA double stranded breaks and interstrand crosslinks. While the structure and biosynthesis of colibactin has been elucidated, chemical-induced regulation of its biosynthetic gene cluster and subsequent production of the genotoxin by pathogenic E. coli are largely unexplored. This research highlights the regulation of the colibactin-producing biosynthetic gene cluster under polymyxin stress. Using a multi-omic approach, we have identified that polymyxin stress enhances the abundance of colibactin biosynthesis proteins (Clb’s) in multiple pks+ E. coli strains, including pro-carcinogenic AIEC: NC101, the probiotic strain: E. coli Nissle 1917, and the antibiotic testing strain: E. coli ATCC 25922. Expression analysis via qPCR revealed that increased transcription of clb genes likely contributes to elevated Clb protein levels in NC101. Enhanced production of Clb’s by NC101 under polymyxin stress matched an increased production of the colibactin prodrug motif, a proxy for the mature genotoxic metabolite. Furthermore, E. coli with heightened tolerance for polymyxin antibiotics induced greater DNA damage, assessed by quantification of γH2AX staining in cultured intestinal epithelial cells. This study establishes a key link between the polymyxin B stress response and colibactin production in pks+ E. coli. Ultimately, our findings will inform future studies investigating colibactin regulation, the microbial response to antibiotics in the gut, and the ability of seemingly innocuous commensal microbes to induce host disease.
2021-07-15 | PXD025088 | Pride
Project description:Colorectal cancer is driven by a sequential cascade of mutations known as the adenoma-carcinoma sequence. Recent studies have revealed that specific bacterial species present in the colonic microbiota can induce mutations and contribute to this malignancy. Specifically, genotoxic colibactin-producing pks+ Escherichia coli strains can induce DNA double strand breaks (DSBs) and promote tumor development in mouse models of colorectal cancer. Here, we investigated the transformation potential of colibactin by using organoids and polarized monolayers derived from primary murine colon epithelial cells and reveal striking phenotypic changes upon short-term infection. This study demonstrates the direct pro-oncogenic potential of pks+ E. coli, as such transformations in vivo could facilitate colitis-associated colorectal carcinogenesis.
2020-12-03 | GSE140929 | GEO
Project description:Various bacteria are suggested to contribute to colorectal cancer (CRC) development, including pks+ E. coli, which produces the genotoxin colibactin that induces characteristic mutational signatures in host epithelial cells. However, it remains unclear how the highly unstable colibactin molecule is able to access host epithelial cells to cause harm. Using the microbiota-dependent ZEB2-transgenic mouse model of invasive CRC, we demonstrate that the oncogenic potential of pks+ E. coli critically depends on bacterial adhesion to host epithelial cells, mediated by the type-1 pilus adhesin FimH and the F9-pilus adhesin FmlH. Blocking bacterial adhesion using a pharmacological FimH inhibitor attenuates colibactin-mediated genotoxicity and CRC exacerbation. We also show that allelic switching of FimH strongly influences genotoxic potential of pks+ E. coli and can induce a genotoxic gain-of-function in the probiotic strain Nissle 1917. Adhesin-mediated epithelial binding subsequently allows the production of the genotoxin colibactin in close proximity to host epithelial cells, which promotes DNA damage and drives CRC development. These findings present promising therapeutic avenues for the development of anti-adhesive therapies aimed at mitigating colibactin-induced DNA damage and inhibiting the initiation and progression of CRC, particularly in individuals at risk for developing CRC.
2024-08-19 | GSE241851 | GEO
Project description:Colibactin, a bacterial genotoxin produced by E. coli harboring the pks genomic island, induces cytopathic effects such as DNA breaks, cell cycle arrest and apoptosis. Patients with a colonic dysfunction due to inflammatory bowel disease such as ulcerative colitis have an elevated likelihood of carrying pks+ E. coli in their colon microbiota but it is not clear whether and how they contribute to the pathogenesis of colitis. Using a gnotobiotic mouse model, we show that pks+ E. coli do not affect colonic integrity under homeostatic conditions, with the microbiota remaining separated from the epithelium by a mucus barrier. However, upon chemical disruption of this barrier by DSS, the microbes gain direct access to the epithelium, causing severe epithelial injury, and development of colitis, while mice colonized with an isogenic ΔclbR mutant incapable of producing colibactin suffer significantly less pronounced effects. While ΔclbR-colonized animals show efficient recovery of the mucus barrier and crypt homeostasis, recovery in WT-colonized mice is impaired. Instead, the mucosa remains in a chronic regenerative state characterized by high proliferation and impaired differentiation of enterocytes and goblet cells, preventing the re-establishment of a functional barrier. In turn, pks+ E. coli remain in direct contact with the epithelium, perpetuating the process and triggering chronic mucosal inflammation that morphologically and transcriptionally resembles human ulcerative colitis. It is characterized by high levels of stromal R-spondin 3. Genetic overexpression of R-spondin 3 in colon myofibroblasts is sufficient to mimic this chronic regenerative state, resulting in barrier disruption and expansion of E. coli. Together, our data reveal that pks+ E. coli are pathobionts that upon contact with the epithelium promote severe injury and interfere with recovery, initiating chronic tissue dysfunction and inflammation.
2023-07-10 | GSE205403 | GEO
Project description:The complex reservoir of metabolite-producing bacteria in the gastrointestinal tract contributes tremendously to human health and disease. Bacterial composition, and by extension gut metabolomic composition, is undoubtably influenced by the use of modern antibiotics. Herein, we demonstrate that polymyxin B, a last resort antibiotic used for chronic multidrug resistant infections infections, influences the production of the genotoxic metabolite colibactin from adherent-invasive Escherichia coli (AIEC) NC101. Colibactin can augment colorectal cancer (CRC) through DNA double stranded breaks and interstrand crosslinks. While the structure and biosynthesis of colibactin has been elucidated, chemical-induced regulation of its biosynthetic gene cluster and subsequent production of the genotoxin by pathogenic E. coli are largely unexplored. This research highlights the regulation of the colibactin-producing biosynthetic gene cluster under polymyxin stress. Using a multi-omic approach, we have identified that polymyxin stress enhances the abundance of colibactin biosynthesis proteins (Clbs) in multiple pks+ E. coli strains, including pro-carcinogenic AIEC: NC101, the probiotic strain: E. coli Nissle 1917, and the antibiotic testing strain: E. coli ATCC 25922. Expression analysis via qPCR revealed that increased transcription of clb genes likely contributes to elevated Clb protein levels in NC101. Enhanced production of Clbs by NC101 under polymyxin stress matched an increased production of the colibactin prodrug motif, a proxy for the mature genotoxic metabolite. Furthermore, E. coli with heightened tolerance for polymyxin antibiotics induced greater DNA damage, assessed by quantification of yH2AX staining in cultured intestinal epithelial cells. This study establishes a key link between the polymyxin B stress response and colibactin production in pks+ E. coli. Ultimately, our findings will inform future studies investigating colibactin regulation, the microbial response to antibiotics in the gut, and the ability of seemingly innocuous commensal microbes to induce host disease.
2021-03-25 | MSV000087101 | MassIVE
Project description:Colibactin, a potent genotoxin of Escherichia coli, causes DNA double strand breaks (DSBs). We investigated if colibactin creates a particular DNA damage signature in infected human cells. Genomic contexts of colibactin-induced DSBs were enriched for a distinct AT-rich hexameric sequence motif. A survey of somatic mutations at the colibactin target sites of several thousand cancer genomes revealed significant enrichment of the motif in colorectal cancers. Moreover, the exact break point location corresponded with mutational hot spots in these cancers corresponding to a distinct trinucleotide signature. This work provides evidence for a role of colibactin in the etiology of human cancer.
2020-04-22 | GSE145594 | GEO
Project description:Escherichia coli BarA-UvrY regulates the pks island and kills Staphylococci via the genotoxin colibactin
| PRJNA787071 | ENA
Project description:The complex reservoir of metabolite-producing bacteria in the gastrointestinal tract contributes tremendously to human health and disease. Bacterial composition, and by extension gut metabolomic composition, is undoubtably influenced by the use of modern antibiotics. Herein, we demonstrate that polymyxin B, a last resort antibiotic used for chronic multidrug resistant infections infections, influences the production of the genotoxic metabolite colibactin from adherent-invasive Escherichia coli (AIEC) NC101. Colibactin can augment colorectal cancer (CRC) through DNA double stranded breaks and interstrand crosslinks. While the structure and biosynthesis of colibactin has been elucidated, chemical-induced regulation of its biosynthetic gene cluster and subsequent production of the genotoxin by pathogenic E. coli are largely unexplored. This research highlights the regulation of the colibactin-producing biosynthetic gene cluster under polymyxin stress. Using a multi-omic approach, we have identified that polymyxin stress enhances the abundance of colibactin biosynthesis proteins (Clbs) in multiple pks+ E. coli strains, including pro-carcinogenic AIEC: NC101, the probiotic strain: E. coli Nissle 1917, and the antibiotic testing strain: E. coli ATCC 25922. Expression analysis via qPCR revealed that increased transcription of clb genes likely contributes to elevated Clb protein levels in NC101. Enhanced production of Clbs by NC101 under polymyxin stress matched an increased production of the colibactin prodrug motif, a proxy for the mature genotoxic metabolite. Furthermore, E. coli with heightened tolerance for polymyxin antibiotics induced greater DNA damage, assessed by quantification of yH2AX staining in cultured intestinal epithelial cells. This study establishes a key link between the polymyxin B stress response and colibactin production in pks+ E. coli. Ultimately, our findings will inform future studies investigating colibactin regulation, the microbial response to antibiotics in the gut, and the ability of seemingly innocuous commensal microbes to induce host disease.
2021-03-25 | MSV000087101 | GNPS