Background: Altered microbiome composition and aberrant promoter hypermethylation of tumor suppressor genes (TSGs) are two important hallmarks of colorectal cancer (CRC). Here we performed concurrent 16S rRNA gene sequencing and methyl-CpG binding domain-based capture sequencing in 33 tissue biopsies (5 normal colonic mucosa tissues, 4 pairs of adenoma and adenoma-adjacent tissues, and 10 pairs of CRC and CRC-adjacent tissues) to identify significant associations between TSG promoter hypermethylation and CRC-associated bacteria, followed by functional validation of the methylation-associated bacteria.
Results: Fusobacterium nucleatum and Hungatella hathewayi were identified as the top two methylation-regulating bacteria. Targeted analysis on bona fide TSGs revealed that H. hathewayi and Streptococcus spp. significantly correlated with CDX2 and MLH1 promoter hypermethylation, respectively. Mechanistic validation with cell-line and animal models revealed that F. nucleatum and H. hathewayi upregulated DNA methyltransferase. H. hathewayi inoculation also promoted colonic epithelial cell proliferation in germ-free and conventional mice.
Conclusion: Our integrative analysis revealed previously unknown epigenetic regulation of TSGs in host cells through inducing DNA methyltransferase by F. nucleatum and H. hathewayi, and established the latter as CRC-promoting bacteria. Video abstract.
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http://dx.doi.org/10.1186/s40168-020-00847-4 | DOI Listing |
Int J Mol Sci
January 2025
Department of Women's and Children's Health, University of Padova, 35128 Padova, Italy.
Fragile X syndrome (FXS) is a genetic neurodevelopmental disorder that causes a range of developmental problems including cognitive and behavioral impairment and learning disabilities. FXS is caused by full mutations (FM) of the gene expansions to over 200 repeats, with hypermethylation of the cytosine-guanine-guanine (CGG) tandem repeated region in its promoter, resulting in transcriptional silencing and loss of gene function. Female carriers of FM are typically less impaired than males.
View Article and Find Full Text PDFBiomolecules
January 2025
Department of Epidemiology, School of Public Health, Sun Yat-sen University, Guangzhou 510080, China.
The DNA methylation of can regulate its gene expression and may play a role in the occurrence and progression of colorectal cancer (CRC). However, the association between DNA methylation and the prognosis of CRC patients has not yet been reported. In this study, differential methylation analysis was conducted in both blood and tissue cohorts, and differential expression analysis was performed in the tissue cohort with in vitro validation.
View Article and Find Full Text PDFAging Cell
January 2025
Institute of Human Genetics, Julius Maximilians University, Würzburg, Germany.
Ribosomal RNA is the main component of the ribosome, which is essential for protein synthesis. The diploid human genome contains several hundred copies of the rDNA transcription unit (TU). Droplet digital PCR and deep bisulfite sequencing were used to determine the absolute copy number (CN) and the methylation status of individual rDNA TU in blood samples of healthy individuals.
View Article and Find Full Text PDFHemasphere
January 2025
Université Paris Cité, Institut Cochin, INSERM U1016, CNRS UMR8104 Assistance Publique-Hôpitaux de Paris.Centre, Laboratory of Hematology, Hôpital Cochin Paris France.
Lower risk (LR) myelodysplastic syndromes (MDS) are heterogeneous hematopoietic stem and progenitor disorders caused by the accumulation of somatic mutations in various genes including epigenetic regulators that may produce convergent DNA methylation patterns driving specific gene expression profiles. The integration of genomic, epigenomic, and transcriptomic profiling has the potential to spotlight distinct LR-MDS categories on the basis of pathophysiological mechanisms. We performed a comprehensive study of somatic mutations and DNA methylation in a large and clinically well-annotated cohort of treatment-naive patients with LR-MDS at diagnosis from the EUMDS registry (ClinicalTrials.
View Article and Find Full Text PDFInt J Biol Macromol
January 2025
Department of Thoracic Surgery, the First Affiliated Hospital of Xi'an Jiaotong University, Xi'an 710061, China. Electronic address:
Mitochondrial dysfunction and ferroptosis play crucial roles in myocardial ischemia/reperfusion (I/R) following heart transplantation. Microsomal glutathione s transferase 1 (MGST1) is widely distributed in mitochondria and has a protective effect against ferroptosis, and its involvement in myocardial I/R injury has not yet been elucidated. In this study, donor hearts from C57BL/6 male mice were subjected to 12 h of ex-vivo cold ischemia treatment and transplanted into the abdomen of recipient mice for 24 h of reperfusion.
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