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Oxygen sensing is central to metazoan biology and has implications for human disease. Mammalian cells express multiple oxygen-dependent enzymes called 2-oxoglutarate (OG)-dependent dioxygenases (2-OGDDs), but they vary in their oxygen affinities and hence their ability to sense oxygen. The 2-OGDD histone demethylases control histone methylation. Hypoxia increases histone methylation, but whether this reflects direct effects on histone demethylases or indirect effects caused by the hypoxic induction of the HIF (hypoxia-inducible factor) transcription factor or the 2-OG antagonist 2-hydroxyglutarate (2-HG) is unclear. Here, we report that hypoxia promotes histone methylation in a HIF- and 2-HG-independent manner. We found that the H3K27 histone demethylase KDM6A/UTX, but not its paralog KDM6B, is oxygen sensitive. KDM6A loss, like hypoxia, prevented H3K27 demethylation and blocked cellular differentiation. Restoring H3K27 methylation homeostasis in hypoxic cells reversed these effects. Thus, oxygen directly affects chromatin regulators to control cell fate.
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http://dx.doi.org/10.1126/science.aaw1026 | DOI Listing |
Tree Physiol
September 2025
Pollen Biotechnology of Crop Plants Group, Margarita Salas Center of Biological Research, CIB-CSIC, Ramiro de Maeztu 9, 28040, Madrid, Spain.
Somatic embryogenesis (SE) is an in vitro mass propagation system widely employed in plant breeding programs. However, its efficiency in many forest species remains limited due to their recalcitrance. SE relies on the induction of somatic cell reprogramming into embryogenic pathways, a process influenced by transcriptomic changes regulated, among other factors, by epigenetic modifications such as DNA methylation, histone methylation, and histone acetylation.
View Article and Find Full Text PDFNucleic Acids Res
September 2025
Division of Chromatin Regulation, National Institute for Basic Biology, Okazaki 444-8585, Japan.
Methylation of histone H3 at lysine 9 (H3K9me), a hallmark of heterochromatin, is catalyzed by Clr4/Suv39. Clr4/Suv39 contains two conserved domains-an N-terminal chromodomain and a C-terminal catalytic domain-connected by an intrinsically disordered region (IDR). Several mechanisms have been proposed to regulate Clr4/Suv39 activity, but how it is regulated under physiological conditions remains largely unknown.
View Article and Find Full Text PDFNat Rev Cancer
September 2025
Department of Biochemistry and Molecular Biology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA.
Somatic mutations in several genes, including key oncogenes and tumour suppressor genes, are present from early life and can accumulate as an individual ages, indicating that the potential for cancer is present and growing throughout life. However, the risk of developing cancer rises sharply after 50-60 years of age, suggesting that the ability of these mutations to undergo clonal expansion and drive cancer development is dependent on the progressive changes in the epigenome and microenvironment that occur during ageing. Epigenetic changes, including DNA methylation and histone modifications, can drive various hallmarks of ageing in precancerous cells, including induction of senescence, the senescence-associated secretory phenotype, genomic instability and reduction of nuclear integrity, metabolic and inflammatory stress responses, stem cell function and differentiation potential, and redox balance.
View Article and Find Full Text PDFCancer Sci
September 2025
Department of Molecular Oncology, Graduate School of Medicine, Chiba University, Chiba, Japan.
Histone H3K4 modifications are altered in the regulation of gene expression and in multiple cellular processes during cancer development and progression. Understanding the roles of H3K4-modifying enzymes will provide novel insights into therapeutic tools for cancer treatment. H3K4-modifying enzymes catalyze the addition or removal of covalent modifications with specific substrate preferences.
View Article and Find Full Text PDFFront Pharmacol
August 2025
Stem Cell Research Center, Department of Pathology and Pathophysiology, School of Medicine, Tongji University, Shanghai, China.
Bladder cancer (BC) is a disease that predominantly affects older adults, with aging playing a critical role in its onset and progression. Age-associated phenomena, including immunosenescence and chronic inflammation, form a pro-tumor milieu, while genomic instability and epigenetic drift further increase cancer risk. The review highlights the dual role of DNA methylation in BC: global hypomethylation can activate transposable elements and oncogenes, whereas focal hypermethylation silences tumor-suppressor genes like CDKN2A, especially detrimental in older tissues that rely on these genes for senescence control.
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