INTRODUCTION: Variable expressivity is an emerging characteristic of KMT2B-related dystonia. However, it remains poorly understood whether variants reoccurring at specific sites of lysine-specific methlytransferase-2B (KMT2B) can drive intra- and interfamilial clinical heterogeneity. Our goal was to ascertain independent families with variants affecting residue Arg2565 of KMT2B. METHODS: Whole-exome/genome sequencing, multi-site recruitment, genotype-phenotype correlations, and DNA methylation episignature analysis were performed. RESULTS: We report four individuals from two families harboring the variant c.7693C > G, p.Arg2565Gly. In an additional patient, a de-novo c.7693C > T, p.Arg2565Cys variant was identified. The observed phenotypic spectrum ranged from childhood-onset dystonia (N = 2) over unspecific intellectual disability syndromes (N = 2) to undiagnosed behavioral symptoms in adulthood (N = 1). Samples bearing p.Arg2565Gly had a KMT2B-typical episignature, although the effect on methylation was less pronounced than in carriers of loss-of-function KMT2B variants. CONCLUSIONS: We established the existence of a KMT2B missense-mutation hotspot associated with varying degrees of disease severity and expression, providing information for patient counseling and elucidation of pathomechanisms.
- MeSH
- dítě MeSH
- dospělí MeSH
- dystonické poruchy * genetika MeSH
- dystonie genetika MeSH
- histonlysin-N-methyltransferasa * genetika MeSH
- lidé středního věku MeSH
- lidé MeSH
- missense mutace MeSH
- mladiství MeSH
- mladý dospělý MeSH
- rodokmen * MeSH
- sekvenování exomu MeSH
- vývojové poruchy u dětí genetika MeSH
- Check Tag
- dítě MeSH
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mladiství MeSH
- mladý dospělý MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- kazuistiky MeSH
Biological mechanisms related to cancer development can leave distinct molecular fingerprints in tumours. By leveraging multi-omics and epidemiological information, we can unveil relationships between carcinogenesis processes that would otherwise remain hidden. Our integrative analysis of DNA methylome, transcriptome, and somatic mutation profiles of kidney tumours linked ageing, epithelial-mesenchymal transition (EMT), and xenobiotic metabolism to kidney carcinogenesis. Ageing process was represented by associations with cellular mitotic clocks such as epiTOC2, SBS1, telomere length, and PBRM1 and SETD2 mutations, which ticked faster as tumours progressed. We identified a relationship between BAP1 driver mutations and the epigenetic upregulation of EMT genes (IL20RB and WT1), correlating with increased tumour immune infiltration, advanced stage, and poorer patient survival. We also observed an interaction between epigenetic silencing of the xenobiotic metabolism gene GSTP1 and tobacco use, suggesting a link to genotoxic effects and impaired xenobiotic metabolism. Our pan-cancer analysis showed these relationships in other tumour types. Our study enhances the understanding of kidney carcinogenesis and its relation to risk factors and progression, with implications for other tumour types.
- MeSH
- DNA vazebné proteiny genetika metabolismus MeSH
- epigeneze genetická MeSH
- epitelo-mezenchymální tranzice * genetika MeSH
- glutathion-S-transferasa fí genetika metabolismus MeSH
- histonlysin-N-methyltransferasa genetika metabolismus MeSH
- karcinogeneze * genetika MeSH
- lidé MeSH
- metylace DNA * MeSH
- multiomika MeSH
- mutace * MeSH
- nádorové supresorové proteiny genetika metabolismus MeSH
- nádory ledvin * genetika patologie MeSH
- regulace genové exprese u nádorů MeSH
- stárnutí genetika MeSH
- thiolesterasa ubikvitinu MeSH
- transkripční faktory genetika metabolismus MeSH
- transkriptom MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
Methylation of histone H3 at lysine 36 (H3K36me3) marks active chromatin. The mark is interpreted by epigenetic readers that assist transcription and safeguard the integrity of the chromatin fiber. The chromodomain protein MSL3 binds H3K36me3 to target X-chromosomal genes in male Drosophila for dosage compensation. The PWWP-domain protein JASPer recruits the JIL1 kinase to active chromatin on all chromosomes. Unexpectedly, depletion of K36me3 had variable, locus-specific effects on the interactions of those readers. This observation motivated a systematic and comprehensive study of K36 methylation in a defined cellular model. Contrasting prevailing models, we found that K36me1, K36me2 and K36me3 each contribute to distinct chromatin states. A gene-centric view of the changing K36 methylation landscape upon depletion of the three methyltransferases Set2, NSD and Ash1 revealed local, context-specific methylation signatures. Set2 catalyzes K36me3 predominantly at transcriptionally active euchromatin. NSD places K36me2/3 at defined loci within pericentric heterochromatin and on weakly transcribed euchromatic genes. Ash1 deposits K36me1 at regions with enhancer signatures. The genome-wide mapping of MSL3 and JASPer suggested that they bind K36me2 in addition to K36me3, which was confirmed by direct affinity measurement. This dual specificity attracts the readers to a broader range of chromosomal locations and increases the robustness of their actions.
- MeSH
- chromatin * metabolismus MeSH
- DNA vazebné proteiny metabolismus genetika MeSH
- Drosophila melanogaster genetika metabolismus MeSH
- heterochromatin metabolismus genetika MeSH
- histonlysin-N-methyltransferasa * metabolismus genetika MeSH
- histony * metabolismus MeSH
- lysin metabolismus MeSH
- methyltransferasy metabolismus genetika MeSH
- metylace MeSH
- protein-serin-threoninkinasy MeSH
- proteiny Drosophily * metabolismus genetika MeSH
- transkripční faktory metabolismus genetika MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
A comprehensive international consensus on the cytogenetic risk-group stratification of KMT2A-rearranged (KMT2A-r) pediatric acute myeloid leukemia (AML) is lacking. This retrospective (2005-2016) International Berlin-Frankfurt-Münster Study Group study on 1256 children with KMT2A-r AML aims to validate the prognostic value of established recurring KMT2A fusions and additional cytogenetic aberrations (ACAs) and to define additional, recurring KMT2A fusions and ACAs, evaluating their prognostic relevance. Compared with our previous study, 3 additional, recurring KMT2A-r groups were defined: Xq24/KMT2A::SEPT6, 1p32/KMT2A::EPS15, and 17q12/t(11;17)(q23;q12). Across 13 KMT2A-r groups, 5-year event-free survival probabilities varied significantly (21.8%-76.2%; P < .01). ACAs occurred in 46.8% of 1200 patients with complete karyotypes, correlating with inferior overall survival (56.8% vs 67.9%; P < .01). Multivariable analyses confirmed independent associations of 4q21/KMT2A::AFF1, 6q27/KMT2A::AFDN, 10p12/KMT2A::MLLT10, 10p11.2/KMT2A::ABI1, and 19p13.3/KMT2A::MLLT1 with adverse outcomes, but not those of 1q21/KMT2A::MLLT11 and trisomy 19 with favorable and adverse outcomes, respectively. Newly identified ACAs with independent adverse prognoses were monosomy 10, trisomies 1, 6, 16, and X, add(12p), and del(9q). Among patients with 9p22/KMT2A::MLLT3, the independent association of French-American-British-type M5 with favorable outcomes was confirmed, and those of trisomy 6 and measurable residual disease at end of induction with adverse outcomes were identified. We provide evidence to incorporate 5 adverse-risk KMT2A fusions into the cytogenetic risk-group stratification of KMT2A-r pediatric AML, to revise the favorable-risk classification of 1q21/KMT2A::MLLT11 to intermediate risk, and to refine the risk-stratification of 9p22/KMT2A::MLLT3 AML. Future studies should validate the associations between the newly identified ACAs and outcomes and unravel the underlying biological pathogenesis of KMT2A fusions and ACAs.
- MeSH
- akutní myeloidní leukemie * genetika mortalita MeSH
- chromozomální aberace MeSH
- dítě MeSH
- genová přestavba MeSH
- histonlysin-N-methyltransferasa * genetika MeSH
- kojenec MeSH
- lidé MeSH
- mladiství MeSH
- předškolní dítě MeSH
- prognóza MeSH
- protoonkogenní protein MLL * genetika MeSH
- retrospektivní studie MeSH
- Check Tag
- dítě MeSH
- kojenec MeSH
- lidé MeSH
- mladiství MeSH
- mužské pohlaví MeSH
- předškolní dítě MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
PRDM9-mediated reproductive isolation was first described in the progeny of Mus musculus musculus (MUS) PWD/Ph and Mus musculus domesticus (DOM) C57BL/6J inbred strains. These male F1 hybrids fail to complete chromosome synapsis and arrest meiosis at prophase I, due to incompatibilities between the Prdm9 gene and hybrid sterility locus Hstx2. We identified 14 alleles of Prdm9 in exon 12, encoding the DNA-binding domain of the PRDM9 protein in outcrossed wild mouse populations from Europe, Asia, and the Middle East, 8 of which are novel. The same allele was found in all mice bearing introgressed t-haplotypes encompassing Prdm9. We asked whether 7 novel Prdm9 alleles in MUS populations and the t-haplotype allele in 1 MUS and 3 DOM populations induce Prdm9-mediated reproductive isolation. The results show that only combinations of the dom2 allele of DOM origin and the MUS msc1 allele ensure complete infertility of intersubspecific hybrids in outcrossed wild populations and inbred mouse strains examined so far. The results further indicate that MUS mice may share the erasure of PRDM9msc1 binding motifs in populations with different Prdm9 alleles, which implies that erased PRDM9 binding motifs may be uncoupled from their corresponding Prdm9 alleles at the population level. Our data corroborate the model of Prdm9-mediated hybrid sterility beyond inbred strains of mice and suggest that sterility alleles of Prdm9 may be rare.
Chromosomal rearrangements of the human KMT2A/MLL gene are associated with de novo as well as therapy-induced infant, pediatric, and adult acute leukemias. Here, we present the data obtained from 3401 acute leukemia patients that have been analyzed between 2003 and 2022. Genomic breakpoints within the KMT2A gene and the involved translocation partner genes (TPGs) and KMT2A-partial tandem duplications (PTDs) were determined. Including the published data from the literature, a total of 107 in-frame KMT2A gene fusions have been identified so far. Further 16 rearrangements were out-of-frame fusions, 18 patients had no partner gene fused to 5'-KMT2A, two patients had a 5'-KMT2A deletion, and one ETV6::RUNX1 patient had an KMT2A insertion at the breakpoint. The seven most frequent TPGs and PTDs account for more than 90% of all recombinations of the KMT2A, 37 occur recurrently and 63 were identified so far only once. This study provides a comprehensive analysis of the KMT2A recombinome in acute leukemia patients. Besides the scientific gain of information, genomic breakpoint sequences of these patients were used to monitor minimal residual disease (MRD). Thus, this work may be directly translated from the bench to the bedside of patients and meet the clinical needs to improve patient survival.
- MeSH
- akutní lymfatická leukemie * genetika MeSH
- akutní myeloidní leukemie * genetika MeSH
- dítě MeSH
- dospělí MeSH
- fúze genů MeSH
- histonlysin-N-methyltransferasa * genetika MeSH
- kojenec MeSH
- lidé středního věku MeSH
- lidé MeSH
- mladiství MeSH
- předškolní dítě MeSH
- protoonkogenní protein MLL * genetika MeSH
- senioři MeSH
- Check Tag
- dítě MeSH
- dospělí MeSH
- kojenec MeSH
- lidé středního věku MeSH
- lidé MeSH
- mladiství MeSH
- předškolní dítě MeSH
- senioři MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- MeSH
- akutní lymfatická leukemie farmakoterapie genetika patologie MeSH
- akutní nemoc MeSH
- buněčný rodokmen genetika MeSH
- genová přestavba MeSH
- histonlysin-N-methyltransferasa genetika MeSH
- indukční chemoterapie metody MeSH
- kineziny genetika MeSH
- lidé MeSH
- lidské chromozomy, pár 11 genetika MeSH
- lidské chromozomy, pár 6 genetika MeSH
- malování chromozomů metody MeSH
- mladiství MeSH
- myeloidní leukemie genetika patologie MeSH
- myosiny genetika MeSH
- protoonkogenní protein MLL genetika MeSH
- translokace genetická * MeSH
- Check Tag
- lidé MeSH
- mladiství MeSH
- ženské pohlaví MeSH
- Publikační typ
- dopisy MeSH
- kazuistiky MeSH
Hybrid sterility contributes to speciation by preventing gene flow between related taxa. Prdm9, the first and only hybrid male sterility gene known in vertebrates, predetermines the sites of recombination between homologous chromosomes and their synapsis in early meiotic prophase. The asymmetric binding of PRDM9 to heterosubspecific homologs of Mus musculus musculus × Mus musculus domesticus F1 hybrids and increase of PRDM9-independent DNA double-strand break hotspots results indificult- to- repair double-strand breaks, incomplete synapsis of homologous chromosomes, and meiotic arrest at the first meiotic prophase. Here, we show that Prdm9 behaves as a major hybrid male sterility gene in mice outside the Mus musculus musculus × Mus musculus domesticus F1 hybrids, in the genomes composed of Mus musculus castaneus and Mus musculus musculus chromosomes segregating on the Mus musculus domesticus background. The Prdm9cst/dom2 (castaneus/domesticus) allelic combination secures meiotic synapsis, testes weight, and sperm count within physiological limits, while the Prdm9msc1/dom2 (musculus/domesticus) males show a range of fertility impairment. Out of 5 quantitative trait loci contributing to the Prdm9msc1/dom2-related infertility, 4 control either meiotic synapsis or fertility phenotypes and 1 controls both, synapsis, and fertility. Whole-genome genotyping of individual chromosomes showed preferential involvement of nonrecombinant musculus chromosomes in asynapsis in accordance with the chromosomal character of hybrid male sterility. Moreover, we show that the overall asynapsis rate can be estimated solely from the genotype of individual males by scoring the effect of nonrecombinant musculus chromosomes. Prdm9-controlled hybrid male sterility represents an example of genetic architecture of hybrid male sterility consisting of genic and chromosomal components.
- MeSH
- chromozomy MeSH
- histonlysin-N-methyltransferasa genetika metabolismus MeSH
- meióza * genetika MeSH
- mužská infertilita * genetika MeSH
- myši MeSH
- sperma metabolismus MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Aneuploidy (abnormal chromosome number) accompanies reduced ovarian function in humans and mice, but the reasons behind this concomitance remain underexplored. Some variants in the human gene encoding histone-3-lysine-4,36-trimethyltransferase PRDM9 are associated with aneuploidy, and other variants with ovarian function reduced by premature ovarian failure (POF), but no link between POF and aneuploidy has been revealed. SHR/OlaIpcv rat females lacking PRDM9 manifest POF-a reduced follicle number, litter size, and reproductive age. Here, we explored this model to test how POF relates to oocyte euploidy. The mutant rat females displayed increased oocyte aneuploidy and embryonic death of their offspring compared to controls. Because rat PRDM9 positions meiotic DNA breaks, we investigated the repair of these breaks. Fertile control rodents carry pachytene oocytes with synapsed homologous chromosomes and repaired breaks, while sterile Prdm9-deficient mice carry pachytene-like oocytes with many persisting breaks and asynapsed chromosomes. However, most PRDM9-lacking rat oocytes displayed a few persisting breaks and non-homologous synapsis (NHS). HORMAD2 protein serves as a barrier to sister-chromatid repair and a signal for the synapsis and DNA repair checkpoints. NHS but not asynapsis was associated with HORMAD2 levels similar to the levels on rat pachytene chromosomes with homologous synapsis. NHS was accompanied by crossing-over decreased below the minimum that is essential for euploidy. We argue that the increased mutant rat aneuploidy is due to NHS, which allows some oocytes to pass meiotic checkpoints without one crossing-over per chromosomal pair, leading to segregation errors, and thereby NHS links POF to aneuploidy.
- MeSH
- aneuploidie * MeSH
- chromozomy MeSH
- histonlysin-N-methyltransferasa * genetika metabolismus MeSH
- krysa rodu rattus MeSH
- meióza * genetika MeSH
- oocyty metabolismus MeSH
- párování chromozomů * genetika MeSH
- potkani inbrední SHR MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Polycomb repressive complex 2 (PRC2) is involved in maintaining transcriptionally silent chromatin states through methylating lysine 27 of histone H3 by the catalytic subunit enhancer of zeste [E(z)]. Here, we report the diversity of PRC2 core subunit proteins in different eukaryotic supergroups with emphasis on the early-diverged lineages and explore the molecular evolution of PRC2 subunits by phylogenetics. For the first time, we identify the putative ortholog of E(z) in Discoba, a lineage hypothetically proximal to the eukaryotic root, strongly supporting emergence of PRC2 before the diversification of eukaryotes. Analyzing 283 species, we robustly detect a common presence of E(z) and ESC, indicating a conserved functional core. Full-length Su(z)12 orthologs were identified in some lineages and species only, indicating, nonexclusively, high divergence of VEFS-Box-containing Su(z)12-like proteins, functional convergence of sequence-unrelated proteins, or Su(z)12 dispensability. Our results trace E(z) evolution within the SET-domain protein family, proposing a substrate specificity shift during E(z) evolution based on SET-domain and H3 histone interaction prediction.
