Biology subjects

Ferry, L.

Publications and source records attributed to Ferry, L..

10 recordsLinked to original sources

bioRxiv2026

New histone deposition recruits the DNA methylation maintenance machinery at sites of DNA damage repair

Faithful inheritance of DNA methylation contributes to the memory of epigenetic states and protects against disease. While the mechanisms underlying DNA methylation maintenance at replication forks are well characterized, whether and how DNA methylation is altered or maintained at sites of DNA damage repair is still poorly understood. Here, by exploiting sequencing, imaging and proteomic approaches in mammalian cells exposed to UV radiation, we show that the majority of DNA methylation marks are maintained during UV damage repair and we dissect the molecular machinery involved in DNA methylation control. We detect the recruitment to sites of repair synthesis of the DNMT1 and DNMT3A DNA methylating enzymes, driven by the DNMT1 cofactor UHRF1 and by UV damage repair endonucleases. We also uncover a crosstalk with histone dynamics, whereby newly deposited H3.3 histones at UV damage sites promote the recruitment of DNMT1. Functionally, we reveal the importance of the DNA methylation maintenance machinery for the transcriptional response to UV damage and sustained cell proliferation. This work provides a comprehensive picture of DNA methylation control mechanisms following DNA damage, with important implications for our understanding of human diseases with an altered methylome.

molecular biology↗

bioRxiv2026

DNA methylation links lagging strand replication to transposable element control

DNA methylation is an essential epigenetic mark that silences transposable elements (TEs) in mammalian genomes1,2. Following DNA replication, methylation patterns must be faithfully restored3,4, yet how the two processes are coordinated remains unclear. Here, using strand-specific, genome-wide analyses5-7 in mouse embryonic stem cells, we show that DNA methylation maintenance is coupled to the lagging-strand synthesis in TE-rich regions. Paradoxically, despite this targeting, the lagging strand is more permissive for TE integration than the leading strand. Notably, insertions of full-length LINE-1s, SINEs, and satellite repeats are all enriched on the lagging strand over evolutionary time. Consequently, most TEs, particularly young elements, are oriented head-on relative to replication forks in the mouse genome, creating an unfavorable genomic configuration8 that is preferentially targeted by DNA methylation maintenance. Mechanistically, DNA methylation maintenance is coupled to the lagging-strand replication via UHRF1-LIG19 and PCNA-PAF1510 interactions, and the interference in this mechanism slows Okazaki fragment maturation, and thereby potentially may facilitate TE retention. Together, we show a mechanism of TE control during DNA replication with an unexpected evolutionary interplay in which DNA methylation may facilitate, rather than solely prevent, TE expansion.

Molecular Biology↗

bioRxiv2024

DNA methylation protects cancer cells against non-canonical senescence

Inhibitors of DNA methylation such as 5-aza-deoxycytidine are widely used in experimental and clinical settings. However, their mechanism of action is such that DNA damage inevitably co-occurs with loss of DNA methylation, making it challenging to discern their respective effects. Here we deconvolute the effects of decreased DNA methylation and DNA damage on cancer cells, by using degron alleles of key DNA methylation regulators. We report that cancer cells with decreased DNA methylation --but no DNA damage-- enter cellular senescence, with G1 arrest, SASP expression, and SA-{beta}-gal positivity. This senescence is independent of p53 and Rb, but involves p21, which is cytoplasmic and inhibits apoptosis, and cGAS, playing a STING-independent role in the nucleus. Xenograft experiments show that tumor cells can be made senescent in vivo by decreasing DNA methylation. These findings reveal the intrinsic effects of loss of DNA methylation in cancer cells and have practical implications for future therapeutic approaches.

molecular biology↗

bioRxiv2023

Non-canonical functions of UHRF1 maintain DNA methylation homeostasis in cancer cells

DNA methylation is an essential epigenetic chromatin modification, and its maintenance in mammals requires the protein UHRF1. It is yet unclear if UHRF1 functions solely by stimulating DNA methylation maintenance by DNMT1, or if it has important additional functions. Using degron alleles, we show that UHRF1 depletion causes a much greater loss of DNA methylation than DNMT1 depletion. This is not caused by passive demethylation as UHRF1-depleted cells proliferate more slowly than DNMT1-depleted cells. Instead, bioinformatics, proteomics and genetics experiments establish that UHRF1, besides activating DNMT1, interacts with DNMT3A and DNMT3B and promotes their activity. In addition, we show that UHRF1 antagonizes active DNA demethylation by TET2. Therefore, UHRF1 has non-canonical roles that contribute importantly to DNA methylation homeostasis; these findings have practical implications for epigenetics in health and disease.

molecular biology↗

bioRxiv2023

E4F1 and ZNF148 are transcriptional activators of the A57C and wildtype TERT promoter

Point mutations within the TERT promoter are the most recurrent somatic non-coding mutations identified across different cancer types, including glioblastoma, melanoma, hepatocellular carcinoma, and bladder cancer. They are most abundant at C146T and C124T and rarer at A57C, with the latter originally described as a familial case but subsequently shown also to occur somatically. All three mutations create de novo ETS (E-twenty-six specific) binding sites and result in the reactivation of the TERT gene, allowing cancer cells to achieve replicative immortality. Here, we employed a systematic proteomics screen to identify transcription factors preferentially binding to the C146T, C124T and A57C mutations. While we confirmed binding of multiple ETS factors to the mutant C146T and C124T sequences, we identified E4F1 as an A57C-specific binder and ZNF148 as a TERT WT binder that is excluded from the TERT promoter by the C124T allele. Both proteins are activating transcription factors that bind specifically to the A57C and wildtype (at position 124) TERT promoter sequence in corresponding cell lines and upregulate TERT transcription and telomerase activity. Our work describes new regulators of TERT gene expression with possible roles in cancer.

cancer biology↗

bioRxiv2023

Resolving the heterogeneity of L1 DNA methylation reveals the epigenetic and transcriptional interplay between L1s and their integration sites.

Long interspersed element-1 (L1) retrotransposons play important roles in human disease and evolution. Their global activity is repressed by DNA methylation, but studying the regulation of individual copies has been difficult. Here, we combine short- and long-read sequencing to resolve the DNA methylation profiles of these repeated sequences in a panel of normal and cancer cells genome-wide at single-locus resolution. We unveil key principles underpinning L1 methylation heterogeneity among cell-types, families and integration sites. First, intronic L1 methylation is intimately associated with gene transcription. Conversely, L1s can influence the methylation status of the upstream region over short distances (300 bp). This phenomenon is accompanied by the binding of specific transcription factors, which drive the expression of L1 and chimeric transcripts. Finally, L1 hypomethylation alone is generally insufficient to trigger L1 expression due to redundant silencing pathways. Our results illuminate the epigenetic and transcriptional interplay between retrotransposons and their host genome. GRAPHICAL ABSTRACT O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=200 SRC="FIGDIR/small/522582v3_ufig1.gif" ALT="Figure 1"> View larger version (52K): org.highwire.dtl.DTLVardef@c78bbcorg.highwire.dtl.DTLVardef@a7112dorg.highwire.dtl.DTLVardef@58abf2org.highwire.dtl.DTLVardef@180d055_HPS_FORMAT_FIGEXP M_FIG C_FIG HIGHLIGHTSO_LIBs-ATLAS-seq profiles L1 position and methylation genome-wide C_LIO_LIL1 has a frequent but short-range (300 bp) influence on the DNA methylation status of the upstream sequence C_LIO_LIHypomethylated L1s are bound by tissue-specific transcription factors which drive L1 and chimeric transcripts synthesis C_LIO_LIL1 hypomethylation alone is insufficient to enable its transcription at most loci C_LI

genomics↗

bioRxiv2021

Cancer/Testis genes are predictive of breast tumor subtypes

Breast cancer is the most prevalent type of cancer in women worldwide. Within breast tumors, the basal-like subtype has the worst prognosis and no dedicated therapy, therefore new tools to understand, detect, and treat these tumors are needed. Certain germline genes are re-expressed in tumors, and constitute the Cancer/Testis genes; their misexpression has diagnostic and therapeutic applications. Here, we designed a new approach to examine Cancer/ Testis gene misexpression in breast tumors. We identify several new markers in Luminal and HER-2 positive tumors, some of which predict response to chemotherapy. We then use machine learning to identify the 2 Cancer/Testis genes most associated with basal-like breast tumors: HORMAD1 and CT83. We show that these genes are expressed by tumor cells but not the microenvironment, and that they are not expressed by normal breast progenitors, in other words their activation occurs de novo. We find these genes are epigenetically repressed by DNA methylation, and that their activation upon DNA demethylation is irreversible, providing a memory of past epigenetic disturbances. Basal-like tumors expressing both genes have a poorer outcome than tumors expressing either gene alone or neither gene. Therefore, these findings suggest a potential synergistic effect between Cancer/Testis genes in basal breast tumors; these findings have consequences for the understanding, diagnosis, and therapy of the breast tumors with the worse outcomes.

cancer biology↗

bioRxiv2021

A genome-wide knock-out screen for actors of epigenetic silencing reveals new regulators of germline genes and 2-cell like cell state

Epigenetic mechanisms are essential to establish and safeguard cellular identities in mammals. They dynamically regulate the expression of genes, transposable elements, and higher-order chromatin structures. Expectedly, these chromatin marks are indispensable for mammalian development and alterations often lead to diseases such as cancer. Molecularly, epigenetic mechanisms rely on factors to establish patterns, interpret them into a transcriptional output, and maintain them across cell divisions. A global picture of these phenomena has started to emerge over the years, yet many of the molecular actors remain to be discovered. In this context, we have developed a reporter system sensitive to epigenetic perturbations to report on repressive pathways based on Dazl, which is normally repressed in mouse ES cells. We used this system for a genome-wide CRISPR knock-out screen, which yielded expected hits (DNMT1, UHRF1, MGA), as well as novel candidates. We prioritized the candidates by secondary screens, and led further experiments on 6 of them: ZBTB14, KDM5C, SPOP, MCM3AP, BEND3, and KMT2D. Our results show that all 6 candidates regulate the expression of germline genes. In addition, we find that removal of ZBTB14, KDM5C, SPOP and MCM3AP led to similar transcriptional responses, including a reactivation of the 2-cell like cell (2CLC) signature. Therefore, our genetic screen has identified new regulators of key cellular states.

molecular biology↗

bioRxiv2020

DNA methylation during development and regeneration of the annelid Platynereis dumerilii

BackgroundMethylation of cytosines in DNA (5mC methylation) is a major epigenetic modification that modulates gene expression and is important for embryonic development and cell reprogramming in vertebrates. In mammals, 5mC methylation in promoter regions is linked to transcriptional repression. Transcription regulation by 5mC methylation notably involves the Nucleosome Remodeling and Deacetylase complex (NuRD complex) which bridges DNA methylation and histone modifications. Less is known about roles and mechanisms of 5mC methylation in non-vertebrate animals. In this paper, we study 5mC methylation in the marine annelid worm Platynereis dumerilii, an emerging evolutionary and developmental biology model capable of regenerating the posterior part of its body upon amputation. The regenerated region includes both differentiated structures and a growth zone consisting of stem cells required for the continuous growth of the worm. ResultsUsing in silico and experimental approaches, we show that P. dumerilii displays a high level of DNA methylation comparable to that of mammalian somatic cells. 5mC methylation in P. dumerilii is dynamic along the life cycle of the animal and markedly decreases at the transition between larval to post-larval stages. We identify a full repertoire of mainly singlecopy genes encoding the machinery associated to 5mC methylation or members of the NuRD complex in P. dumerilii and show, through phylogenetic analyses, that this repertoire is close to the one inferred for the last common ancestor of bilaterians. These genes are dynamically expressed during P. dumerilii development, growth and regeneration. Treatment with the DNA hypomethylating agent Decitabine, impairs P. dumerilii larval development and regeneration, and has long-term effects on post-regenerative growth by affecting the functionality of stem cells of the growth zone. ConclusionsOur data indicate high-level of 5mC methylation in the annelid P. dumerilii, highlighting that this feature is not specific to vertebrates in the bilaterian clade. Analysis of DNA methylation levels and machinery gene expression during development and regeneration, as well as the use of a chemical inhibitor of DNA methylation, suggest an involvement of 5mC methylation in P. dumerilii development, regeneration and stem cell-based post-regenerative growth. We also present data indicating that P. dumerilii constitutes a promising model to study biological roles and mechanisms of DNA methylation in non-vertebrate bilaterians and to provide new knowledge about evolution of the functions of this key epigenetic modification in bilaterian animals.

developmental biology↗

bioRxiv2020

USP9X deubiquitinase couples the pluripotency network and cell metabolism to regulate ESC differentiation potential

Embryonic stem cells (ESC) have the unique ability to differentiate into all three germ cell layers. ESC transition through different states of pluripotency in response to growth factor signals and environmental cues before becoming terminally differentiated. Here, we demonstrated, by a multi-omic strategy, that the deubiquitinase USP9X regulates the developmental potential of ESC, and their transition from a naive to a more developmentally advance, or primed, state of pluripotency. We show that USP9X facilitates developmental gene expression and induces modifications of the mitochondrial bioenergetics, including decreased routing of pyruvate towards its oxidation and reduced respiration. In addition, USP9X binds to the pluripotency factor ESRRB, regulates its abundance and the transcriptional levels of a subset of its target genes. Finally, under permissive culture conditions, depletion of Usp9X accelerates cell differentiation in all cell lineages. We thus identified a new regulator of naive pluripotency and show that USP9X couples ESRRB pluripotency transcriptional network and cellular metabolism, both of which are important for ESC fate and pluripotency.

cell biology↗