Fun30 chromatin remodeler helps in dealing with torsional stress and camptothecin‐induced DNA damage

Ferroptosis is a lipid peroxidation-dependent mechanism of regulated cell death known to suppress tumor proliferation and progression. Although several genetic and protein hallmarks have been identified in ferroptotic cell death, it remains challenging to fully characterize ferroptosis signaling pathways and to find suitable biomarkers. Moreover, changes taking place in the epigenome of ferroptotic cells remain poorly studied. In this context, we aimed to investigate the role of chromatin remodeler forkhead box protein A1 (FOXA1) in RSL3-treated multiple myeloma cells because, similar to ferroptosis, this transcription factor has been associated with changes in the lipid metabolism, DNA damage, and epithelial-to-mesenchymal transition (EMT). RNA sequencing and Western blot analysis revealed that FOXA1 expression is consistently upregulated upon ferroptosis induction in different in vitro and in vivo disease models. In silico motif analysis and transcription factor enrichment analysis further suggested that ferroptosis-mediated FOXA1 expression is orchestrated by specificity protein 1 (Sp1), a transcription factor known to be influenced by lipid peroxidation. Remarkably, FOXA1 upregulation in ferroptotic myeloma cells did not alter hormone signaling or EMT, two key downstream signaling pathways of FOXA1. CUT&RUN genome-wide transcriptional binding site profiling showed that GPX4-inhibition by RSL3 triggered loss of binding of FOXA1 to pericentromeric regions in multiple myeloma cells, suggesting that this transcription factor is possibly involved in genomic instability, DNA damage, or cellular senescence under ferroptotic conditions.

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The CHD6 chromatin remodeler is an oxidative DNA damage response factor

Nature Communications ◽

10.1038/s41467-018-08111-y ◽

2019 ◽

Vol 10 (1) ◽

Cited By ~ 6

Author(s):

Shaun Moore ◽

N. Daniel Berger ◽

Martijn S. Luijsterburg ◽

Cortt G. Piett ◽

Fintan K. T. Stanley ◽

...

Keyword(s):

Dna Damage ◽

Dna Damage Response ◽

Oxidative Dna Damage ◽

Response Factor ◽

Chromatin Remodeler ◽

Damage Response

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DDRE-11. DEVELOPMENT OF THE FIRST-IN-CLASS INHIBITOR OF CHD4 - SENSITIZING RESISTANT GLIOMAS

Neuro-Oncology ◽

10.1093/neuonc/noaa215.256 ◽

2020 ◽

Vol 22 (Supplement_2) ◽

pp. ii63-ii63

Author(s):

Elmar Nurmemmedov ◽

Santosh Kesari

Keyword(s):

Dna Damage ◽

Therapeutic Option ◽

Regulation Of Gene Expression ◽

Physiological Role ◽

High Recurrence Rate ◽

Chromatin Remodeler ◽

Damage Repair ◽

In Vitro Data

Abstract Glioblastoma is a lethal brain tumor with high recurrence rate. CHD4 overexpression, which drives resistance to DNA damage, is one of the major sources of recurrence. Since standard GBM treatments like radiation and temozolomide chemotherapy create DNA damage, inhibition of CHD4 offers a new therapeutic option for resensitizing GBM. CHD4 is a ubiquitously expressed ATP-dependent chromatin remodeler, which plays a crucial role in epigenetic regulation of gene expression and in DNA damage repair. Structurally, CHD4 contains an HMG-like domain, PHD domains, two chromodomains, a catalytic ATPase module, two domains of unknown function (DUF) and a C-terminal domain CHDCT2. Currently, no specific inhibitors targeting this chromatin remodeler have been reported yet. We aim to develop the first-in-class inhibitor targeting chromo-domain of CHD4. We have performed in silico screens to identify small molecules binding to the chromo-domains of CHD4. We present our growing in vitro data demonstrating biophysical properties and mechanism-of-action of these novel inhibitors. We expect that the experiments proposed here will result in the development of the first-in-class CHD4 inhibitor which can be used in the future not only to better study the physiological role of CHD4 but also to determine its potential as a novel targeted therapy for GBM.

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Cell cycle-dependent positive and negative functions of Fun30 chromatin remodeler in DNA damage response

DNA Repair ◽

10.1016/j.dnarep.2016.12.009 ◽

2017 ◽

Vol 50 ◽

pp. 61-70 ◽

Cited By ~ 4

Author(s):

Jasmine Siler ◽

Bowen Xia ◽

Carina Wong ◽

Morgan Kath ◽

Xin Bi

Keyword(s):

Cell Cycle ◽

Dna Damage ◽

Dna Damage Response ◽

Chromatin Remodeler ◽

Damage Response ◽

Cycle Dependent

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Poly(ADP-ribosyl)ation links the chromatin remodeler SMARCA5/SNF2H to RNF168-dependent DNA damage signaling

Journal of Cell Science ◽

10.1242/jcs.109413 ◽

2012 ◽

Vol 126 (4) ◽

pp. 889-903 ◽

Cited By ~ 85

Author(s):

G. Smeenk ◽

W. W. Wiegant ◽

J. A. Marteijn ◽

M. S. Luijsterburg ◽

N. Sroczynski ◽

...

Keyword(s):

Dna Damage ◽

Chromatin Remodeler ◽

Dna Damage Signaling

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Topoisomerase 2β Induces DNA Breaks To Regulate Human Papillomavirus Replication

mBio ◽

10.1128/mbio.00005-21 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Paul Kaminski ◽

Shiyuan Hong ◽

Takeyuki Kono ◽

Paul Hoover ◽

Laimonis Laimins

Keyword(s):

Dna Damage ◽

Human Papillomavirus ◽

Genome Replication ◽

Type Ii ◽

Torsional Stress ◽

Dna Breaks ◽

Double Strand Dna Breaks ◽

Damage Repair ◽

Topologically Associated Domains ◽

Repair Pathways

ABSTRACT Topoisomerases regulate higher-order chromatin structures through the transient breaking and religating of one or both strands of the phosphodiester backbone of duplex DNA. TOP2β is a type II topoisomerase that induces double-strand DNA breaks at topologically associated domains (TADS) to relieve torsional stress arising during transcription or replication. TADS are anchored by CCCTC-binding factor (CTCF) and SMC1 cohesin proteins in complexes with TOP2β. Upon DNA cleavage, a covalent intermediate DNA-TOP2β (TOP2βcc) is transiently generated to allow for strand passage. The tyrosyl-DNA phosphodiesterase TDP2 can resolve TOP2βcc, but failure to do so quickly can lead to long-lasting DNA breaks. Given the role of CTCF/SMC1 proteins in the human papillomavirus (HPV) life cycle, we investigated whether TOP2β proteins contribute to HPV pathogenesis. Our studies demonstrated that levels of both TOP2β and TDP2 were substantially increased in cells with high-risk HPV genomes, and this correlated with large amounts of DNA breaks. Knockdown of TOP2β with short hairpin RNAs (shRNAs) reduced DNA breaks by over 50% as determined through COMET assays. Furthermore, this correlated with substantially reduced formation of repair foci such as phosphorylated H2AX (γH2AX), phosphorylated CHK1 (pCHK1), and phosphorylated SMC1 (pSMC1) indicative of impaired activation of DNA damage repair pathways. Importantly, knockdown of TOP2β also blocked HPV genome replication. Our previous studies demonstrated that CTCF/SMC1 factors associate with HPV genomes at sites in the late regions of HPV31, and these correspond to regions that also bind TOP2β. This study identifies TOP2β as responsible for enhanced levels of DNA breaks in HPV-positive cells and as a regulator of viral replication. IMPORTANCE High-risk human papillomaviruses (HPVs) infect epithelial cells and induce viral genome amplification upon differentiation. HPV proteins activate DNA damage repair pathways by inducing high numbers of DNA breaks in both viral and cellular DNAs. This activation is required for HPV genome replication. TOP2β is a type II topoisomerase that induces double-strand DNA breaks at topologically associated domains (TADS) to relieve torsional stress arising during transcription or replication. Our studies demonstrate that TOP2β levels are increased in HPV-positive cells and that this is required for HPV replication. Importantly, our studies further show that knockdown of TOP2β reduces the number of breaks by over 50% in HPV-positive cells and that this correlates with substantially impaired activation of DNA repair pathways. This study identifies a critical mechanism by which HPV replication is regulated by the topoisomerase TOP2β through DNA break formation.

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