scholarly journals Nuclear deformation causes DNA damage by increasing replication stress

2020 ◽  
Author(s):  
Pragya Shah ◽  
Chad M. Hobson ◽  
Svea Cheng ◽  
Marshall Colville ◽  
Matthew Paszek ◽  
...  
Keyword(s):  
Dna Damage ◽  
Nuclear Envelope ◽  
Cancer Cells ◽  
Molecular Mechanisms ◽  
Cancer Metastasis ◽  
Replication Stress ◽  
Mechanical Deformation ◽  
Nuclear Deformation ◽  
Dna Replication Stress ◽  
Fork Stalling

SummaryCancer metastasis, i.e., the spreading of tumor cells from the primary tumor to distant organs, is responsible for the vast majority of cancer deaths. In the process, cancer cells migrate through narrow interstitial spaces substantially smaller in cross-section than the cell. During such confined migration, cancer cells experience extensive nuclear deformation, nuclear envelope rupture, and DNA damage. The molecular mechanisms responsible for the confined migration-induced DNA damage remain incompletely understood. While in some cell lines, DNA damage is closely associated with nuclear envelope rupture, we show that in others, mechanical deformation of the nucleus is sufficient to cause DNA damage, even in the absence of nuclear envelope rupture. This deformation-induced DNA damage, unlike nuclear envelope rupture-induced DNA damage, occurs primarily in S/G2 phase of the cell cycle and is associated with replication forks. Nuclear deformation, resulting from either confined migration or external cell compression, increases replication stress, possibly by increasing replication fork stalling, providing a molecular mechanism for the deformation-induced DNA damage. Thus, we have uncovered a new mechanism for mechanically induced DNA damage, linking mechanical deformation of the nucleus to DNA replication stress. This mechanically induced DNA damage could not only increase genomic instability in metastasizing cancer cells, but could also cause DNA damage in non-migrating cells and tissues that experience mechanical compression during development, thereby contributing to tumorigenesis and DNA damage response activation.

scholarly journals Uniform Widespread Nuclear Phosphorylation of Histone H2AX Is an Indicator of Lethal DNA Replication Stress

Cancers ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 355 ◽  
Author(s):  
Eric Moeglin ◽  
Dominique Desplancq ◽  
Sascha Conic ◽  
Mustapha Oulad-Abdelghani ◽  
Audrey Stoessel ◽  
...  
Keyword(s):  
Dna Damage ◽  
Cell Death ◽  
Cancer Cells ◽  
Drug Efficacy ◽  
Replication Stress ◽  
Strand Break ◽  
Histone H2ax ◽  
C Terminus ◽  
Dna Replication Stress ◽  
Stressed Cells

Phosphorylated histone H2AX (γ-H2AX), a central player in the DNA damage response (DDR), serves as a biomarker of DNA double-strand break repair. Although DNA damage is generally visualized by the formation of γ-H2AX foci in injured nuclei, it is unclear whether the widespread uniform nuclear γ-H2AX (called pan-nuclear) pattern occurring upon intense replication stress (RS) is linked to DDR. Using a novel monoclonal antibody that binds exclusively to the phosphorylated C-terminus of H2AX, we demonstrate that H2AX phosphorylation is systematically pan-nuclear in cancer cells stressed with RS-inducing drugs just before they die. The pan-nuclear γ-H2AX pattern is abolished by inhibition of the DNA-PK kinase. Cell death induction of cancer cells treated with increasing combinations of replication and kinase (ATR and Chk1) inhibitory drugs was proportional to the appearance of pan-nuclear γ-H2AX pattern. Delivery of labeled anti-γ-H2AX Fabs in stressed cells demonstrated at a single cell level that pan-nuclear γ-H2AX formation precedes irreversible cell death. Moreover, we show that H2AX is not required for RS-induced cell death in HeLa cells. Thus, the nuclear-wide formation of γ-H2AX is an incident of RS-induced cell death and, thus, the pan nuclear H2AX pattern should be regarded as an indicator of lethal RS-inducing drug efficacy.

scholarly journals Targeting TOPK sensitises tumour cells to radiation-induced damage by enhancing replication stress

2020 ◽  
Author(s):  
Katharine J. Herbert ◽  
Rathi Puliyadi ◽  
Remko Prevo ◽  
Gonzalo Rodriguez-Berriguete ◽  
Anderson Ryan ◽  
...  
Keyword(s):  
Lung Cancer ◽  
Dna Damage ◽  
Cancer Cells ◽  
Radiation Treatment ◽  
Replication Stress ◽  
Exogenous Dna ◽  
Normal Tissues ◽  
Fork Stalling ◽  
Dna Foci

Abstract T-LAK-originated protein kinase (TOPK) overexpression is a feature of multiple cancers, yet is absent from most phenotypically normal tissues. As such, TOPK expression profiling and the development of TOPK-targeting pharmaceutical agents have raised hopes for its future potential in the development of targeted therapeutics. Results presented in this paper confirm the value of TOPK as a potential target for the treatment of solid tumours, and demonstrate the efficacy of a TOPK inhibitor (OTS964) when used in combination with radiation treatment. Using H460 and Calu-6 lung cancer xenograft models, we show that pharmaceutical inhibition of TOPK potentiates the efficacy of fractionated irradiation. Furthermore, we provide in vitro evidence that TOPK plays a hitherto unknown role during S phase, showing that TOPK depletion increases fork stalling and collapse under conditions of replication stress and exogenous DNA damage. Transient knockdown of TOPK was shown to impair recovery from fork stalling and to increase the formation of replication-associated single-stranded DNA foci in H460 lung cancer cells. We also show that TOPK interacts directly with CHK1 and Cdc25c, two key players in the checkpoint signalling pathway activated after replication fork collapse. This study thus provides novel insights into the mechanism by which TOPK activity supports the survival of cancer cells, facilitating checkpoint signalling in response to replication stress and DNA damage.

scholarly journals Targeting the DNA replication stress phenotype of KRAS mutant cancer cells

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Tara Al Zubaidi ◽  
O. H. Fiete Gehrisch ◽  
Marie-Michelle Genois ◽  
Qi Liu ◽  
Shan Lu ◽  
...  
Keyword(s):  
Dna Replication ◽  
Single Molecule ◽  
Replication Stress ◽  
Proton Radiation ◽  
Wild Type ◽  
Cellular Effects ◽  
Proton Treatment ◽  
Dna Replication Stress ◽  
Fork Stalling ◽  
Mutant Cells

AbstractMutant KRAS is a common tumor driver and frequently confers resistance to anti-cancer treatments such as radiation. DNA replication stress in these tumors may constitute a therapeutic liability but is poorly understood. Here, using single-molecule DNA fiber analysis, we first characterized baseline replication stress in a panel of unperturbed isogenic and non-isogenic cancer cell lines. Correlating with the observed enhanced replication stress we found increased levels of cytosolic double-stranded DNA in KRAS mutant compared to wild-type cells. Yet, despite this phenotype replication stress-inducing agents failed to selectively impact KRAS mutant cells, which were protected by CHK1. Similarly, most exogenous stressors studied did not differentially augment cytosolic DNA accumulation in KRAS mutant compared to wild-type cells. However, we found that proton radiation was able to slow fork progression and preferentially induce fork stalling in KRAS mutant cells. Proton treatment also partly reversed the radioresistance associated with mutant KRAS. The cellular effects of protons in the presence of KRAS mutation clearly contrasted that of other drugs affecting replication, highlighting the unique nature of the underlying DNA damage caused by protons. Taken together, our findings provide insight into the replication stress response associated with mutated KRAS, which may ultimately yield novel therapeutic opportunities.

scholarly journals MTA2 sensitizes gastric cancer cells to PARP inhibition by induction of DNA replication stress

2021 ◽  
Vol 14 (10) ◽  
pp. 101167
Author(s):  
Jinwen Shi ◽  
Xiaofeng Zhang ◽  
Jin'e Li ◽  
Wenwen Huang ◽  
Yini Wang ◽  
...  
Keyword(s):  
Gastric Cancer ◽  
Dna Replication ◽  
Cancer Cells ◽  
Replication Stress ◽  
Parp Inhibition ◽  
Gastric Cancer Cells ◽  
Dna Replication Stress

scholarly journals Microenvironment-mediated cancer dormancy: Insights from metastability theory

2021 ◽  
Vol 119 (1) ◽  
pp. e2111046118
Author(s):  
Sadra Bakhshandeh ◽  
Carsten Werner ◽  
Peter Fratzl ◽  
Amaia Cipitria
Keyword(s):  
Cancer Cells ◽  
Molecular Mechanisms ◽  
Cancer Metastasis ◽  
Droplet Growth ◽  
Protective Mechanism ◽  
Dormant State ◽  
Strong Focus ◽  
Tumor Tissues ◽  
Cancer Dormancy ◽  
Thermodynamic Phase

Dormancy is an evolutionarily conserved protective mechanism widely observed in nature. A pathological example is found during cancer metastasis, where cancer cells disseminate from the primary tumor, home to secondary organs, and enter a growth-arrested state, which could last for decades. Recent studies have pointed toward the microenvironment being heavily involved in inducing, preserving, or ceasing this dormant state, with a strong focus on identifying specific molecular mechanisms and signaling pathways. Increasing evidence now suggests the existence of an interplay between intracellular as well as extracellular biochemical and mechanical cues in guiding such processes. Despite the inherent complexities associated with dormancy, proliferation, and growth of cancer cells and tumor tissues, viewing these phenomena from a physical perspective allows for a more global description, independent from many details of the systems. Building on the analogies between tissues and fluids and thermodynamic phase separation concepts, we classify a number of proposed mechanisms in terms of a thermodynamic metastability of the tumor with respect to growth. This can be governed by interaction with the microenvironment in the form of adherence (wetting) to a substrate or by mechanical confinement of the surrounding extracellular matrix. By drawing parallels with clinical and experimental data, we advance the notion that the local energy minima, or metastable states, emerging in the tissue droplet growth kinetics can be associated with a dormant state. Despite its simplicity, the provided framework captures several aspects associated with cancer dormancy and tumor growth.

scholarly journals miR-200 deficiency promotes lung cancer metastasis by activating cancer-associated fibroblasts

2020 ◽  
Author(s):  
Bin Xue ◽  
Chen-Hua Chuang ◽  
Haydn M. Prosser ◽  
Cesar Seigi Fuziwara ◽  
Claudia Chan ◽  
...  
Keyword(s):  
Lung Cancer ◽  
Lung Adenocarcinoma ◽  
Cancer Cells ◽  
Molecular Mechanisms ◽  
Cancer Metastasis ◽  
Lung Cancer Mortality ◽  
Tumor Stroma ◽  
Metastatic Potential ◽  
Human Lung Cancer ◽  
Cancer Associated Fibroblasts

AbstractLung adenocarcinoma, the most prevalent lung cancer subtype, is characterized by its high propensity to metastasize. Despite the importance of metastasis in lung cancer mortality, its underlying cellular and molecular mechanisms remain largely elusive. Here, we identified miR-200 miRNAs as potent suppressors for lung adenocarcinoma metastasis. miR-200 expression is specifically repressed in mouse metastatic lung adenocarcinomas, and miR-200 decrease strongly correlates with poor patient survival. Consistently, deletion of mir-200c/141 in the KrasLSL-G12D/+; Trp53flox/flox lung adenocarcinoma mouse model significantly promoted metastasis, generating a desmoplastic tumor stroma highly reminiscent of metastatic human lung cancer. miR-200 deficiency in lung cancer cells promotes the proliferation and activation of adjacent cancer-associated fibroblasts (CAFs), which in turn elevates the metastatic potential of cancer cells. miR-200 regulates the functional interaction between cancer cells and CAFs, at least in part, by targeting Notch ligand Jagged1 and Jagged2 in cancer cells and inducing Notch activation in adjacent CAFs. Hence, the interaction between cancer cells and CAFs constitutes an essential mechanism to promote metastatic potential.

scholarly journals Protective Mechanisms Against DNA Replication Stress in the Nervous System

Genes ◽  
2020 ◽  
Vol 11 (7) ◽  
pp. 730
Author(s):  
Clara Forrer Charlier ◽  
Rodrigo A. P. Martins
Keyword(s):  
Dna Damage ◽  
Nervous System ◽  
Dna Replication ◽  
Neurological Diseases ◽  
Replication Stress ◽  
Nervous System Development ◽  
Stress Generation ◽  
Genome Replication ◽  
Cns Development ◽  
Dna Replication Stress

The precise replication of DNA and the successful segregation of chromosomes are essential for the faithful transmission of genetic information during the cell cycle. Alterations in the dynamics of genome replication, also referred to as DNA replication stress, may lead to DNA damage and, consequently, mutations and chromosomal rearrangements. Extensive research has revealed that DNA replication stress drives genome instability during tumorigenesis. Over decades, genetic studies of inherited syndromes have established a connection between the mutations in genes required for proper DNA repair/DNA damage responses and neurological diseases. It is becoming clear that both the prevention and the responses to replication stress are particularly important for nervous system development and function. The accurate regulation of cell proliferation is key for the expansion of progenitor pools during central nervous system (CNS) development, adult neurogenesis, and regeneration. Moreover, DNA replication stress in glial cells regulates CNS tumorigenesis and plays a role in neurodegenerative diseases such as ataxia telangiectasia (A-T). Here, we review how replication stress generation and replication stress response (RSR) contribute to the CNS development, homeostasis, and disease. Both cell-autonomous mechanisms, as well as the evidence of RSR-mediated alterations of the cellular microenvironment in the nervous system, were discussed.

scholarly journals α5β1 integrin recycling promotes Arp2/3-independent cancer cell invasion via the formin FHOD3

2015 ◽  
Vol 210 (6) ◽  
pp. 1013-1031 ◽  
Author(s):  
Nikki R. Paul ◽  
Jennifer L. Allen ◽  
Anna Chapman ◽  
Maria Morlan-Mairal ◽  
Egor Zindy ◽  
...  
Keyword(s):  
Cancer Cells ◽  
Cell Invasion ◽  
Molecular Mechanisms ◽  
Cancer Metastasis ◽  
Cancer Cell Invasion ◽  
Coupling Protein ◽  
Α5β1 Integrin ◽  
In Cells

Invasive migration in 3D extracellular matrix (ECM) is crucial to cancer metastasis, yet little is known of the molecular mechanisms that drive reorganization of the cytoskeleton as cancer cells disseminate in vivo. 2D Rac-driven lamellipodial migration is well understood, but how these features apply to 3D migration is not clear. We find that lamellipodia-like protrusions and retrograde actin flow are indeed observed in cells moving in 3D ECM. However, Rab-coupling protein (RCP)-driven endocytic recycling of α5β1 integrin enhances invasive migration of cancer cells into fibronectin-rich 3D ECM, driven by RhoA and filopodial spike-based protrusions, not lamellipodia. Furthermore, we show that actin spike protrusions are Arp2/3-independent. Dynamic actin spike assembly in cells invading in vitro and in vivo is regulated by Formin homology-2 domain containing 3 (FHOD3), which is activated by RhoA/ROCK, establishing a novel mechanism through which the RCP–α5β1 pathway reprograms the actin cytoskeleton to promote invasive migration and local invasion in vivo.

Abstract 3031: Replication stress and DNA damage promote genomic instability in near-tetraploid colorectal cancer cells

2015 ◽  
Author(s):  
Isabel Quintanilla ◽  
Darawalee Wangsa ◽  
Markus Brown ◽  
Amaia Ercilla ◽  
Greg Klus ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Dna Damage ◽  
Cancer Cells ◽  
Genomic Instability ◽  
Replication Stress ◽  
Colorectal Cancer Cells

scholarly journals Physiological and Pathological Roles of RAD52 at DNA Replication Forks

Cancers ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 402 ◽  
Author(s):  
Eva Malacaria ◽  
Masayoshi Honda ◽  
Annapaola Franchitto ◽  
Maria Spies ◽  
Pietro Pichierri
Keyword(s):  
Dna Replication ◽  
Cancer Cells ◽  
Molecular Mechanisms ◽  
Full Range ◽  
Therapeutic Targets ◽  
Replication Stress ◽  
Replication Forks ◽  
Dna Double Strand Breaks ◽  
Rad52 Protein ◽  
New Biomarkers

Understanding basic molecular mechanisms underlying the biology of cancer cells is of outmost importance for identification of novel therapeutic targets and biomarkers for patient stratification and better therapy selection. One of these mechanisms, the response to replication stress, fuels cancer genomic instability. It is also an Achille’s heel of cancer. Thus, identification of pathways used by the cancer cells to respond to replication-stress may assist in the identification of new biomarkers and discovery of new therapeutic targets. Alternative mechanisms that act at perturbed DNA replication forks and involve fork degradation by nucleases emerged as crucial for sensitivity of cancer cells to chemotherapeutics agents inducing replication stress. Despite its important role in homologous recombination and recombinational repair of DNA double strand breaks in lower eukaryotes, RAD52 protein has been considered dispensable in human cells and the full range of its cellular functions remained unclear. Very recently, however, human RAD52 emerged as an important player in multiple aspects of replication fork metabolism under physiological and pathological conditions. In this review, we describe recent advances on RAD52’s key functions at stalled or collapsed DNA replication forks, in particular, the unexpected role of RAD52 as a gatekeeper, which prevents unscheduled processing of DNA. Last, we will discuss how these functions can be exploited using specific inhibitors in targeted therapy or for an informed therapy selection.

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