scholarly journals Pharmacological Inhibition of WEE1 Potentiates the Antitumoral Effect of the dl922-947 Oncolytic Virus in Malignant Mesothelioma Cell Lines

2020 ◽  
Vol 21 (19) ◽  
pp. 7333
Author(s):  
Carmelina Antonella Iannuzzi ◽  
Paola Indovina ◽  
Iris Maria Forte ◽  
Sarah Di Somma ◽  
Anna Maria Malfitano ◽  
...  
Keyword(s):  
Dna Damage ◽  
Cell Lines ◽  
Malignant Mesothelioma ◽  
Chromatin Condensation ◽  
Protein A ◽  
Dna Lesions ◽  
Cell Cycle Checkpoint ◽  
Dna Damage Checkpoint ◽  
Antitumor Effects ◽  
Checkpoint Kinase

Malignant mesothelioma (MM) is a very aggressive asbestos-related cancer, for which no therapy proves to be effective. We have recently shown that the oncolytic adenovirus dl922-947 had antitumor effects in MM cell lines and murine xenografts. Previous studies demonstrated that dl922-947-induced host cell cycle checkpoint deregulation and consequent DNA lesions associated with the virus efficacy. However, the cellular DNA damage response (DDR) can counteract this virus action. Therefore, we assessed whether AZD1775, an inhibitor of the G2/M DNA damage checkpoint kinase WEE1, could enhance MM cell sensitivity to dl922-947. Through cell viability assays, we found that AZD1775 synergized with dl922-947 selectively in MM cell lines and increased dl922-947-induced cell death, which showed hallmarks of apoptosis (annexinV-positivity, caspase-dependency, BCL-XL decrease, chromatin condensation). Predictably, dl922-947 and/or AZD1775 activated the DDR, as indicated by increased levels of three main DDR players: phosphorylated histone H2AX (γ-H2AX), phospho-replication protein A (RPA)32, phospho-checkpoint kinase 1 (CHK1). Dl922-947 also increased inactive Tyr-15-phosphorylated cyclin-dependent kinase 1 (CDK1), a key WEE1 substrate, which is indicative of G2/M checkpoint activation. This increase in phospho-CDK1 was effectively suppressed by AZD1775, thus suggesting that this compound could, indeed, abrogate the dl922-947-induced DNA damage checkpoint in MM cells. Overall, our data suggest that the dl922-947-AZD1775 combination could be a feasible strategy against MM.

scholarly journals The Interactions of DNA Repair, Telomere Homeostasis, and p53 Mutational Status in Solid Cancers: Risk, Prognosis, and Prediction

Cancers ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 479
Author(s):  
Pavel Vodicka ◽  
Ladislav Andera ◽  
Alena Opattova ◽  
Ludmila Vodickova
Keyword(s):  
Cell Cycle ◽  
Dna Damage ◽  
Dna Repair ◽  
Dna Lesions ◽  
Cell Cycle Checkpoint ◽  
Solid Cancer ◽  
Genomic Integrity ◽  
Repair Capacity ◽  
Mutational Status ◽  
Telomere Homeostasis

The disruption of genomic integrity due to the accumulation of various kinds of DNA damage, deficient DNA repair capacity, and telomere shortening constitute the hallmarks of malignant diseases. DNA damage response (DDR) is a signaling network to process DNA damage with importance for both cancer development and chemotherapy outcome. DDR represents the complex events that detect DNA lesions and activate signaling networks (cell cycle checkpoint induction, DNA repair, and induction of cell death). TP53, the guardian of the genome, governs the cell response, resulting in cell cycle arrest, DNA damage repair, apoptosis, and senescence. The mutational status of TP53 has an impact on DDR, and somatic mutations in this gene represent one of the critical events in human carcinogenesis. Telomere dysfunction in cells that lack p53-mediated surveillance of genomic integrity along with the involvement of DNA repair in telomeric DNA regions leads to genomic instability. While the role of individual players (DDR, telomere homeostasis, and TP53) in human cancers has attracted attention for some time, there is insufficient understanding of the interactions between these pathways. Since solid cancer is a complex and multifactorial disease with considerable inter- and intra-tumor heterogeneity, we mainly dedicated this review to the interactions of DNA repair, telomere homeostasis, and TP53 mutational status, in relation to (a) cancer risk, (b) cancer progression, and (c) cancer therapy.

scholarly journals Labile iron pool correlates with iron content in the nucleus and the formation of oxidative DNA damage in mouse lymphoma L5178Y cell lines.

2003 ◽  
Vol 50 (1) ◽  
pp. 211-215 ◽  
Author(s):  
Marcin Kruszewski ◽  
Teresa Iwaneńko
Keyword(s):  
Hydrogen Peroxide ◽  
Dna Damage ◽  
Cell Lines ◽  
Oxidative Dna Damage ◽  
Transition Metal Ions ◽  
Dna Lesions ◽  
Labile Iron Pool ◽  
Labile Iron ◽  
Iron Pool ◽  
Mouse Lymphoma

Labile iron pool (LIP) constitutes a crossroad of metabolic pathways of iron-containing compounds and is midway between the cellular need for iron, its uptake and storage. In this study we investigated oxidative DNA damage in relation to the labile iron pool in a pair of mouse lymphoma L5178Y (LY) sublines (LY-R and LY-S) differing in sensitivity to hydrogen peroxide. The LY-R cells, which are hydrogen peroxide-sensitive, contain 3 times more labile iron than the hydrogen peroxide-resistant LY-S cells. Using the comet assay, we compared total DNA breakage in the studied cell lines treated with hydrogen peroxide (25 microM for 30 min at 4 degrees C). More DNA damage was found in LY-R cells than in LY-S cells. We also compared the levels of DNA lesions sensitive to specific DNA repair enzymes in both cell lines treated with H(2)O(2). The levels of endonuclease III-sensitive sites and Fapy-DNA glycosylase-sensitive sites were found to be higher in LY-R cells than in LY-S cells. Our data suggest that the sensitivity of LY-R cells to H(2)O(2) is partially caused by the higher yield of oxidative DNA damage, as compared to that in LY-S cells. The critical factor appears to be the availability of transition metal ions that take part in the OH radical-generating Fenton reaction (very likely in the form of LIP).

scholarly journals Monitoring S. pombe genome stress by visualizing end-binding protein Ku

2020 ◽  
Author(s):  
Chance Jones ◽  
Susan L Forsburg
Keyword(s):  
Dna Damage ◽  
Fission Yeast ◽  
Protein Complex ◽  
Genome Stability ◽  
Binding Protein ◽  
Dna Lesions ◽  
Live Cells ◽  
Dna Damage Checkpoint ◽  
Unique Pattern ◽  
Ku Protein

AbstractStudies of genome stability have exploited visualization of fluorescently tagged proteins in live cells to characterize DNA damage, checkpoint, and repair responses. In this report, we describe a new tool for fission yeast, a tagged version of the end-binding protein Pku70 which is part of the KU protein complex. We compare Pku70 localization to other markers upon treatment to various genotoxins, and identify a unique pattern of distribution. Pku70 provides a new tool to define and characterize DNA lesions and the repair response.

scholarly journals A role for the DNA-damage checkpoint kinase Chk1 in the virulence program of the fungus Ustilago maydis

2009 ◽  
Vol 122 (22) ◽  
pp. 4130-4140 ◽  
Author(s):  
N. Mielnichuk ◽  
C. Sgarlata ◽  
J. Perez-Martin
Keyword(s):  
Dna Damage ◽  
Ustilago Maydis ◽  
Dna Damage Checkpoint ◽  
Checkpoint Kinase

scholarly journals Ubiquitination of the DNA-damage checkpoint kinase CHK1 by TRAF4 is required for CHK1 activation

2020 ◽  
Vol 13 (1) ◽  
Author(s):  
Xinfang Yu ◽  
Wei Li ◽  
Haidan Liu ◽  
Qipan Deng ◽  
Xu Wang ◽  
...  
Keyword(s):  
Dna Damage ◽  
Dna Damage Checkpoint ◽  
Checkpoint Kinase

scholarly journals Distinct Phosphatases Mediate the Deactivation of the DNA Damage Checkpoint Kinase Rad53

2008 ◽  
Vol 283 (25) ◽  
pp. 17123-17130 ◽  
Author(s):  
Anna Travesa ◽  
Alba Duch ◽  
David G. Quintana
Keyword(s):  
Dna Damage ◽  
Dna Damage Checkpoint ◽  
Checkpoint Kinase

scholarly journals Recruitment of DNA Damage Checkpoint Proteins to Damage in Transcribed and Nontranscribed Sequences

2006 ◽  
Vol 26 (1) ◽  
pp. 39-49 ◽  
Author(s):  
Guochun Jiang ◽  
Aziz Sancar
Keyword(s):  
Cell Cycle ◽  
Dna Damage ◽  
Excision Repair ◽  
Dna Lesions ◽  
Human Cells ◽  
Dna Damage Checkpoint ◽  
Damage Site ◽  
Checkpoint Response ◽  
Checkpoint Proteins ◽  
Transcription Complexes

ABSTRACT We developed a chromatin immunoprecipitation method for analyzing the binding of repair and checkpoint proteins to DNA base lesions in any region of the human genome. Using this method, we investigated the recruitment of DNA damage checkpoint proteins RPA, Rad9, and ATR to base damage induced by UV and acetoxyacetylaminofluorene in transcribed and nontranscribed regions in wild-type and excision repair-deficient human cells in G1 and S phases of the cell cycle. We find that all 3 damage sensors tested assemble at the site or in the vicinity of damage in the absence of DNA replication or repair and that transcription enhances recruitment of checkpoint proteins to the damage site. Furthermore, we find that UV irradiation of human cells defective in excision repair leads to phosphorylation of Chk1 kinase in both G1 and S phase of the cell cycle, suggesting that primary DNA lesions as well as stalled transcription complexes may act as signals to initiate the DNA damage checkpoint response.

scholarly journals Undamaged DNA Transmits and Enhances DNA Damage Checkpoint Signals in Early Embryos

2007 ◽  
Vol 27 (19) ◽  
pp. 6852-6862 ◽  
Author(s):  
Aimin Peng ◽  
Andrea L. Lewellyn ◽  
James L. Maller
Keyword(s):  
Cell Cycle ◽  
Dna Damage ◽  
Nuclear Dna ◽  
Cell Cycle Checkpoint ◽  
Dna Damage Checkpoint ◽  
Checkpoint Signaling ◽  
Checkpoint Response ◽  
Egg Extracts ◽  
Cycle Checkpoint ◽  
Damaged Dna

ABSTRACT In Xenopus laevis embryos, the midblastula transition (MBT) at the 12th cell division marks initiation of critical developmental events, including zygotic transcription and the abrupt inclusion of gap phases into the cell cycle. Interestingly, although an ionizing radiation-induced checkpoint response is absent in pre-MBT embryos, introduction of a threshold amount of undamaged plasmid or sperm DNA allows a DNA damage checkpoint response to be activated. We show here that undamaged threshold DNA directly participates in checkpoint signaling, as judged by several dynamic changes, including H2AX phosphorylation, ATM phosphorylation and loading onto chromatin, and Chk1/Chk2 phosphorylation and release from nuclear DNA. These responses on physically separate threshold DNA require γ-H2AX and are triggered by an ATM-dependent soluble signal initiated by damaged DNA. The signal persists in egg extracts even after damaged DNA is removed from the system, indicating that the absence of damaged DNA is not sufficient to end the checkpoint response. The results identify a novel mechanism by which undamaged DNA enhances checkpoint signaling and provide an example of how the transition to cell cycle checkpoint activation during development is accomplished by maternally programmed increases in the DNA-to-cytoplasm ratio.

scholarly journals Breaching the DNA damage checkpoint via PF-00477736, a novel small-molecule inhibitor of checkpoint kinase 1

2008 ◽  
Vol 7 (8) ◽  
pp. 2394-2404 ◽  
Author(s):  
Alessandra Blasina ◽  
Jill Hallin ◽  
Enhong Chen ◽  
Maria Elena Arango ◽  
Eugenia Kraynov ◽  
...  
Keyword(s):  
Dna Damage ◽  
Small Molecule ◽  
Small Molecule Inhibitor ◽  
Dna Damage Checkpoint ◽  
Checkpoint Kinase ◽  
Checkpoint Kinase 1 ◽  
Molecule Inhibitor
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