Dun1, a Chk2-related kinase, is the central regulator of securin-separase dynamics during DNA damage signaling

Abstract The DNA damage checkpoint halts cell cycle progression in G2 in response to genotoxic insults. Central to the execution of cell cycle arrest is the checkpoint-induced stabilization of securin-separase complex (yeast Pds1-Esp1). The checkpoint kinases Chk1 and Chk2 (yeast Chk1 and Rad53) are thought to critically contribute to the stability of securin-separase complex by phosphorylation of securin, rendering it resistant to proteolytic destruction by the anaphase promoting complex (APC). Dun1, a Rad53 paralog related to Chk2, is also essential for checkpoint-imposed arrest. Dun1 is required for the DNA damage-induced transcription of DNA repair genes; however, its role in the execution of cell cycle arrest remains unknown. Here, we show that Dun1′s role in checkpoint arrest is independent of its involvement in the transcription of repair genes. Instead, Dun1 is necessary to prevent Pds1 destruction during DNA damage in that the Dun1-deficient cells degrade Pds1, escape G2 arrest and undergo mitosis despite the presence of checkpoint-active Chk1 and Rad53. Interestingly, proteolytic degradation of Pds1 in the absence of Dun1 is mediated not by APC but by the HECT domain-containing E3 ligase Rsp5. Our results suggest a regulatory scheme in which Dun1 prevents chromosome segregation during DNA damage by inhibiting Rsp5-mediated proteolytic degradation of securin Pds1.

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The Role of Nitric Oxide in Cancer: Master Regulator or NOt?

International Journal of Molecular Sciences ◽

10.3390/ijms21249393 ◽

2020 ◽

Vol 21 (24) ◽

pp. 9393

Author(s):

Faizan H. Khan ◽

Eoin Dervan ◽

Dibyangana D. Bhattacharyya ◽

Jake D. McAuliffe ◽

Katrina M. Miranda ◽

...

Keyword(s):

Nitric Oxide ◽

Cell Cycle ◽

Dna Damage ◽

Cell Cycle Arrest ◽

Cell Cycle Progression ◽

Epithelial To Mesenchymal Transition ◽

Tumour Microenvironment ◽

Master Regulator ◽

Mesenchymal Transition ◽

Cycle Arrest

Nitric oxide (NO) is a key player in both the development and suppression of tumourigenesis depending on the source and concentration of NO. In this review, we discuss the mechanisms by which NO induces DNA damage, influences the DNA damage repair response, and subsequently modulates cell cycle arrest. In some circumstances, NO induces cell cycle arrest and apoptosis protecting against tumourigenesis. NO in other scenarios can cause a delay in cell cycle progression, allowing for aberrant DNA repair that promotes the accumulation of mutations and tumour heterogeneity. Within the tumour microenvironment, low to moderate levels of NO derived from tumour and endothelial cells can activate angiogenesis and epithelial-to-mesenchymal transition, promoting an aggressive phenotype. In contrast, high levels of NO derived from inducible nitric oxide synthase (iNOS) expressing M1 and Th1 polarised macrophages and lymphocytes may exert an anti-tumour effect protecting against cancer. It is important to note that the existing evidence on immunomodulation is mainly based on murine iNOS studies which produce higher fluxes of NO than human iNOS. Finally, we discuss different strategies to target NO related pathways therapeutically. Collectively, we present a picture of NO as a master regulator of cancer development and progression.

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The Capacity of the Hypomethylating Agents Azacytidine and Decitabine to Induce Apoptosis and Cell Cycle Arrest Depends on the Activation of the DNA-Damage Response Pathway.

Blood ◽

10.1182/blood.v112.11.1655.1655 ◽

2008 ◽

Vol 112 (11) ◽

pp. 1655-1655

Author(s):

Simone Boehrer ◽

Lionel Ades ◽

Nicolas Tajeddine ◽

Lorenzo Galluzzi ◽

Stephane de Botton ◽

...

Keyword(s):

Cell Cycle ◽

Dna Damage ◽

Cell Cycle Arrest ◽

Cell Lines ◽

Dna Damage Response ◽

Cell Cycle Progression ◽

Hypomethylating Agents ◽

Cycle Progression ◽

Cycle Arrest ◽

Damage Response

Abstract Background: The hypomethylating agents azacytidine (AZA) and decitabine (DEC) have shown clinical efficacy in patients (pts) with MDS. There is in vitro evidence that both agents, in addition to their hypomethylating effect, also function by inducing apoptosis, cell cycle arrest and/or the activation of a DNA damage response (DDR). However, the exact contributions of those mechanisms of action and their functional interdependence remain to be defined. Methods: A panel of MDS (P39, MDS-1)- and AML (HL-60, KG-1)-derived cell lines were incubated with increasing dosages of AZA (1–2μM) and DEC (1–2μM) and the drugs capacity to induce apoptosis (DiOC6(3)/PI), cell cycle arrest (PI) and/or a DDR (immunoflourescence staining of P-ATM, P-Chk-1, P-Chk-2, γ-H2AX) were assessed in absence and presence of the ATM-inhibitor KU-55933 and the Chk-1 inhibitor UCN-01. Results: We show that both drugs induced dose-dependent apoptosis in myeloid cell lines: whereas AZA increased apoptosis in KG-1 and HL-60 by about 10% (48h, 2μM) the respective incubation with DEC augmented apoptosis by about 20% (HL-60) to 30% (KG-1). P39 cells were resistant to AZA and increased apoptosis by 15% after 48h of 2μM DEC, and MDS-1 cells were resistant to both drugs. In addition, both drugs induced a G2/M-arrest in P39 (+15% after 48h with 2μM of AZA or DEC) and HL-60 (+20% after 48h with 2μM of AZA or DEC) cells, but not in KG-1 and MDS-1 cells. Noteworthy, both drugs induced a DDR in the apoptosis-sensitive KG-1 cells (but not P39 cells) as evidenced by the appearance of nuclear P-ATM and γ-H2AX foci. Surprisingly, this activation of P-ATM did not induce the nuclear translocation of P-Chk-1-Ser317 or P-Chk-2-Ser68. To more clearly define the importance of the DDR in AZA- and DEC-induced apoptosis and G2/M-arrest, experiments were recapitulated in the presence of the ATM-inhibitor KU-55933 and the Chk-1 inhibitor UCN-01. Inhibition of ATM abrogated the apoptosis-inducing activity of AZA and DEC in KG-1 cells (without influencing cell cycle progression), whereas inhibition of Chk-1 remained without effect. In contrast, in P39 and HL-60 cells, inhibition of ATM neither affected cell cycle progression, nor sensitivity towards the drugs. Nevertheless, inhibition of Chk-1 by UCN-01 completely abrogated the G2/M-arresting effect of AZA (and diminished that of DEC) in P39 and HL-60 cells. Conclusions: We provide novel evidence for the cell-type dependent capacity of the hypomethylating agents 5-azacytidine and decitabine to induce apoptosis, cell-cycle arrest and DDR in cell lines representing different subtypes of MDS and AML. Moreover, we show the crucial role of ATM and Chk-1 activation – as part of the DDR – in mediating AZA and DEC apoptosis-inducing and cell cycle-arresting effects, respectively, providing evidence that hypomethylating agents confer their beneficial effects by employing different pathways of the DDR.

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Novel tetrahydroacridine and cyclopentaquinoline derivatives with fluorobenzoic acid moiety induce cell cycle arrest and apoptosis in lung cancer cells by activation of DNA damage signaling

Tumor Biology ◽

10.1177/1010428317695011 ◽

2017 ◽

Vol 39 (3) ◽

pp. 101042831769501 ◽

Cited By ~ 7

Author(s):

Paweł Szymański ◽

Paulina Olszewska ◽

Elżbieta Mikiciuk-Olasik ◽

Antoni Różalski ◽

Agnieszka Maszewska ◽

...

Keyword(s):

Lung Cancer ◽

Cell Cycle ◽

Dna Damage ◽

Cell Cycle Arrest ◽

Cancer Cells ◽

Lung Cancer Cells ◽

Cyclin Dependent Kinase ◽

Induce Cell Cycle Arrest ◽

Dna Damage Signaling ◽

Cycle Arrest

Lung cancer is still the leading cause of cancer-related death worldwide, indicating a necessity to develop more effective therapy. Acridine derivatives are potential anticancer agents due to their ability to intercalate DNA as well as inhibit enzymes involved in replication and transcription. Recently, we have evaluated anticancer activity of 32 novel acridine-based compounds. We found that the most effective were tetrahydroacridine and cyclopentaquinoline derivatives with fluorobenzoic acid containing eight and nine carbon atoms in the aliphatic chain. The aim of this study was to determine the molecular mechanisms of compounds-induced cell cycle arrest and apoptosis in human lung adenocarcinoma cells. All compounds activated Ataxia telangiectasia mutated kinase and phosphorylated histone H2A.X at Ser139 indicating DNA damage. Treatment of cells with the compounds increased phosphorylation and accumulation of p53 that regulate cell cycle as well as apoptosis. All compounds induced G0/1 cell cycle arrest by phosphorylation of cyclin-dependent kinase 2 at Tyr15 resulting in attenuation of the kinase activity. In addition, cyclopentaquinoline derivatives induced expression of cyclin-dependent kinase 2 inhibitor, p21; however, tetrahydroacridine derivatives had no significant effect on p21. Moreover, all compounds decreased the mitochondrial membrane potential accompanied by increased expression of Bax and down-regulation of Bcl-2, suggesting activation of the mitochondrial pathway. All compounds also significantly attenuated the migration rates of lung cancer cells. Collectively, our findings suggest a central role of activation of DNA damage signaling in response to new acridine derivatives treatment to induce cell cycle arrest and apoptosis in cancer cells and provide support for their further development as potential drug candidates.

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Induction of DNA Damage Signaling upon Rift Valley Fever Virus Infection Results in Cell Cycle Arrest and Increased Viral Replication

Journal of Biological Chemistry ◽

10.1074/jbc.m111.296608 ◽

2012 ◽

Vol 287 (10) ◽

pp. 7399-7410 ◽

Cited By ~ 50

Author(s):

Alan Baer ◽

Dana Austin ◽

Aarthi Narayanan ◽

Taissia Popova ◽

Markus Kainulainen ◽

...

Keyword(s):

Cell Cycle ◽

Dna Damage ◽

Virus Infection ◽

Cell Cycle Arrest ◽

Rift Valley ◽

Rift Valley Fever ◽

Rift Valley Fever Virus ◽

Valley Fever ◽

Dna Damage Signaling ◽

Cycle Arrest

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Computational Model of G2-M DNA Damage Checkpoint Regulation in Normal and p53-null Cancer Cells

10.1101/2020.06.17.158246 ◽

2020 ◽

Author(s):

Yongwoon Jung ◽

Pavel Kraikivski

Keyword(s):

Cell Cycle ◽

Dna Damage ◽

Computational Model ◽

Cell Cycle Arrest ◽

Cancer Cells ◽

Cell Cycle Progression ◽

Dna Damage Checkpoint ◽

Cycle Progression ◽

Normal Cells ◽

Cycle Arrest

AbstractCancer and normal cells can respond differently to the same stressful conditions. Their dynamic responses under normal and stressful conditions are governed by complex molecular regulatory networks. We developed a computational model of G2-M DNA damage checkpoint regulation to study normal and cancer cell cycle progression under normal and stressful conditions. Our model is successful in explaining cancer cell cycle arrest in conditions when some cell cycle and DNA damage checkpoint regulators are inhibited, whereas the same conditions only delay entry into mitosis in normal cells. We use the model to explain known phenotypes of gene deletion mutants and predict phenotypes of yet uncharacterized mutants in normal and cancer cells. We also use sensitive analyses to identify the ranges of model parameter values that lead to the cell cycle arrest in cancer cells. Our results can be used to predict the effect of a potential treatment on cell cycle progression of normal and cancer cells.

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Fungal Ku prevents permanent cell cycle arrest by suppressing DNA damage signaling at telomeres

Nucleic Acids Research ◽

10.1093/nar/gkv082 ◽

2015 ◽

Vol 43 (4) ◽

pp. 2138-2151 ◽

Cited By ~ 7

Author(s):

Carmen de Sena-Tomás ◽

Eun Young Yu ◽

Arturo Calzada ◽

William K. Holloman ◽

Neal F. Lue ◽

...

Keyword(s):

Cell Cycle ◽

Dna Damage ◽

Cell Cycle Arrest ◽

Dna Damage Signaling ◽

Cycle Arrest ◽

Permanent Cell

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Acceleration or Brakes: Which Is Rational for Cell Cycle-Targeting Neuroblastoma Therapy?

Biomolecules ◽

10.3390/biom11050750 ◽

2021 ◽

Vol 11 (5) ◽

pp. 750

Author(s):

Kiyohiro Ando ◽

Akira Nakagawara

Keyword(s):

Cell Cycle ◽

Dna Damage ◽

Cell Cycle Progression ◽

Parp Inhibitors ◽

Cell Cycle Checkpoint ◽

Mitotic Catastrophe ◽

Malignant Neoplasms ◽

Checkpoint Kinases ◽

Molecular Features ◽

Cycle Checkpoint

Unrestrained proliferation is a common feature of malignant neoplasms. Targeting the cell cycle is a therapeutic strategy to prevent unlimited cell division. Recently developed rationales for these selective inhibitors can be subdivided into two categories with antithetical functionality. One applies a “brake” to the cell cycle to halt cell proliferation, such as with inhibitors of cell cycle kinases. The other “accelerates” the cell cycle to initiate replication/mitotic catastrophe, such as with inhibitors of cell cycle checkpoint kinases. The fate of cell cycle progression or arrest is tightly regulated by the presence of tolerable or excessive DNA damage, respectively. This suggests that there is compatibility between inhibitors of DNA repair kinases, such as PARP inhibitors, and inhibitors of cell cycle checkpoint kinases. In the present review, we explore alterations to the cell cycle that are concomitant with altered DNA damage repair machinery in unfavorable neuroblastomas, with respect to their unique genomic and molecular features. We highlight the vulnerabilities of these alterations that are attributable to the features of each. Based on the assessment, we offer possible therapeutic approaches for personalized medicine, which are seemingly antithetical, but both are promising strategies for targeting the altered cell cycle in unfavorable neuroblastomas.

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Design, Synthesis and Pharmacological Evaluation of Three Novel Dehydroabietyl Piperazine Dithiocarbamate Ruthenium (II) Polypyridyl Complexes as Potential Antitumor Agents: DNA Damage, Cell Cycle Arrest and Apoptosis Induction

Molecules ◽

10.3390/molecules26051453 ◽

2021 ◽

Vol 26 (5) ◽

pp. 1453

Author(s):

Haoran Wang ◽

Jianhua Wei ◽

Hong Jiang ◽

Ye Zhang ◽

Caina Jiang ◽

...

Keyword(s):

Cell Cycle ◽

Dna Damage ◽

Cell Cycle Arrest ◽

Antitumor Agents ◽

Mechanistic Study ◽

Ros Generation ◽

Polypyridyl Complexes ◽

Expression Levels ◽

Cycle Arrest ◽

Study Results

The use of cisplatin is severely limited by its toxic side-effects, which has spurred chemists to employ different strategies in the development of new metal-based anticancer agents. Here, three novel dehydroabietyl piperazine dithiocarbamate ruthenium (II) polypyridyl complexes (6a–6c) were synthesized as antitumor agents. Compounds 6a and 6c exhibited better in vitro antiproliferative activity against seven tumor cell lines than cisplatin, they displayed no evident resistance in the cisplatin-resistant cell line A549/DPP. Importantly, 6a effectively inhibited tumor growth in the T-24 xenograft mouse model in comparison with cisplatin. Gel electrophoresis assay indicated that DNA was the potential targets of 6a and 6c, and the upregulation of p-H2AX confirmed this result. Cell cycle arrest studies demonstrated that 6a and 6c arrested the cell cycle at G1 phase, accompanied by the upregulation of the expression levels of the antioncogene p27 and the down-regulation of the expression levels of cyclin E. In addition, 6a and 6c caused the apoptosis of tumor cells along with the upregulation of the expression of Bax, caspase-9, cytochrome c, intracellular Ca2+ release, reactive oxygen species (ROS) generation and the downregulation of Bcl-2. These mechanistic study results suggested that 6a and 6c exerted their antitumor activity by inducing DNA damage, and consequently causing G1 stage arrest and the induction of apoptosis.

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