scholarly journals A role of the mitotic spindle checkpoint in the cellular response to DNA replication stress

2006 ◽  
Vol 99 (3) ◽  
pp. 759-769 ◽  
Author(s):  
Anette Duensing ◽  
Xiaoyi Teng ◽  
Ying Liu ◽  
Michelle Tseng ◽  
Nicole Spardy ◽  
...  
Keyword(s):  
Dna Replication ◽  
Mitotic Spindle ◽  
Cellular Response ◽  
Spindle Checkpoint ◽  
Replication Stress ◽  
Mitotic Spindle Checkpoint ◽  
Dna Replication Stress

Abstract LB-164: DNA ligase IV modulates the cellular response to DNA replication stress

2016 ◽  
Author(s):  
Grace Hooks ◽  
Yasmin Anchondo ◽  
Neelam Sharma ◽  
Jac Nickoloff ◽  
Amanda Ashley
Keyword(s):  
Dna Replication ◽  
Cellular Response ◽  
Replication Stress ◽  
Dna Ligase ◽  
Dna Ligase Iv ◽  
Ligase Iv ◽  
Dna Replication Stress

scholarly journals Chk1 and p21 Cooperate to Prevent Apoptosis during DNA Replication Fork Stress

2006 ◽  
Vol 17 (1) ◽  
pp. 402-412 ◽  
Author(s):  
Rene Rodriguez ◽  
Mark Meuth
Keyword(s):  
Dna Replication ◽  
Cellular Response ◽  
Replication Fork ◽  
Replication Stress ◽  
S Phase ◽  
Cell Cycle Checkpoints ◽  
Primary Role ◽  
Excess Thymidine ◽  
Dna Replication Stress ◽  
Interfering Rna

Cells respond to DNA replication stress by triggering cell cycle checkpoints, repair, or death. To understand the role of the DNA damage response pathways in determining whether cells survive replication stress or become committed to death, we examined the effect of loss of these pathways on cellular response to agents that slow or arrest DNA synthesis. We show that replication inhibitors such as excess thymidine, hydroxyurea, and camptothecin are normally poor inducers of apoptosis. However, these agents become potent inducers of death in S-phase cells upon small interfering RNA-mediated depletion of the checkpoint kinase Chk1. This death response is independent of p53 and Chk2. p21-deficient cells, on the other hand, produce a more robust apoptotic response upon Chk1 depletion. p21 is normally induced only late after thymidine treatment. In Chk1-depleted cells p21 induction occurs earlier and does not require p53. Thus, Chk1 plays a primary role in the protection of cells from death induced by replication fork stress, whereas p21 mediates through its role in regulating entry into S phase. These findings are of potential importance to cancer therapy because we demonstrate that the efficacy of clinically relevant agents can be enhanced by manipulation of these signaling pathways.

scholarly journals Role of a Candida albicans Nrm1/Whi5 homologue in cell cycle gene expression and DNA replication stress response

2012 ◽  
Vol 84 (4) ◽  
pp. 778-794 ◽  
Author(s):  
Ayala Ofir ◽  
Kay Hofmann ◽  
Esther Weindling ◽  
Tsvia Gildor ◽  
Katherine S. Barker ◽  
...  
Keyword(s):  
Gene Expression ◽  
Cell Cycle ◽  
Candida Albicans ◽  
Dna Replication ◽  
Stress Response ◽  
Replication Stress ◽  
Cell Cycle Gene ◽  
Dna Replication Stress ◽  
Cell Cycle Gene Expression

scholarly journals APOBEC3B Is Induced By Activation of DNA Repair Pathway and Modulates the Survival and Treatment Response in Human Multiple Myeloma

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 407-407 ◽  
Author(s):  
Lijie Xing ◽  
Jiye Liu ◽  
Liang Lin ◽  
Shih-Feng Cho ◽  
Kenneth Wen ◽  
...  
Keyword(s):  
Dna Replication ◽  
Cell Lines ◽  
Drug Sensitivity ◽  
Replication Stress ◽  
Growth And Survival ◽  
Dna Replication Stress ◽  
Equity Ownership ◽  
Lethal Doses

Abstract Constitutive genomic complexity, ongoing DNA damage, and accumulating mutations are observed with progression from monoclonal gammopathy of undetermined significance (MGUS) to active multiple myeloma (MM) to relapsed/refractory disease. Apolipoprotein B mRNA editing catalytic polypeptide-like 3B (APOBEC3B), a DNA cytosine deaminase, plays a prominent role in inducing mutations in multiple human cancers. In MM, APOBEC3B is linked to sub-clonal diversification, intra-tumor heterogeneity, and tumor evolution. Moreover, upregulation of APOBEC3B is associated with poor MM prognosis, suggesting that targeting MM cells with high APOBEC3B may represent a novel therapeutic approach. We here studied the upstream mechanisms of APOBEC3B dysregulation and further defined functional consequences of molecular manipulation of APOBEC3B in MM cells. We characterized its sequelae to identify novel strategies for cancer prevention or treatment by targeting this key driver gene of cancer mutagenesis. Since the expression of APOBEC3B is associated with replication stress in breast cancer, we first asked whether APOBEC3B levels are altered in MM cell lines upon treatments with Melphalan (Mel), an alkylating agent used to treat MM which is known to induce replication stress; or with ionizing radiation (IR). Using quantitative RT-PCR and Western blotting, we found that sub-lethal doses of Mel or IR induce APOBEC3B expression in a dose- and time-dependent manner in MM cell lines (n=7) associated with the phosphorylation of γH2AX. Interestingly bortezomib (btz), even at sub-lethal doses which triggers DNA damage signaling, also induced APOBEC3B expression in H929, MM1S, and U266 MM cells. Since DNA replication stress activates the ATR/ATM pathway, we next investigated whether these kinases mediate APOBEC3B induction following Mel- or IR- or btz-induced DNA replication stress. H929 and MM1S cells were treated with Mel or IR in the presence or absence of ATM or ATR inhibitors, and these cells were then lysed and assayed for APOBEC3B expression. Importantly, inhibition of ATR or ATM activation pathway significantly decreased Mel- or IR or btz-induced APOBEC3B, suggesting that replication stress induced by Mel, IR, or btz, activates transcription of APOBEC3B via an ATM/ATR dependent pathway in vitro. To test the effect of APOBEC3B on cell growth and survival, we used gene-specific CRISPR knock out (KO), shRNA knockdown (KD), and inducible-shRNA KD to study the functional impact of perturbation of APOBEC3B in MM cells. Both KO and KD of APOBEC3B decreased growth and survival in multiple MM cell lines sensitive or resistant to dexamethasone or lenalidomide. Using zombie aqua and annexin V-based flow cytometric analysis, we showed that APOBEC3B inhibition enhanced growth arrest, followed by apoptosis, in these MM cells. These data suggest an important role of increased APOBEC3B levels in MM cell survival. We next analyzed available data sources for MM cell lines from Cancer Cell Line Encyclopedia (CCLE) and the Genomics of Drug Sensitivity in Cancer (GDSC), which include microarray gene expression and drug sensitivity information. APOBEC3B expression negatively correlates with MM cell sensitivity to JQ1, a BET inhibitor which has been reported to inhibit MM cell growth and survival in vitro and in vivo. Importantly, in MM cell lines which are relatively resistant to pomalidomide and JQ1 than other cell lines, APOBEC3B KD by its shRNA enhances sensitivity to both drugs. Taken together, our findings provide new insights into the role of APOBEC3B in triggering cytidine deaminase-induced mutagenesis associated with progression of disease. Furthermore, we show that DNA replication stress triggered by Mel, IR, or btz upregulates APOBEC3B expression, which in turn confers drug resistance. The role of APOBEC in disease pathogenesis and progression, coupled with its role mediating drug resistance, suggest potential utility of targeting APOBEC in novel MM therapies. Disclosures Munshi: OncoPep: Other: Board of director. Anderson:Bristol Myers Squibb: Consultancy; Millennium Takeda: Consultancy; Celgene: Consultancy; C4 Therapeutics: Equity Ownership, Other: Scientific founder; OncoPep: Equity Ownership, Other: Scientific founder; Gilead: Membership on an entity's Board of Directors or advisory committees.

scholarly journals Regulation of ETAA1-mediated ATR activation couples DNA replication fidelity and genome stability

2019 ◽  
Vol 218 (12) ◽  
pp. 3943-3953 ◽  
Author(s):  
Divya Achuthankutty ◽  
Roshan Singh Thakur ◽  
Peter Haahr ◽  
Saskia Hoffmann ◽  
Alexandros P. Drainas ◽  
...  
Keyword(s):  
Dna Replication ◽  
Cellular Response ◽  
Genome Stability ◽  
Genome Instability ◽  
Replication Stress ◽  
Regulatory Control ◽  
Replicative Stress ◽  
Dna Replication Stress ◽  
Stress Dependent ◽  
Atr Kinase

The ATR kinase is a master regulator of the cellular response to DNA replication stress. Activation of ATR relies on dual pathways involving the TopBP1 and ETAA1 proteins, both of which harbor ATR-activating domains (AADs). However, the exact contribution of the recently discovered ETAA1 pathway to ATR signaling in different contexts remains poorly understood. Here, using an unbiased CRISPR-Cas9–based genome-scale screen, we show that the ATR-stimulating function of ETAA1 becomes indispensable for cell fitness and chromosome stability when the fidelity of DNA replication is compromised. We demonstrate that the ATR-activating potential of ETAA1 is controlled by cell cycle– and replication stress–dependent phosphorylation of highly conserved residues within its AAD, and that the stimulatory impact of these modifications is required for the ability of ETAA1 to prevent mitotic chromosome abnormalities following replicative stress. Our findings suggest an important role of ETAA1 in protecting against genome instability arising from incompletely duplicated DNA via regulatory control of its ATR-stimulating potential.

scholarly journals Defining the role of APC in the mitotic spindle checkpoint in vivo: APC-deficient cells are resistant to Taxol

Oncogene ◽  
2010 ◽  
Vol 29 (49) ◽  
pp. 6418-6427 ◽  
Author(s):  
S Radulescu ◽  
R A Ridgway ◽  
P Appleton ◽  
K Kroboth ◽  
S Patel ◽  
...  
Keyword(s):  
Mitotic Spindle ◽  
Spindle Checkpoint ◽  
Mitotic Spindle Checkpoint
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