Caspase-2 regulates S-phase cell cycle events to protect from DNA damage accumulation independent of apoptosis

In addition to its classical role in apoptosis, accumulating evidence suggests that caspase-2 has non-apoptotic functions, including regulation of cell division. Loss of caspase-2 is known to increase proliferation rates but how caspase-2 is regulating this process is currently unclear. We show that caspase-2 is activated in dividing cells in G1- and early S-phase. In the absence of caspase-2, cells exhibit numerous S-phase defects including delayed exit from S-phase, S-phase-associated chromosomal aberrations, and increased DNA damage following S-phase arrest. In addition, caspase-2-deficient cells have a higher frequency of stalled replication forks, decreased DNA fiber length, and impeded progression of DNA replication tracts. This indicates that caspase-2 reduces replication stress and promotes replication fork protection to maintain genomic stability. These functions are independent of the pro-apoptotic function of caspase-2 because blocking caspase-2-induced cell death had no effect on cell division or DNA damage-induced cell cycle arrest. Thus, our data supports a model where caspase-2 regulates cell cycle events to protect from the accumulation of DNA damage independently of its pro-apoptotic function.

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Effects of fluoride on DNA damage, S-phase cell-cycle arrest and the expression of NF-κB in primary cultured rat hippocampal neurons

Toxicology Letters ◽

10.1016/j.toxlet.2008.03.002 ◽

2008 ◽

Vol 179 (1) ◽

pp. 1-5 ◽

Cited By ~ 114

Author(s):

Ming Zhang ◽

Aiguo Wang ◽

Tao Xia ◽

Ping He

Keyword(s):

Cell Cycle ◽

Dna Damage ◽

Cell Cycle Arrest ◽

Hippocampal Neurons ◽

S Phase ◽

Phase Cell ◽

Cycle Arrest

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Regulation of DNA Replication Licensing and Re-Replication by Cdt1

International Journal of Molecular Sciences ◽

10.3390/ijms22105195 ◽

2021 ◽

Vol 22 (10) ◽

pp. 5195

Author(s):

Hui Zhang

Keyword(s):

Cell Cycle ◽

Dna Damage ◽

Dna Replication ◽

Genome Stability ◽

E3 Ligase ◽

S Phase ◽

Replication Initiation ◽

Nuclear Antigen ◽

Repair Synthesis ◽

Ubiquitin E3 Ligase

In eukaryotic cells, DNA replication licensing is precisely regulated to ensure that the initiation of genomic DNA replication in S phase occurs once and only once for each mitotic cell division. A key regulatory mechanism by which DNA re-replication is suppressed is the S phase-dependent proteolysis of Cdt1, an essential replication protein for licensing DNA replication origins by loading the Mcm2-7 replication helicase for DNA duplication in S phase. Cdt1 degradation is mediated by CRL4Cdt2 ubiquitin E3 ligase, which further requires Cdt1 binding to proliferating cell nuclear antigen (PCNA) through a PIP box domain in Cdt1 during DNA synthesis. Recent studies found that Cdt2, the specific subunit of CRL4Cdt2 ubiquitin E3 ligase that targets Cdt1 for degradation, also contains an evolutionarily conserved PIP box-like domain that mediates the interaction with PCNA. These findings suggest that the initiation and elongation of DNA replication or DNA damage-induced repair synthesis provide a novel mechanism by which Cdt1 and CRL4Cdt2 are both recruited onto the trimeric PCNA clamp encircling the replicating DNA strands to promote the interaction between Cdt1 and CRL4Cdt2. The proximity of PCNA-bound Cdt1 to CRL4Cdt2 facilitates the destruction of Cdt1 in response to DNA damage or after DNA replication initiation to prevent DNA re-replication in the cell cycle. CRL4Cdt2 ubiquitin E3 ligase may also regulate the degradation of other PIP box-containing proteins, such as CDK inhibitor p21 and histone methylase Set8, to regulate DNA replication licensing, cell cycle progression, DNA repair, and genome stability by directly interacting with PCNA during DNA replication and repair synthesis.

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Involvement of the p38 MAPK signaling pathway in S-phase cell-cycle arrest induced by Furazolidone in human hepatoma G2 cells

Journal of Applied Toxicology ◽

10.1002/jat.2829 ◽

2012 ◽

Vol 33 (12) ◽

pp. 1500-1505 ◽

Cited By ~ 6

Author(s):

Yu Sun ◽

Shusheng Tang ◽

Xi Jin ◽

Chaoming Zhang ◽

Wenxia Zhao ◽

...

Keyword(s):

Cell Cycle ◽

Cell Cycle Arrest ◽

Signaling Pathway ◽

P38 Mapk ◽

Mapk Signaling ◽

S Phase ◽

Mapk Signaling Pathway ◽

Phase Cell ◽

Human Hepatoma ◽

Cycle Arrest

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S-Phase Cell Cycle Arrest, Apoptosis, and Molecular Mechanisms of Aplasia Ras homolog Member I–Induced Human Ovarian Cancer SKOV3 Cell Lines

International Journal of Gynecological Cancer ◽

10.1097/igc.0000000000000105 ◽

2014 ◽

Vol 24 (4) ◽

pp. 629-634 ◽

Cited By ~ 10

Author(s):

Qiaoying Zhu ◽

Jianming Hu ◽

Huijuan Meng ◽

Yufei Shen ◽

Jinhua Zhou ◽

...

Keyword(s):

Cell Cycle ◽

Ovarian Cancer ◽

Molecular Mechanisms ◽

Significant Inhibition ◽

S Phase ◽

Phase Cell ◽

Cell Cycle Distribution ◽

Human Ovarian Cancer ◽

Skov3 Cell ◽

Skov3 Cells

ObjectiveAplasia Ras homolog member I (ARHI) is associated with human ovarian cancer (HOC) growth and proliferation; however, the mechanisms are unclear. The purpose of this study was to investigateARHIeffects in HOC SKOV3 cells.MethodsWe transfected SKOV3 cells with PIRES2-EGFP-ARHI and measured growth inhibition rates, cell cycle distribution, apoptosis rates, and expression of P-STAT3 (phosphorylated signal transduction and activators of transcription 3) and P-ERK (phosphorylated extracellular signal regulated protein kinase).ResultsOur data showed significant inhibition of growth, significantly increased S-phase arrest and apoptosis rates, and reduction of P-STAT3 and P-ERK1/2 expression levels.ConclusionsWe propose the mechanism may involveARHI-induced phosphorylation of ERK1/2 and STAT3 protein kinases, thereby blocking proliferation signaling pathways, to induce HOC SKOV3 apoptosis.

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Cdc5L interacts with ATR and is required for the S‐phase cell‐cycle checkpoint

EMBO Reports ◽

10.1038/embor.2009.122 ◽

2009 ◽

Vol 10 (9) ◽

pp. 1029-1035 ◽

Cited By ~ 51

Author(s):

Nianxiang Zhang ◽

Ramandeep Kaur ◽

Shamima Akhter ◽

Randy J Legerski

Keyword(s):

Cell Cycle ◽

S Phase ◽

Cell Cycle Checkpoint ◽

Phase Cell ◽

Cycle Checkpoint

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SPK1 is an essential S-phase-specific gene of Saccharomyces cerevisiae that encodes a nuclear serine/threonine/tyrosine kinase

Molecular and Cellular Biology ◽

10.1128/mcb.13.9.5829-5842.1993 ◽

1993 ◽

Vol 13 (9) ◽

pp. 5829-5842

Author(s):

P Zheng ◽

D S Fay ◽

J Burton ◽

H Xiao ◽

J L Pinkham ◽

...

Keyword(s):

Saccharomyces Cerevisiae ◽

Cell Cycle ◽

Dna Damage ◽

Dna Synthesis ◽

Genomic Library ◽

Excision Repair ◽

Low Frequency ◽

S Phase ◽

Upstream Region ◽

Specific Gene

SPK1 was originally discovered in an immunoscreen for tyrosine-protein kinases in Saccharomyces cerevisiae. We have used biochemical and genetic techniques to investigate the function of this gene and its encoded protein. Hybridization of an SPK1 probe to an ordered genomic library showed that SPK1 is adjacent to PEP4 (chromosome XVI L). Sporulation of spk1/+ heterozygotes gave rise to spk1 spores that grew into microcolonies but could not be further propagated. These colonies were greatly enriched for budded cells, especially those with large buds. Similarly, eviction of CEN plasmids bearing SPK1 from cells with a chromosomal SPK1 disruption yielded viable cells with only low frequency. Spk1 protein was identified by immunoprecipitation and immunoblotting. It was associated with protein-Ser, Thr, and Tyr kinase activity in immune complex kinase assays. Spk1 was localized to the nucleus by immunofluorescence. The nucleotide sequence of the SPK1 5' noncoding region revealed that SPK1 contains two MluI cell cycle box elements. These elements confer S-phase-specific transcription to many genes involved in DNA synthesis. Northern (RNA) blotting of synchronized cells verified that the SPK1 transcript is coregulated with other MluI box-regulated genes. The SPK1 upstream region also includes a domain highly homologous to sequences involved in induction of RAD2 and other excision repair genes by agents that induce DNA damage. spk1 strains were hypersensitive to UV irradiation. Taken together, these findings indicate that SPK1 is a dual-specificity (Ser/Thr and Tyr) protein kinase that is essential for viability. The cell cycle-dependent transcription, presence of DNA damage-related sequences, requirement for UV resistance, and nuclear localization of Spk1 all link this gene to a crucial S-phase-specific role, probably as a positive regulator of DNA synthesis.

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Xanthohumol Induces Growth Inhibition and Apoptosis in Ca Ski Human Cervical Cancer Cells

Evidence-based Complementary and Alternative Medicine ◽

10.1155/2015/921306 ◽

2015 ◽

Vol 2015 ◽

pp. 1-10 ◽

Cited By ~ 13

Author(s):

Wai Kuan Yong ◽

Sri Nurestri Abd Malek

Keyword(s):

Cell Cycle ◽

Cervical Cancer ◽

Cancer Cells ◽

Cancer Cell ◽

Morphological Changes ◽

S Phase ◽

Phase Cell ◽

Cervical Cancer Cell Line ◽

Dependent Manner ◽

Cervical Cancer Cells

We investigate induction of apoptosis by xanthohumol on Ca Ski cervical cancer cell line. Xanthohumol is a prenylated chalcone naturally found in hop plants, previously reported to be an effective anticancer agent in various cancer cell lines. The present study showed that xanthohumol was effective to inhibit proliferation of Ca Ski cells based on IC50values using sulforhodamine B (SRB) assay. Furthermore, cellular and nuclear morphological changes were observed in the cells using phase contrast microscopy and Hoechst/PI fluorescent staining. In addition, 48-hour long treatment with xanthohumol triggered externalization of phosphatidylserine, changes in mitochondrial membrane potential, and DNA fragmentation in the cells. Additionally, xanthohumol mediated S phase arrest in cell cycle analysis and increased activities of caspase-3, caspase-8, and caspase-9. On the other hand, Western blot analysis showed that the expression levels of cleaved PARP, p53, and AIF increased, while Bcl-2 and XIAP decreased in a dose-dependent manner. Taken together, these findings indicate that xanthohumol-induced cell death might involve intrinsic and extrinsic apoptotic pathways, as well as downregulation of XIAP, upregulation of p53 proteins, and S phase cell cycle arrest in Ca Ski cervical cancer cells. This work suggests that xanthohumol is a potent chemotherapeutic candidate for cervical cancer.

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