The effects of the mycotoxin austdiol on cell cycle progression, cytotoxicity and genotoxicity in Chinese hamster ovary (CHO-K1) cells

2016 ◽  
Vol 9 (2) ◽  
pp. 237-246 ◽  
Author(s):  
L.P. Franchi ◽  
T.A.J. De Souza ◽  
W.J. Andrioli ◽  
I.M.S. Lima ◽  
J.K. Bastos ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Dna Damage ◽  
Chinese Hamster Ovary ◽  
Cell Cycle Progression ◽  
Animal Feed ◽  
Chinese Hamster ◽  
Negative Control ◽  
Dna Breaks ◽  
M Phase ◽  
Potential Contaminant

Austdiol is a mycotoxin mainly produced by Aspergillus ustus and Mycoleptodiscus indicus. These fungi are found in rye, oats, barley, corn and feed grains; thus, as a potential contaminant of human food and animal feed, this mycotoxin is of great concern. As such, the elucidation of the cytotoxicity and mutagenicity of austdiol is important. In this study, austdiol was purified from a rice-oat solid medium culture of M. indicus using chromatographic separation techniques. Chinese hamster ovary (CHO-K1) cells were then used to study the effect of austdiol on mammalian cell cycle, clonogenicity and DNA damage. Austdiol induced cell cycle arrest in G2/M phase, with a decreased S phase population and increased sub-G1 population. Austdiol also increased the polyploid population. These events resulted in cell death detected 7 days after treatment by clonogenic assay. DNA damage represents the main mechanism of action of austdiol, which induces DNA breaks and increases the frequency of micronuclei and nucleoplasmic bridges in binucleated cells in a CHO-K1 cell line. Moreover, cells exposed to austdiol and doxorubicin (DXR) combined treatments presented a reduced number of colonies and increased frequencies of micronuclei and nucleoplasmic bridges compared with negative control and cells treated with austdiol or DXR alone.

Effect of cadmium on cell cycle progression in chinese hamster ovary cells

2004 ◽  
Vol 149 (2-3) ◽  
pp. 125-136 ◽  
Author(s):  
Pei-Ming Yang ◽  
Shu-Jun Chiu ◽  
Kwei-Ann Lin ◽  
Lih-Yuan Lin
Keyword(s):  
Cell Cycle ◽  
Chinese Hamster Ovary ◽  
Cell Cycle Progression ◽  
Chinese Hamster Ovary Cells ◽  
Chinese Hamster ◽  
Cycle Progression ◽  
Ovary Cells

scholarly journals CtIP-dependent DNA resection is required for DNA damage checkpoint maintenance but not initiation

2012 ◽  
Vol 197 (7) ◽  
pp. 869-876 ◽  
Author(s):  
Arne Nedergaard Kousholt ◽  
Kasper Fugger ◽  
Saskia Hoffmann ◽  
Brian D. Larsen ◽  
Tobias Menzel ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Dna Damage ◽  
Cell Cycle Progression ◽  
Dna Lesions ◽  
Cell Cycle Checkpoint ◽  
Dna Breaks ◽  
Checkpoint Signaling ◽  
Cycle Checkpoint ◽  
Dna End Resection ◽  
End Resection

To prevent accumulation of mutations, cells respond to DNA lesions by blocking cell cycle progression and initiating DNA repair. Homology-directed repair of DNA breaks requires CtIP-dependent resection of the DNA ends, which is thought to play a key role in activation of ATR (ataxia telangiectasia mutated and Rad3 related) and CHK1 kinases to induce the cell cycle checkpoint. In this paper, we show that CHK1 was rapidly and robustly activated before detectable end resection. Moreover, we show that the key resection factor CtIP was dispensable for initial ATR–CHK1 activation after DNA damage by camptothecin and ionizing radiation. In contrast, we find that DNA end resection was critically required for sustained ATR–CHK1 checkpoint signaling and for maintaining both the intra–S- and G2-phase checkpoints. Consequently, resection-deficient cells entered mitosis with persistent DNA damage. In conclusion, we have uncovered a temporal program of checkpoint activation, where CtIP-dependent DNA end resection is required for sustained checkpoint signaling.

A combined in vitro/bioinformatic investigation of redox regulatory mechanisms governing cell cycle progression

2004 ◽  
Vol 18 (2) ◽  
pp. 196-205 ◽  
Author(s):  
J. E. Conour ◽  
W. V. Graham ◽  
H. R. Gaskins
Keyword(s):  
Cell Cycle ◽  
Cell Cycle Progression ◽  
Chinese Hamster ◽  
Nucleotide Metabolism ◽  
Regulatory Mechanisms ◽  
Cycle Phase ◽  
Cycle Progression ◽  
Redox Environment ◽  
M Phase ◽  
Intracellular Redox

The intracellular reduction-oxidation (redox) environment influences cell cycle progression; however, underlying mechanisms are poorly understood. To examine potential mechanisms, the intracellular redox environment was characterized per cell cycle phase in Chinese hamster ovary fibroblasts via flow cytometry by measuring reduced glutathione (GSH), reactive oxygen species (ROS), and DNA content with monochlorobimane, 2′,7′-dichlorohydrofluorescein diacetate (H2DCFDA), and DRAQ5, respectively. GSH content was significantly greater in G2/M compared with G1phase cells, whereas GSH was intermediate in S phase cells. ROS content was similar among phases. Together, these data demonstrate that G2/M cells are more reduced than G1cells. Conventional approaches to define regulatory mechanisms are subjective in nature and focus on single proteins/pathways. Proteome databases provide a means to overcome these inherent limitations. Therefore, a novel bioinformatic approach was developed to exhaustively identify putative redox-regulated cell cycle proteins containing redox-sensitive protein motifs. Using the InterPro ( http://www.ebi.ac.uk/interpro/ ) database, we categorized 536 redox-sensitive motifs as: 1) active/functional-site cysteines, 2) electron transport, 3) heme, 4) iron binding, 5) zinc binding, 6) metal binding (non-Fe/Zn), and 7) disulfides. Comparing this list with 1,634 cell cycle-associated proteins from Swiss-Prot and SpTrEMBL ( http://us.expasy.org/sprot/ ) revealed 92 candidate proteins. Three-fourths (69 of 92) of the candidate proteins function in the central cell cycle processes of transcription, nucleotide metabolism, (de)phosphorylation, and (de)ubiquitinylation. The majority of oxidant-sensitive candidate proteins (68.9%) function during G2/M phase. As the G2/M phase is more reduced than the G1phase, oxidant-sensitive proteins may be temporally regulated by oscillation of the intracellular redox environment. Combined with evidence of intracellular redox compartmentalization, we propose a spatiotemporal mechanism that functionally links an oscillating intracellular redox environment with cell cycle progression.

scholarly journals Regulation of Cell Division in Bacteria by Monitoring Genome Integrity and DNA Replication Status

2019 ◽  
Vol 202 (2) ◽  
Author(s):  
Peter E. Burby ◽  
Lyle A. Simmons
Keyword(s):  
Cell Cycle ◽  
Dna Damage ◽  
Cell Division ◽  
Dna Replication ◽  
Cell Cycle Progression ◽  
Genome Instability ◽  
Sos Response ◽  
Bacterial Cells ◽  
Cycle Progression ◽  
Content Type

ABSTRACT All organisms regulate cell cycle progression by coordinating cell division with DNA replication status. In eukaryotes, DNA damage or problems with replication fork progression induce the DNA damage response (DDR), causing cyclin-dependent kinases to remain active, preventing further cell cycle progression until replication and repair are complete. In bacteria, cell division is coordinated with chromosome segregation, preventing cell division ring formation over the nucleoid in a process termed nucleoid occlusion. In addition to nucleoid occlusion, bacteria induce the SOS response after replication forks encounter DNA damage or impediments that slow or block their progression. During SOS induction, Escherichia coli expresses a cytoplasmic protein, SulA, that inhibits cell division by directly binding FtsZ. After the SOS response is turned off, SulA is degraded by Lon protease, allowing for cell division to resume. Recently, it has become clear that SulA is restricted to bacteria closely related to E. coli and that most bacteria enforce the DNA damage checkpoint by expressing a small integral membrane protein. Resumption of cell division is then mediated by membrane-bound proteases that cleave the cell division inhibitor. Further, many bacterial cells have mechanisms to inhibit cell division that are regulated independently from the canonical LexA-mediated SOS response. In this review, we discuss several pathways used by bacteria to prevent cell division from occurring when genome instability is detected or before the chromosome has been fully replicated and segregated.

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

Biomolecules ◽  
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.

scholarly journals STAU2 protein level is controlled by caspases and the CHK1 pathway and regulates cell cycle progression in the non-transformed hTERT-RPE1 cells

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Lionel Condé ◽  
Yulemi Gonzalez Quesada ◽  
Florence Bonnet-Magnaval ◽  
Rémy Beaujois ◽  
Luc DesGroseillers
Keyword(s):  
Gene Expression ◽  
Cell Cycle ◽  
Cell Proliferation ◽  
Dna Damage ◽  
Steady State ◽  
Posttranscriptional Regulation ◽  
Cell Cycle Progression ◽  
Rna Binding ◽  
Regulation Of Gene Expression ◽  
Cycle Progression

AbstractBackgroundStaufen2 (STAU2) is an RNA binding protein involved in the posttranscriptional regulation of gene expression. In neurons, STAU2 is required to maintain the balance between differentiation and proliferation of neural stem cells through asymmetric cell division. However, the importance of controlling STAU2 expression for cell cycle progression is not clear in non-neuronal dividing cells. We recently showed that STAU2 transcription is inhibited in response to DNA-damage due to E2F1 displacement from theSTAU2gene promoter. We now study the regulation of STAU2 steady-state levels in unstressed cells and its consequence for cell proliferation.ResultsCRISPR/Cas9-mediated and RNAi-dependent STAU2 depletion in the non-transformed hTERT-RPE1 cells both facilitate cell proliferation suggesting that STAU2 expression influences pathway(s) linked to cell cycle controls. Such effects are not observed in the CRISPR STAU2-KO cancer HCT116 cells nor in the STAU2-RNAi-depleted HeLa cells. Interestingly, a physiological decrease in the steady-state level of STAU2 is controlled by caspases. This effect of peptidases is counterbalanced by the activity of the CHK1 pathway suggesting that STAU2 partial degradation/stabilization fines tune cell cycle progression in unstressed cells. A large-scale proteomic analysis using STAU2/biotinylase fusion protein identifies known STAU2 interactors involved in RNA translation, localization, splicing, or decay confirming the role of STAU2 in the posttranscriptional regulation of gene expression. In addition, several proteins found in the nucleolus, including proteins of the ribosome biogenesis pathway and of the DNA damage response, are found in close proximity to STAU2. Strikingly, many of these proteins are linked to the kinase CHK1 pathway, reinforcing the link between STAU2 functions and the CHK1 pathway. Indeed, inhibition of the CHK1 pathway for 4 h dissociates STAU2 from proteins involved in translation and RNA metabolism.ConclusionsThese results indicate that STAU2 is involved in pathway(s) that control(s) cell proliferation, likely via mechanisms of posttranscriptional regulation, ribonucleoprotein complex assembly, genome integrity and/or checkpoint controls. The mechanism by which STAU2 regulates cell growth likely involves caspases and the kinase CHK1 pathway.

Sign in / Sign up

Export Citation Format

Share Document