Activation of the S phase DNA damage checkpoint by mitomycin C

Mladenov, Emil; Tsaneva, Irina R.; Anachkova, Boyka

doi:10.1002/jcp.20957

Cited by 43 publications

(30 citation statements)

References 42 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…ATM is principally activated after induction of DSBs, thus, one possible explanation for our results is that Snm1B is required for the introduction of DSBs that occur during replication fork collapse in response to ICLs. To test this hypothesis, we used pulsed-field gel electrophoresis to separate intact chromosomes from broken DNA after exposure of cells to MMC (Hanada et al, 2006;Mladenov et al, 2007). As shown, clone 5 cells showed both a delay and an overall reduction in the amount of broken DNA compared to control cells indicating that Snm1B is required for replication fork collapse (Figure 6a and b), thus validating our hypothesis.…”

Section: Snm1b Is Required For Replication Fork Collapse At Iclssupporting

confidence: 71%

“…Similar to the ATR pathways, ATM signaling is also mediated by two parallel pathways involving ATM-Chk2 and ATM-Nbs1-Smc1 Lambert and Carr, 2005). The involvement of ATM in checkpoint signaling in response to ICLs has not been previously described, and in fact experiments to detect such an involvement have largely proven negative (Pichierri and Rosselli, 2004b;Mladenov et al, 2007). This situation is likely due to the fact that activation of ATM only occurs after fork collapse, which usually takes place many hours after introduction of the ICLinducing drug, whereas most checkpoint assays are performed within a few hours of drug treatment.…”

Section: Discussionmentioning

confidence: 99%

“…Cells were harvested after trypsinization, and agarose plugs containing 10 6 cells were prepared and DNAs separated by pulse-field gel electrophoresis as described previously (Hanada et al, 2006;Mladenov et al, 2007).…”

Section: Evaluation Of Dna Synthesismentioning

confidence: 99%

See 2 more Smart Citations

Snm1B/Apollo mediates replication fork collapse and S Phase checkpoint activation in response to DNA interstrand cross-links

et al. 2008

View full text Add to dashboard Cite

The removal of DNA interstrand cross-links (ICLs) has proven to be notoriously complicated due to the involvement of multiple pathways of DNA repair, which include the Fanconi anemia/BRCA pathway, homologous recombination and components of the nucleotide excision and mismatch repair pathways. Members of the SNM1 gene family have also been shown to have a role in mediating cellular resistance to ICLs, although their precise function has remained elusive. Here, we show that knockdown of Snm1B/Apollo in human cells results in hypersensitivity to mitomycin C (MMC), but not to IR. We also show that Snm1B-deficient cells exhibit a defective S phase checkpoint in response to MMC, but not to IR, and this finding may account for the specific sensitivity to the cross-linking drug. Interestingly, although previous studies have largely implicated ATR as the major kinase activated in response to ICLs, we show that it is activation of the ATMmediated checkpoint that is defective in Snm1B-deficient cells. The requirement for Snm1B in ATM checkpoint activation specifically after ICL damage is correlated with its role in promoting double-strand break formation, and thus replication fork collapse. Consistent with this result Snm1B was found to interact directly with Mus81-Eme1, an endonuclease previously implicated in fork collapse. In addition, we also show that Snm1B interacts with the Mre11-Rad50-Nbs1 (MRN) complex and with FancD2 further substantiating its role as a checkpoint/DNA repair protein.

show abstract

Section: Snm1b Is Required For Replication Fork Collapse At Iclssupporting

confidence: 71%

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Snm1B/Apollo mediates replication fork collapse and S Phase checkpoint activation in response to DNA interstrand cross-links

et al. 2008

View full text Add to dashboard Cite

show abstract

“…4A and data in ref. 45), trabectedin also promoted the translocation of RAD51 to the nucleus of cells in which DSBs had been generated, most likely as structural intermediates required for the correct processing of the trabectedin-DNA adducts (15). The observation that RAD51 was codetected with gH2AX in the same nuclear foci (Fig.…”

Section: Discussionmentioning

confidence: 85%

Relevance of the Fanconi anemia pathway in the response of human cells to trabectedin

Casado

Rı́o

Marco³

et al. 2008

Molecular Cancer Therapeutics

View full text Add to dashboard Cite

Trabectedin (Yondelis; ET-743) is a potent anticancer drug that binds to DNA by forming a covalent bond with a guanine in one strand and one or more hydrogen bonds with the opposite strand. Using a fluorescence-based melting assay, we show that one single trabectedin-DNA adduct increases the thermal stability of the double helix by >20°C. As deduced from the analysis of phosphorylated H2AX and Rad51 foci, we observed that clinically relevant doses of trabectedin induce the formation of DNA double-strand breaks in human cells and activate homologous recombination repair in a manner similar to that evoked by the DNA interstrand cross-linking agent mitomycin C (MMC). Because one important characteristic of this drug is its marked cytotoxicity on cells lacking a functional Fanconi anemia (FA) pathway, we compared the response of different subtypes of FA cells to MMC and trabectedin. Our data clearly show that human cells with mutations in FANCA, FANCC, FANCF, FANCG, or FANCD1 genes are highly sensitive to both MMC and trabectedin. However, in marked contrast to MMC, trabectedin does not induce any significant accumulation of FA cells in G 2 -M. The critical relevance of FA proteins in the response of human cells to trabectedin reported herein, together with observations showing the role of the FA pathway in cancer suppression, strongly suggest that screening for mutations in FA genes may facilitate the identification of tumors displaying enhanced sensitivity to this novel anticancer drug.

show abstract

“…Fluorescence-activated cell sorting (FACS) analysis was carried out as previously described (Mladenov et al, 2007).…”

Section: Cells and Treatmentmentioning

confidence: 99%

Lack of Effect of RuvB-Like Proteins on DNA Damage Signaling Activation

Gospodinov

Anachkova²

2010

Zeitschrift Für Naturforschung C

Self Cite

View full text Add to dashboard Cite

Ataxia telangiectasia mutated (ATM) kinase is a central player in cellular response to DNA damage. Phosphorylation of the histone H2AX by ATM is required for the accumulation of repair proteins at the sites of double-strand breaks. Recently, it was reported that the histone acetyltransferase Tat interactive protein-60 (TIP60) is required to acetylate ATM prior to its activation. The RuvB-like proteins TIP48 and TIP49 are known to be necessary for the assembly and functional activity of the TIP60 acetyltransferase complex. In the present communication, we investigated the requirements of TIP48 and TIP49 for ATM activation by monitoring the cell cycle distribution and H2AX phosphorylation after irradiation of TIP48-and TIP49-depleted cells. We found that neither the cell cycle nor γ-H2AX were affected in TIP48-and TIP49-silenced cells, suggesting that the TIP60 chromatin modifi cation complex is not engaged in DNA damage signaling upstream of ATM.

show abstract

Activation of the S phase DNA damage checkpoint by mitomycin C

Cited by 43 publications

References 42 publications

Snm1B/Apollo mediates replication fork collapse and S Phase checkpoint activation in response to DNA interstrand cross-links

Snm1B/Apollo mediates replication fork collapse and S Phase checkpoint activation in response to DNA interstrand cross-links

Relevance of the Fanconi anemia pathway in the response of human cells to trabectedin

Lack of Effect of RuvB-Like Proteins on DNA Damage Signaling Activation

Contact Info

Product

Resources

About