Yeast recombination pathways triggered by topoisomerase II-mediated DNA breaks

Sabourin, Michelle; Nitiss, John L.; Nitiss, Karin C.; Tatebayashi, Kazuo; Ikeda, Hideo; Osheroff, Neil

doi:10.1093/nar/gkg497

Cited by 41 publications

(46 citation statements)

References 91 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Saccharomyces cerevisiae cells defective in rad52 as well as strains with defects in other recombination repair genes, such as rad50, mre11, and rad54 mutants, are hypersensitive to topoisomerase II poisons (6,7). Similar results have been observed in fission yeast mutants that are defective in DNA repair by homologous recombination (8).…”

Section: Introductionsupporting

confidence: 60%

“…In a previous report, a slight increase in sensitivity was seen with yeast cells expressing an etoposide-hypersensitive allele of yeast topoisomerase II (7). In this article, we examine a series of different deletion strains using overexpression of either etoposide-hypersensitive or 4 ¶-(9-acridinylamino)-methanesulfon-m -anisidide (mAMSA) -hypersensitive alleles to test whether NHEJ is involved in repairing topoisomerase II-mediated DNA damage.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Roles of nonhomologous end-joining pathways in surviving topoisomerase II–mediated DNA damage

Malik

Nitiss

Enriquez-Rios

et al. 2006

Molecular Cancer Therapeutics

View full text Add to dashboard Cite

Topoisomerase II is a target for clinically active anticancer drugs. Drugs targeting these enzymes act by preventing the religation of enzyme-DNA covalent complexes leading to protein-DNA adducts that include single-and doublestrand breaks. In mammalian cells, nonhomologous repair pathways are critical for repairing topoisomerase II -mediated DNA damage. Because topoisomerase IItargeting agents, such as etoposide, can also induce chromosomal translocations that can lead to secondary malignancies, understanding nonhomologous repair of topoisomerase II -mediated DNA damage may help to define strategies that limit this critical side effect on an important class of anticancer agents. Using Saccharomyces cerevisiae as a model eukaryote, we have determined the contribution of genes required for nonhomologous endjoining (NHEJ) for repairing DNA damage arising from treatment with topoisomerase II poisons, such as etoposide and 4 ¶-(9-acridinylamino)methanesulfon-m-anisidide (mAMSA). To increase cellular sensitivity to topoisomerase II poisons, we overexpressed either wild-type or drughypersensitive alleles of yeast topoisomerase II. Using this approach, we found that yku70 (hdf1), yku80 (hdf2), and other genes required for NHEJ were important for cell survival following exposure to etoposide. The clearest increase in sensitivity was observed with cells overexpressing an etoposide-hypersensitive allele of TOP2 (Ser 740 Trp). Hypersensitivity was also seen in some end-joining defective mutants exposed to the intercalating agent mAMSA, although the increase in sensitivity was less pronounced. To confirm that the increase in sensitivity was not solely due to the elevated expression of TOP2 or due to specific effects of the drug-hypersensitive TOP2 alleles, we also found that deletion of genes required for NHEJ increased the sensitivity of rad52 deletions to both etoposide and mAMSA. Taken together, these results show a clear role for NHEJ in the repair of DNA damage induced by topoisomerase II -targeting agents and suggest that this pathway may participate in translocations generated by drugs, such as etoposide.

show abstract

Section: Introductionsupporting

confidence: 60%

Section: Introductionmentioning

confidence: 99%

Roles of nonhomologous end-joining pathways in surviving topoisomerase II–mediated DNA damage

Malik

Nitiss

Enriquez-Rios

et al. 2006

Molecular Cancer Therapeutics

View full text Add to dashboard Cite

show abstract

“…Yet, even the partial contribution from HR in vertebrate Top1 damage repair would be intriguing in light of our recent finding that vertebrate Top2-mediated DNA damage (induced by Top2 inhibitors) is predominantly repaired by NHEJ, not HR (21). In yeast, HR is responsible for the repair of Top2-mediated DNA damage, whereas NHEJ has only a minor role (49). Thus, the roles of DSB repair pathways in topoisomerase-mediated DNA damage are quite different between yeast and vertebrates.…”

Section: Discussionmentioning

confidence: 99%

Loss of Nonhomologous End Joining Confers Camptothecin Resistance in DT40 Cells

Adachi

Koyama

2004

Journal of Biological Chemistry

View full text Add to dashboard Cite

DNA topoisomerase I (Top1) generates transient DNA single-strand breaks via the formation of cleavage complexes in which the enzyme is linked to the 3 -phosphate of the cleavage strand. The anticancer drug camptothecin (CPT) poisons Top1 by trapping cleavage complexes, thereby inducing Top1-linked single-strand breaks. Such DNA lesions are converted into DNA double-strand breaks (DSBs) upon collision with replication forks, implying that DSB repair pathways could be involved in the processing/repair of Top1-mediated DNA damage. Here we report that Top1-mediated DNA damage is repaired primarily by homologous recombination, a major pathway of DSB repair. Unexpectedly, however, we found that nonhomologous end joining (NHEJ), another DSB repair pathway, has no positive role in the relevant repair; notably, DT40 cell mutants lacking either of the NHEJ factors (namely, Ku70, DNA-dependent protein kinase catalytic subunit, and DNA ligase IV) were resistant to killing by CPT. In addition, we showed that the absence of NHEJ alleviates the requirement of homologous recombination in the repair of CPT-induced DNA damage. Our results indicate that NHEJ can be a cytotoxic pathway in the presence of CPT, shedding new light on the molecular mechanisms for the formation and repair of Top1-mediated DNA damage in vertebrates. Thus, our data have significant implications for cancer chemotherapy involving Top1 inhibitors.DNA double-strand breaks (DSBs) 1 can be caused by a variety of exogenous and endogenous agents, posing a major threat to genome integrity. If left unrepaired, DSBs may cause cell death (1, 2). Vertebrate cells have evolved two distinct pathways for repairing DSBs, homologous recombination (HR) and nonhomologous end joining (NHEJ) (2-5). The HR reaction requires a wide variety of proteins including Rad51, Rad52, and Rad54 (2), whereas NHEJ relies on Ku (a heterodimer of Ku70 and Ku86), DNA-PKcs, Artemis, Xrcc4, and DNA ligase IV (the LIG4 gene product) (3, 5, 6). The requirement for DNA ligase IV in this pathway is exclusive as other DNA ligases (I and III) are unable to substitute for the ligase function (7,8). In contrast to HR that allows for accurate repair of DSBs, NHEJ is typically an imprecise, error-prone pathway.In accordance with the essential roles of HR and NHEJ in DSB repair, cells deficient in HR or NHEJ have been shown to be highly sensitive to ionizing radiation (7-14). In the chicken B-lymphocyte DT40 cell line (15), the extent of radiosensitivity of RAD54 Ϫ/Ϫ cells is similar to that of DNA-PKcs Ϫ/Ϫ/Ϫ or LIG4 Ϫ/Ϫ cells (8, 14), and RAD54 Ϫ/Ϫ /DNA-PKcs Ϫ/Ϫ/Ϫ double mutant cells are much more radiosensitive than each single mutant (14). These results clearly indicate that HR and NHEJ contribute equally, and independently, to the repair of radiation-induced DSBs.Perturbation of fundamental cellular processes such as DNA replication or the action of DNA topoisomerases often causes DSBs. DNA topoisomerases are ubiquitous nuclear enzymes that participate in many aspects of DNA metabolisms, including DNA ...

show abstract

“…Furthermore, we show that pretreatment of cells with aclarubicin (aclacinomycin A), eliminated the difference between BRCA-deficient and BRCAproficient cells, proving that the observed etoposide sensitivity was due to the induction of the specialized DNA DSBs that arise by the action of the drug on the enzyme topoisomerase II (10). The marked sensitivity of BRCA-deficient cancer cells to specific cytotoxic agents may have important implications for the optimum systemic therapy of breast and ovarian tumors in the clinic.…”

Section: Introductionmentioning

confidence: 77%

BRCA1 and BRCA2 Deficient Cells Are Sensitive to Etoposide-induced DNA Double Strand Breaks via Topoisomerase II

Treszezamsky

Feng

Junran

et al. 2005

International Journal of Radiation Oncology*Biology*Physics

View full text Add to dashboard Cite

The function of BRCA1 and BRCA2 in DNA repair could affect the sensitivity of cells to cytotoxic agents, and would therefore be an important component of planning therapy for breast and ovarian cancers. Previously, both BRCA1-and BRCA2-deficient tumors were shown to be sensitive to mitomycin C, and the mechanism was presumed to be a defect in the repair of interstrand crosslinks by homologous recombination. Here, we show that both BRCA1 and BRCA2 determine the sensitivity to the cytotoxic drug, etoposide, using genetic complementation of BRCA-deficient cells. Etoposide is known to bind to topoisomerase II and prevent the resolution of the ''cleavable complex,'' in which one DNA duplex is passed through a second duplex. The specificity of this BRCAdependent sensitivity was confirmed by the use of aclarubicin, which is a catalytic inhibitor of topoisomerase II and prevents the formation of the cleavable complex. In the presence of aclarubicin, the differential sensitivity of BRCA-proficient and BRCA-deficient cells was lost. Thus, etoposide requires the presence of topoisomerase II to show specific sensitization in the absence of the function of BRCA1 or BRCA2. We conclude that homologous recombination is used in the repair of DNA damage caused by topoisomerase II poisons. Overall, these results suggest that etoposide is a potentially useful drug in the treatment of BRCA-deficient human cancers. [Cancer Res 2007;67(15):7078-81]

show abstract

Yeast recombination pathways triggered by topoisomerase II-mediated DNA breaks

Cited by 41 publications

References 91 publications

Roles of nonhomologous end-joining pathways in surviving topoisomerase II–mediated DNA damage

Roles of nonhomologous end-joining pathways in surviving topoisomerase II–mediated DNA damage

Loss of Nonhomologous End Joining Confers Camptothecin Resistance in DT40 Cells

BRCA1 and BRCA2 Deficient Cells Are Sensitive to Etoposide-induced DNA Double Strand Breaks via Topoisomerase II

Contact Info

Product

Resources

About