ATM is required for the repair of Topotecan-induced replication-associated double-strand breaks
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ATM is required for the repair of Topotecan-induced replication-associated double-strand breaks. / Köcher, Sabrina; Spies-Naumann, Anja; Kriegs, Malte; Dahm-Daphi, Jochen; Dornreiter, Irena.
In: RADIOTHER ONCOL, Vol. 108, No. 3, 01.09.2013, p. 409-14.Research output: SCORING: Contribution to journal › SCORING: Journal article › Research › peer-review
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TY - JOUR
T1 - ATM is required for the repair of Topotecan-induced replication-associated double-strand breaks
AU - Köcher, Sabrina
AU - Spies-Naumann, Anja
AU - Kriegs, Malte
AU - Dahm-Daphi, Jochen
AU - Dornreiter, Irena
N1 - Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.
PY - 2013/9/1
Y1 - 2013/9/1
N2 - PURPOSE: DNA replication is a promising target for anti-cancer therapies. Therefore, the understanding of replication-associated DNA repair mechanisms is of great interest. One key factor of DNA double-strand break (DSB) repair is the PIK kinase Ataxia-Telangiectasia Mutated (ATM) but it is still unclear whether ATM is involved in the repair of replication-associated DSBs. Here, we focused on the involvement of ATM in homology-directed repair (HDR) of indirect DSBs associated with replication.MATERIAL AND METHODS: Experiments were performed using ATM-deficient and -proficient human cells. Replication-associated DSBs were induced with Topotecan (TPT) and compared with γ-irradiation (IR). Cell survival was measured by clonogenic assay. Overall DSB repair and HDR were evaluated by detecting residual γH2AX/53BP1 and Rad51 foci, respectively. Cell cycle distribution was analysed by flow cytometry and protein expression by Western blot.RESULTS: ATM-deficiency leads to enhanced numbers of residual DSBs, resulting in a pronounced S/G2-block and decreased survival upon TPT-treatment. In common with IR, persisting Rad51 foci were detected following TPT-treatment.CONCLUSIONS: These results demonstrate that ATM is essentially required for the completion of HR-mediated repair of TPT-induced DSBs formed indirectly at replication forks.
AB - PURPOSE: DNA replication is a promising target for anti-cancer therapies. Therefore, the understanding of replication-associated DNA repair mechanisms is of great interest. One key factor of DNA double-strand break (DSB) repair is the PIK kinase Ataxia-Telangiectasia Mutated (ATM) but it is still unclear whether ATM is involved in the repair of replication-associated DSBs. Here, we focused on the involvement of ATM in homology-directed repair (HDR) of indirect DSBs associated with replication.MATERIAL AND METHODS: Experiments were performed using ATM-deficient and -proficient human cells. Replication-associated DSBs were induced with Topotecan (TPT) and compared with γ-irradiation (IR). Cell survival was measured by clonogenic assay. Overall DSB repair and HDR were evaluated by detecting residual γH2AX/53BP1 and Rad51 foci, respectively. Cell cycle distribution was analysed by flow cytometry and protein expression by Western blot.RESULTS: ATM-deficiency leads to enhanced numbers of residual DSBs, resulting in a pronounced S/G2-block and decreased survival upon TPT-treatment. In common with IR, persisting Rad51 foci were detected following TPT-treatment.CONCLUSIONS: These results demonstrate that ATM is essentially required for the completion of HR-mediated repair of TPT-induced DSBs formed indirectly at replication forks.
U2 - 10.1016/j.radonc.2013.06.024
DO - 10.1016/j.radonc.2013.06.024
M3 - SCORING: Journal article
C2 - 23928469
VL - 108
SP - 409
EP - 414
JO - RADIOTHER ONCOL
JF - RADIOTHER ONCOL
SN - 0167-8140
IS - 3
ER -
