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Published in: Journal of Experimental & Clinical Cancer Research 1/2019

Open Access 01-12-2019 | Ionizing Radiation | Research

Olaparib and ionizing radiation trigger a cooperative DNA-damage repair response that is impaired by depletion of the VRK1 chromatin kinase

Authors: Ignacio Campillo-Marcos, Pedro A. Lazo

Published in: Journal of Experimental & Clinical Cancer Research | Issue 1/2019

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Abstract

Background

The VRK1 chromatin kinase regulates the organization of locally altered chromatin induced by DNA damage. The combination of ionizing radiation with inhibitors of DNA damage responses increases the accumulation of DNA damage in cancer cells, which facilitates their antitumor effect, a process regulated by VRK1.

Methods

Tumor cell lines with different genetic backgrounds were treated with olaparib to determine their effect on the activation of DNA repair pathways induced by ionizing radiation. The effect of combining olaparib with depletion of the chromatin kinase VRK1 was studied in the context of double-strand breaks repair pathway after treatment with ionizing radiation. The initiation and progression of DDR were studied by specific histone acetylation, as a marker of local chromatin relaxation, and formation of γH2AX and 53BP1 foci.

Results

In this work, we have studied the effect that VRK1 by itself or in collaboration with olaparib, an inhibitor of PARP, has on the DNA oxidative damage induced by irradiation in order to identify its potential as a new drug target. The combination of olaparib and ionizing radiation increases DNA damage permitting a significant reduction of their respective doses to achieve a similar amount of DNA damage detected by γH2AX and 53BP1 foci. Different treatment combinations of olaparib and ionizing radiation permitted to reach the maximum level of DNA damage at lower doses of both treatments. Furthermore, we have studied the effect that depletion of the VRK1 chromatin kinase, a regulator of DDR, has on this response. VRK1 knockdown impaired all steps in the DDR induced by these treatments, which were detected by a reduction of sequential markers such as H4K16 ac, γH2AX, NBS1 and 53BP1. Moreover, this effect of VRK1 is independent of TP53 or ATM, two genes frequently mutated in cancer.

Conclusion

The protective DNA damage response induced by ionizing radiation is impaired by the combination of olaparib with depletion of VRK1, and can be used to reduce doses of radiation and their associated toxicity. Proteins implicated in DNA damage responses are suitable targets for development of new therapeutic strategies and their combination can be an alternative form of synthetic lethality.
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Literature
18.
go back to reference Fong PC, Yap TA, Boss DS, Carden CP, Mergui-Roelvink M, Gourley C, De Greve J, Lubinski J, Shanley S, Messiou C, et al. Poly (ADP)-ribose polymerase inhibition: frequent durable responses in BRCA carrier ovarian cancer correlating with platinum-free interval. J Clin Oncol. 2010;28:2512–9. https://doi.org/10.1200/JCO.2009.26.9589.CrossRef Fong PC, Yap TA, Boss DS, Carden CP, Mergui-Roelvink M, Gourley C, De Greve J, Lubinski J, Shanley S, Messiou C, et al. Poly (ADP)-ribose polymerase inhibition: frequent durable responses in BRCA carrier ovarian cancer correlating with platinum-free interval. J Clin Oncol. 2010;28:2512–9. https://​doi.​org/​10.​1200/​JCO.​2009.​26.​9589.CrossRef
35.
go back to reference Bremer M, Doerge RM: Statistics at the bench: a step-by step handbook for biologists. New York: Cold Spring Harbor Laboratory Press; 2009. ISBN: 978-0-97969-857-7. Bremer M, Doerge RM: Statistics at the bench: a step-by step handbook for biologists. New York: Cold Spring Harbor Laboratory Press; 2009. ISBN: 978-0-97969-857-7.
Metadata
Title
Olaparib and ionizing radiation trigger a cooperative DNA-damage repair response that is impaired by depletion of the VRK1 chromatin kinase
Authors
Ignacio Campillo-Marcos
Pedro A. Lazo
Publication date
01-12-2019
Publisher
BioMed Central
Published in
Journal of Experimental & Clinical Cancer Research / Issue 1/2019
Electronic ISSN: 1756-9966
DOI
https://doi.org/10.1186/s13046-019-1204-1

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