2016
Robert, Carine; Nagaria, Pratik K; Pawar, Nisha; Adewuyi, Adeoluwa; Gojo, Ivana; Meyers, David J; Cole, Philip A; Rassool, Feyruz V
In: Leuk Res, vol. 45, pp. 14-23, 2016, ISSN: 1873-5835.
Abstract | Links | BibTeX | Tags: Acetylation, Acute, Benzamides, Chromatin, Cultured, DNA Breaks, DNA End-Joining Repair, Double-Stranded, Histone Deacetylase Inhibitors, Humans, Ku Autoantigen, Leukemia, Myeloid, Poly (ADP-Ribose) Polymerase-1, Pyridines, Tumor Cells
@article{1299967,
title = {Histone deacetylase inhibitors decrease NHEJ both by acetylation of repair factors and trapping of PARP1 at DNA double-strand breaks in chromatin},
author = {Carine Robert and Pratik K Nagaria and Nisha Pawar and Adeoluwa Adewuyi and Ivana Gojo and David J Meyers and Philip A Cole and Feyruz V Rassool},
doi = {10.1016/j.leukres.2016.03.007},
issn = {1873-5835},
year = {2016},
date = {2016-06-01},
journal = {Leuk Res},
volume = {45},
pages = {14-23},
abstract = {Histone deacetylase inhibitors (HDACi) induce acetylation of histone and non-histone proteins, and modulate the acetylation of proteins involved in DNA double-strand break (DSB) repair. Non-homologous end-joining (NHEJ) is one of the main pathways for repairing DSBs. Decreased NHEJ activity has been reported with HDACi treatment. However, mechanisms through which these effects are regulated in the context of chromatin are unclear. We show that pan-HDACi, trichostatin A (TSA), causes differential acetylation of DNA repair factors Ku70/Ku80 and poly ADP-ribose polymerase-1 (PARP1), and impairs NHEJ. Repair effects are reversed by treatments with p300/CBP inhibitor C646, with significantly decreased acetylation of PARP1. In keeping with these findings, TSA treatment significantly increases PARP1 binding to DSBs in chromatin. Notably, AML patients treated with HDACi entinostat (MS275) in vivo also show increased formation of poly ADP-ribose (PAR) that co-localizes with DSBs. Further, we demonstrate that PARP1 bound to chromatin increases with duration of TSA exposure, resembling PARP "trapping". Knockdown of PARP1 inhibits trapping and mitigates HDACi effects on NHEJ. Finally, combination of HDACi with potent PARP inhibitor talazoparib (BMN673) shows a dose-dependent increase in PARP "trapping", which correlates with increased apoptosis. These results provide a mechanism through which HDACi inhibits deacetylation and increases binding of PARP1 to DSBs, leading to decreased NHEJ and cytotoxicity of leukemia cells.},
keywords = {Acetylation, Acute, Benzamides, Chromatin, Cultured, DNA Breaks, DNA End-Joining Repair, Double-Stranded, Histone Deacetylase Inhibitors, Humans, Ku Autoantigen, Leukemia, Myeloid, Poly (ADP-Ribose) Polymerase-1, Pyridines, Tumor Cells},
pubstate = {published},
tppubtype = {article}
}
Histone deacetylase inhibitors (HDACi) induce acetylation of histone and non-histone proteins, and modulate the acetylation of proteins involved in DNA double-strand break (DSB) repair. Non-homologous end-joining (NHEJ) is one of the main pathways for repairing DSBs. Decreased NHEJ activity has been reported with HDACi treatment. However, mechanisms through which these effects are regulated in the context of chromatin are unclear. We show that pan-HDACi, trichostatin A (TSA), causes differential acetylation of DNA repair factors Ku70/Ku80 and poly ADP-ribose polymerase-1 (PARP1), and impairs NHEJ. Repair effects are reversed by treatments with p300/CBP inhibitor C646, with significantly decreased acetylation of PARP1. In keeping with these findings, TSA treatment significantly increases PARP1 binding to DSBs in chromatin. Notably, AML patients treated with HDACi entinostat (MS275) in vivo also show increased formation of poly ADP-ribose (PAR) that co-localizes with DSBs. Further, we demonstrate that PARP1 bound to chromatin increases with duration of TSA exposure, resembling PARP "trapping". Knockdown of PARP1 inhibits trapping and mitigates HDACi effects on NHEJ. Finally, combination of HDACi with potent PARP inhibitor talazoparib (BMN673) shows a dose-dependent increase in PARP "trapping", which correlates with increased apoptosis. These results provide a mechanism through which HDACi inhibits deacetylation and increases binding of PARP1 to DSBs, leading to decreased NHEJ and cytotoxicity of leukemia cells.