Inhibition of histone deacetylase in cancer cells slows down replication forks, activates dormant origins, and induces DNA damage.
Inhibition of histone deacetylase in cancer cells slows down replication forks, activates dormant origins, and induces DNA damage.
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DOI：
10.1158/0008-5472.can-09-3028
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发表时间：
2010-06-01
期刊：
影响因子：
11.2
通讯作者：
Pommier Y
中科院分区：
文献类型：
--
作者：
Conti C;Leo E;Eichler GS;Sordet O;Martin MM;Fan A;Aladjem MI;Pommier Y
Protein acetylation is a reversible process regulated by histone deacetylases (HDACs) that is often altered in human cancers. SAHA (suberoylanilide hydroxamic acid) is the first histone deacetylase inhibitor (HDACi) to be approved for clinical use as an anticancer agent. Given that histone acetylation is a key determinant of chromatin structure, we investigated how SAHA may affect DNA replication and integrity to gain deeper insights into the basis for its anticancer activity. Nuclear replication factories were visualized with confocal immunofluorescence microscopy and with single-replicon analyses conducted by genome-wide molecular combing after pulse labeling with two thymidine-analogues. Additionally, nascent strand real-time polymerase chain reaction (RT-PCR) in the human β-globin locus was used to assess the effects of SAHA on replication fork origin firing. We found that pharmacological concentrations of SAHA induce replication-mediated DNA damage, on the basis of single-cell and single-DNA molecule analyses. Molecular combing indicated slowdown in replication speed along with activation of dormant replication origins in response to SAHA. Similar results were obtained using siRNA-mediated depletion of HDAC3 expression, implicating this HDAC member as a likely target in the SAHA response. Activation of dormant origins was confirmed by molecular analyses of the β-globin locus control region. Our findings indicate that SAHA produces profound alterations in DNA replication that cause DNA damage, establishing a critical link between robust chromatin acetylation and DNA replication in human cancer cells.
