Histone Deacetylase Inhibitors (HDI) Cause DNA Damage in Leukemia Cells: A Mechanism for Leukemia-Specific HDI-Dependent Apoptosis?

• Published in: Molecular cancer research 2006-08, Vol.4 (8), p.563-573
• Main Authors: Gaymes, Terry J, Padua, Rose Ann, Pla, Marika, Orr, Stephen, Omidvar, Nader, Chomienne, Christine, Mufti, Ghulam J, Rassool, Feyruz V
• Format: Article
• Language: English
• Subjects: Animals; Apoptosis - drug effects; Apoptosis - radiation effects; Ataxia Telangiectasia Mutated Proteins; Butyrates - pharmacology; Cell Cycle Proteins - metabolism; Chromatin Assembly and Disassembly - drug effects; DNA Damage - drug effects; DNA Damage - radiation effects; DNA damage and repair mechanisms; DNA-Binding Proteins - metabolism; Gamma Rays; hematologic, other; Histone Deacetylase Inhibitors; Histones - metabolism; HL-60 Cells; Humans; Hydroxamic Acids - pharmacology; K562 Cells; leukemias and cellular stress responses; Mice; Mice, Transgenic; Organ Specificity - drug effects; Peptides, Cyclic - pharmacology; Phosphorylation - drug effects; Protein-Serine-Threonine Kinases - metabolism; RNA Interference; small molecules and other therapeutic agents; Staurosporine - pharmacology; Transfection; Tumor Suppressor Proteins - metabolism
• ISSN: 1541-7786; 1557-3125
• DOI: 10.1158/1541-7786.MCR-06-0111

Histone deacetylase inhibitors (HDI) increase gene expression through induction of histone acetylation. However, it remains unclear whether increases in specific gene expression events determine the apoptotic response following HDI administration. Herein, we show that a variety of HDI trigger in hematopoietic cells not only widespread histone acetylation and DNA damage responses but also actual DNA damage, which is significantly increased in leukemic cells compared with normal cells. Thus, increase in H2AX and ataxia telangiectasia mutated (ATM) phosphorylation, early markers of DNA damage, occurs rapidly following HDI administration. Activation of the DNA damage and repair response following HDI treatment is further emphasized by localizing DNA repair proteins to regions of DNA damage. These events are followed by subsequent apoptosis of neoplastic cells but not normal cells. Our data indicate that induction of apoptosis by HDI may result predominantly through accumulation of excessive DNA damage in leukemia cells, leading to activation of apoptosis. (Mol Cancer Res 2006;4(8):563–73)