Artesunate induces oxidative DNA damage, sustained DNA double-strand breaks, and the ATM/ATR damage response in cancer cells.

Abstract

Artesunate, the active agent from Artemisia annua L. used in the traditional Chinese medicine, is being applied as a first-line drug for malaria treatment, and trials are ongoing that include this drug in cancer therapy. Despite increasing interest in its therapeutic application, the mode of cell killing provoked by artesunate in human cells is unknown. Here, we show that artesunate is a powerful inducer of oxidative DNA damage, giving rise to formamidopyrimidine DNA glycosylase-sensitive sites and the formation of 8-oxoguanine and 1,N6-ethenoadenine. Oxidative DNA damage was induced in LN-229 human glioblastoma cells dose dependently and was paralleled by cell death executed by apoptosis and necrosis, which could be attenuated by radical scavengers such as N-acetyl cysteine. Oxidative DNA damage resulted in DNA double-strand breaks (DSB) as determined by γH2AX foci that colocalized with 53BP1. Upon chronic treatment with artesunate, the level of DSB continuously increased over the treatment period up to a steady-state level, which is in contrast to ionizing radiation that induced a burst of DSB followed by a decline due to their repair. Knockdown of Rad51 by short interfering RNA and inactivation of DNA-PK strongly sensitized glioma cells to artesunate. These data indicate that both homologous recombination and nonhomologous end joining are involved in the repair of artesunate-induced DSB. Artesunate provoked a DNA damage response (DDR) with phosphorylation of ATM, ATR, Chk1, and Chk2. Overall, these data revealed that artesunate induces oxidative DNA lesions and DSB that continuously increase during the treatment period and accumulate until they trigger DDR and finally tumor cell death.

• Authors: Nicole Berdelle, Teodora Nikolova, Steve Quiros, Thomas Efferth, Bernd Kaina
• Journal: Molecular cancer therapeutics (Mol Cancer Ther) Vol. 10 Issue 12 Pg. 2224-33 (Dec 2011) ISSN: 1538-8514 [Electronic] United States
• PMID: 21998290 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Antineoplastic Agents, Phytogenic
• Artemisinins
• Cell Cycle Proteins
• DNA-Binding Proteins
• Tumor Suppressor Proteins
• Artesunate
• ATM protein, human
• ATR protein, human
• Ataxia Telangiectasia Mutated Proteins
• Protein Serine-Threonine Kinases

Topics

• Antineoplastic Agents, Phytogenic (pharmacology, therapeutic use)
• Apoptosis (drug effects, genetics)
• Artemisinins (pharmacology, therapeutic use)
• Artesunate
• Ataxia Telangiectasia Mutated Proteins
• Cell Cycle Proteins (metabolism)
• DNA Breaks, Double-Stranded (drug effects)
• DNA Damage (drug effects)
• DNA Repair (drug effects, genetics)
• DNA-Binding Proteins (metabolism)
• Drug Evaluation, Preclinical
• Humans
• Models, Biological
• Neoplasms (drug therapy, genetics, metabolism, pathology)
• Oxidative Stress (drug effects, genetics)
• Protein Serine-Threonine Kinases (metabolism)
• Tumor Cells, Cultured
• Tumor Suppressor Proteins (metabolism)
• Up-Regulation (drug effects)