BACKGROUND Radiation-induced DNA double-strand break (DSB) repair can be tested by using pulsed-field gel electrophoresis (PFGE) in agarose-encapsulated cells. However, previous studies have reported that this assay is impaired by the spontaneous DNA breakage in this medium. We investigated the mechanisms of this fragmentation with the principal aim of eliminating it in order to improve the est...

Today’s medical word is highly dependent on severel natural products (e.g. taxol) in fighting different kinds of cancer and in constantly working to found new compounds. In this respect, 3-hydrogenkwadaphnin is a new diterpene ester isolated from Dendrostellera lessertii (Thymelaceae). It has been previously shown that this new compound has high anti-tumor activity and the capability of arresti...

Rheum turkestanicum Janischew. (Polygonaceae) is a plant that grows in central Asia and in north-east of Iran. Traditionally, people use roots of R. turkestanicum as an anti-diabetic and anti-hypertensive as well as anticancer agent. In this study the cytotoxicity and apoptogenic properties of ethyl acetate (EtOAc), n-hexane and H2O extracts from Rheum turkestanicum Janischew. (Polygonaceae) ro...

Abstract Introduction Ewing's sarcoma is an aggressive childhood malignancy whose outcome has not substantially improved over the last two decades. In this study, combination treatments of HSP90 inhibitor AUY922 with either ATR VE821 or ATM KU55933 were investigated for their effectiveness in cells. Methods Effects determined p53 wild-type and null cell lines by flow cytometric analyses death, ...

A number of anticancer drugs exert their effect by causing DNA damage and subsequent apoptosis induction. Reactive oxygen species (ROS), such as hydrogen peroxide (H(2)O(2)) and super oxide anion (O(2)(-)), participate in apoptosis and DNA damage induced by some anticancer drugs, however, the precise mechanism of apoptosis via ROS formation remains to be clarified. I investigated the mechanism ...

Mitochondrial transcription factor A (mtTFA; also designated Tfam) is necessary for both transcription and maintenance of mitochondrial DNA. mtTFA preferentially recognizes cisplatin-damaged DNA, as well as oxidized DNA. Increased apoptosis has been observed in mtTFA knockout animals, suggesting that mtTFA is involved in apoptosis. A fraction of p53 protein localizes to mitochondria at the onse...

DNA damage or unprotected telomeres can trigger apoptosis via signaling pathways that directly sense abnormal DNA structures and activate the p53 transcription factor. We describe a p53-independent mechanism that acts in parallel to the canonical DNA damage response pathway in Drosophila to induce apoptosis after exposure to ionizing radiation. Following recovery from damage-induced cell cycle ...

Increasing evidence indicates that neurodegeneration involves the activation of the cell cycle machinery in postmitotic neurons. However, the purpose of these cell cycle-associated events in neuronal apoptosis remains unknown. Here we tested the hypothesis that cell cycle activation is a critical component of the DNA damage response in postmitotic neurons. Different genotoxic compounds (etoposi...

Rheum turkestanicum Janischew. (Polygonaceae) is a plant that grows in central Asia and in north-east of Iran. Traditionally, people use roots of R. turkestanicum as an anti-diabetic and anti-hypertensive as well as anticancer agent. In this study the cytotoxicity and apoptogenic properties of ethyl acetate (EtOAc), n-hexane and H2O extracts from Rheum turkestanicum Janischew. (Polygonaceae) ro...