BACKGROUND The protein kinase CK2 sustains multiple pro-survival functions in cellular DNA damage response and its level is tightly regulated in normal cells but elevated in cancers. Because CK2 is thus considered as potential therapeutic target, DNA double-strand break (DSB) formation and rejoining, apoptosis induction and clonogenic survival was assessed in irradiated mammalian cells upon che...

The term "bystander effect" is used to describe an effect in which cells that have not been exposed to radiation are affected by irradiated cells though various intracellular signaling mechanisms. In this study we analyzed the kinetics and mechanisms of bystander effect and radioadaptation in embryonic zebrafish cells (ZF4) exposed to chronic low dose of gamma rays. ZF4 cells were irradiated fo...

BACKGROUND Early serous carcinomas predominate in the fimbria of women with BRCA mutations (BRCA+). An entity in non-neoplastic mucosa sharing several properties of early serous carcinomas--the "p53 signature"--has been described in the distal fallopian tube and proposed as a precursor to serous carcinomas. This study compared the prevalence of p53 signatures in ovarian cortical inclusion cysts...

INTRODUCTION Low dose-rate radioimmunotherapy (RIT) using (125)I-labelled monoclonal antibodies ((125)I-mAbs) is associated with unexpected high cytotoxicity per Gy. METHODS We investigated whether this hypersensitivity was due to lack of detection of DNA damage by the targeted cells. DNA damage was measured with the alkaline comet assay, gamma-H2AX foci and the micronucleus test in p53(-/-) ...

Background: Humans are exposed to ionizing radiation from different sources that include natural, occupational, medical, accidental exposures. Evaluation of the effect of low level of neutron exposure to human cells in vitro has important implications to human health. Attempts were made to measure genome damage, transcriptional profile of DNA damage response and repair genes in peripheral blood...

The normal tissue tolerance levels to fractionated radiotherapy have been appreciated by a century of careful clinical observations and radiobiological studies in animals. During clinical fractionated radiotherapy, these normal tissue tolerance levels are respected, and severe sequelae of radiotherapy are avoided in the majority of patients. Notwithstanding, a minority of patients experience un...

Ataxia telangiectasia (AT) cells, with their defective double-strand break (DSB) repair processes, exhibit high sensitivity to low-LET radiation such as X-rays irradiation and gamma beams. Since heavy ion beam treatment for cancer is becoming increasingly common in Japan and elsewhere, it is important to also determine their sensitivity to high-LET radiation. For this purpose we irradiated AT a...

Norethindrone is a commonly used drug for contraception and hormone replacement therapy, whose carcinogenic potential is still controversial. We applied a novel and particularly sensitive method to screen for DNA damage with special attention to double-strand breaks (DSBs) and identified norethindrone to be likely genotoxic and therefore potentially mutagenic: a p53-reporter assay served as a f...

Introduction: Missions beyond low Earth orbit (LEO) will expose astronauts to ionizing radiation (IR) in the form of solar energetic particles (SEP) and galactic cosmic rays (GCR) including high atomic number energy (HZE) nuclei. The gastrointestinal (GI) system is documented be highly radiosensitive with even relatively dose IR exposures capable inducing mucosal lesions disrupting epithelial b...