We studied the formation of double strand breaks (DSBs) as intermediates in the repair of DNA interstrand crosslinks (ICLs) by homologous recombination (HR). The plasmid EGFP-N1 was crosslinked with trioxsalen to give one ICL per plasmid on average. HeLa cells were transfected with the crosslinked plasmids and the ICL repair was monitored by following the restoration of the GFP expression. It w...

Current drinking water standards for chromium are for the combined total of both hexavalent and trivalent chromium (Cr(VI) and Cr(III)). However, recent studies have shown that Cr(III) is not carcinogenic to rodents, whereas mice chronically exposed to high levels of Cr(VI) developed duodenal tumors. These findings may suggest the need for environmental standards specific for Cr(VI). Whether th...

DNA double strand break (DSB) formation induced by ionizing radiation exposure is indicated by the DSB biomarkers γ-H2AX and 53BP1. Knowledge about DSB foci formation in-vitro after internal irradiation of whole blood samples with radionuclides in solution will help us to gain detailed insights about dose-response relationships in patients after molecular radiotherapy (MRT). Therefore, we studi...

Oral exposure to high concentrations of hexavalent chromium [Cr(VI)] induces intestinal redox changes, villus cytotoxicity, crypt hyperplasia, and intestinal tumors in mice. To assess the effects of Cr(VI) in a cell model relevant to the intestine, undifferentiated (proliferating) and differentiated (confluent) Caco-2 cells were treated with Cr(VI), hydrogen peroxide or rotenone for 2-24 hours....

Introduction: A high risk for development of severe side effects after radiotherapy may be correlated with high cellular radiosensitivity. To enhance radiation therapy efficiency a fast and reliable in-vitro test is desirable to identify radiosensitive patients. The aim of present study was to identify the mechanism of radiation induced DNA double-strand breaks (DSBs) and DSB r...

The radiation environment in deep space, where astronauts are behind the shelter provided by the Earth’s magnetosphere, is a major health concern. Galactic cosmic rays (GCR) and solar particle events (SPE) are two basic sources of space radiation in the solar system. The health risks of exposure to high levels of space radiation can be observed either as acute and delayed effects. Zhang et al. ...

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 The epidermal growth factor receptor (EGFR) signaling pathway plays a significant role in radiation resistance. There is evidence that EGFR nuclear translocation is associated with DNA double-strand breaks (DSB) repair. Nimotuzumab has shown the effect of radiosensitization in various cancer cells, but little is known about the relationship between nimotuzumab and EGFR nuclear transl...