Antioxidants Prevent DNA Double-Strand Breaks From X-Ray–Based Cardiac Examinations

DNA Double-Strand Breaks

The activation-induced cytidine deaminase (AID) is required for somatic hypermutation (SHM) and class-switch recombination (CSR) of immunoglobulin (Ig) genes, both of which are associated with DNA double-strand breaks (DSBs). As AID is capable of deaminating deoxy-cytidine (dC) to deoxy-uracil (dU), it might induce nicks (single strand DNA breaks) and also DNA DSBs via a U-DNA glycosylase-media...

Residual DNA double strand breaks correlates with excess acute toxicity from radiotherapy

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...

DNA Double-Strand Breaks Relieve

X-ray induced DNA double-strand breaks in human sperm.

A methodology for quantifying DNA double-strand breaks in human sperm is described. Sperm from three healthy human donors on three separate days each were irradiated with 12.5, 25, 50 and 100 cGy X-rays. Linear dose-response effects were observed in migrated DNA from sperm nuclei when electrophoresed under neutral conditions. RNase and proteinase K treatments for longer duration were necessary,...

DNA Double-Strand Breaks Come into Focus

The Mre11-Rad50-Nbs1 (MRN) complex senses DNA double-strand breaks and recruits different repair pathway and checkpoint proteins to break foci. Two new studies (Williams et al., 2009; Lloyd et al., 2009) identify Nbs1 as a key factor in this process and reveal how an N-terminal protein recruitment module in Nbs1 binds to different response factors through shared phosphopeptide motifs.