Replication fork barriers to study site-specific DNA replication perturbation.

DNA replication ensures the complete and accurate duplication of the genome. The traditional approach to analysing perturbation of DNA replication is to use chemical inhibitors, such as hydroxyurea or aphidicolin, that slow or stall replication fork progression throughout the genome. An alternative approach is to perturb replication at a single site in the genome that permits a more forensic investigation of the cellular response to the stalling or disruption of a replication fork.

Cell-free chromatin particles released from dying host cells are global instigators of endotoxin sepsis in mice.

We have earlier reported that cell-free chromatin (cfCh) particles that are released from dying cells, or those that circulate blood, can readily enter into healthy cells, illegitimately integrate into their genomes and induce dsDNA breaks, apoptosis and intense activation of inflammatory cytokines. We hypothesized that sepsis is caused by cfCh released from dying host cells following microbial infection leading to bystander host cell apoptosis and inflammation which are perpetuated in a vicious cycle with release of more cfCh from dying host cells. To test this hypothesis we used three cfCh inactivating agents namely 1) anti-histone antibody complexed nanoparticles which inactivate cfCh by binding to histones; 2) DNase I which inactivates cfCh by degrading its DNA component, and 3) a novel pro-oxidant combination of Resveratrol and Copper which, like DNase I, inactivates cfCh by degrading its DNA component.

Prevention of radiation-induced bystander effects by agents that inactivate cell-free chromatin released from irradiated dying cells.

Radiation-induced bystander effect (RIBE) is a poorly understood phenomenon wherein non-targeted cells exhibit effects of radiation. We have reported that cell-free chromatin (cfCh) particles that are released from dying cells can integrate into genomes of surrounding healthy cells to induce DNA damage and inflammation. This raised the possibility that RIBE might be induced by cfCh released from irradiated dying cells.