Cancer cells depend on a dangerous DNA repair trick

Cancer cells with defective SETX protein accumulate dangerous RNA-DNA tangles called R-loops that cause DNA breaks, forcing them to rely on an error-prone emergency repair system called break-induced replication (BIR). Scripps Research scientists discovered that blocking BIR proteins like PIF1, RAD52, and XPF would selectively kill these cancer cells without harming healthy cells. This finding could lead to new targeted treatments for cancers that accumulate high levels of R-loops.