Cancer ResearchDNA Repair Gene EXO1 Goes Rogue and Reveals a Targetable Cancer Weakness
Researchers at Penn State have found that a DNA-repair gene called EXO1, normally protective, becomes harmful when cells produce too much of it. Instead of repairing DNA, excess EXO1 starts cutting strands it shouldn't, destabilizing the genome in ways linked to cancer. The gene is overexpressed in 20–30% of breast and ovarian cancers, plus melanoma and several others. Critically, these EXO1-high tumors behave like cancers with BRCA mutations—even without those mutations—suggesting patients could benefit from targeted BRCA-directed therapies. EXO1 may serve as a new biomarker to guide more personalized, effective cancer treatment with fewer side effects.