This DNA repair gene went rogue and exposed a cancer weakness

Scientists at Penn State College of Medicine discovered that the EXO1 gene, which normally repairs DNA, can become dangerous when cells produce it in excessive amounts. The gene functions like molecular scissors, but when overproduced, it begins cutting DNA it should not, causing damage linked to cancer. Research published in Nature Communications showed that EXO1 is overexpressed in 20 to 30 percent of breast and ovarian cancers, as well as in melanoma and other cancer types. Cells with high EXO1 levels behave similarly to cells with BRCA mutations, which increase the risk of hereditary breast and ovarian cancer. These findings could help identify patients who might respond to specific chemotherapies originally designed for BRCA-mutant tumors, potentially expanding the applicability of these drugs.