LIG1 loss exposes a therapeutic vulnerability in triple-negative breast cancer

MedicalXpress | Jul 17, 2026

Loss of one copy of the DNA ligase I (LIG1) gene in triple-negative breast cancers (TNBC) with TP53 mutations confers resistance to chemotherapy, but researchers at Baylor College of Medicine and collaborating institutions have identified a vulnerability in these cells and used it to their advantage. The team identified underlying molecular mechanisms of platinum resistance that they neutralized with combinations of available drugs to reduce tumor growth in animal models. This work also highlights LIG1 status as a patient stratification factor for ongoing and future clinical trials. The study appeared in Molecular Cancer Therapeutics.