biostudies-literatureUnknown46Rajaram SNew treatments are urgently required for triple-negative breast cancer (TNBC). As TP53 is mutated in approximately 80% of TNBC, it is theoretically an attractive target for new drugs for this disease. Arsenic trioxide (ATO), which is used to treat promyelocytic leukaemia, was recently shown to reactivate mutant p53 and restore wild-type functionality. The aim of this study was to evaluate ATO as a potential new treatment for TNBC. Using a panel of 20 cell lines, we found that TNBC cell lines were more sensitive to ATO than non-TNBC cell lines (P = 0.045). Consistent with its ability to reactivate mutant p53, ATO was a more potent inhibitor of proliferation in cell lines with mutant TP53 than the wildtype TP53 (P = 0.027). Direct evidence of mutant p53 reactivation was the induction of multTranslational oncology102025https://www.ebi.ac.uk/biostudies/studies/S-EPMC11225897biostudies-literatureTargeting mutant p53 with arsenic trioxide: A preclinical study focusing on triple negative breast cancer.PMC11225897Synnott NCRajaram SDuffy MJMadden SFCrown JfalseTargeting mutant p53 with arsenic trioxide: A preclinical study focusing on triple negative breast cancer.New treatments are urgently required for triple-negative breast cancer (TNBC). As TP53 is mutated in approximately 80% of TNBC, it is theoretically an attractive target for new drugs for this disease. Arsenic trioxide (ATO), which is used to treat promyelocytic leukaemia, was recently shown to reactivate mutant p53 and restore wild-type functionality. The aim of this study was to evaluate ATO as a potential new treatment for TNBC. Using a panel of 20 cell lines, we found that TNBC cell lines were more sensitive to ATO than non-TNBC cell lines (P = 0.045). Consistent with its ability to reactivate mutant p53, ATO was a more potent inhibitor of proliferation in cell lines with mutant TP53 than the wildtype TP53 (P = 0.027). Direct evidence of mutant p53 reactivation was the induction of mult2024-01-01T00:00:00Z2024 Aug2026-05-29T11:20:13.471Z2025-04-04T12:54:15.198ZS-EPMC112258973887067810.1016/j.tranon.2024.102025