Reactive Oxygen Species and Antioxidants in Cancer Treatment

These data pertain to 2 publications on the effect of tamoxifen and irradiation on ROS and antioxidants. Earlier, we reported that tamoxifen-resistant (TAM-R) breast cancer cells are cross-resistant to irradiation. In PMID: 36755288, we investigated the mechanisms associated with tamoxifen-induced radioresistance, aiming to prevent or reverse resistance and improve breast cancer treatment. Wild-type ERα-positive MCF7 and ERα-negative MDA-MB-231 breast cancer cells and their TAM-R counterparts were analyzed for cellular metabolism using the Seahorse metabolic analyzer. Real-time ROS production, toxicity, and antioxidant capacity in response to H2O2, tamoxifen, and irradiation were determined. Real-time measurement of ROS after tamoxifen and H2O2 exposure indicated lower ROS levels and toxicity in TAM-R cells. Consistently, higher antioxidant levels were found in TAM-R cells, providing protection from irradiation-induced ROS. In PMID: 38292333, total antioxidant capacity (TAC) was analyzed in head and neck cancer (HNSCC) tumor cells in vitro and in serum of HNSCC patients before, during, and after radiotherapie . We found that irradiation induced NRF2 expression and upregulated TAC, which may compromise the effect of RT-induced ROS.