Sensitization of estrogen receptor-positive breast cancer cell lines to 4-hydroxytamoxifen by isothiocyanates present in cruciferous plants

Purpose Tamoxifen has been used for the treatment of estrogen receptor (ER)-positive breast cancers and in women who are at an increased risk of breast cancer. Acquired resistance to this drug and its toxicity still pose a clinically significant problem, especially in the prevention setting. Isothiocyanates present in cruciferous plants, such as sulforaphane or erucin, have been shown to reduce growth of breast cancer cells in vivo and in vitro. In this study, we explored their ability to sensitize cancer cells to 4-hydroxytamoxifen.