Modulation of cisplatin sensitivity in human ovarian carcinoma A2780 and SKOV3 cell lines by sulforaphane

•Synergic (A2780) and antagonistic (SKOV3) interactions between SFN and cisPt.•Potentiation (A2780) and protection (SKOV3) against cisPt-induced DNA damage.•Greater genomic stability of A2780 cells in comparison with SKOV3.•Different activation of Nrf-2 pathway by SFN in A2780 compared to SKOV3 cells. Cisplatin resistance is one of the major obstacles in the treatment of ovarian cancer. In an effort to look for new possibilities of how to overcome this difficulty, we studied the mechanisms of the interactions between sulforaphane (SFN) and cisplatin (cisPt) in combined treatment of human ovarian carcinoma A2780 and SKOV3 cell lines. Synergy (A2780) and antagonism (SKOV3) found in MTT assay was confirmed by apoptosis. While SFN significantly potentiated cisPt-induced DNA damage in A2780 cells, it protected SKOV3 cells against cisPt-crosslinking. We revealed a less efficient Nrf-2 pathway inducibility by SFN in A2780 compared to SKOV3 cells, when activation of the Nrf-2 pathway incites its protectivity against cisPt. Thus, different activation of the Nrf-2 pathway may explain the dual effects of SFN.