RESUMO
The linking of ethacrynic acid with ethylenediamine and 1,4-butanediamine gave EDEA and BDEA, respectively, as membrane-permeable divalent pro-inhibitors of glutathione S-transferase (GST). Their divalent glutathione conjugates showed subnanomolar inhibition and divalence-binding to GSTmu (GSTM) (PDB: 5HWL) at â¼0.35 min-1. In cisplatin-resistant SK-OV-3, COC1, SGC7901 and A549 cells, GSTM activities probed by 15 nM BDEA or EDEA revealed 5-fold and 1.0-fold increases in cisplatin-resistant SK-OV-3 and COC1 cells, respectively, in comparison with the susceptible parental cells. Being tolerable by HEK293 and LO2 cells, BDEA at 0.2 µM sensitised resistant SK-OV-3 and COC1 cells by â¼3- and â¼5-folds, respectively, released cytochrome c and increased apoptosis; EDEA at 1.0 µM sensitised resistant SK-OV-3 and A549 cells by â¼5- and â¼7-fold, respectively. EDEA at 1.7 µg/g sensitised resistant SK-OV-3 cells to cisplatin at 3.3 µg/g in nude mouse xenograft model. BDEA and EDEA are promising leads for probing cellular GSTM and sensitising cisplatin-resistant ovarian cancers.