Aim:Ferroptosis is a non-apoptotic form of cell death caused by lethal lipid peroxidation.Several small molecule ferroptosis inducers(FINs)have been reported,yet little information is available regarding their interac...Aim:Ferroptosis is a non-apoptotic form of cell death caused by lethal lipid peroxidation.Several small molecule ferroptosis inducers(FINs)have been reported,yet little information is available regarding their interaction with the ATP-binding cassette(ABC)transporters P-glycoprotein(P-gp,ABCB1)and ABCG2.We thus sought to characterize the interactions of FINs with P-gp and ABCG2,which may provide information regarding oral bioavailability and brain penetration and predict drug-drug interactions.Methods:Cytotoxicity assays with ferroptosis-sensitive A673 cells transfected to express P-gp or ABCG2 were used to determine the ability of the transporters to confer resistance to FINs;confirmatory studies were performed in OVCAR8 and NCI/ADR-RES cells.The ability of FINs to inhibit P-gp or ABCG2 was determined using the fluorescent substrates rhodamine 123 or purpuin-18,respectively.Results:P-gp overexpression conferred resistance to FIN56 and the erastin derivatives imidazole ketone erastin and piperazine erastin.P-gp-mediated resistance to imidazole ketone erastin and piperazine erastin was also reversed in UO-31 renal cancer cells by CRISPR-mediated knockout of ABCB1.The FINs ML-162,GPX inhibitor 26a,and PACMA31 at 10µM were able to increase intracellular rhodamine 123 fluorescence over 10-fold in P-gp-expressing MDR-19 cells.GPX inhibitor 26a was able to increase intracellular purpurin-18 fluorescence over 4-fold in ABCG2-expressing R-5 cells.Conclusion:Expression of P-gp may reduce the efficacy of these FINs in cancers that express the transporter and may prevent access to sanctuary sites such as the brain.The ability of some FINs to inhibit P-gp and ABCG2 suggests potential drug-drug interactions.展开更多
基金This research was funded by the Intramural Research Program of the National Institutes of Health,the National Cancer Institute.
文摘Aim:Ferroptosis is a non-apoptotic form of cell death caused by lethal lipid peroxidation.Several small molecule ferroptosis inducers(FINs)have been reported,yet little information is available regarding their interaction with the ATP-binding cassette(ABC)transporters P-glycoprotein(P-gp,ABCB1)and ABCG2.We thus sought to characterize the interactions of FINs with P-gp and ABCG2,which may provide information regarding oral bioavailability and brain penetration and predict drug-drug interactions.Methods:Cytotoxicity assays with ferroptosis-sensitive A673 cells transfected to express P-gp or ABCG2 were used to determine the ability of the transporters to confer resistance to FINs;confirmatory studies were performed in OVCAR8 and NCI/ADR-RES cells.The ability of FINs to inhibit P-gp or ABCG2 was determined using the fluorescent substrates rhodamine 123 or purpuin-18,respectively.Results:P-gp overexpression conferred resistance to FIN56 and the erastin derivatives imidazole ketone erastin and piperazine erastin.P-gp-mediated resistance to imidazole ketone erastin and piperazine erastin was also reversed in UO-31 renal cancer cells by CRISPR-mediated knockout of ABCB1.The FINs ML-162,GPX inhibitor 26a,and PACMA31 at 10µM were able to increase intracellular rhodamine 123 fluorescence over 10-fold in P-gp-expressing MDR-19 cells.GPX inhibitor 26a was able to increase intracellular purpurin-18 fluorescence over 4-fold in ABCG2-expressing R-5 cells.Conclusion:Expression of P-gp may reduce the efficacy of these FINs in cancers that express the transporter and may prevent access to sanctuary sites such as the brain.The ability of some FINs to inhibit P-gp and ABCG2 suggests potential drug-drug interactions.
