A Phenylfurocoumarin Derivative Reverses ABCG2-Mediated Multidrug Resistance In Vitro and In Vivo |
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| Authors: | Shoji Kokubo Shinobu Ohnuma Megumi Murakami Haruhisa Kikuchi Shota Funayama Hideyuki Suzuki Taiki Kajiwara Akihiro Yamamura Hideaki Karasawa Norihiko Sugisawa Kosuke Ohsawa Kuniyuki Kano Junken Aoki Takayuki Doi Takeshi Naitoh Suresh V Ambudkar Michiaki Unno |
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| Affiliation: | 1.Department of Surgery, Tohoku University Graduate School of Medicine, Sendai 980-8574, Japan; (S.K.); (M.M.); (H.S.); (T.K.); (A.Y.); (H.K.); (N.S.); (T.N.); (M.U.);2.Laboratory of Cell Biology, Center for Cancer Research, National Cancer Institute, NIH, Bethesda, MD 20892, USA;3.Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai 980-8578, Japan; (H.K.); (S.F.); (K.O.); (K.K.); (J.A.); (T.D.) |
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| Abstract: | The ATP-binding cassette subfamily G member 2 (ABCG2) transporter is involved in the development of multidrug resistance in cancer patients. Many inhibitors of ABCG2 have been reported to enhance the chemosensitivity of cancer cells. However, none of these inhibitors are being used clinically. The aim of this study was to identify novel ABCG2 inhibitors by high-throughput screening of a chemical library. Among the 5812 compounds in the library, 23 compounds were selected in the first screening, using a fluorescent plate reader-based pheophorbide a (PhA) efflux assay. Thereafter, to validate these compounds, a flow cytometry-based PhA efflux assay was performed and 16 compounds were identified as potential inhibitors. A cytotoxic assay was then performed to assess the effect these 16 compounds had on ABCG2-mediated chemosensitivity. We found that the phenylfurocoumarin derivative (R)-9-(3,4-dimethoxyphenyl)-4-((3,3-dimethyloxiran-2-yl)methoxy)-7H-furo 3,2-g]chromen-7-one (PFC) significantly decreased the IC50 of SN-38 in HCT-116/BCRP colon cancer cells. In addition, PFC stimulated ABCG2-mediated ATP hydrolysis, suggesting that this compound interacts with the substrate-binding site of ABCG2. Furthermore, PFC reversed the resistance to irinotecan without causing toxicity in the ABCG2-overexpressing HCT-116/BCRP cell xenograft mouse model. In conclusion, PFC is a novel inhibitor of ABCG2 and has promise as a therapeutic to overcome ABCG2-mediated MDR, to improve the efficiency of cancer chemotherapy. |
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| Keywords: | ABCG2 inhibitor multidrug resistance phenylfurocoumarin ABC transporter chemosensitivity |
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