Enxia Zhang1, Jiasi Liu1, Lei Shi1, Xin Guo1, Ze Liang1, Jiaxin Zuo1, Hong Xu2, Huaxin Wang2, Xiaohong Shu1, Shanshan Huang1, Shubiao Zhang3, Xiaohui Kang4, Yuhong Zhen5. 1. College of Pharmacy, Dalian Medical University, Dalian, 116044, China. 2. College of Basic Medical Sciences, Dalian Medical University, Dalian, 116044, China. 3. Key Laboratory of Biotechnology and Bioresources Utilization of Ministry of Education, Dalian Minzu University, Dalian, 116600, China. 4. College of Pharmacy, Dalian Medical University, Dalian, 116044, China; State Key Laboratory of Fine Chemicals, Dalian University of Technology, Dalian, 116024, China. Electronic address: kangxh@dmu.edu.cn. 5. College of Pharmacy, Dalian Medical University, Dalian, 116044, China. Electronic address: zhenyhwaner@aliyun.com.
Abstract
AIMS: To investigate the effect of 7-O-geranylquercetin (GQ), a derivative of quercetin (Q), on reversing drug resistance in breast cancer MCF-7/ADR cells and reveal the mechanisms related to P-glycoprotein (P-gp). MAIN METHODS: Cell viability was determined by MTT assay. Accumulation of adriamycin (ADR) in cells was determined by confocal fluorescence microscope and microplate reader while that of rhodamine (Rh) was measured by flow cytometry. Expression levels of P-gp and MDR1 gene in cells were detected by western blot and Real-Time PCR, respectively. Molecular docking of GQ and Q with P-gp was conducted using AutoDock program. Xenograft model was established by inoculating MCF-7/ADR cells in BALB/c-nude mice. Tumor bearing mice were administered with ADR via tail vein injection and/or GQ (Q) by gavage. Expression levels of P-gp in tissues were detected by western blot and immunohistochemistry. KEY FINDINGS: GQ could reverse drug resistance of MCF-7/ADR cells to ADR. GQ inhibited the efflux of ADR by down-regulating the expression of P-gp protein and its encoding gene MDR1 in MCF-7/ADR cells. Molecular modeling showed that GQ matched with P-gp better than Q. GQ enhanced the antitumor effects of ADR and decreased the expression of P-gp in mice and its activities were higher than that of Q. GQ could reverse drug resistance of MCF-7/ADR cells by down-regulating the expression of P-gp in vitro and in vivo. SIGNIFICANCES: The reversal effect of GQ on P-gp-mediated drug resistance indicates its potential as a reversal agent for drug resistance in cancer chemotherapy.
AIMS: To investigate the effect of 7-O-geranylquercetin (GQ), a derivative of quercetin (Q), on reversing drug resistance in breast cancerMCF-7/ADR cells and reveal the mechanisms related to P-glycoprotein (P-gp). MAIN METHODS: Cell viability was determined by MTT assay. Accumulation of adriamycin (ADR) in cells was determined by confocal fluorescence microscope and microplate reader while that of rhodamine (Rh) was measured by flow cytometry. Expression levels of P-gp and MDR1 gene in cells were detected by western blot and Real-Time PCR, respectively. Molecular docking of GQ and Q with P-gp was conducted using AutoDock program. Xenograft model was established by inoculating MCF-7/ADR cells in BALB/c-nude mice. Tumor bearing mice were administered with ADR via tail vein injection and/or GQ (Q) by gavage. Expression levels of P-gp in tissues were detected by western blot and immunohistochemistry. KEY FINDINGS:GQ could reverse drug resistance of MCF-7/ADR cells to ADR. GQ inhibited the efflux of ADR by down-regulating the expression of P-gp protein and its encoding gene MDR1 in MCF-7/ADR cells. Molecular modeling showed that GQ matched with P-gp better than Q. GQ enhanced the antitumor effects of ADR and decreased the expression of P-gp in mice and its activities were higher than that of Q. GQ could reverse drug resistance of MCF-7/ADR cells by down-regulating the expression of P-gp in vitro and in vivo. SIGNIFICANCES: The reversal effect of GQ on P-gp-mediated drug resistance indicates its potential as a reversal agent for drug resistance in cancer chemotherapy.