目的 研究欧前胡素对人乳腺癌MCF-7/他莫昔芬（tamoxifen，TAM）的多药耐药逆转作用及相关机制。方法 分别用欧前胡素、TAM、欧前胡素联合他莫昔芬处理人乳腺癌MCF-7细胞和人乳腺癌他莫昔芬耐药株MCF-7/TAM细胞，采用MTT法检测MCF-7/TAM细胞耐药性、细胞活力以及联合用药逆转倍数；伤口愈合实验、Transwell实验、集落形成实验检测MCF-7/TAM细胞迁移、侵袭和集落形成能力；免疫印迹法检测细胞多药耐药相关蛋白1（multidrug resistance-associated protein 1，MRP1）、多药耐药1（multidrug resistance 1，MDR1）、谷胱甘肽S-转移酶π（glutathione S-transferase π ，GST-π）蛋白表达情况变化；将MCF-7/TAM细胞株接种于裸鼠皮下构建裸鼠乳腺癌TAM耐药移植瘤模型，分别将成功构建移植瘤裸鼠随机分为对照组、TAM（4.6 mg/kg）组、欧前胡素（20 mg/kg）组、TAM（4.6 mg/kg）联合欧前胡素低剂量（10 mg/kg）组、TAM（4.6 mg/kg）联合欧前胡素高剂量（20 mg/kg）组，ig给药21 d，期间测量肿瘤体积并称量体质量；给药结束后处死裸鼠剖取肿瘤组织称量肿瘤质量，采用TUNEL法检测肿瘤细胞凋亡情况；采用免疫组化法检测增殖标志物Ki-67的蛋白表达情况及病理情况；采用定量逆转录聚合酶链式反应（reverse transcription quantitative polymerase chain reaction，RT-qPCR）法和免疫印迹法检测多药耐药蛋白MRP1、MDR1、GST-π蛋白表达情况。结果 欧前胡素抑制MCF-7/TAM细胞增殖作用呈剂量相关性；欧前胡素联合TAM给药组显著抑制细MCF-7/TAM细胞迁移、侵袭和集落形成能力（P＜0.05、0.01）、显著下调多药耐药蛋白MRP1、MDR1、GST-π的蛋白表达（P＜0.05、0.01）；欧前胡素联合TAM能够逆转人乳腺癌TAM耐药的多药耐药性，抑制肿瘤增殖（P＜0.05）、增加肿瘤细胞凋亡（P＜0.05、0.01）、显著下调多药耐药蛋白MRP1、MDR1、GST-π的蛋白表达（P＜0.05、0.01）。结论 欧前胡素可增强乳腺癌MCF-7/TAM细胞TAM的敏感性，降低MRP1、MDR1、GST-π的蛋白表达，抑制乳腺癌TAM的耐药性。

Objective Investigate the role of imperatorin in reversing multidrug resistance in breast cancer MCF-7/tamoxifen (TAM) cells and its related mechanism. Methods Breast cancer MCF-7 cells and MCF-7/TAM cells were treated with imperatorin, TAM, and imperatorin combined with TAM in vitro, respectively. The drug resistance, cell viability and reversal ratio of MCF-7/TAM cells were detected by MTT assay. MCF-7/TAM cell migration, invasion and colony formation were evaluated by wound healing test, Transwell test and colony formation test, Western blotting was used to detect the changes in the protein expression of multidrug resistance-associated protein 1 (MRP1), multidrug resistance 1 (MDR1) and glutathione S-transferase π (GST-π). The MCF-7/TAM cell line was inoculated subcutaneously in nude mice to construct a TAM resistant xenograft model of breast cancer in nude mice, and the nude mice who successfully constructed xenografts were randomly divided into control group, TAM (4.6 mg/kg) group, imperatorin (20 mg/kg) group, TAM (4.6 mg/kg) combined with imperatorin low-dose (10 mg/kg) group, and TAM (4.6 mg/kg) combined with imperatorin high-dose (20 mg/kg) group, ig administration was performed for 21 days, during which tumor volume was measured and body weight was weighed. After the end of administration, nude mice were sacrificed to dissect tumor tissues to weigh the tumor mass, and the apoptosis of tumor cells was detected by TUNEL method. Immunohistochemistry was used to detect the expression and pathology of marker of proliferation Ki-67. Reverse transcription quantitative polymerase chain reaction，RT-qPCR and Western blotting were used to detect the protein expressions of multidrug resistance proteins MRP1, MDR1 and GST-π.Results In vitro, imperatorin inhibited the proliferation of MCF-7/TAM cells in a dose-dependent manner, and the combination of imperatorin and TAM significantly inhibited the migration, invasion and colony formation ability of fine MCF-7/TAM cells ( P < 0.05, 0.01), and significantly down-regulate the expression of multidrug resistant proteins MRP1, MDR1 and GST-π (P < 0.05, 0.01). In vivo, imperatorin combined with TAM could reverse the multidrug resistance of TAM-resistant human breast cancer, inhibit tumor proliferation (P < 0.05), increase tumor cell apoptosis (P < 0.05, 0.01), and significantly down-regulate the expression of multidrug resistant proteins MRP1, MDR1 and GST-π (P < 0.05, 0.01). Conclusion Imperatorin can enhance the TAM sensitivity of MCF-7/TAM cells, reduce the expression of MRP1, MDR1 and GST-π, and inhibit TAM resistance in breast cancer.

R285.5

国家自然科学基金项目(82060733);江西省卫生健康委员会项目(202311141);中药改良创新江西省重点实验室(2024SSY07131);大学生校级创新创业项目(X202310412252);校级研究生创新专项基金(JZYC23S77,JZYC23S71);江西中医药大学研究生教改项目(jzyjg-2023-07)