中文摘要：

目的 探讨补骨脂素对乳腺癌干细胞拓扑异构酶Ⅱα（topoisomerase,TopoⅡα）表达的影响。方法 选用乳腺癌多药耐药细胞株（MCF-7/ADR）为模型,用免疫磁珠法筛选乳腺癌干细胞;运用光学显微镜观察乳腺癌干细胞生长状态;用CCK-8法检测补骨脂素对乳腺癌干细胞的毒性作用以及阿霉素和阿霉素与补骨脂素联合用药组对乳腺癌干细胞的IC50,计算逆转倍数;运用RT-PCR检测拓扑异构酶Ⅱα基因mRNA表达水平;运用Western blot法检测拓扑异构酶Ⅱα蛋白表达水平。结果 在光学显微镜下,乳腺癌干细胞呈球形生长;补骨脂素对乳腺癌干细胞的IC10为（6.77±0.23）μg/mL,IC20为（10.36±0.21）μg/mL;阿霉素对乳腺癌干细胞的IC50为（90.03±3.56）μg/mL,阿霉素与补骨脂素联合用药对乳腺癌干细胞的IC50为（21.47±0.82）μg/mL,逆转倍数为4.19倍;补骨脂素处理后,拓扑异构酶Ⅱα基因mRNA表达水平均升高,与对照组相比,6μg/mL组升高1.9倍（P=0.008,差异有统计学意义）,10μg/mL组升高2.7倍（P=0.000,差异有统计学意义）;补骨脂素处理后,拓扑异构酶Ⅱα蛋白表达均升高,与对照组相比,6μg/mL组升高1.8倍（P=0.003,差异有统计学意义）,10μg/mL组升高2.4倍（P=0.000,差异有统计学意义）。结论 补骨脂素能够上调乳腺癌干细胞拓扑异构酶基因和蛋白的表达,增加药物的作用靶点,逆转乳腺癌干细胞对阿霉素的耐药。

英文摘要：

Objective To explore the effect of psoralen on topoisomerase IIα（TopoIIα） expression of breast cancer stem cells. Methods CD44^＋ CD24 ^-/tow breast cancer stem cells were sorted from MCF-7/ADR by magneticactivated cell sorting（MACS）. We observed the growth characteristics of these stem cells through optical microscope and detected the growth-inhibitory effects of psoralen on breast cancer stem cells by CCK-8 assay and IC50 of adriamycin and adriamycin combined with psoralen to calculate the reversal index. The mRNA and protein expressions of Topo IIα were detected using RT-PCR and Western blot, respectively. Results Under the optical microscope, breast cancer stem cells presented spheres. IC10 and IC20 of psoralen on breast cancer stem cells were （6.77±0.23） μg/mL and （10.36 ± 0. 21） μg/mL. IC50 of adriamycin and adriamycin combined with psoralen on breast cancer stem cells was （90.03±3.56）μg/mL and （21.47±0.82）μg/mL, the reversal index was 4.19. Psoralen significantly raised the expressions of Topo Ⅱα at mRNA and protein levels. Conclusion Psoralen reversed the resistance of adriamycin by increasing the gene and protein expressions of breast cancer stem cells Topo ]μg/mL and the drug targets.