Elevated expression of drug efflux pumps such as multidrug resistant protein-1 (MDR1/ABCB1) and multidrug resistance associated protein-1 (MRP1/ABCC1) in cancer stem cells (CSCs) among a bulky tumor cell population was attributed to drug resistance. For the first time, we have quantitatively evaluated the cytotoxic profile of camptothecin (CPT) against the CSC. In the present study, a Qdot based total internal reflection fluorescence (TIRF) detection system effectively interpreted that drug resistance to CPT was reduced in the CSC under ABCB1 inhibited conditions. This study revealed that quantitative finding of the EC50 value for apoptosis and necrosis in correlation with the ABC inhibitor and CSC population using TIRF could provide more details of the anti-cancer efficacy of chemotherapeutic agents.

中文翻译：

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基于喜树碱对TIRF的抗乳腺癌干细胞抗癌活性的测定，对ABC转运蛋白介导的耐药性进行定量评估。

大量肿瘤细胞群中癌症干细胞（CSC）中诸如多药耐药蛋白-1（MDR1 / ABCB1）和多药耐药相关蛋白-1（MRP1 / ABCC1）等药物外排泵的表达升高归因于耐药性。首次，我们定量评估了喜树碱（CPT）对CSC的细胞毒性谱。在本研究中，基于Qdot的全内反射荧光（TIRF）检测系统有效地解释了在ABCB1抑制条件下CSC对CPT的耐药性降低了。这项研究表明，使用TIRF定量发现与ABC抑制剂和CSC群体相关的凋亡和坏死EC50值可以提供化学治疗剂抗癌功效的更多细节。