Szwed Marzena, Laroche-Clary Audrey, Robert Jacques, Jozwiak Zofia
Department of Thermobiology, Faculty of Biology and Environmental Protection, University of Lodz, Pomorska 141/143 Street, 90-236, Lodz, Poland.
INSERM U916, Institut Bergonié, Université de Bordeaux, 33076, Bordeaux, France.
Cell Oncol (Dordr). 2016 Apr;39(2):107-18. doi: 10.1007/s13402-015-0256-2. Epub 2015 Nov 26.
Doxorubicin (DOX) is a small molecular cytotoxic agent that can be transferred efficiently to cancer cells by nanocarriers. This anthracycline antibiotic serves as an effective anti-neoplastic drug against both hematological and solid malignancies. Here, we set out to assess the capacity of a novel doxorubicin - transferrin conjugate (DOX-TRF) to provoke apoptosis in human normal and leukemia cells through free radicals produced via a redox cycle of doxorubicin (DOX) when released from its conjugate.
After DOX-TRF exposure, we determined the time-course of apoptotic and necrotic events, the generation of reactive oxygen species (ROS), changes in mitochondrial membrane potential, as well as alterations in cytochrome c levels and intracellular calcium concentrations in human leukemia-derived cell lines (CCRF-CEM, K562 and its doxorubicin-resistant derivative K562/DOX) and normal peripheral blood-derived mononuclear cells (PBMC).
We found that DOX-TRF can induce apoptosis in all leukemia-derived cell lines tested, which was associated with morphological changes and decreases in mitochondrial membrane potential. In comparison to free DOX treated cells, we observed a time-dependency between a higher level of ROS generation and a higher drop in mitochondrial membrane potential, particularly in the doxorubicin-resistant cell line. In addition, we found that the apoptotic cell death induced by DOX-TRF was directly associated with a release of cytochrome c from the mitochondria and an increase in intracellular calcium level in all human leukemia-derived cell lines tested.
Our data indicate that DOX-TRF is considerably more cytotoxic to human leukemia cells than free DOX. In addition, we show that DOX-TRF can effectively produce free radicals, which are directly involved in apoptosis induction.
阿霉素（DOX）是一种小分子细胞毒性药物，可通过纳米载体有效转运至癌细胞。这种蒽环类抗生素是一种有效的抗肿瘤药物，对血液系统恶性肿瘤和实体瘤均有疗效。在此，我们旨在评估新型阿霉素-转铁蛋白偶联物（DOX-TRF）在从偶联物中释放时，通过阿霉素（DOX）的氧化还原循环产生的自由基诱导人正常细胞和白血病细胞凋亡的能力。
DOX-TRF处理后，我们测定了人白血病来源细胞系（CCRF-CEM、K562及其阿霉素耐药衍生物K562/DOX）和正常外周血来源单核细胞（PBMC）中凋亡和坏死事件的时间进程、活性氧（ROS）的产生、线粒体膜电位的变化，以及细胞色素c水平和细胞内钙浓度的改变。
我们发现DOX-TRF可诱导所有测试的白血病来源细胞系凋亡，这与形态学变化和线粒体膜电位降低有关。与游离DOX处理的细胞相比，我们观察到较高水平的ROS产生与线粒体膜电位较大幅度下降之间存在时间依赖性，特别是在阿霉素耐药细胞系中。此外，我们发现DOX-TRF诱导的凋亡性细胞死亡与所有测试的人白血病来源细胞系中线粒体细胞色素c的释放和细胞内钙水平的升高直接相关。
我们的数据表明，DOX-TRF对人白血病细胞的细胞毒性比游离DOX大得多。此外，我们表明DOX-TRF可有效产生自由基，这些自由基直接参与凋亡诱导。
