Szwed Marzena, Kania Katarzyna D, Jozwiak Zofia
Department of Thermobiology, Faculty of Biology and Environmental Protection, University of Lodz, Pomorska 141/143 Street, 90-236 Lodz, Poland.
Laboratory of Transcriptional Regulation, Institute of Medical Biology, Polish Academy of Sciences, Lodowa 106, 93-232 Łódź, Poland.
Biochimie. 2014 Dec;107 Pt B:358-66. doi: 10.1016/j.biochi.2014.10.005. Epub 2014 Oct 13.
Doxorubicin (DOX), one of the oldest member of the anthracycline antibiotics, has been administered for over 50 years to patients with leukemias and solid tumors. However, the high unspecified DOX toxicity, related to reactive oxygen species (ROS), affects its limitation in clinical application. Therefore we proposed the usage of human transferrin as a doxorubicin carrier in order to improve the quality of doxorubicin application in conventional chemotherapy. In this study we continue our investigations related to the mechanism of the toxicity of doxorubicin-transferrin (DOX-TRF) conjugate in human leukemia cells. Consequently, we are now concentrating on the influence of this compound on the antioxidative system in K562 and CCRF-CEM cell lines (chronic erythromyeloblastoid leukemia and acute lymphoblastic leukemia cells, respectively). We carried out a neutral red cytotoxicity assay, reduced (GSH) and total (GSH + GSSG) glutathione content, alterations in the activity of catalase and enzymes responsible for maintaining glutathione in reduced form. Exposure of leukemia cells to the investigated anticancer agents caused a time-dependent depletion of intracellular GSH, accompanied by an increase of catalase activity. Moreover, analysis of GSH-related enzymes showed a significant increase in the activities of thioredoxin reductase and glutathione peroxidase after DOX-TRF application. In contrast, glutathione reductase activity was reduced by conjugate treatment to 50%. Significant differences between the pro-oxidative actions of the investigated anticancer compounds were observed in RT-PCR experiments, which confirmed that changes in the activity of catalase and GSH-related enzymes are strictly correlated with their gene transcription changes.
阿霉素（DOX）是蒽环类抗生素中使用历史最久的药物之一，已用于白血病和实体瘤患者治疗超过50年。然而，与活性氧（ROS）相关的阿霉素高非特异性毒性影响了其临床应用。因此，我们提议使用人转铁蛋白作为阿霉素载体，以提高阿霉素在传统化疗中的应用质量。在本研究中，我们继续研究阿霉素 - 转铁蛋白（DOX - TRF）偶联物对人白血病细胞毒性的机制。因此，我们现在专注于该化合物对K562和CCRF - CEM细胞系（分别为慢性红白血病和急性淋巴细胞白血病细胞）抗氧化系统的影响。我们进行了中性红细胞毒性测定、还原型（GSH）和总谷胱甘肽（GSH + GSSG）含量测定、过氧化氢酶活性变化以及负责维持谷胱甘肽还原形式的酶活性变化的研究。白血病细胞暴露于所研究的抗癌药物会导致细胞内GSH随时间依赖性消耗，同时过氧化氢酶活性增加。此外，对与GSH相关的酶的分析表明，应用DOX - TRF后硫氧还蛋白还原酶和谷胱甘肽过氧化物酶的活性显著增加。相反，共轭处理使谷胱甘肽还原酶活性降低至50%。在RT - PCR实验中观察到所研究的抗癌化合物的促氧化作用之间存在显著差异，这证实了过氧化氢酶和与GSH相关的酶活性变化与其基因转录变化密切相关。
