Krüger Katharina, Ziegler Verena, Hartmann Christina, Henninger Christian, Thomale Jürgen, Schupp Nicole, Fritz Gerhard
Institute of Toxicology, Medical Faculty, Heinrich Heine University Düsseldorf, 40225 Düsseldorf, Germany.
Institute of Cell Biology, University Duisburg-Essen, 45122 Essen, Germany.
Toxicol Appl Pharmacol. 2016 Feb 1;292:103-14. doi: 10.1016/j.taap.2015.12.023. Epub 2015 Dec 29.
The platinating agent cisplatin (CisPt) is commonly used in the therapy of various types of solid tumors. The anticancer efficacy of CisPt largely depends on the formation of bivalent DNA intrastrand crosslinks, which stimulate mechanisms of the DNA damage response (DDR), thereby triggering checkpoint activation, gene expression and cell death. The clinically most relevant adverse effect associated with CisPt treatment is nephrotoxicity that results from damage to renal tubular epithelial cells. Here, we addressed the question whether the HMG-CoA-reductase inhibitor lovastatin affects the DDR of renal cells by employing rat renal proximal tubular epithelial (NRK-52E) cells as in vitro model. The data show that lovastatin has extensive inhibitory effects on CisPt-stimulated DDR of NRK-52E cells as reflected on the levels of phosphorylated ATM, Chk1, Chk2, p53 and Kap1. Mitigation of CisPt-induced DDR by lovastatin was independent of the formation of DNA damage as demonstrated by (i) the analysis of Pt-(GpG) intrastrand crosslink formation by Southwestern blot analyses and (ii) the generation of DNA strand breaks as analyzed on the level of nuclear γH2AX foci and employing the alkaline comet assay. Lovastatin protected NRK-52E cells from the cytotoxicity of high CisPt doses as shown by measuring cell viability, cellular impedance and flow cytometry-based analyses of cell death. Importantly, the statin also reduced the level of kidney DNA damage and apoptosis triggered by CisPt treatment of mice. The data show that the lipid-lowering drug lovastatin extensively counteracts pro-apoptotic signal mechanisms of the DDR of tubular epithelial cells following CisPt injury.
铂类药物顺铂（CisPt）常用于治疗各种类型的实体瘤。顺铂的抗癌疗效很大程度上取决于二价DNA链内交联的形成，这种交联会刺激DNA损伤反应（DDR）机制，从而触发检查点激活、基因表达和细胞死亡。与顺铂治疗相关的临床上最相关的不良反应是肾小管上皮细胞损伤导致的肾毒性。在此，我们通过使用大鼠肾近端小管上皮（NRK-52E）细胞作为体外模型，探讨了HMG-CoA还原酶抑制剂洛伐他汀是否会影响肾细胞的DDR。数据表明，洛伐他汀对顺铂刺激的NRK-52E细胞DDR具有广泛的抑制作用，这在磷酸化ATM、Chk1、Chk2、p53和Kap1的水平上得到体现。洛伐他汀减轻顺铂诱导的DDR与DNA损伤的形成无关，这通过以下两点得以证明：（i）通过蛋白质印迹分析对Pt-(GpG)链内交联形成进行分析；（ii）在核γH2AX焦点水平上进行分析并采用碱性彗星试验对DNA链断裂的产生进行分析。通过测量细胞活力、细胞阻抗以及基于流式细胞术的细胞死亡分析表明，洛伐他汀保护NRK-52E细胞免受高剂量顺铂的细胞毒性作用。重要的是，该他汀类药物还降低了顺铂处理小鼠后肾脏DNA损伤和细胞凋亡的水平。数据表明，降脂药物洛伐他汀广泛对抗顺铂损伤后肾小管上皮细胞DDR的促凋亡信号机制。
