Department of Orthopaedic Surgery, Eberhard Karls University Tuebingen, D‑72076 Tuebingen, Germany.
Department of Orthopaedic Surgery, Laboratory of Cell Biology, Eberhard Karls University Tuebingen, D‑72072 Tuebingen, Germany.
Oncol Rep. 2020 Jan;43(1):337-345. doi: 10.3892/or.2019.7409. Epub 2019 Nov 20.
Ewing sarcomas (ES) are highly malignant mesenchymal tumors, which most often occur in children and adolescents. The current treatment of choice comprises wide resection in combination with multimodal chemotherapy including etoposide (Eto). Due to the serious side effects associated with common chemotherapeutics and prevalent multidrug resistance in recurrent and metastatic ES, there is a growing demand for alternative strategies and add‑on drugs. Previous research has demonstrated efficient cell death induction by Eto in combination with arsenic trioxide (ATO) in ES cell lines. The aim of the present study was to investigate the effect of different temporal sequences of ATO and Eto administration on apoptosis induction and to explore the effect of both drugs on inhibitory glycogen synthase kinase‑3β (GSK3‑β) phosphorylation as well as multidrug transporter gene expression. The intensity of caspase activation was mainly determined by the Eto doses in A673 and TC‑71 cells, whereas in RD‑ES cells ATO application actively suppressed Eto‑induced apoptosis. This coincided with an increase in inhibitory GSK‑3β phosphorylation in ATO‑treated RD‑ES cells. Inherent mRNA expression of multidrug resistance‑associated protein 1 (MRP1) was low in the ES cell lines compared to that observed in the mesenchymal stem cells (MSC), whereas multidrug resistance protein 1 (MDR1) gene expression was considerably increased in the ES cell lines. ATO treatment reduced MRP1 mRNA expression in the A673 and TC‑71 cells, while expression was induced in the MSC and RD‑ES cells. In contrast, MDR1 mRNA expression was specifically induced by ATO in the A673 and TC‑71 cells, reinforcing the expression differences between MSC and the ES cell lines. Although a reliable cell death induction by the combination of ATO and Eto has been previously shown in ES cell lines, the present study showed marked heterogeneity of the ES cell response to ATO and Eto treatment, illustrating the difficulty of prediction of individual treatment outcome in ES.
尤因肉瘤 (ES) 是一种高度恶性的间充质肿瘤，主要发生在儿童和青少年中。目前的治疗选择包括广泛的切除手术，结合包括依托泊苷 (Eto) 在内的多模式化疗。由于与常用化疗药物相关的严重副作用以及复发性和转移性 ES 中普遍存在的多药耐药性，人们对替代策略和附加药物的需求不断增加。先前的研究表明，依托泊苷 (Eto) 与三氧化二砷 (ATO) 联合使用可有效诱导 ES 细胞系中的细胞死亡。本研究旨在探讨 ATO 和 Eto 给药的不同时间顺序对细胞凋亡诱导的影响，并研究两种药物对抑制糖原合酶激酶 3β (GSK3-β) 磷酸化以及多药转运体基因表达的影响。A673 和 TC-71 细胞中 caspase 激活的强度主要取决于 Eto 剂量，而 RD-ES 细胞中 ATO 的应用则积极抑制 Eto 诱导的细胞凋亡。这与 ATO 处理的 RD-ES 细胞中抑制性 GSK-3β 磷酸化增加一致。ES 细胞系中多药耐药相关蛋白 1 (MRP1) 的固有 mRNA 表达水平低于间充质干细胞 (MSC)，而 ES 细胞系中多药耐药蛋白 1 (MDR1) 基因表达水平显著增加。ATO 处理降低了 A673 和 TC-71 细胞中 MRP1 的 mRNA 表达，而在 MSC 和 RD-ES 细胞中则诱导表达。相反，ATO 特异性诱导 A673 和 TC-71 细胞中 MDR1 的 mRNA 表达，这强化了 MSC 和 ES 细胞系之间的表达差异。尽管先前已经证明 ATO 和 Eto 联合使用可可靠地诱导 ES 细胞系中的细胞死亡，但本研究表明 ES 细胞对 ATO 和 Eto 处理的反应存在明显的异质性，表明 ES 中个体治疗效果的预测存在困难。
