Abstract The aim of this study was to investigate the role of nuclear factor erythroid 2-related factor 2 (Nrf2) and key downstream targeting molecule, malic enzyme-1 (ME-1), in the induction of 5-fluorouracil (5-FU) resistance. Resistant MKN-45 (MKN-45/DR) cell line was generated by employing IC50 concentration of the agent followed by a resting cycles. Cell viability and apoptosis were evaluated by MTT assay, DAPI staining and flow cytometry. mRNA expression levels of Nrf2 and ME-1 were measured by qRT-PCR technique. Morphology analysis and combination index calculation were assessed by ImagJ and compuSyn softwares, respectively. The value for IC50 in 5-FU resistant cells increased from 8.81 ± 0.209–142.4 ± 0.060 μM with a considerable morphological changes from round to elongated shape (p = 0.016). Nrf2 and ME-1 expression levels were decreased in resistant cells with a marked increase in MDR1 mRNA level compared to sensitive cells. Combination of Nrf2 inhibitors, luteolin and brusatol had synergistic effects on 5-FU induced cytotoxicity. Moreover, combined incubation of MKN-45/DR cells with these inhibitors, exponentially increased Nrf2 and ME-1 mRNA levels (p

中文翻译：

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Nrf2-ME-1轴与胃癌细胞系5-FU耐药相关

摘要 本研究的目的是研究核因子红细胞 2 相关因子 2 (Nrf2) 和关键下游靶向分子苹果酸酶-1 (ME-1) 在诱导 5-氟尿嘧啶 (5-FU ） 抵抗性。抗性 MKN-45 (MKN-45/DR) 细胞系是通过使用 IC50 浓度的药剂然后静息循环产生的。通过 MTT 测定、DAPI 染色和流式细胞术评估细胞活力和凋亡。通过qRT-PCR技术测量Nrf2和ME-1的mRNA表达水平。形态分析和组合指数计算分别通过 ImagJ 和 compuSyn 软件进行评估。5-FU 抗性细胞中的 IC50 值从 8.81 ± 0.209–142.4 ± 0.060 μM 增加，从圆形到细长形状有相当大的形态变化（p = 0.016）。与敏感细胞相比，抗性细胞中 Nrf2 和 ME-1 的表达水平降低，MDR1 mRNA 水平显着增加。Nrf2 抑制剂、木犀草素和 brusatol 的组合对 5-FU 诱导的细胞毒性具有协同作用。此外，将 MKN-45/DR 细胞与这些抑制剂联合培养，Nrf2 和 ME-1 mRNA 水平呈指数增加（p