Metabolic reprogramming contributes significantly to tumor development and is tightly linked to drug resistance. The chemotherapeutic agent etoposide (VP-16) has been used clinically in the treatment of lung cancer but possess different sensitivity and efficacy towards SCLC and NSCLC. Here, we assessed the impact of etoposide on glycolytic metabolism in SCLC and NSCLC cell lines and investigated the role of metabolic rewiring in mediating etoposide resistance. glycolytic differences of drug-treated cancer cells were determined by extracellular acidification rate (ECAR), glucose consumption, lactate production and western blot. DNA damage was evaluated by the comet assay and western blot. Chemoresistant cancer cells were analyzed by viability, apoptosis and western blot. Chromatin immunoprecipitation (ChIP) was used for analysis of DNA-protein interaction. Here we showed that exposure to chemotherapeutic drug etoposide induces an exacerbation of ROS production which activates HIF-1α-mediated the metabolic reprogramming toward increased glycolysis and lactate production in non-small cell lung cancer (NSCLC). We identified lactic acidosis as the key that confers multidrug resistance through upregulation of multidrug resistance-associated protein 1 (MRP1, encoded by ABCC1), a member of ATP-binding cassette (ABC) transporter family. Mechanistically, lactic acid coordinates TGF-β1/Snail and TAZ/AP-1 pathway to induce formation of Snail/TAZ/AP-1 complex at the MRP1/ABCC1 promoter. Induction of MRP1 expression inhibits genotoxic and apoptotic effects of chemotherapeutic drugs by increasing drug efflux. Furthermore, titration of lactic acid with NaHCO3 was sufficient to overcome resistance. The chemotherapeutic drug etoposide induces the shift toward aerobic glycolysis in the NSCLC rather than SCLC cell lines. The increased lactic acid in extracellular environment plays important role in etoposide resistance through upregulation of MRP expression. These data provide first evidence for the increased lactate production, upon drug treatment, contributes to adaptive resistance in NSCLC and reveal potential vulnerabilities of lactate metabolism and/or pathway suitable for therapeutic targeting.

中文翻译：

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乳酸诱导的 MRP1 表达有助于非小细胞肺癌细胞中基于代谢的依托泊苷抵抗

代谢重编程对肿瘤发展有显着贡献，并且与耐药性密切相关。化疗药物依托泊苷（VP-16）已在临床上用于肺癌的治疗，但对小细胞肺癌和非小细胞肺癌具有不同的敏感性和疗效。在这里，我们评估了依托泊苷对 SCLC 和 NSCLC 细胞系糖酵解代谢的影响，并研究了代谢重排在介导依托泊苷耐药中的作用。通过细胞外酸化率 (ECAR)、葡萄糖消耗、乳酸产生和蛋白质印迹确定药物处理的癌细胞的糖酵解差异。通过彗星试验和蛋白质印迹评估 DNA 损伤。通过活力、细胞凋亡和蛋白质印迹分析化学抗性癌细胞。染色质免疫沉淀 (ChIP) 用于分析 DNA-蛋白质相互作用。在这里，我们表明，暴露于化疗药物依托泊苷会导致 ROS 生成加剧，这会激活 HIF-1α 介导的代谢重编程，从而增加非小细胞肺癌 (NSCLC) 的糖酵解和乳酸生成。我们确定乳酸酸中毒是通过上调多药耐药相关蛋白 1（MRP1，由 ABCC1 编码）（ATP 结合盒（ABC）转运蛋白家族的成员）来赋予多药耐药性的关键。从机制上讲，乳酸协调 TGF-β1/Snail 和 TAZ/AP-1 通路以诱导在 MRP1/ABCC1 启动子处形成 Snail/TAZ/AP-1 复合物。MRP1 表达的诱导通过增加药物流出来抑制化疗药物的基因毒性和细胞凋亡作用。此外，用 NaHCO3 滴定乳酸足以克服阻力。化疗药物依托泊苷诱导非小细胞肺癌而非小细胞肺癌细胞系向有氧糖酵解转变。细胞外环境中增加的乳酸通过上调 MRP 表达在依托泊苷抵抗中起重要作用。这些数据为药物治疗后乳酸产生的增加提供了第一个证据，有助于非小细胞肺癌的适应性耐药，并揭示了乳酸代谢和/或适合治疗靶向的途径的潜在脆弱性。细胞外环境中增加的乳酸通过上调 MRP 表达在依托泊苷抵抗中起重要作用。这些数据为药物治疗后乳酸产生的增加提供了第一个证据，有助于非小细胞肺癌的适应性耐药，并揭示了乳酸代谢和/或适合治疗靶向的途径的潜在脆弱性。细胞外环境中增加的乳酸通过上调 MRP 表达在依托泊苷抵抗中起重要作用。这些数据为药物治疗后乳酸产生的增加提供了第一个证据，有助于非小细胞肺癌的适应性耐药，并揭示了乳酸代谢和/或适合治疗靶向的途径的潜在脆弱性。