Background

Cisplatin resistance is one of the major obstacles in non-small cell lung cancer (NSCLC) treatment. Intriguingly, elevated lactate levels were observed in cisplatin-resistant cells, which spurred further investigation into their underlying biological mechanisms.

Methods

Lactate levels were measured by lactate detection kit. Cisplatin-resistance NSCLC cells were established using progressive concentration of cisplatin. Cell viability, proliferation, and apoptosis were detected by CCK-8, EdU, and flow cytometry, respectively. Cell proliferation in vivo was determined by immunohistochemistry of Ki67 and apoptotic cells were calculated by the TUNEL. MeRIP-PCR was used to measure FOXO3 m6A levels. The interactions of genes were analyzed via RIP, ChIP, Dual-luciferase reporter, and RNA pull-down, respectively.

Results

Elevated lactate levels were observed in both NSCLC patients and cisplatin-resistance cells. Lactate treatment increased cisplatin-resistance cell viability in vitro and promoted tumor growth in vivo. Mechanistically, lactate downregulated FOXO3 by YTHDF2-mediated m6A modification. FOXO3 transcriptionally reduced MAGI1-IT1 expression. FOXO3 overexpression inhibited the lactate-induced promotion of cisplatin resistance in NSCLC, which were reversed by MAGI1-IT1 overexpression. MAGI1-IT1 and IL6R competitively bound miR-664b-3p. FOXO3 overexpression or MAGI1-IT1 knockdown repressed lactate-mediated cisplatin resistance in vivo.

Conclusion

Lactate promoted NSCLC cisplatin resistance through regulating FOXO3/MAGI1-IT1/miR-664b-3p/IL6R axis in YTHDF2-mediated m6A modification.

中文翻译：

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乳酸通过调节 m6A 修饰介导的 FOXO3/MAGI1-IT1/miR-664b-3p/IL-6R 轴促进 NSCLC 中的顺铂耐药

背景

顺铂耐药是非小细胞肺癌（NSCLC）治疗的主要障碍之一。有趣的是，在顺铂耐药细胞中观察到乳酸水平升高，这激发了对其潜在生物学机制的进一步研究。

方法

通过乳酸检测试剂盒测量乳酸水平。使用渐进浓度的顺铂建立顺铂耐药性 NSCLC 细胞。分别通过CCK-8、EdU和流式细胞仪检测细胞活力、增殖和凋亡。通过Ki67免疫组化测定体内细胞增殖，通过TUNEL计算凋亡细胞。MeRIP-PCR 用于测量 FOXO3 m6A 水平。分别通过 RIP、ChIP、双荧光素酶报告基因和 RNA pull-down 分析基因的相互作用。

结果

在 NSCLC 患者和顺铂耐药细胞中均观察到乳酸水平升高。乳酸治疗可增加体外顺铂耐药细胞的活力，并促进体内肿瘤生长。从机制上讲，乳酸通过 YTHDF2 介导的 m6A 修饰下调 FOXO3。FOXO3 转录减少 MAGI1-IT1 表达。FOXO3 过表达抑制乳酸诱导的 NSCLC 中顺铂耐药性的促进，MAGI1-IT1 过表达可逆转这种情况。MAGI1-IT1 和 IL6R 竞争性结合 miR-664b-3p。FOXO3 过表达或 MAGI1-IT1 敲低可抑制体内乳酸介导的顺铂耐药性。

结论

乳酸通过在 YTHDF2 介导的 m6A 修饰中调节 FOXO3/MAGI1-IT1/miR-664b-3p/IL6R 轴来促进 NSCLC 顺铂耐药。