目前尚不清楚癌细胞如何克服细胞凋亡并在肿瘤微环境内营养匮乏的条件下维持进展。磷酸烯醇丙酮酸羧激酶（PEPCK 或 PCK）催化糖异生中的第一个限速反应，这是葡萄糖限制条件下癌细胞增殖所需的重要代谢改变。然而，PCK介导的糖异生是否影响非小细胞肺癌（NSCLC）的凋亡细胞死亡，其潜在机制仍不清楚。在含有低或高浓度的培养基中培养的A549细胞系中进行RNA-seq、Western blot和RT-PCR。葡萄糖浓度（1 mM 与 20 mM），以深入了解癌细胞在葡萄糖限制条件下如何重新连接其代谢。采用稳定同位素示踪代谢组学技术 (LC-MS) 来精确定量 PCK2 调节的 TCA 循环的代谢通量。使用流式细胞术评估 NSCLC 细胞的早期和晚期凋亡率以及线粒体 ROS。 Transwell 实验和基于荧光素酶的体内成像用于确定 PCK2 在 NSCLC 细胞迁移和侵袭中的作用。对 BALB/c 裸鼠进行异种移植以评估 PCK2 对体内肿瘤生长的影响。通过蛋白质印迹、免疫组织化学和 TUNEL 测定来评估线粒体凋亡的蛋白水平。本研究报告，在葡萄糖剥夺时，线粒体驻留 PCK (PCK2) 的上调依赖于内质网应激诱导的激活转录因子 4 (ATF4) 的表达。非小细胞肺癌细胞。此外，研究发现 PCK2 介导的代谢需要减少 TCA 循环和氧化磷酸化的负担以及线粒体活性氧的产生。这些代谢改变反过来减少了 Caspase9-Caspase3-PARP 信号通路的激活，从而驱动细胞凋亡。重要的是，沉默PCK2会增加低糖条件下NSCLC细胞的凋亡，并在体外和体内抑制肿瘤生长。综上所述，PCK2介导的代谢是NSCLC细胞在葡萄糖剥夺下获得抗凋亡的重要代谢适应。版权所有© 2024 张、何、刘、张、秦、张、程、李、王。

It is unknown how cancer cells override apoptosis and maintain progression under nutrition-deprived conditions within the tumor microenvironment. Phosphoenolpyruvate carboxykinase (PEPCK or PCK) catalyzes the first rate-limiting reaction in gluconeogenesis, which is an essential metabolic alteration that is required for the proliferation of cancer cells under glucose-limited conditions. However, if PCK-mediated gluconeogenesis affects apoptotic cell death of non small cell lung cancer (NSCLC) and its potential mechanisms remain unknown.RNA-seq, Western blot and RT-PCR were performed in A549 cell lines cultured in medium containing low or high concentrations of glucose (1 mM vs. 20 mM) to gain insight into how cancer cells rewire their metabolism under glucose-restriction conditions. Stable isotope tracing metabolomics technology (LC-MS) was employed to allow precise quantification of metabolic fluxes of the TCA cycle regulated by PCK2. Flow Cytometry was used to assess the rates of early and later apoptosis and mitochondrial ROS in NSCLC cells. Transwell assays and luciferase-based in vivo imaging were used to determine the role of PCK2 in migration and invasion of NSCLC cells. Xenotransplants on BALB/c nude mice to evaluate the effects of PCK2 on tumor growth in vivo. Western blot, Immunohistochemistry and TUNEL assays to evaluate the protein levels of mitochondrial apoptosis.This study report that the mitochondrial resident PCK (PCK2) is upregulated in dependent of endoplasmic reticulum stress-induced expression of activating transcription factor 4 (ATF4) upon glucose deprivation in NSCLC cells. Further, the study finds that PCK2-mediated metabolism is required to decrease the burden of the TCA cycles and oxidative phosphorylation as well as the production of mitochondrial reactive oxygen species. These metabolic alterations in turn reduce the activation of Caspase9-Caspase3-PARP signal pathway which drives apoptotic cell death. Importantly, silencing PCK2 increases apoptosis of NSCLC cells under low glucose condition and inhibits tumor growth both in vitro and in vivo.In summary, PCK2-mediated metabolism is an important metabolic adaptation for NSCLC cells to acquire resistance to apoptosis under glucose deprivation.Copyright © 2024 Zhang, He, Liu, Zhang, Qin, Zhang, Cheng, Li and Wang.