Abstract：
Metformin is currently a strong candidate antitumor agent for multiple cancers, and has the potential to inhibit cancer cell viability, growth, and proliferation. Metabolic reprogramming is a critical feature of cancer cells. However, the effects of metformin which targets glucose metabolism on HepG2 cancer cells remain unclear. In this study, to explore the effects of metformin on glucose metabolism in HepG2 cells, we conducted real-time metabolomic monitoring of live HepG2 cells treated with metformin using 13C in-cell NMR spectroscopy. Metabolic tracing with U-13C6-glucose revealed that metformin significantly increased the production of 13C-G3P and 13C-glycerol, which were reported to attenuate liver cancer development, but decreased the production of potential oncogenesis-supportive metabolites, including 13C-lactate, 13C-alanine, 13C-glycine, and 13C-glutamate. Moreover, the expression levels of enzymes associated with the measured metabolites were carried out. The results showed that the levels of ALT1, MCT4, GPD2 and MPC1 were greatly reduced, which were consistent with the changes of measured metabolites in 13C in-cell NMR spectroscopy. Overall, our approach directly provides fundamental insights into the effects of metformin on glucose metabolism in live HepG2 cells, and highlights the potential mechanism of metformin, including the increase in production of G3P and glycerol derived from glucose, as well as the inhibition of glucose incorporation into lactate, alanine, glutamate, and glycine.
摘要：
二甲双胍目前是多种癌症的强大候选抗肿瘤药物，并有可能抑制癌细胞的活力，增长,和扩散。代谢重编程是癌细胞的关键特征。然而,靶向葡萄糖代谢的二甲双胍对HepG2癌细胞的影响尚不清楚.在这项研究中,探讨二甲双胍对HepG2细胞糖代谢的影响,我们使用13C细胞内核磁共振波谱对二甲双胍处理的活HepG2细胞进行了实时代谢组学监测.用U-13C6-葡萄糖的代谢示踪显示二甲双胍显著增加13C-G3P和13C-甘油的产生,据报道可以减轻肝癌的发展，但是减少了潜在的致癌支持性代谢物的产生，包括13C-乳酸，13C-丙氨酸，13C-甘氨酸，和13C-谷氨酸。此外，进行与测量的代谢物相关的酶的表达水平。结果表明，ALT1、MCT4、GPD2和MPC1的水平大大降低，这与13C细胞内NMR光谱中测得的代谢物的变化一致。总的来说,我们的方法直接提供了对二甲双胍对活HepG2细胞葡萄糖代谢影响的基本见解，并强调了二甲双胍的潜在机制，包括G3P和源自葡萄糖的甘油的产量增加，以及抑制葡萄糖掺入乳酸，丙氨酸,谷氨酸,还有甘氨酸.
