Wu De-Hai, Liang Hao, Lu Shou-Nan, Wang Hao, Su Zhi-Lei, Zhang Lei, Ma Jian-Qun, Guo Mian, Tai Sheng, Yu Shan
Department of General Surgery, the Second Affiliated Hospital of Harbin Medical University, Harbin, China.
Department of Esophageal Mediastinum, Harbin Medical University Cancer Hospital, Harbin, China.
Cell Physiol Biochem. 2018;50(3):924-935. doi: 10.1159/000494477. Epub 2018 Oct 24.
BACKGROUND/AIMS: Increasing evidence shows that reprogramming of energy metabolism is a hallmark of cancer. Considering the emergence of microRNAs as crucial modulators of cancer, this study aimed to better understand the molecular mechanisms of miR-124 in regulating glycolysis in human pancreatic cancer.
RT-PCR was used to investigate the expression of monocarboxylate transporters (MCTs) in pancreatic ductal adenocarcinoma (PDAC) patient samples and the PANC-1 cell line. A public database and immunochemistry were used for comprehensive analysis of MCT1 expression. The targeting of MCT1 by miR-124 was predicted by software and validated for the MCT1 3'-UTR by dual-luciferase reporter analysis. Cell proliferation, apoptosis, migration, xenografting, and the intracellular pH and L-lactate levels were assessed. Hypoxia-inducible factor-α (HIF-1α) and lactate dehydrogenase A (LDH-A) expression levels were determined by RT-PCR and western blotting.
MCT1 expression was higher in PDAC tissue than in normal tissue. Inhibition of MCT1 affected lactate metabolism, resulting in a higher intracellular pH and less proliferation of PANC-1 cells. MCT1 was the target gene of miR-124. In in vitro experiments, miR-124 inhibited the glycolytic activity of PANC-1 cells by targeting MCT1, further decreasing the tumor phenotype by increasing the intracellular pH through LDH-A and HIF-1α. In in vivo experiments, overexpression of miR-124 and silencing of MCT1 significantly inhibited tumor growth.
miR-124 inhibits the progression of PANC-1 by targeting MCT1 in the lactate metabolic pathway. Our findings provide novel evidence for further functional studies of miR-124, which might be useful for future therapeutic approaches to PDAC.
背景/目的：越来越多的证据表明能量代谢重编程是癌症的一个标志。鉴于微小RNA作为癌症关键调节因子的出现，本研究旨在更好地理解miR-124在调节人胰腺癌糖酵解中的分子机制。
采用逆转录聚合酶链反应（RT-PCR）研究单羧酸转运体（MCTs）在胰腺导管腺癌（PDAC）患者样本和PANC-1细胞系中的表达。利用公共数据库和免疫化学对MCT1表达进行综合分析。通过软件预测miR-124对MCT1的靶向作用，并通过双荧光素酶报告基因分析对MCT1 3'-非翻译区（UTR）进行验证。评估细胞增殖、凋亡、迁移、异种移植以及细胞内pH值和L-乳酸水平。通过RT-PCR和蛋白质印迹法测定缺氧诱导因子-α（HIF-1α）和乳酸脱氢酶A（LDH-A）的表达水平。
MCT1在PDAC组织中的表达高于正常组织。抑制MCT1影响乳酸代谢，导致PANC-1细胞内pH值升高且增殖减少。MCT1是miR-124的靶基因。在体外实验中，miR-124通过靶向MCT1抑制PANC-1细胞的糖酵解活性，通过LDH-A和HIF-1α升高细胞内pH值，进一步降低肿瘤表型。在体内实验中，miR-124的过表达和MCT1的沉默显著抑制肿瘤生长。
miR-124通过靶向乳酸代谢途径中的MCT1抑制PANC-1的进展。我们的发现为miR-124的进一步功能研究提供了新证据，这可能对未来PDAC的治疗方法有用。
