乳酸调控PFKFB3的机制及对肿瘤细胞糖代谢的作用研究

Metabolic change is an important hallmark of cancer. Glucose deficiency and high lactic acid is a common phenomenon in solid tumors due to disorganized tumor vasculature and poor material exchange. We recently revealed that non-glycolytic mode, promoted by lactic acid, renders cancer cells adaptive to metabolic microenvironments with limited glucose supply. PFKFB3 that catalyzes the formation of fructose-2,6-diphosphate is an important regulator of glycolysis. To further clarify the relationship between lactic acid, PFKFB3 and glycolysis, We will conduct the following experiments: 1) Combined with proteasome inhibitors and co-immunoprecipitation methods to clarify lactic acid promotes PFKFB3 degradation via the ubiquitin pathway. 2) Combined with microarray and bioinformatics to predict the important signaling pathways that promoting PFKFB3 degradation by lactic acid. Cdh1 has been identified as a key candidate gene, and We will verify in vitro and in vivo experiments. 3) screening and identification of key upstream molecules through which lactic acid up-regulates Cdh1. The proposed studies will identify lactic acid inhibits tumor cells glycolysis via promoting PFKFB3 ubiquitin mediated degradation and elucidate the molecular mechanism of PFKFB3 regulation by lactic acid. Targeting PFKFB3 and its upstream key molecules will be a new strategy for cancer treatment.

代谢改变是肿瘤的重要特征。肿瘤血管紊乱，没有良好的物质交换，葡萄糖缺乏和高乳酸是实体肿瘤普遍存在的现象。我们前期研究证实乳酸导致肿瘤细胞的糖代谢方式从糖酵解向非糖酵解改变，因而赋予实体瘤在葡萄糖缺乏条件下生长的能力。催化形成果糖-2,6-二磷酸的PFKFB3是糖酵解过程的重要调控因子。为进一步阐明乳酸、PFKFB3与糖酵解三者之间的关系，我们将开展以下工作：1，结合蛋白酶体抑制剂并采用免疫共沉淀的方法明确乳酸通过泛素化途径促进PFKFB3的降解；2，结合基因芯片及生物信息学方法预测乳酸促进PFKFB3降解的重要信号通路，目前已确定Cdh1为关键的候选基因，我们将在体内外实验中验证；3，筛选并鉴定乳酸上调Cdh1的关键上游分子。通过本研究将明确乳酸通过增加PFKFB3的泛素化降解抑制肿瘤细胞的糖酵解，并阐明乳酸调控PFKFB3的分子机制，靶向PFKFB3及其上游关键分子是治疗肿瘤的新策略。

代谢改变是肿瘤的重要特征。肿瘤血管紊乱，没有良好的物质交换，葡萄糖缺乏和高乳酸是实体肿瘤普遍存在的现象。我们前期研究证实乳酸导致肿瘤细胞的糖代谢方式从糖酵解向非糖酵解改变，因而赋予实体瘤在葡萄糖缺乏条件下生长的能力。催化形成果糖-2,6-二磷酸的PFKFB3是糖酵解过程的重要调控因子。为进一步阐明乳酸、PFKFB3与糖酵解三者之间的关系，本项目开展了以下工作：1）乳酸处理后4T1 细胞内的PFKFB3 泛素化降解增加；2）乳酸通过APC/C-Cdh1 途径降解PFKFB3 抑制4T1细胞的糖酵解；3）WT1转录因子可以负向调控Cdh1的表达；4）乳酸可能通过WT1-Cdh1-PFKFB3途径影响4T1细胞的糖酵解，干预乳酸及其下游信号通路，可以抑制乳腺癌的生长。本研究明确乳酸通过增加PFKFB3的泛素化降解抑制肿瘤细胞的糖酵解，并阐明了乳酸通过WT1-Cdh1途径调控PFKFB3的分子机制，靶向PFKFB3及其上游关键分子是治疗肿瘤的新策略。