p53 R249S突变是肝细胞癌（HCC）中最常见且独特的p53热点突变，与HCC发生发展密切相关。既往研究模型无法完整重现HCC发生过程且分子机制未明。我们前期成功构建p53 R249S突变的H1人胚胎干细胞，并将其定向分化为肝细胞，结合成瘤实验、RNA-seq等技术发现：该模型成功模拟HCC发生的表型和基因型；进一步研究发现p53 R249S结合E2F3促进FOXM1转录，同时检测到FOXM1下游大量靶基因表达上调；且FOXM1可以上调糖酵解通路关键酶PGK1，增加糖酵解促进HCC发生。目前p53 R249S如何通过E2F3调控FOXM1转录及下游糖代谢重编程活化的分子机制尚未完全阐明。现拟在前期工作基础上进一步采用蛋白免疫共沉淀，ChIP-seq，代谢组学等方法阐明具体分子机制，结合病例资料分析其临床意义。本项目旨在研究p53 R249S在HCC发生中的促癌机制，探索HCC新靶标。

p53 R249S mutation is the most common and unique p53 hotspot mutation in hepatocellular carcinoma (HCC), which is closely related to the development of HCC. Previous research models can’t fully recapitulate the HCC occurrence process and the underlying mechanisms are still unknown. We successfully constructed p53 R249S mutant H1 human embryonic stem cells and differentiated them into hepatocytes. Using tumorigenesis assay and RNA-seq, we found that the model successfully recopied the phenotypes and genotypes of HCC occurrence; further research found that p53 R249S, binding with E2F3, promoted the transcription of FOXM1, and a large number of downstream targets of FOXM1 were up-regulated; and FOXM1 can up-regulate the key enzyme of glycolysis pathway PGK1, increase glycolysis and promote HCC occurrence. At present, the molecular mechanisms of how p53 R249S regulates FOXM1 and glucometabolism reprogramming have not been fully elucidated. Based on the previous work, it is planned to use protein immunocoprecipitation, ChIP-seq and metabolomics to clarify the specific molecular mechanisms. This project aims to study the oncogenic mechanisms of p53 R249S in the occurrence of HCC and explore new targets for HCC.