转录因子ZEB1通过改变三维基因组结构调控SPP1促进肠癌肝转移的机制研究

结直肠癌肝转移是导致结直肠癌患者死亡的主要原因，其机制尚不清楚。申请者前期通过多组学分析建立了转移性结直肠癌的三维基因组和表达谱图谱，发现三维基因组结构如A/B分区转换、TADs、染色质环(chromatin loop)的改变与肠癌发生、转移密切相关，其中SPP1 loop在肠癌转移中持续增强，伴随SPP1持续高表达，motif 分析发现转录因子ZEB1在SPP1 loop上富集，ChIP-seq数据表明ZEB1在SPP1启动子区有明显结合，由此推断转录因子与三维基因组的互作可能在肠癌肝转移中发挥重要作用。本项目拟通过干扰ZEB1表达结合CRISPR技术敲除SPP1 loop结构，在细胞和动物模型中验证三维基因组结构变化调控基因表达对结直肠癌转移的具体作用机制，并在临床样本中分析ZEB1与SPP1表达对结直肠癌肝转移的临床相关性和预后影响，从而为发现结直肠癌肝转移治疗新靶点提供新思路。

Liver metastasis of colorectal cancer is the main cause of death in patients with colorectal cancer, and its mechanism is not clear. The applicant established the three-dimensional genome and expression profile of metastatic colorectal cancer through multi-omics analysis. It was found that changes in three-dimensional genome, such as compartments A / B switching, TADs and chromatin loop, were closely related to the occurrence and metastasis of colorectal cancer. SPP1 loop continued to increase in the metastasis of colorectal cancer, with the sustained high expression of SPP1, motif analysis found that the transcription factor ZEB1 was enriched in SPP1 loop. ChIP-seq data show that ZEB1 binds to the promoter region of SPP1. It is inferred that the interaction between transcription factors and three-dimensional genome may play an important role in liver metastasis of colorectal cancer. This project intends to verify the specific mechanism of three-dimensional genome structure regulation gene expression in colorectal cancer metastasis by interfering with ZEB1 expression and CRISPR technology to knock out the SPP1 loop structure in cell and animal models, and to analyze the clinical correlation and prognosis of ZEB1 and SPP1 expression in clinical samples of colorectal cancer liver metastasis, so as to provide new ideas for finding new therapeutic targets for colorectal cancer liver metastasis.