基于单细胞测序探索SAA1诱导转录因子FOXO3a磷酸化调控结直肠癌肝转移的分子机制研究

肿瘤转移微环境(TME)中肿瘤相关成纤维细胞(CAFs)是结直肠癌肝转移(CRLM)的关键调控细胞之一，其驱动CRLM的具体下游机制尚未完全明确。我们前期通过单细胞测序发现：在肝脏TME中, SAA1在正常成纤维细胞与CAFs中的表达具有最显著差异，通过对差异表达基因富集分析发现PI3K信号通路与转录因子FOXO3a参与SAA1下游调节；预实验敲除CAFs中SAA1后，肿瘤细胞PI3K通路显著失活，转录因子FOXO3a磷酸化下降，侵袭能力降低，提示肝脏TME中CAFs通过“SAA1-PI3K-FOXO3a”轴调控CRLM的发生。在此基础上申请人拟结合人体组织、细胞和动物模型，利用基因敲除、基因过表达和抑制剂的方法，明确CAFs源性SAA1在CRLM中的生物学功能，阐明“SAA1-PI3K-FOXO3a”轴调控CRLM的具体机制，并通过相关抑制剂探索可能治疗靶点，为后续转化医学研究提供基础。

Tumor associated fibroblasts (CAFs) in tumor metastasis microenvironment (TME) are the key regulatory cells of colorectal cancer liver metastasis (CRLM). The specific downstream mechanism of driving CRLM is still unknown. Our previous single-cell sequencing found that: in liver TME, the expression of SAA1 in normal fibroblasts and CAFs had the most significant difference. Through the analysis of differential gene enrichment, PI3K signaling pathway and transcription factor FOXO3a were found to participate in the downstream regulation of SAA1; pre-experiment knockout of SAA1 in CAFs significantly inactivated PI3K pathway, decreased transcription factor FOXO3a phosphorylation and decreased invasion ability of tumor cells, suggesting that CAFs in liver TME regulate CRLM through "SAA1-PI3K-FOXO3a" axis. On this basis, the applicant intends to clarify the biological function of CAFs derived SAA1 in CRLM, clarify the specific mechanism of "SAA1-PI3K-FOXO3a" axis regulating CRLM, and explore possible therapeutic targets through relevant inhibitors, so as to provide the basis for subsequent translational medicine research.