S100A9通过EMT调控肝细胞癌侵袭转移的机制研究

肝癌主要通过EMT获得侵袭转移能力而导致切除术后高复发。我们分析TCGA中365例肝癌RNA-seq数据，发现S100A9与预后紧密相关。前期实验发现，S100A9可分别通过抑制肝癌细胞TFF1表达而上调SNAIL表达，及促进肝癌细胞Ca2+内流这二种途径共同调控肝癌EMT。本项目将通过临床样本分析，明确S100A9和TFF1判断肝癌切除术后预后的应用价值；通过裸鼠皮下成瘤模型、原位肝癌移植模型和尾静脉肺转移模型，明确S100A9促肝癌增殖、侵袭转移的体内作用；通过蛋白质质谱、RNA-seq、生物信息学分析、荧光素酶报告系统、ChIP、Co-IP、细胞免疫荧光和流式细胞术等实验阐述S100A9/TFF1/SNAIL信号轴和S100A9介导的Ca2+通路共同调控肝癌EMT的机制。本项目将阐明S100A9调控肝癌侵袭转移的机制，有助于开发新的治疗手段、降低肝癌术后复发风险以及提高肝癌整体疗效。

The invasion and metastasis ability of hepatocellular carcinoma (HCC) derives mainly from the epithelial-mesenchymal transition (EMT) and results in high HCC recurrence after tumor resection. We analyzed the clinical and transcriptome sequencing data of 365 HCC tissues from the TCGA database and found that S100A9 was one of the most useful prognostic factors for overall survival. Our previous study showed that S100A9 overexpression upregulated SNAIL by suppression of TFF1 and increased store-operated Ca2+ entry (SOCE) in HCC, thus promoted the EMT process. Using the aforementioned two separate mechanisms, S100A9 can enhance the invasion and metastasis ability of HCC by modulation of EMT. This study aims to investigate the roles of S100A9 and TFF1 in predicting the prognosis of HCC patients through analyzing the clinical samples. Then, subcutaneous tumor model, orthotopic HCC model and tail vein injection model in nude mice will be used to demonstrate that S100A9 can promote HCC proliferation, invasion and metastasis in vivo. Finally, to explore the mechanism how S100A9/SNAIL/TFF1 signal axis and S100A9-mediated intracellular Ca2+ influx modulate EMT in HCC, protein mass spectrometry, RNA-Seq, bioinformatic analysis, co-immunoprecipitation, flow cytometry and immunofluorescence technique will be used appropriately. This study is expected to further clarify the roles of S100A9 in regulating the invasion and metastasis of HCC, to provide a potential target for developing new therapies, to reduce risks of postoperative recurrence and thus to improve overall outcomes of HCC patients.