目的: 探索细胞表面抗原Thy-1 通过调控Notch1 通路促进肝癌HepG2 和MHCC-97 细胞上皮间质转化（EMT）。方法：选用具有高转移特性的MHCC-97 细胞和低转移特性的HepG2 细胞作为研究对象，WB检测细胞内Thy-1、Notch1 蛋白表达水平。用重组慢病毒转染MHCC-97 和HepG2 细胞，构建高表达与低表达Thy-1 蛋白的细胞，再分别用Notch1 激动剂rhNF-κB（1gsu/ml）和Notch1 抑制剂MW167（100 μmol/L）处理细胞24 h。Transwell 实验检测Thy-1 表达变化、rhNF-κB和MW167 处理对细胞侵袭能力的影响，qPCR检测对Notch1 mRNA表达的影响，WB实验检测细胞内EMT相关蛋白表达的影响。结果：MHCC-97细胞中Thy-1、Notch1 蛋白表达量均高于HepG2 细胞（P<0.05）。成功构建Thy-1 过表达的HepG2 细胞和Thy-1 低表达的MHCC-97 细胞。与亲本HepG2 细胞相比，Thy-1 过表达HepG2 细胞侵袭能力显著增强[ （475.78±80.37）vs（183.23±55.34）个，P<0.05）]、波形蛋白表达显著升高（P<0.05）、上皮钙黏素蛋白表达显著降低（P<0.05）、Notch1 mRNA表达水平显著升高（P<0.05）；与亲本MHCC-97 细胞相比，Thy-1 沉默的MHCC-97 细胞侵袭能力显著降低[ （237.44±62.18）vs（543.56±77.94）个，P<0.05）]、波形蛋白表达显著降低（P<0.05）、上皮钙黏素蛋白表达显著升高（P<0.05）、Notch1 mRNA表达水平显著降低（P<0.05）。而Notch1 激活剂或抑制剂处理上述肝癌细胞可逆转由于Thy-1 沉默或过表达所造成的改变。结论：Thy-1 可通过调控Notch1 表达影响肝癌HepG2和MHCC-97 细胞的EMT。

Objective: To explore the role of Thy-1 cell surface antigen（Thy-1）in promoting epithelial-mesenchymal transition (EMT) in liver cancer HepG2 and MHCC-97 cells by regulating Notch1 pathway. Methods: MHCC-97 cells with high metastatic characteristics and HepG2 cells with low metastatic characteristics were selected as subjects. WB was used to detect the expression levels of Thy-1 and Notch1 in cells. MHCC-97 and HepG2 cells were transfected with lentivirus to construct cells with high and low expression of Thy-1 protein. Cells were treated with Notch1 agonist rhNF-κB (1 gsu/ml) and Notch1 inhibitor MW167 (100 μmol/L) for 24 h respectively. Transwell assay was used to detect the effect of Thy-1 expression on cell invasion; qPCR was used to detect the effect on Notch1 mRNA expression; WB was used to detect the effect on intracellular EMT-related protein expression. Results: The expression levels of Thy-1 and Notch1 in MHCC-97 cells were higher than those in HepG2 cells (P<0.05). Thy-1 overexpressing HepG2 cells and Thy-1 low expressing MHCC-97 cells were successfully constructed. Compared with HepG2 cells, the invasion ability of Thy-1 overexpressing HepG2 cells was significantly enhanced (183.23±55.34 vs 475.78±80.37, P<0.05), vimentin expression was significantly increased (P<0.05), epithelial cadherin protein expression was significantly decreased (P<0.05), and the expression level of Notch1 mRNA was significantly increased (P<0.05). Compared with MHCC-97 cells, the invasion ability of Thy-1 silenced MHCC-97 cells was significantly decreased (543.56±77.94 vs 237.44±62.18, P<0.05), the expression of vimentin was significantly decreased (P<0.05), epithelial cadherin protein expression was significantly increased (P<0.05), and Notch1 mRNA expression level was significantly decreased (P<0.05). Treatment of liver cancer cells with Notch1 activators or inhibitors can reverse the changes caused by Thy-1 silencing or overexpression. Conclusion: Thy-1 can affect the EMT process of HepG2 and MHCC-97 cells by regulating the expression of Notch1.

兰州市科技局指导项目资助（No. 2018-ZD-13）