肝细胞癌术后的高复发转移率严重影响了患者预后。纤溶酶原激活系统在肿瘤的侵袭和转移中发挥了重要作用，该系统中uPA可将纤溶酶原转化为有活性的纤溶酶，降解细胞外基质，从而促进肝癌细胞的迁移和侵袭。PAI-2作为uPA活性的重要抑制因子能够通过多种分子机制抑制恶性肿瘤的侵袭和进展。 目前国内外尚未见PAI-2在肝细胞癌侵袭和复发转移中功能和作用机制的相关资料。本研究在前期验证了PAI-2表达对肝细胞癌侵袭转移的抑制作用基础上，分别构建PAI-2的siRNA和过表达质粒，转染不同转移潜能的肝细胞癌细胞系并筛选稳定转染克隆，从正反两方面探讨其在肝癌细胞侵袭转移中的作用及分子机制。同时，应用不同PAI-2表达水平的肝癌细胞建立裸鼠原位移植瘤模型，以携带PAI-2表达质粒的病毒直接进行原位移植瘤内内注射，并探讨PAI-2表达在体内肝癌细胞转移侵袭行为的影响以及其作为肝细胞癌抗复发转移的治疗工具。

The high rates of recurrence and metastasis after liver cancer surgery greatly affects the patient postoperative recovery. The plasminogen activating system plays an important role in the invasion and metastasis of tumors. uPA from the above system could change plasminogen into active plasmin, which would initiate extracellular proteolysis. This will lead to liver cancer cell migration and invasion. PAI-2, as the significant inhibitor of uPA activity, which could inhibit malignant tumor invasion and progress through multi-molecular mechanism. Currently, there is few research on the function and mechanism of PAI-2 in liver cancer invasion and metastasis. This research will respectively build the framework of PAI-2 siRNA and expression plasmid, to transfect hepatocellular carcinoma cell lines with different metastatic potentials and select stable clone transfect based on previous test of inhibiting liver cancer invasion and metastasis. With comprehensive perspectives, the research will discuss PAI-2 molecular mechanism. Meanwhile, a model of orthotopic transplantation tumor of nude mouse will be built applying different levels of PAI-2 expression. The research also plan to directly perform orthotopic transplantation tumor injection with virus of PAI-2 expression plasmid. Moreover, more will be elaborated on PAI-2 expression's influence of body liver cancer cell invasion and metastasis and the the therapeutical effect as liver cell cancer Resisting Recurrence.