纤溶酶原激活物抑制剂2(PAI-2)抑制肝细胞癌侵袭转移的作用机制及作为体内调控靶点的相关研究

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.

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。

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。前期免疫组化结果提示PAI-2表达对肝细胞癌肿瘤生长和门静脉癌栓形成的抑制作用并与患者生存期正相关。.基于上述结果，研究假设PAI2通过抑制纤溶酶原激活系统中的uPA活性限制肝癌的侵袭和转移。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（MHCC97H和BEL-7402）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。结果表明PAI2通过抑制Jak-Stat1通路的活化、与核内RB蛋白结合，减少RB蛋白的降解从而调控Rb-E2F1途径抑制肝癌细胞转移侵袭行为。.体内研究方面，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，经过28天内5个时间点的检测，结果显示PAI2表达水平与移植瘤体积和肝内及远端转移的发生负相关，证实PAI2作为肝细胞癌抗复发转移的治疗靶点的可行性。