松弛素表达的条件复制性溶瘤病毒靶向肝癌栓塞后肿瘤微环境的实验研究

Such as other type of solid tumor, liver cancer has its special microenvironment structure, such as collagen, elastin, fibronectin, laminin and other extracellular matrix proteins, it forms a physical barrier for the chemotherapy drugs to reach tumor cells. Interventional chemoembolization can hold the drugs in the blood vessels, but cannot promote the penetration of chemotherapy drugs deeply into the tumor. Relaxin-hypoxia replicative oncolytic adenovirus has a ability of targeted killing hypoxic cells, which canteins relaxin gene and hypoxia response element. The virus is able to specifically infect, replicate in hypoxic cells, simultaneously, the expression of relaxin protein can increase the permeability of tumor stroma which is beneficial to viral penetrate, therefore leading to a more seriously destruction of tumor. In this study, By using relaxin-hypoxia replicative oncolytic adenovirus, we will evaluate cells infected selectively, infection efficiency, cytotoxic effects in vivro; By performing animal liver tumor model, we will evaluate the synergism of drug penetration, and find out an optimized administration, through its experimental evaluation of cells infected cells selectively, infection efficiency, further evaluate the safety and effectiveness of the treatment. This study will provide a new liver-targeted gene therapy strategies。

诸如肝癌类的实体瘤微环境间质有其特殊结构如胶原、弹性蛋白、纤维粘连蛋白、层粘连蛋白等细胞外基质蛋白，该结构构成物理障碍，阻碍化疗药物到达肿瘤细胞；肝癌介入化疗栓塞能够将药物封闭于肿瘤血管内，却无法加强化疗药物在肿瘤间质内的渗透。松弛素表达的条件复制性溶瘤病毒是一种能够靶向杀伤缺氧细胞的病毒，其携带松弛素基因和缺氧反应元件，感染胞后选择性的在缺氧肿瘤细胞内持续复制导致细胞崩解，同时表达松弛素蛋白，破坏肿瘤间质蛋白，增加肿瘤间质的通透性利于病毒及化疗药物的渗透，达到增效的目的，提高其肿瘤杀伤能效。本研究拟构建松弛素表达的条件复制性溶瘤病毒，通过细胞实验评价其细胞感染选择性、感染效率、细胞毒性效应。通过动物实验评价其对药物渗透的增效作用，优选给药方案，进一步评估其治疗的安全及有效性。本研究将为肝癌靶向基因治疗提供新的策略。

在经肝动脉化疗栓塞（TACE）术中，化疗药物由于致密的肿瘤基质导致弥散受限，单独TACE能降低肝癌间质压力，并提高肝癌组织内部化疗药物渗透距离和浓度，但是提高的程度和化疗药物在肝癌组织中的分布还不足以彻底杀灭肿瘤细胞，有待于进一步提高，因此该研究目的在于探究在经肝动脉灌注松弛素（RLX）联合TACE对化疗药物阿霉素渗透的影响，并进一步评估其治疗效果。研究结果表明松弛素增加了化疗药在兔VX2肝癌模型中的渗透能力，该作用是通过上调基质金属蛋白酶MMPs实现的；经HE、TUNEL和Ki67染色证实，松弛素（RLX）联合TACE通过增加化疗药物阿霉素的渗透性，使肿瘤生长率显著降低，坏死率显著升高，能够协同抑制肝癌进展。该研究成果将为临床提高肝癌介入治疗疗效提供理论依据。