透明质酸酶和药物脂质体对肝癌介入治疗中药物渗透和疗效的影响及机制研究

Transcatheter intraarterial techniques can directly deliver chemotherapeutic agents to tumor and thus improve intratumoral drug concentration. However, to be most effective chemotherapeutic agents must penetrate tumor tissue efficiently, reaching all the cancer cells in a concentration sufficient to exert a therapeutic effect. The applicants have demonstrated that transcatheter intraarterial techniques improve drug penetration in liver cancer but their effect on drug distribution is somewhat limited. Modification of tumor interstitial fluid pressure (IFP) and modification or development of chemotherapeutic agents are the dominant methods for improving drug penetration, in which hyaluronidase and drug liposome deserve special investigation. In this study, we intent to use pegylated recombinant human PH20 (PEGPH20) and liposomal doxorubicin as drug penetration enhancer. We conduct experiments in vitro to evaluate the effect of PEGPH20 on exclusion of pericellular matrices from hepatoma cell lines and the effects of liposomal doxorubicin alone and liposomal doxorubicin combined with PEGPH20 on drug distribution in hepatoma multicellular spheroids. We also perform experiments to investigate pharmacokinetics of PEGPH20 and liposomal doxorubicin in an animal liver tumor model, to evaluate the effects of PEGPH20 and drug liposome on intratumoral drug penetration and therapeutic efficacy of transcatheter therapies for liver cancer and to clarify their mechanisms. This study aims to provide preclinical evidence for the application of pro-drug penetration in transcatheter therapies of liver cancer, contributing to the development of a novel therapeutic strategy for improving the effectiveness of chemotherapy.

经导管介入治疗可直接向肿瘤内输送化疗药物，提高肿瘤内药物浓度。然而理想化疗效果的实现要求药物向肿瘤内充分渗透，以足够药物浓度达到所有肿瘤细胞。申请人已证实经导管动脉内技术可促进肿瘤内药物渗透，但促进作用还不够理想。改变肿瘤间质液压和改进药物剂型是改善肿瘤内药物渗透的主要方法，其中透明质酸酶和药物脂质体是研究热点。本研究采用聚乙二醇化重组人透明质酸酶(PEGPH20)和阿霉素脂质体作为促进药物渗透制剂，在细胞实验中研究PEGPH20对肝癌细胞周围基质的清除作用，评价阿霉素脂质体及联合PEGPH20对药物分布的影响；在动物实验中研究PEGPH20和阿霉素脂质体的药代动力学；并评价PEGPH20和药物脂质体对肝癌经导管介入治疗中药物渗透的促进作用及其与治疗效果的关系，并阐明其治疗机制。本研究将为促药物渗透在肝癌介入领域中的应用提供临床前证据，为提高肝癌介入治疗中化疗效果提供新的策略。

化疗栓塞可促进肿瘤内药物渗透，但促进作用还不够理想。本研究通过体外和体实验探索了透明质酸酶和药物脂质体对肝癌化疗栓塞治疗中药物渗透和疗效的影响及机制。结果发现：(1)透明质酸酶可有效清除体离HepG2肝癌细胞的周围基质；(2)透明质酸酶在拟定的不同药物浓度及作用时间下对HepG2肝癌细胞基本无毒性作用；(3)药物脂质体和透明质酸酶可促进阿霉素在HepG2肿瘤多细胞球体内的药物渗透；(4)透明质酸酶经导管肝动脉内给药可有效降解兔VX2肝肿瘤内透明质酸；同时可有效降低肿瘤内间质液压，给药40分钟后肿瘤间质液压改变趋于稳定；(5)阿霉素脂质体经导管动脉内给药的药代动力学参数劣于阿霉素经导管动脉内给药，在肝癌TACE中应用价值不大；(6)透明质酸酶可能通过降低肿瘤内间质液压、改善肿瘤内化疗药分布，从而导致更大程度的肿瘤坏死。结果提示：经导管肝动脉内注入透明质酸酶可有效降解动物肝肿瘤内透明质酸，降低肿瘤内间质液压，促进阿霉素在肿瘤内的药物渗透，提高TACE抗肿瘤效果。