HSP70热激启动子介导的siRNA-survivin/As2O3纳米热控磁性材料联合靶向治疗肝癌的研究

Hepatocarcinoma is a kind of common malignant tumor endangering the human health seriously. Therefore, it is crucial to explore a novel and efficient medicine and therapy method for the treatment of hepatocarcinoma. In this study，we'll construct a siRNA-survivin plasmid with HSP 70 promotor induced by heat, which is combined with As2O3/Fe3O4 complex. The multiple antitumor applications include gene therapy with survivin RNA interference, thermotherapy using magnetic Fe3O4 nanoparticles, and chemotherapy using As2O3. Xenograft liver tumor model in nude mice and VX2 liver tumor model in rabbit will be established to identify the curative effect and compare the difference between the combinational therapy and treatment with single method. Interventional operation treatment will be applied in rabbits for high liver targeting, which improve the efficiency of gene therapy and reduce the side effect of arsenic trioxide. In this study, we explore a novel and efficient treatment for liver cancer, which expands the methods of nanomedcine and gene therapy; moreover find a new way for the application of arsenic treatment to solid tumors

肝癌是严重威胁人类健康的恶性肿瘤之一，寻求新的有效的治疗方法具有重要意义。本课题拟首先构建HSP70热激启动子调控下的靶向survivin基因的siRNA真核表达质粒，与磁性纳米载体Fe3O4相结合后再与As2O3耦合制成 pHSP-survivin siRNA/As2O3 复合磁性纳米颗粒。该材料注射入肿瘤后，体外磁感应加热，一方面热疗和砷药可杀伤肿瘤细胞，同时热激HSP70启动子表达从而诱导表达siRNA-survivin质粒基因，使survivin基因沉默，实现"高效率基因治疗、砷药、高热"多重杀伤作用。同时建立裸鼠肝癌移植瘤模型和兔VX2肝癌模型，验证和比较联合治疗和单因素治疗的疗效。兔VX2肝癌将使用肝动脉血管介入的方式治疗肝癌，增加肝靶向性，提高基因治疗的效率，同时能降低砷药的全身毒副作用。本研究丰富了纳米医药技术、基因治疗和传统砷药的抗肿瘤的研究内容，为肿瘤联合治疗提供新思路

肝癌是严重威胁人类健康的恶性肿瘤之一，寻求新的有效的治疗方法具有重要意义。本课题首先制备了一种可同时具备热疗、化疗和基因治疗三重功效的新型复合纳米材料PEI-As2O3/Fe3O4。采用CCK8、微核实验、LD50测定等方法对其毒性进行了研究，证实了其具有良好的生物相容性。同时构建survivin-shRNA 载体，转染HepG2肝癌细胞后抑制基因表达率可达60%，实现了survivin基因的靶向封闭。将该质粒载体与PEI-As2O3/Fe3O4复合纳米材料结合后对裸鼠的HepG2肝癌移植瘤模型和兔VX2肝癌模型进行了体内治疗。兔VX2肝癌还采用了肝动脉血管介入的方式来治疗，增加肝靶向性，提高治疗的效率，同时能降低砷药的全身毒副作用。结果显示复合纳米材料热疗组肿瘤体积抑制率分别可到达89.89%和88.42%，与其它组别相比均有显著差异，实现了“高效率基因治疗、砷药、高热”的多重杀伤作用。本研究丰富了纳米医药技术、基因治疗和传统砷药的抗肿瘤的研究内容，为肿瘤联合治疗提供新思路。目前，实验内容共发表论文6篇，一篇审稿中。我们期望，通过进一步的优化和实验，可将这种新型的复合纳米材料应用于肿瘤的联合治疗中。