Nanjing Medical University Affiliated Cancer Hospital & Jiangsu Cancer Hospital & Jiangsu Institute of Cancer Research, Nanjing, Jiangsu, People's Republic of China.
Imaging and Nuclear Medicine, Southeast University, Nanjing, Jiangsu, People's Republic of China.
Int J Nanomedicine. 2022 Jan 26;17:423-441. doi: 10.2147/IJN.S334015. eCollection 2022.
Spatially restricted gene expression circumvents the gene expression and gene vector problem by enabling localized amplification. The objective of this study is to construct a spatially restricted gene expression for liver cancer therapy based upon the MFH-absorbing properties of PEI- MnznFeo, gene therapy and radiation.
MnznFeO (MZF) magnetic nanoparticles were prepared by an improved chemical co-precipitation method, modified by polyethylene imine (PEI), and then the structure, modification characters, biocompatibility, temperature rise and control ability and binding efficiency of the plasmid were characterized. Then, the dual-promoter plasmid PCDNA3.1-EGR1-HSP70-HSVTK was constructed. The recombinant vectors were identified by enzyme digestion analysis and DNA sequencing. The TK gene expression level was detected by realtime-PCR assay in HEK293 cells. Also, the HSV-TK gene expression was detected in SMMC7721 cells with the help of PEI-MnZnFeO. In vitro anti-tumor experiment, MTT assay and flow cytometry were used to evaluate the therapeutic effects of the cultured SMMC7721 cells treated by different ways. In vivo anti-tumor experiment, the xenografted mice were treated by different ways for three times to detect the antitumor effect.
The MnZnFeO magnetic nanoparticles could be successfully prepared through improved co-precipitation process and showed good biocompatibility. And PEI had been coated on MZF complex. The modified PEI-MZF presented favorable dispensability, responsibility to magnetism, good loading capability and transfect capability. Also, pCDNA3.1-Egr1-Hsp70-HSVTK plasmid had been constructed successfully and could be induced by heat and irradiation. It would be used for further target gene therapy research. The antitumor results in vitro showed: The therapeutic effects of nanosized PEI-MZF-HSV-TK complex could significantly inhibit the proliferation of cultured liver cancer cells (SMC7721), induce cell apoptosis and had a prominent cell cycle disturbance in the S phase in vitro. The results in vivo showed: The combined therapy induced by PEI-MZF-HSV-TK could inhabit the growth of hepatocellular carcinoma xenografts by killing and inhabiting the proliferation of the tumor cells.
The novel site-directed heat/radiation-inducible expression system based upon the hyperthermia (by MFH) and radiation possessed superior antitumor effect in vivo and in vitro.
空间限制的基因表达通过局部放大来规避基因表达和基因载体问题。本研究的目的是构建一种基于 PEI-MnznFeo、基因治疗和放射治疗的肝癌治疗的空间限制基因表达。
采用改进的化学共沉淀法制备 MnznFeO（MZF）磁性纳米粒子，用聚乙烯亚胺（PEI）修饰，然后对其结构、修饰特性、生物相容性、升温及控温能力、质粒结合效率进行表征。然后构建双启动子质粒 PCDNA3.1-EGR1-HSP70-HSVTK。通过酶切分析和 DNA 测序鉴定重组载体。用实时-PCR 法检测 HEK293 细胞中 TK 基因的表达水平。此外，在 PEI-MnZnFeO 的帮助下，在 SMMC7721 细胞中检测 HSV-TK 基因的表达。体外抗肿瘤实验中，采用 MTT 法和流式细胞术评价不同方式处理后培养的 SMMC7721 细胞的治疗效果。体内抗肿瘤实验中，采用不同方式处理荷瘤小鼠 3 次，检测其抗肿瘤效果。
通过改进的共沉淀法成功制备了 MnZnFeO 磁性纳米粒子，且表现出良好的生物相容性。PEI 已包覆在 MZF 复合物上。修饰后的 PEI-MZF 具有良好的分散性、磁性响应性、良好的载药能力和转染能力。此外，成功构建了 pCDNA3.1-Egr1-Hsp70-HSVTK 质粒，并能被热和辐射诱导。它将被用于进一步的靶向基因治疗研究。体外抗肿瘤结果显示：纳米级 PEI-MZF-HSV-TK 复合物能显著抑制培养的肝癌细胞（SMC7721）的增殖，诱导细胞凋亡，并在体外显著扰乱细胞周期至 S 期。体内结果显示：PEI-MZF-HSV-TK 联合治疗能通过杀伤和抑制肿瘤细胞增殖抑制肝癌细胞异种移植瘤的生长。
基于热疗（由 MFH 引起）和放射的新型靶向热/辐射诱导表达系统在体内和体外均具有优越的抗肿瘤效果。
