聚乙二醇-聚谷氨酸纳米微球介导双自杀基因治疗金黄地鼠颊癌的实验研究

PEG-PBLG nanoparticles mediated CDglyTK gene in the treatment of buccal carcinoma in golden hamster

目的:观察聚乙二醇-聚谷氨酸(PEG-PBLG)纳米微球介导双融合自杀基因CDglyTK治疗金黄地鼠颊癌的疗效。方法:用二甲基苯并蒽(DMBA)诱导金黄地鼠颊黏膜癌变,建立颊癌动物模型。以PEG-PBLG纳米微球为载体,介导携双自杀基因CDglyTK的真核表达质粒pcDNA3．1(+)-CDglyTK瘤内转染,腹腔注射5-氟胞嘧啶(5-FC)和丙氧鸟苷(GCV),描绘肿瘤生长曲线,RT-PCR检测CDglyTK的mRNA水平,免疫组化检测细胞核增殖抗原的表达,原位末端标记法检测肿瘤细胞凋亡。采用SPSS10．0统计软件包进行两样本均数X^2检验。结果:成功建立金黄地鼠颊癌模型,RT-PCR可检测到转染肿瘤细胞中CDglyTK的mRNA表达;腹腔注射5-FC和GCV后,肿瘤生长受到明显抑制;联合使用5-FC和GCV的金黄地鼠颊癌生长抑制作用明显优于单用5-FC或GCV。5-FC和GCV联合使用组,凋亡指数(AI)显著高于对照组(P＜0．01),同时增殖指数(PI)则显著低于对照组(P＜0．01)。结论:PEG-PBLG纳米载体介导双自杀基因CDglyTK可有效治疗金黄地鼠颊癌,为口腔鳞癌的基因治疗提供了新的思路。

PURPOSE： To observe the therapeutic effect of CDglyTK gene mediated by PEG-PBLG nanoparticles in the treatment of buccal carcinoma in golden hamster. METHODS： Animal models of buccal carcinoma in golden hamster were established by painting 0.5% DMBA. CDglyTK gene in pCEA-CDglyTK was subcloned into pcDNA3.1 （＋） to construct eukaryotic cell expression plasmid pcDNA3.1 （＋）-CDglyTK, and then the recombinant plasmids were transfected into buccal carcinoma in golden hamster by PEG-PBLG nanoparticles.5-fluorocytosine（5-FC） and ganciclovir（GCV） were injected into golden hamster at intervals. Animals were monitored at regular intervals for volume of tumors. CDglyTK mRNA was assayed by RT-PCR. Apoptosis and proliferating cell nuclear antigen were detected respectively by in situ end-labeling and immunohistiochemical assay. The data was analyzed by SPSS10.0 software package for chi-square test. RESULTS： Compared with the control groups, the tumor was suppressed significantly by CDglyTK gene therapy. The expression of CDglyTK gene could be detected by RT-PCR in the transfected tumor. The viability of transfected tumors with 5-FC and GCV was significantly lower than that of transfected tumors with 5-FC or GCV alone. There was significant difference between the apoptosis index （AI） or proliferation index （PI） in tumor between the experimental group and the control groups （P〈O.O1）. CONCLUSIONS： The results suggest that suicide gene therapy with PEG-PBLG mediating CDglyTK proved strong cytotoxicity to buccal carcinoma in golden hamster.It will be possible to validate this strategy in the treatment of oral squamous cell carcinoma. Supported by National Natural Science Foundation of China （Grant No. 30271423） and Natural Science Foundation of Guangdong Province（Grant No.21865）.