异种血管内皮细胞生长因子重组蛋白质疫苗联合阿霉素治疗淋巴瘤的研究

Antitumor Effect of Recombinant Xenopus Laevis Vascular Endothelial Growth Factor (VEGF) as a Vaccine Combined with Adriamycin on EL4 Lymphoma in Mice

目的探讨重组非洲爪蟾血管内皮细胞生长因子(Xenopuslaevisvascularendothelialgrowthfactor,xVEGF)肿瘤疫苗免疫治疗,联合阿霉素抗小鼠淋巴瘤的作用。方法采用C57BL/6小鼠建立EL4淋巴瘤模型。实验小鼠随机分成4组xVEGF联合阿霉素组(简称联合用药组)、阿霉素组、xVEGF组、生理盐水对照组。观察肿瘤生长、小鼠生存率和毒副反应,并检测分泌抗自身VEGF抗体的B细胞、肿瘤微血管密度(microvesseldensity,MVD)和肿瘤细胞凋亡等。结果联合用药组肿瘤明显小于其他3组(P<0.05),其中有3只小鼠肿瘤完全消退;接种肿瘤后48d,联合用药组小鼠生存率为100%,明显高于生理盐水对照组(0%)(P<0.01)。ELISPOT检测发现,异种蛋白质疫苗免疫的小鼠(联合或单用)产生了分泌抗自身VEGF抗体的B细胞,其数量与阿霉素组或生理盐水对照组相比差异有统计学意义(P<0.01)。联合用药组肿瘤MVD明显低于其他3组(P<0.05),肿瘤细胞凋亡指数明显高于其他3组(P<0.05)。结论采用异种同源蛋白质疫苗xVEGF免疫治疗,与阿霉素化疗联合有协同增强的抗小鼠淋巴瘤的作用。

Objective To explore the antitumor effect of immunotherapy with recombinant Xenopus laevis vascular endothelial growth factor （xVEGF） as a vaccine combined with adriamycin on lymphoma model in mice. Methods EL4 lymphoma model was established in C57BL/6 mice. Mice were randomized into four groups： combination therapy, adriamycin alone, xVEGF alone and normal saline （NS） groups, and then were given relevant treatments. The growth of tumor, the survival rate of tumor-bearing mice, and the potential toxicity of regimens above were observed. Anti-VEGF antibody-producing B cells （APBCs） were detected by enzyme-linked immunospot （ELISPOT） assay. In addition, microvessel density （MVD） of tumor was detected by immunohistochemistry, and tumor cell apoptosis was also detected by TUNEL staining. Results The tumor volumes of mice were significantly smaller in combination group than those in other three groups （P〈0. 05）. Complete regression of tumor was observed in 3 of 10 mice in combination group. Forty-eight days after inoculation of tumor cells, the survival rate of mice was significantly higher in combination group than in NS group （P〈0.01）. The anti-VEGF APBC count in combination group or xVEGF group was significantly higher, compared with that in adriamycin group or NS group （P〈0. 01）. MVD in tumor tissues was significantly lower in combination group than those in other three groups （P〈0. 05）. Moreover, tumor cell apoptosis was significantly higher in combination group than those in other three groups （P〈0. 05）. Conclusion In this experimental study, the use of xVEGF vaccine and adriamycin as a combination of immunotherapy with chemotherapy has sucessfully produced synergistic antitumor effect on lymphoma in mice.