白细胞介素-24增强溶瘤腺病毒抗白血病作用机制研究

Mechanisms of enhanced antileukemia activity of conditionally replicating adenovirus(CRAd) ZD55 by interleukin-24

目的:研究白细胞介素-24(IL-24)增强溶瘤腺病毒(CRAd)ZD55抗白血病作用的机制。方法:用流式细胞仪检测ZD55对白血病细胞株Mutz-1的感染率;分别用ZD55、ZD55-IL-24和携带IL-24的非增殖型腺病毒(Ad-IL-24)处理白血病细胞(实验组),对照组为PBS。Western blot检测CRAd对白血病细胞血管内皮生长因子(VEGF)蛋白表达的影响;用免疫组化检测Mutz-1白血病荷瘤模型经CRAd治疗后肿瘤病理组织CD31和VEGF表达。结果:用10、100病毒感染复数(MOI)的ZD55感染白血病细胞48 h,感染率分别为5.1%和42.3%。ZD55-IL-24使VEGF蛋白表达显著下降,而Ad-IL-24感染后未能使VEGF明显下调。ZD55对VEGF蛋白表达有轻度抑制作用。免疫组化结果显示,Ad-IL-24有轻度抑制血管新生作用,ZD55治疗组有明显的抑制血管新生作用,而ZD55-IL-24治疗组血管新生几乎消失。结论:IL-24通过抑制VEGF表达和血管新生增强ZD55在体外和动物实验中的抗白血病作用。

Objective： To investigate the mechanisms of enhanced antileukemia activity of conditionally replicating adenovirus（CRAd） by interleukin-24（IL-24）.Methods： The ability of CRAd ZD55 to infect leukemia cells was detected by flow cytometry.The expressions of vascular endothelial growth factor（VEGF） in leukemia cells treated with PBS,ZD55,ZD55-IL-24,and an adenovirus carrying IL-24（Ad-IL-24） were determined by Western blot analysis.Animal xenograft tumor model was established by Mutz-1 cell line.Deparaffinized tumor sections were incubated with anti-CD31,and VEGF antibody,followed by immunohistochemistry analysis.Results： The GFP-positive cells were 5.1% and 42.3% in Mutz-1 cells treated with ZD55-EGFP vector at MOI of 10 and 100 for 48h,respectively.ZD55-IL-24 treatment resulted in the marked down-regulation of VEGF protein expression and ZD55 inhibited VEGF slightly;however,there was no change observed in the cells treated with Ad-IL-24.Immunohistochemistry analysis showed that Ad-IL-24 inhibited slightly angiogenesis and ZD55 treatment resulted in significant inhibition of angiogenesis.ZD55-IL-24 treatment almost completely inhibited angiogenesis in tumor tissues.Conclusion： IL-24 enhances the antileukemia activity of ZD55 by inhibiting VEGF protein expression and angiogenesis in vitro and in vivo.