聚乙二醇化学修饰的重组L-门冬酰胺酶对小鼠白血病细胞P388的抑制作用

目的 考察聚乙二醇(polyethylene glycol,PEG)化学修饰的重组L-门冬酰胺酶(recombinant Lasparaginase, rL-ASP)的抗肿瘤活性。 方法 PEG 化学修饰rL-ASP, 获得的化学修饰酶(polyethylene glycolmodified recombinant L-asparaginase, rL-ASP-PEG)利用十二烷基硫酸钠-聚丙烯酰胺凝胶电泳法(sodium dodecyl sulfate polyacrylamide gel electrophoresis,SDS-PAGE)观察其分子大小变化, 四甲基偶氮唑盐(3-(4, 4-dimcthylthioazol-2-yl)-2, 5-diphenyl-tetrazolium bromide, MTT)法和流式细胞仪(flow cytometer, FCM)检测rL-ASP-PEG 对体外培养的小鼠白血病细胞P₃₃₈增殖作用的抑制作用, 腹腔给药考察rL-ASPPEG对小鼠移植性实体瘤P₃₃₈ 抑瘤效果, 透射电镜(transmission electron microscopy, TEM)观察rL-ASPPEG引起的肿瘤组织超微病理变化。 结果 SDSPAGE显示, rL-ASP-PEG 的分子量大于rL-ASP;MTT实验表明, rL-ASP-PEG 能抑制体外培养的小鼠P₃₈₈白血病细胞的增殖, 半数有效浓度(inhibitory concentration50 %, IC₅₀)为2.056 IU·ml^-1。FCM 结果表明, rL-ASP-PEG 主要将肿瘤细胞P₃₈₈ 抑制在G₀ +G₁期,S 期细胞减少。DBA/2 荷瘤小鼠的抑瘤实验表明rL-ASP-PEG 对移植性实体瘤P₃₃₈ 有显著抑制作用, P 值<0.001。超微病理切片显示rL-ASP-PEG引起肿瘤组织坏死。 结论 rL-ASP 经过聚乙二醇化学修饰后, 具有肿瘤抑制作用。

Antitumor effects of recombinant L-asparaginase modified by polyethylene glycol for mice leukemia cell P388

AIM: To study the antitumor effects of chemical modification enzyme which recombinant L-asparaginase (rL-ASP)modified by monomethoxy-polyethylene glycol (mPEG). METHODS: PEG modification of rLASP formed rL-ASP-PEG and compared molecular weight of rL-ASP and rL-ASP-PEG with sodium dodecyl sulfaete polyacrylamide gel electrophoresis (SDS-PAGE).Anti-tumor activity was tested by (3-(4, 4-dimcthylthioazol-2-yl)-2, 5-diphenyl tetrazolium bromide analysis(MTT)and apoptosis was valued by flow cytometry (FCM)in vivo.The effect of Anti-tumor activity was evaluated by weights of solid tumor of P₃₃₈ on DBA/2 mice in vitro.Transmission electron microscopy (TEM)observed the effects of rLASP-PEG inhibiting P₃₈₈ solid tumor on DBA/2 mice. RESULTS: rL-ASP-PEG had significant antitumor effects on P₃₈₈ cells, and the inhibitory concentration 50 %(IC₅₀)of rL-ASP-PEG was 2.056 IU·ml^-1 .FCM data showed that the ultramicro pathological picture of transplant tumor in TEM that L-ASP-PEG reacting showed the tumor cells necrosis. CONCLUSION: rL-ASP-PEG shows a significant effect of antitumor.