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P_(388)的抑制作用

Antitumor effects of recombinant L-asparaginase modified by polyethylene glycol for mice leukemia cell P_(388)

目的 :考察聚乙二醇 (polyethyleneglycol,PEG)化学修饰的重组L 门冬酰胺酶 (recombinantL asparaginase ,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 (polyethylenegly colmodifiedrecombinantL asparaginase ,rL ASP PEG)利用十二烷基硫酸钠 聚丙烯酰胺凝胶电泳法 (sodi umdodecylsulfatepolyacrylamidegelelectrophoresis ,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 tetrazoliumbromide ,MTT)法和流式细胞仪 (flowcytometer,FCM )检测rL ASP PEG对体外培养的小鼠白血病细胞P3 3 8增殖作用的抑制作用 ,腹腔给药考察rL ASP PEG对小鼠移植性实体瘤P3 3 8抑瘤效果 ,透射电镜(transmissionelectronmicroscopy ,TEM )观察rL ASP PEG引起的肿瘤组织超微病理变化。结果 :SDS PAGE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P3 88白血病细胞的增殖 ,半数有效浓度 (inhibitoryconcen tration 5 0 % ,IC50 )为 2 .0 5 6IU·ml-1。FCM结果表明 ,rL ASP PEG主要将肿瘤细胞P3 88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P3 3 8有显著抑制作用 。

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 rL-ASP 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 P 338 on DBA/2 mice in vitro. Transmission electron microscopy (TEM) observed the effects of rL-ASP-PEG inhibiting P 388 solid tumor on DBA/2 mice. RESULTS: rL-ASP-PEG had significant antitumor effects on P 388 cells, and the inhibitory concentration 50% (IC 50) 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.