AsO3对Molt—4细胞系P15^IMK4b基因的去甲基化作用

目的：探讨砷剂与甲基化及基出表达的关系。方法：以As2O3处理因高甲基化致P15^IMK4b基因失活的T淋巴母细胞白血病细胞系Molt-4细胞，采用甲基敏感酶限制件酶切PCR、RT-PCR、流式细胞仪和免疫细胞化学染色检测加药前后门5基出洲A甲基化、dmA和蛋自表达的变化及对细胞周期的影响。结果：As2O3处理48h后，P15基因甲基化减低至消失，P15mRNA恢复表达，P15蛋自表达增加26．12％(P<0．05)，细胞阻滞于Gn、G4期。结论：As2O3可通过去除P15抑癌基因甲基化、恢复其表达治疗白血病。

Dual effect of Molt-4 cell line onset with roscovitine

Objective： To observe the effect of roscovitine （ROSC） as some Cyclin-dependent kinases （CDKs）, inhibitor onset with the Molt-4 cell lines. Methods： DNA assay of single cells by flow cytometry was used to detect the effect of cell cycle arrest and Annexin-V/FITC assay was used to detect the effect of cell apoptosis when the Molt-4 cell lines cultured with different concentration ROSC in different time points. Results： It showed that ROSC exerted strong inhibitory effect on proliferation and cell cycle progression of Molt-4 cell lines, accumulation of G2/M cells arrested took place after onset with 10 IJm and 20 μm ROSC more than 6 h; at the same time, the cell apoptosis of Molt-4 cells would be detected. According with the time and concentration increasing, the cell apoptosis rate would rise. Conclusion： It is concluded that Roscovitine （ROSC） as some Cyclin-dependent kinases （CDKs）, inhibitor, has dual effects to Molt-4 cells, not only the effect of cell cycle arrest but also the effect of cell apoptosis.

丙戊酸钠和亚砷酸对Molt-4细胞的协同抑制作用

目的 观察丙戊酸钠(VPA)以及亚砷酸(As2O3)对人类急性T细胞白血病细胞株Molt-4增生、分化和细胞周期的影响以及二者的协同作用.方法 用MTT法观察细胞生长曲线及药物对细胞增生的抑制作用,流式细胞仪检测给药前后DNA含量变化等方法,观察了As2O3和VPA对Molt-4细胞体外抗癌的协同作用.结果 VPA和As2O3均可明显抑制细胞增生,VPA对Molt-4细胞抑制率为50%的浓度即JC50卯为4.904 mmol/L;As2O3的IC50为9.925μmol/L;当二者联用时在体外有相加作用(Q值均＞0.85),在5 mmol/L VPA与10 μmol/L As2O3联用时抑制率达(70.31±2.54)%.流式细胞术检测示经不同浓度VPA处理后G1期细胞由28.21%增加至71.89%,S期细胞由71.75%减低至9.49%.结论 VPA和As2O3均可明显抑制细胞增生,两者合用有协同相加作用,其机制有待进一步研究.