叶酸对人T淋巴细胞性白血病细胞体外的作用

Effects of Folic Acid on Human T Lymphoid Leukemia Cell Line CEM Cells

目的探讨叶酸对人T淋巴细胞性白血病细胞株(CEM)细胞的作用。方法1.四氮甲基唑蓝(MTT)法检测叶酸不同浓度.不同作用时间对CEM细胞增殖影响;2光镜下观察不同浓度叶酸作用于CEM细胞24、48、72 h细胞形态变化;3.流式细胞术检测叶酸持续作用于CEM细胞48 h细胞凋亡率、细胞周期分布及细胞表面凋亡相关蛋白Bcl-2、C-myc表达;4.DNA 电泳分析凋亡细胞DNA片段化的生化改变;5.MTT法检测叶酸对甲氨蝶呤(MTX)抗肿瘤作用影响。结果1叶酸对CEM 的增殖有明显抑制作用,在(0 4～3.0)×10-4μg/L时抑制作用最明显,抑制率30%～40%;2.叶酸分别作用于CEM细胞24、48、72 h后,光镜下可见CEM细胞出现典型的细胞凋亡各阶段的变化,在浓度为(0 2～6.0)×10-4 μg/L均可见到凋亡细胞, 尤其在(0 4～3.0)×10-4 μg/L凋亡率较高;3流式细胞术分析,叶酸浓度为3 0×10-4 μg/L时诱导凋亡作用最强,凋亡率为6.19%,CEM细胞经叶酸处理后细胞周期无明显变化规律,但叶酸作用于CEM细胞48 h,在Pl荧光的直方图上可见凋亡细胞在G1/G0期前出现一亚二倍体峰,细胞表面凋亡相关蛋白Bcl-2、C-myc表达率均明显下降;4.CEM细胞经0 4×10-4 μg/L和3.0×10-4 μg/L 叶酸处理48h,提取DNA电泳,可见典型的梯状条带;5.叶酸在浓度为(0.2～12.0)×10-4 μg/L

Objective To investigate the effects of the folic acid on human T lymphoid leukemia cell line CEM cells. Methods 1. MTT method was used to detect the proliferation of CEM cells co- cultured with folic acid of different concentrations and time;2. E-xamine the changes of morphology by light microscopy with Giemsa stain;3. Detect the percentage of apoptosis and cell cycle distribution as well as the expression of the apoptosis protein(Bcl- 2,C- myc) by flow cytometry;4. Detect DNA fragments by Agaiose elec-trophoresis;5. Detect the influence of folic acid to the anticancer effects of methotrexatc(MTX) by MTT methods. Results 1 Folic acid could inhibit the proliferation of CEM cells, and the optimal inhibitive concentrations range from 0. 4 × 10-4 μg/L to 3. 0 × 10 -4 μg/L,the inhibition rate was about 30% - 40% ; 2. Co - cultured with folic acid at 24,48, 72 hours, examined by light microscopy with Giemsa stain, apoptosis cells were found in all study groups but the higher apoptosis rate was found co - cultured with folic acid at concentration of (0.4 - 3.0) × 10-4μg/L;3.The highest apoptosis rate was 6. 19% found at the concentration of 3 × 10-4 μg/L, but the cell cycle distribution had no statistical difference with control group, the expression of apoptosis related protein Bcl - 2 and C-myc was decreased;4 DNA was extracted from CEM cells co - cultured with 0.4× 10 -4 μg/L and 3 × 10-4 μg/L folic acid for 48 hours. UNA ladders were visible by agarose electrophoresis of DNA fragments; 5. Folic acid did not affect the antitumor effect of MTX at the concentration from 0 2× 10-4 μg/L to 12.0×10-4 μg/L. Conclusion Folic acid may suppress proliferation and induce apoptosis of CEM cell