维甲酸诱导HL-60细胞凋亡的研究

The Study of Retinoic Acid Induces Apoptosis in HL 60 Cells

目的：观察维甲酸（ＲＡ）在体外诱导ＨＬ６０细胞（人早幼粒细胞白血病细胞株）凋亡的作用，探讨维甲酸治疗早幼粒细胞白血病的作用机制。方法：用ＤＮＡ电泳、ＤＮＡ片段定量测定技术、流式细胞术分析及光镜和电镜观察凋亡细胞。结果：在体外培养中加维甲酸５０ｍｇ／Ｌ孵育４ｈ，ＤＮＡ片段率达５５７％±１２１％，而对照为１２５％±４９％（Ｐ＜０００１，ｎ＝９）；流式细胞术检测发现，在５０ｍｇ／Ｌ维甲酸作用下，细胞凋亡达５０％，对照为９％。电镜观察维甲酸组ＨＬ６０细胞出现典型的凋亡细胞形态改变。维甲酸诱导ＨＬ６０细胞凋亡具有剂量及时间依赖性，维甲酸作用６ｈ，出现凋亡高峰；随维甲酸浓度升高，诱导凋亡作用明显增强。在环孢素Ａ（ＣｓＡ）存在时，低浓度的维甲酸也有明显诱导ＨＬ６０细胞凋亡作用。结论：维甲酸在体外能诱导ＨＬ６０细胞凋亡，ＣｓＡ能增强维甲酸诱导ＨＬ６０细胞凋亡活性。研究提示诱导白血病细胞凋亡是维甲酸治疗急性早幼粒细胞白血病的重要机制之一。

Objective:To observe the effect of inducing apoptosis in promyelocytic leukemia cell line HL 60 cells by retinoic acid(RA) for investigating the mechanism of RA in treatment of promyelocytic leukemia. Methods: Apoptosis was detected with quantitation of DNA fragmentation,agarose gel electrophoresis of DNA ladder,flowcytometric analysis and morphological examination of apoptotic cells. Results: When HL 60 cells were incubated with RA 50 mg/L for 4 h,DNA fragmentation was 55 7%±12 1% as compared to 12 5%±4 9% with the control(P<0 001).Flowcytometric analysis showed that apoptotic cells amounted to 50%,while control was only 9%.Examination with electron microscopy showed typical morphological change of apoptosis in HL 60 cells induced by RA.Induced apoptosis in HL 60 cells by RA was dose and time dependent that showed when the cells were incubated with RA for 6h,it induced higher DNA fragmentation,and when the concentration of RA increased it expressed stronger activity in induced apoptosis.At the same time cyclosporine A was found to enhance apoptosis in HL 60 cells induced by RA. Conclusion: RA can induce apoptosis in HL 60 cells in vitro,and cyclosporine A can boosted up apoptosis induced by RA.This implies that inducing apoptosis in leukemia cell may be the important role of RA in the treatment of promyelocytic leukemia.