维生素K_2诱导人骨髓增生异常综合征细胞株MUTZ-1细胞凋亡机制的研究

Possible Mechanism Underlying Apoptotic Induction Effect of Vitamin K_2 on Human MDS Cell Line MUTZ-1

为了研究维生素K2(VK2)诱导人骨髓增生异常综合征(MDS)细胞株MUTZ-1细胞凋亡的作用机制,采用流式细胞术Annexin-VFITC/PI双染分析细胞凋亡率和PI染色分析细胞周期的改变,用RT-PCR技术检测抗凋亡基因bcl-2、survivin和促凋亡基因bax的表达,用发光比色法检测caspase-3活性。研究结果显示:细胞的凋亡率随着VK2浓度的增加和作用时间的延长逐渐增高并呈明显的时间浓度依赖性(P<0.05),且随着药物浓度的增加和作用时间的延长S期和G2期细胞逐渐减少(P<0.05),G0/G1期细胞逐渐增多(P<0.01),细胞被阻滞在G0/G1期,并且在G0/G1期前出现明显的亚G1峰,即凋亡峰;抗凋亡基因bcl-2、survivin的表达随着VK2浓度的增高明显下调(P<0.05),而促凋亡基因bax表达无明显变化(P>0.05);caspase-3的活性随着VK2浓度的增加和作用时间的延长而逐渐增强。结论:VK2主要是通过激活caspase-3途径诱导MUTZ-1细胞发生凋亡,同时抗凋亡基因bcl-2、survivin在细胞凋亡过程中也起重要作用。

The study was aimed to investigate the possible mechanism of vitamin K2 （VK2） on myelodysplastic syndrome（MDS）cell line MUTZ-1 in vitro. The flow cytometry was used to analyze apoptosis rate and the change of cell cycle. The expression of apoptosis-related genes bcl-2, survivin and bax were detected by reverse transcription -polymerase chain reaction（RT-PCR）. The activity of caspase-3 was detected by chemiluminescence assay. The results indicated that the apoptosis peak on FCM and positive Annexin-V FITC on cell membrane showed that VK2 induced apoptosis of MUTZ- 1 tells in a dose-and-time-dependent manner, S and （32 cell decrement, G0/G1 cell arrest, VK2 significantly down-regulated the expression of bcl-2 and survivin, but had no effect on the expression of bax, the acdvity of caspase-3 was significantly increased. It is concluded that VK2 induces apoptosis of MUTZ-1 cells through activating caspase-3 pathways and the apoptosis-related genes bcl-2 and survivin may play important roles in the process of apoptosis induction.