维生素K2对K562细胞生长抑制作用的实验研究

目的:研究维生素K2(VK2)对慢性粒细胞白血病急性变细胞株K562细胞的生长抑制作用及其机制。方法:采用形态学检测VK2作用后的细胞形态改变,MTT方法检测VK2对K562细胞的生长抑制作用,流式细胞仪Annexin-VFITC/PI分析细胞凋亡,PI染色分析细胞周期变化,RT-PCR技术检测抗凋亡基因bcl-2、促凋亡基因bax的表达。结果:经VK2作用后细胞出现明显的形态学改变:细胞变小,核固缩,核染色质聚集边挤于核膜内侧呈新月形以及典型凋亡小体形成等;MTT结果显示VK2对K562细胞有明显的抑制作用,作用72 h半数抑制浓度为25.1μmol.L-1;流式细胞仪检测结果显示随着VK2浓度的增加凋亡率逐渐增高(P<0.05),随着作用时间的延长凋亡率也逐渐增高(P<0.05);VK2作用72 h,S期细胞逐渐减少(r=-0.99,P<0.05),G0/G1期细胞逐渐增加(r=1.00),细胞被阻滞在G0/G1期;随着VK2浓度的增高抗凋亡基因bcl-2表达明显下调,而促凋亡基因bax表达无明显差异。结论:VK2通过诱导K562细胞凋亡抑制其增殖,并呈浓度和时间依赖性;抗凋亡基因bcl-2下调可能是VK2诱导K562细胞发生凋亡的机制之一。

Inhibition effect of Vitamin K2 on K562 cells growth

Objective To studythe inhibiting effects of vitamin K2(VK2) onthe treatment of K562 cells andits possiblemechanism.Methods The changes of morphologic features of K562 cells were observed.Cell apoptosis and cell cycle shiftwere alsoinvestigated by flowcytometry(FCM).The expressions of apoptosis-related genesbcl-2 andbaxwere delected byretrotrans criptase polymerase chain reaction(RT-PCR).Results Apoptosis peak on FCMand positive Annexin-VFITC oncell membrane showedthat VK2induced apoptosis of K562 cell in a dose-andtime-dependent manner,resultingin G0/G1cellarrest;VK2significantly down-regulatedthe apoptosis-related genesbcl-2 expression,but there were no changes ofbaxex-pression.Conclusion VK2induces apoptosis of K562 cells andthe apoptosis-related genesbcl-2 down-regulation might playanimportant role inthis process.