欧前胡素调节MAPK/mTOR/p70S6K信号通路对急性髓系白血病细胞恶性生物学行为的影响

目的 探讨欧前胡素(IMP)对急性髓系白血病(AML)细胞恶性生物学行为的影响以及对MAPK/mTOR/p70S6K信号通路的调节机制。方法 将人AML细胞HL-60进行培养传代,并分为对照组(未处理组),ERK抑制剂组(PD98059组),IMP低、中、高剂量组,IMP高剂量+ERK激活剂组(IMP高+Cearoin组),每组均设置6个重复。MTT法检测IMP对HL-60细胞的毒性;MTT法、软琼脂克隆形成实验检测HL-60细胞的增殖活性;流式细胞仪术检测HL-60细胞凋亡;Transwell小室检测HL-60细胞迁移和侵袭能力;ELISA检测HL-60细胞培养液中TNF-α、IL-1β、IL-6的水平;Western blot检测通路相关蛋白及Bcl-2、Beclin-1、LC3Ⅱ/Ⅰ蛋白的表达。结果 与未处理组比较,PD98059组和IMP低、中、高剂量组HL-60细胞的存活率、克隆形成数量、迁移和侵袭数量、促炎因子TNF-α、IL-1β、IL-6水平以及ERK1/2、mTOR、p70S6K磷酸化水平、Bcl-2表达显著降低(P<0.05),细胞凋亡率、自噬相关蛋白Becl...     

姜黄素对HL-60细胞的增殖抑制与凋亡诱导的影响

目的研究姜黄素对人原髓细胞白血病HL-60细胞的增殖抑制及凋亡诱导作用,探讨其诱导细胞凋亡的机理。方法应用MTT比色法、细胞荧光染色法和Western blotting检测姜黄素对HL-60细胞的增殖抑制、凋亡诱导以及对HL-60细胞表达Bcl-2、Caspase9和c-myc的影响。结果姜黄素对HL-60细胞的增殖抑制与剂量相关(P<0.05);经姜黄素作用后HL-60细胞的形态差异明显,表现凋亡的特征性变化,而且姜黄素作用后HL-60细胞的Bcl-2和原癌基因c-myc的表达量低于对照组(P<0.05),而Caspase9的表达量则明显高于对照组(P<0.05)。结论姜黄素可有效抑制体外培养的HL-60细胞增殖,其诱导HL-60细胞凋亡的途径可能通过线粒体介导。     

MAPK信号通路对地塞米松抑制Jurkat细胞增殖及诱导凋亡的影响

目的研究丝裂原活化蛋白激酶(MAPK)信号通路对地塞米松(Dexamethasone,DEX)诱导急性淋巴细胞白血病Jurkat细胞凋亡及抑制细胞增殖的影响。方法观察地塞米松、PD98059、SP600125、SB203580及地塞米松分别联合PD98059、SP600125、SB203580对Jurkat细胞增殖及凋亡的抑制作用。以急性淋巴细胞白血病Jurkat细胞为研究对象,应用WST-1法检测细胞的增殖活力;流式细胞术分析细胞凋亡。结果地塞米松对Jurkat细胞24 h和48 h抑制细胞增殖50%的药物浓度(IC50)分别为829、335μM。100μM以上地塞米松以时间、剂量依赖方式抑制Jurkat细胞增殖;地塞米松分别联合PD98059、SP600125可增加对Jurkat细胞增殖的抑制效应,联合SB203580对地塞米松抑制Jurkat细胞增殖无影响。10μM地塞米松联合20μM PD98059可显著增加地塞米松诱导Jurkat细胞凋亡的作用,细胞凋亡率由8.5%升至28.4%。结论急性淋巴细胞白血病Jurkat细胞为糖皮质激素耐药细胞。阻断p38MAPK对地塞米松抑制Jurkat细胞增殖无明显影响。阻断ERK、JNK信号通路均可增强地塞米松对Jurkat细胞的杀伤作用,达到逆转Jurkat细胞对地塞米松的耐药。急性淋巴细胞白血病Jurkat细胞糖皮质激素耐药可能与ERK、JNK通路的活化有关。     

黄芩苷元选择性诱导人白血病K562细胞凋亡

目的研究黄芩苷元诱导人白血病细胞凋亡的作用及机理。方法MTT法测细胞毒活性，Hoechst 33258荧光染色法观察凋亡小体形成，流式细胞仪Annexin V FITC-PI法检测细胞凋亡发生率，PI染色法检测凋亡峰及细胞周期，同时流式细胞仪检测细胞Bcl-2，Fas和Caspase 3蛋白表达情况。结果黄芩苷元能选择性抑制人白血病K562细胞生长且呈浓度依赖关系，并能诱导细胞凋亡，细胞增殖被阻滞于S期；同时细胞Fas和Caspase 3蛋白表达增高，而Bcl-2蛋白表达不变。结论黄芩苷元能激活Caspase 3蛋白表达，诱导人白血病K562细胞凋亡且呈时效量效关系，此作用与Fas蛋白表达上调有关，与Bcl-2蛋白表达无关。     

半胱氨酸酶3和Bcl-2在三氧化二砷诱导Namalwa细胞凋亡过程中的表达及意义

目的:了解半胱氨酸酶3(Caspase 3)和Bcl-2在三氧化二砷(As2O3)诱导Burkitt’s淋巴瘤细胞系Namalwa凋亡效应中的作用。方法:琼脂糖凝胶电泳法和Annexin V/PI双染色流式细胞术检测细胞凋亡。应用Caspase 3抑制剂DEVD-CHO和As2O3共同处理细胞,检测Caspase 3和Bcl-2蛋白表达水平的变化。结果:As2O3使Namalwa细胞Caspase 3表达增加,Bcl-2蛋白表达降低。DEVD-CHO能抑制细胞凋亡,但不影响As2O3诱导Bcl-2蛋白表达水平降低的效应。结论:Caspase 3激活可能是As2O3诱导Namalwa细胞凋亡的机制之一。     

柑橘提取物诺必擂停对K562、HL-60细胞株增殖抑制作用

目的观察柑橘提取物诺必擂停对白血病细胞株K562、HL-60增殖的抑制作用。方法采用MTT法检测诺必擂停对细胞增殖的抑制率,电镜下观察细胞的形态变化。结果诺必擂停对白血病细胞株K562、HL-60的增殖有显著的抑制作用。电镜下可见细胞凋亡的形态学表现。结论柑橘提取物诺必擂停能够明显抑制白血病细胞株K562、HL-60的体外增殖,其机制与诱导K562、HL-60的凋亡有关。     

三氧化二砷通过JNK信号通路诱导K562细胞凋亡

目的:探讨c-Jun氨基末端激酶(JNK)信号通路在三氧化二砷(As2O3)诱导K562细胞凋亡中的作用及机制。方法:体外培养K562细胞,用As2O3及特异性JNK抑制剂SP600125对K562细胞进行处理;倒置相差显微镜下观察细胞形态学变化;MTT法检测不同时间点细胞增殖抑制率;AnnexinV/PI染色结合流式细胞术检测细胞凋亡率;ELISA检测p-JNK蛋白表达的变化;流式细胞术检测突变型P53表达。结果:ELISA显示4μmol/LAs2O3作用48h后p-JNK蛋白表达增强,经SP600125预处理后,As2O3诱导的K562细胞p-JNK蛋白表达明显减弱(P<0.01),As2O3诱导的细胞增殖抑制率和细胞凋亡率均下降,与As2O3单作用组相比突变型P53表达增加(P<0.05)。结论:JNK信号转导通路在As2O3诱导K562细胞凋亡过程中发挥重要作用,是As2O3诱导K562细胞凋亡的主要途径之一。     

三氧化二砷诱导K562细胞凋亡过程中血管内皮因子的变化

目的 通过观察三氧化二砷(As2O3)对人类慢性髓系白血病(CML)细胞株K562细胞的作用.探讨其治疗CML的作用机制.方法 将K562细胞与不同浓度As2O3共同孵育,于24、48、72 h用MTT方法检测K562细胞存活率,用AnnexinV-FITC检测凋亡细胞,同时用酶联免疫吸附法(ELISA)检测K562细胞上清液中血管内皮因子(VEGF)的浓度.结果 As2O3＜2 μmol·L-1时,对K562细胞增殖抑制和诱导凋亡的作用与空白对照组比较,无统计学意义(P＞0.05);As2O3＞2 μmol·L-1时则具统计学意义(P＜0.05);在相同作用时间下,AS2O3 浓度升高对K562细胞的增殖抑制率及细胞凋亡率亦升高;当As2O3＞8 μmol·L-1时,对K562细胞的抑制及细胞凋亡率不再上升. As2O3＜2 μmol·L-1时上清液中VEGF浓度与空白对照组比较无显著性(P＞0.05);As2O3＞2 μmol·L-1时VEGF的浓度差异有显著性(P＜0.05),且随As2O3 浓度的增加VEGF浓度上升;当As2O3＞8 μmol·L-1时则变化不显著(P＞0.05).结论 As2O3可抑制K562细胞增殖,并具诱导凋亡作用, As2O3在2.0～10.0 μmol·L-1梯度浓度,作用在24～72 h时段,表现为时间和剂量依赖性,还可下调VEGF表达水平.     

联合应用化疗药物对三氧化二砷耐药白血病细胞的毒性实验研究

目的:探讨化疗药物联合应用对三氧化二砷(As2O3)耐药白血病细胞(K562/AS2)的毒性作用。方法:细胞毒实验采用MTT法,二药合用时细胞毒性作用采用ChouTalalay联合指数法分析,细胞表面P糖蛋白(Pgp)和细胞内柔红霉素(DNR)浓度测定采用流式细胞术测定。结果:K562/AS2细胞对三氧化二砷、柔红霉素、鬼臼乙叉苷(VP16)、三尖杉酯碱(H)、米托蒽醌(NVT)和阿糖胞苷(AraC)的耐药倍数分别为7.4、2.9、3.8、3.6、2.8和1.1。K562细胞和K562/AS2细胞的细胞表面Pgp或细胞内任意荧光强度无显著的统计学意义(P>0.05)。As2O3与DNR、VP16、H或NVT联合应用时,对K562、K562/AS2和Pgp表达的白血病细胞(K562/A02)细胞的联合指数均大于1。异搏定与DNR联合应用时,对K562和K562/AS2细胞的联合指数均大于1,但是对K562/A02细胞的联合指数均小于1。结论:K562/AS2细胞对As2O3、DNR、VP16和NVT耐药,其机制与Pgp表达无关。异搏定联合应用DNR可以逆转K562/A02对DNR的耐药性,不能逆转DNR对As2O3耐药细胞的耐药性。As2O3与DN、VP16、H和NVT联合应用时,对K562、K562/AS2和K562/A02细胞的毒性均为拮抗作用。     

熊果酸对HL-60细胞株凋亡及Bcl-2和bax表达的影响

目的探讨熊果酸(UA)抑制人急性髓性白血病细胞系(HL-60)细胞增殖和诱导凋亡作用,并观察Bcl-2和bax基因表达的影响。方法体外培养HL-60细胞。MTT比色法检测增殖活性;流式细胞术(FCM)检测细胞凋亡和细胞周期分布;Western Blot分析Bcl-2和bax基因表达。结果 UA显著抑制HL-60细胞增殖,呈浓度依赖性;UA呈浓度依赖性诱导HL-60细胞凋亡,明显阻滞于细胞周期G1期;UA以浓度依赖方式下调Bcl-2蛋白表达和上调bax蛋白表达。结论 UA抑制HL-60细胞增殖和诱导凋亡,其作用机制与下调Bcl-2上调bax蛋白表达相关。     

Bcl-xL is a dominant antiapoptotic protein that inhibits homoharringtonine-induced apoptosis in leukemia cells

Homoharringtonine (HHT) has been reported to be effective in a portion of patients with acute myeloid leukemia (AML) or chronic myeloid leukemia (CML). To investigate its mechanism of action, cell growth inhibition and cytotoxicity of HHT were investigated in three AML cell lines, HL-60, NB4, and U937, and in three CML cell lines, K562, KU812, and KCL22. AML cells were more sensitive than CML cells to HHT-induced cytotoxicity. Using HL-60 cells, it was revealed that HHT decreased the levels of myeloid cell leukemia 1 (Mcl-1), X-linked inhibitor of apoptosis protein (XIAP), survivin, and B-cell lymphoma 2 (Bcl-2)-homology domain 3 (BH3)-only proteins as well as the mitochondrial membrane potential. The levels of Bcl-2, Bcl-2-associated X protein (Bax), and Bcl-2 homologous antagonist/killer (Bak) proteins in HL-60 cells were not changed after HHT treatment. U937, K562, KU812, and KCL22 cells expressed B-cell lymphoma-extra large (Bcl-xL) and were less responsive to HHT-induced apoptosis than HL-60 cells. Silencing Mcl-1 or Bcl-xL, but not XIAP or survivin, enhanced HHT-induced apoptosis in U937 cells. The levels of HHT-induced apoptosis in K562, KCL22, and KU812 cells were inversely correlated with the levels of Bcl-xL but not those of Bcl-2 or Mcl-1. K562 cells expressing high levels of Bcl-xL but no Bcl-2 were less responsive to HHT-induced apoptosis than KCL22 cells that expressed lower levels of Bcl-xL and higher levels of Bcl-2 protein. In K562 cells, knockdown of Bcl-xL, but not of Mcl-1, enhanced HHT-induced apoptosis. Transfection of Bcl-xL into KCL22 cells attenuated HHT-induced apoptosis. These data suggest that Bcl-xL plays a more important role than Bcl-2 and Mcl-1 in protecting against HHT-induced apoptosis.     

四种砷拮抗剂对三氧化二坤诱导的三种粒系白血病细胞凋亡和端粒酶活性的减量调节作用

目的：研究巯基供体N-乙酰兰胱氨酸（NAC）和二巯丁二钠（NDMS）、抗氧化剂过氧化氢酶（CAT）和Ca^2 清除剂（Quin2）对三氧化二砷诱导的三种粒系白血病细胞凋亡和端粒酶活性改变的调控作用。方法：用流式细胞仪和PCR ELISA法分别检测NAC、NDMS、CAT或Quin2与三氧化二砷共同作用于三种粒系白血病细胞后其凋亡和端粒酶活性的变化。结果：三氧化二砷0.6、2.7和8.1μmol/L可分别诱导急性早幼粒细胞白血病细胞株NB4,慢性粒细胞白血病细胞株K562,急性粒细胞白血病细胞株HL-60细胞发生40%-60%的凋亡,同时下调三种细胞的端粒酶活性。NAC4mmol/L,NDMS200μmol/L,CAT80kU/L,Quin 2 20μmol/L不同程度抑制这种凋亡作用,NAC和CAT既可独立降低三种细胞的端粒酶活性,也可促进三氧化二砷对端粒酶的下调作用,而Quin2可抑制K562和HL-60细胞中的这种下调作用。结论：三氧化二砷诱导的三种细胞的凋亡过程涉及了疏基失活、自由基的改变、细胞内Ca^2 浓度改变及端粒酶活性下降,NAC、NDMS、CAT及Quin2可不同程度拮抗三氧化二砷对三种细胞的作用。     

Inhibition by ascorbic acid of apoptosis induced by oxidative stress in HL-60 myeloid leukemia cells

The human myeloid leukemia cell line HL-60 transports the oxidized form of ascorbic acid, dehydroascorbic acid (DHA), and accumulates reduced ascorbic acid. We studied the effect of ascorbic acid loading on apoptosis induced by serum- and glucose-free culture and by oxidative stress induced by H2O2. Uptake accumulation studies indicated that incubation of HL-60 cells with DHA resulted in the accumulation of intracellular ascorbic acid which decreased with time when cells were incubated in DHA-free medium. Exposure of HL-60 cells to increasing concentrations of H2O2 resulted in dose-dependent intracellular accumulation of peroxides, as determined by the use of the oxidation-sensitive fluorescent probe 2',7'-dichlorofluorescin-diacetate (DCFH-DA), which was accompanied by a decrease in intracellular ascorbic acid and an increase in apoptosis. A dramatic decrease in intracellular ascorbic acid was noted when preloaded HL-60 cells were exposed to 150 microM H2O2 (the concentration dropped from 5.2 +/- 0.6 mM to 3.6 +/- 0.1 mM in cells preincubated with 150 microM DHA). A dose-dependent protective effect of DHA was observed. Ascorbic acid loading also provided strong protection from apoptosis associated with serum- and glucose-free culture. Flow cytometry studies showed that exposure of HL-60 cells to 150 microM H2O2 resulted in decreased Bcl-2 expression that was associated with enhanced apoptosis (up to 33.6 +/- 2.6%). No significant variation of Bcl-2 expression was measured following exposure of HL-60 cells, loaded with ascorbic acid, to 150 microM H2O2 and only a slight increase (up to 10.1 +/- 3.1%) in apoptosis. These findings indicate that ascorbic acid can inhibit apoptosis induced by oxidative stress in HL-60 cells.     

DNA引物酶抑制剂碘化-3,3′-二乙基-9-甲基-硫杂羰花青诱导人白血病HL-60细胞凋亡

目的研究DNA引物酶抑制剂碘化-3,3′-二乙基-9-甲基-硫杂羰花青(DMTCCI)诱导人粒细胞性白血病HL-60细胞凋亡并探索其机制。方法分别采用不同浓度的DMTCCI处理培养于RPMI-1640培养基的HL-60细胞。采用MTT法检测DMTCCI对HL-60细胞的生长抑制作用。采用流式细胞仪和DNA琼脂糖凝胶电泳方法检测细胞凋亡。采用蛋白免疫印迹(Western blotting)法观察凋亡相关蛋白survivin， Bcl-xL， Bad， Bax， Bcl-2， caspase-9， caspase-3， caspase-6， PARP， DFF45和lamin B的表达。采用ApoAlert Caspase-3分析试剂盒检测caspase-3的活性。结果DMTCCI具有抑制人白血病HL-60细胞增殖的作用，其IC₅₀值为0.24 μmol·L^-1。流式细胞仪和DNA琼脂糖凝胶电泳结果显示，DMTCCI可诱导HL-60细胞凋亡。在经DMTCCI处理的HL-60细胞中，survivin和Bcl-xL蛋白的表达水平下调，Bad和Bax蛋白的表达水平上调，Bcl-2蛋白的表达水平无变化，caspase-9，caspase-3，caspase-6，PARP，DFF45和lamin B被分别裂解，产生相应裂解产物。在HL-60细胞中，caspase-3的活性在1 μmol·L^-1 DMTCCI处理3 h时明显升高，在处理12 h时达到最高峰。结论DMTCCI可抑制人白血病HL-60细胞的增殖并诱导其发生细胞凋亡。Bcl-2家族蛋白、survivin和caspases家族蛋白可能参与了上述诱导HL-60细胞凋亡的过程。     

The mitotic-arresting and apoptosis-inducing effects of diosgenyl saponins on human leukemia cell lines

Diosgenyl saponins are the most abundant steroid saponins, and exert a large variety of biological functions. In a previous report, we showed that dioscin was able to induce cytotoxicity and apoptosis in human myeloblast leukemia HL-60 cells. This study further investigated the action mechanisms underlying this effect. The activation of caspase-9 and -3, but not caspase-8, together with the down-regulation of anti-apoptotic Bcl-2 protein, demonstrated that the apoptotic signaling triggered by dioscin was mediated through the intrinsic mitochondria-dependent pathway. We also investigated its anti-proliferative effect on human chronic myelogenous leukemia K562 cells. Flow cytometry analysis showed that dioscin treatment induced the accumulation of cells in the G(2)/M phase. Cytomorphology with DAPI and Wright-Giemsa staining demonstrated the enlargement of cell volume and multinucleation in the treated cells. Subsequent apoptosis was delineated with phosphatidylserine externalization and DNA hypodiploidy. Trillin was one of the hydrolysates of dioscin. We demonstrated that it could induce multinucleation in HL-60, K562 and human promyelocytic leukemia NB(4) cells, suggesting its extensive mitotic-arresting effects. As the diosgenyl sapogenin, diosgenin was also shown to be able to induce multinucleation and apoptosis in K562 cells in a similar manner to dioscin. These findings suggest that diosgenyl saponins have the properties to induce mitotic arrest and apoptosis, suggesting that they may be a new kind of antimitotic agent.     

Riccardin D, a novel macrocyclic bisbibenzyl, induces apoptosis of human leukemia cells by targeting DNA topoisomerase II

We studied the effect of riccardin D, a macrocyclic bisbibenzyl, which was isolated from the Chinese liverwort plant, on human leukemia cells and the underlying molecular mechanism. Riccardin D had a significant antiproliferative effect on human leukemia cell lines HL-60, K562 and its multidrug resistant (MDR) counterpart K562/A02 cells, but showed no effect on the topoisomerase-II-deficient HL-60/MX2 cells, as measured by the 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) assay. The pBR322 DNA relaxation assay revealed that riccardin D selectively inhibited the activity of topoisomerase II (topo II). The suppression of topo II activity by riccardin D was stronger than that of etoposide, a known topo II inhibitor. After treatment with riccardin D, nuclear extracts of leukemia K562 and K562/A02 cells left the majority of pBR322 DNA in a supercoiled form. Further examination showed that riccardin D effectively induced HL-60, K562 and K562/A02 apoptosis as evidenced by externalization of phosphatidylserine and formation of DNA ladder fragments. The activation of cytochrome c, caspase-9, caspase-3 and cleaved poly ADP-ribose polymerase (PARP) was also enhanced, as estimated by Western blot analysis. By contrast, riccardin D was unable to induce apoptosis in the topoisomerase-II-deficient HL-60/MX2 cells, indicating that the induction of apoptosis by riccardin D was due to the inhibition of topo II activity. In addition, riccardin D was able to significantly decrease P-glycoprotein (P-gp) expression in K562/A02 cells. Taken together, our data demonstrate that riccardin D is a novel DNA topo II inhibitor which can induce apoptosis of human leukemia cells and that it has therapeutic potential for both regular and MDR strains of leukemia cells.     

DNA引物酶抑制剂碘化-3,3''-二乙基-9-甲基-硫杂羰花青诱导人白血病HL-60细胞凋亡

目的 研究DNA引物酶抑制剂碘化-3,3'-二乙基-9-甲基-硫杂羰花青(DMTCCI)诱导人粒细胞性白血病HL-60细胞凋亡并探索其机制.方法 分别采用不同浓度的DMTCCI处理培养于RPMI-1640培养基的HL-60细胞.采用MTT法检测DMTCCI对HL-60细胞的生长抑制作用.采用流式细胞仪和DNA琼脂糖凝胶电泳方法检测细胞凋亡.采用蛋白免疫印迹(Western blotting)法观察捌亡相关蛋白survivin,Bcl-xL,Bad,Bax,Bcl-2,caspase-9,caspase-3,caspase-6,PARP,DFF45和lamin B的表达.采用ApoAlert Caspase-3分析试剂盒检测caspase-3的活性.结果 DMTCCI具有抑制人白血病HL-60细胞增殖的作用,其IC50值为0.24μmol·L-1.流式细胞仪和DNA琼脂糖凝胶电泳结果显示,DMTCCI可诱导HL-60细胞凋亡.在经DMTCCI处理的HL-60细胞中,survivin和Bcl-xL蛋白的表达水平下调,Bad和Bax蛋白的表达水平上调,Bcl-2蛋白的表达水平无变化,caspase-9,caspase-3,caspase-6,PARP, DFF45和lamin B被分别裂解,产生相应裂解产物.在HL-60细胞中,caspase-3的活性在1μmol·L-1 DMTCCI处理3 h时明显升高,在处理12 h时达到最高峰.结论 DMTCCI可抑制人白血病HL-60细胞的增殖并诱导其发生细胞凋亡.Bcl-2家族蛋白、survivin和caspases家族蛋白可能参与了上述诱导HL-60细胞凋亡的过程.     

二氢青蒿素诱导HL-60细胞凋亡

目的探讨二氢青蒿素对人早幼粒白血病细胞(HL-60)的治疗作用。方法采用台盼蓝染色法和MTT法测定二氢青蒿素对HL-60细胞存活的影响,吖啶橙/溴化乙啶(AO/EB)荧光双染色、DNA凝胶电泳、流式细胞术检测细胞凋亡,Western印迹分析凋亡相关蛋白的表达。结果二氢青蒿素可抑制HL-60细胞存活,诱导HL-60细胞凋亡,同时降低HL-60细胞Bcl-2蛋白的表达,增加Bax蛋白和凋亡执行蛋白半胱氨酸天冬氨酸蛋白酶(caspase)-3的表达,并呈浓度依赖性。结论二氢青蒿素可诱导HL-60细胞凋亡,其机制可能是通过对线粒体凋亡通路中Bcl-2,Bax和caspase-3蛋白表达的调控而发挥作用。     

选择性COX-2抑制剂NS-398诱导白血病细胞凋亡的作用机制

目的探讨选择性环氧合酶-2(COX-2)抑制剂NS-398诱导白血病细胞系K562细胞凋亡的分子机制。方法采用流式细胞术检测细胞凋亡;采用蛋白印迹法(Western blot)检测凋亡相关蛋白Bcl-2、半胱氨酸酶-3(Caspase-3)的表达;并应用流式细胞术检测Caspase-3的活性。结果①NS-398作用K562细胞24h后,对照组未出现凋亡峰,各药物处理组(100~400μmol·L-1)均出现明显的凋亡峰,其凋亡率分别为(10.51±1.04)%、(27.79±2.40)%、(45.72±3.32)%和(60.22±2.03)%(P<0.01)。②不同浓度NS-398处理后,K562细胞中Bcl-2蛋白表达下降,而Caspase-3蛋白表达增加,与对照组相比差异具有显著性(P<0.05)。③NS-398能以剂量依赖方式促进Caspase-3活性的增加,表达活化Caspase-3的细胞百分率分别为(2.67±0.22)%、(9.53±0.15)%、(21.28±0.43)%、(39.63±0.8)%和(63.40±0.69)%(P<0.01)。结论选择性COX-2抑制剂NS-398可能通过调节Bcl-2蛋白表达、活化Caspase-3,从而诱导白血病K562细胞凋亡。