FoxO3a在三氧化二砷诱导的人乳腺癌MCF-7细胞凋亡中的表达和意义

目的 探讨FoxO3a在三氧化二砷(As2O3)诱导人乳腺癌细胞MCF-7凋亡过程中的表达变化及其可能的机制。方法 将不同浓度的As2O3(2.0、4.0、8.0μmol/L)与MCF-7细胞共同培养24h后,采用流式细胞术检测MCF-7细胞凋亡;采用免疫细胞化学及Western blot技术检测FoxO3a和Caspase 3蛋白的表达,各实验均设相应的阴性对照组。结果 经不同浓度As2O3作用后,MCF-7细胞凋亡率逐渐增加,分别为(6.26±0.94)%、(9.30±1.63)%和(13.02±3.82)%,且呈剂量依赖关系(rs=0.949, P<0.01);免疫细胞化学染色显示FoxO3a蛋白胞核表达增强,且Caspase-3蛋白表达增强（P<0.05);Western blot条带显示FoxO3a蛋白表达水平逐渐升高,且激活型Caspase-3蛋白表达水平逐渐升高（P<0.05)。结论 As2O3可通过增强FoxO3a蛋白的活性,激活Caspase-3蛋白的表达而诱导MCF-7细胞凋亡。     

CA3诱导肝癌HepG2细胞凋亡及其机制CSCD

目的探讨CA3(CIL56)对肝癌HepG2细胞增殖及凋亡的影响及其机制。方法体外培养HepG2细胞,分别加入不同浓度CA3(0、0.25、0.5、1.0、2.0和4.0 mmol/L)作用24和48 h。增强型CCK-8试剂检测不同浓度CA3对细胞增殖的影响;流式细胞术检测细胞凋亡率;检测细胞内活性氧(ROS)的变化;Western blot法分析YAP1、Bcl-2、Bax、Caspase-3蛋白的表达。结果增强型CCK-8试剂检测结果显示,0.25、0.5、1.0、2.0、4.0 mmol/L的CA3作用HepG2细胞24和48 h后,细胞增殖率分别为(80.5±0.3)%、(79.4±0.2)%、(76.2±0.2)%、(76.4±0.1)%、(49.3±0.4)%和(75.3±0.2)%、(64.8±0.3)%、(48.4±0.2)%、(32.2±0.4)%、(31.9±0.2)%。流式细胞术结果显示,CA3浓度升高至2 mmol/L时,凋亡率增加到58.48%。CA3处理后,HepG2细胞内活性氧产量增加,YAP1、Bcl-2蛋白表达降低,Bax、Caspase-3表达增高。结论 CA3可抑制HepG2细胞增殖并诱导凋亡,其机制可能与细胞内活性氧产量增加,调节YAP1、Bcl-2、Bax及Caspase-3蛋白的表达有关。     

体外联合应用NS-398与5-FU抑制肝癌HepG2细胞生长的研究

目的研究体外联合应用选择性COX-2抑制剂NS-398与5-氟尿嘧啶(5-FU)对肝癌细胞生长的抑制作用.方法应用MTT法观察NS-398、5-FU及NS-398 5-FU对人肝癌细胞株HepG2的生长抑制作用;通过荧光显微镜、透射电镜、流式细胞仪研究NS-398、5-FU及NS-398 5-FU对HepG2的凋亡诱导作用.结果NS-398和5-FU对肝癌细胞HepG2的生长有显著抑制作用,NS-398和5-FU联合应用时抑制效应较单一应用更为明显.透射电镜、荧光显微镜观察和流式细胞仪检测显示,HepG2细胞经NS-398、5-FU及NS-398 5-FU处理后出现典型的细胞凋亡形态变化和Sub-G1峰.结论联合应用选择性COX-2抑制剂NS-398有增强5-FU抑制肝癌细胞生长的作用.     

NS-398联合表阿霉素对肝癌HepG2细胞增殖及survivin表达的影响

[目的]探讨表阿霉素联合COX-2抑制剂NS-398对HepG2细胞增殖及survivin表达的影响.[方法]不同浓度表阿霉素单药或联合不同浓度NS-398分别作用于肝癌HepG2细胞株,MTT法测定表阿霉素联合NS-398对细胞生长的抑制率,RT-PCR和免疫荧光法分别检测HepG2细胞中survivin mRNA与survivin蛋白表达量的变化.[结果]单药表阿霉素对HepG2细胞有显著的抑制作用,且与NS-398联合应用后抑制作用更明显.正常无药对照组HepG2细胞中survivin蛋白和mRNA均呈强表达,表达水平分别为68.970±1.156和0.919±0.021;且在胞浆中survivin蛋白表达强于胞核.表阿霉素组HepG2细胞中survivin蛋白(47.630±0.863)和mRNA (0.749±0.014)水平均明显降低,联合组survivin蛋白(27.544±0.748)和mRNA(0.481±0.012)水平降低更显著(F=1065.233,P＜0.05;F=304.553,P＜0.05).[结论]NS-398联合表阿霉素可明显抑制HepG2细胞生长,NS-398可显著增强表阿霉素的抗癌作用;两者联合可明显下调HepG2细胞株中survivin蛋白和mRNA的表达.     

COX-2抑制剂NS-398对肝癌细胞放射增敏作用的实验研究

目的探讨环氧合酶-2（COX-2）抑制剂NS-398对肝癌细胞系HCC-9810的放射增敏作用及其机制。方法MTT实验测定NS-398对肝癌细胞系HCC-9810细胞毒性;成克隆实验检测NS- 398对HCC-9810的放射增敏作用;电镜观察细胞形态学改变;流式细胞仪（FCM）分析细胞凋亡率;逆转录聚合酶链反应（RT-PCR）、FCM观察Bcl-2、Bax mRNA及蛋白表达。结果NS-398对HCC-9810细胞毒性呈现浓度、时间依赖性。10μmol/L NS-398作用24 h细胞增殖抑制率仅为3%,由D_q计算增敏比（SER）为1．29,细胞存活曲线“肩区”减小。NS-398处理HCC-9810细胞后放射诱导凋亡的敏感性增高,Bax mRNA和蛋白表达上调,呈NS-398剂量依赖性关系,而Bcl-2表达无明显变化,Bax/ BcL-2比值增高。结论NS-398对肝癌细胞系HCC-9810有放射增敏作用,且可能是通过上调Bax基因表达增强放射诱导凋亡作用及抑制亚致死损伤修复实现的。     

NS-398对胰腺癌细胞株PC-3放射增敏作用及其机制的研究

目的:应用选择性环氧合酶-2(COX-2)抑制剂NS-398作用于胰腺癌细胞株PC-3,观察其放射增敏作用,并对其可能机制进行初步探讨。方法:体外培养胰腺癌细胞株PC-3;以流式细胞术(FCM)单抗标记技术检测PC-3细胞的COX-2表达水平;以MTT实验检测细胞增殖抑制情况及NS-398对细胞放射敏感性的影响;以FCM分析细胞周期变化以RT-PCR及FCM分析凋亡相关基因Bcl-2、Bax表达变化。结果:FCM显示PC-3细胞存在COX-2的异常高表达;MTT实验显示,与单纯照射组比较,联合NS-398照射组的细胞生存率显著降低〔(78.45±3.46)%vs(57.42±2.58)%,χ2=5.52,P=0.016〕;FCM显示,NS-398联合放射组S期细胞比值显著下降(χ2=4.91,P=0.029),而G2～M期细胞比值显著增加(χ2=3.92,P=0.041),NS-398和放射线可协同作用,使PC-3细胞的周期再分布显著变化;RT-PCR及FCM显示,NS-398可致细胞内Bcl-2/Bax比值下降。结论:选择性COX-2抑制剂NS-398可增强胰腺癌细胞PC-3的放射敏感性,其机制可能与改变细...     

Caspase-8和Bcl-2在PIG11诱导HepG2细胞凋亡中的作用

目的:利用本实验室已建立PIG11蛋白稳定低表达的HepG2细胞株和PIG11蛋白稳定高表达HepG2细胞株,研究Caspase-8和Bcl-2在PIG11诱导HepG2细胞凋亡中的作用,进一步探讨PIG11基因表达对HepG2细胞凋亡的机制。方法:细胞培养,分组:HepG2细胞、pLXSN-PIG11-HepG2(pLXSN-PIG11转染建立PIG11蛋白高表达HepG2细胞)、pLXSN-HepG2(pLXSN空载体转染HepG2细胞)、miR-PIG11-HepG2(miRNA干扰PIG11蛋白低表达HepG2细胞)、miR-HepG2(干扰空载体HepG2细胞)。Hoechst33342染色荧光和PI染色流式细胞仪检测各组细胞凋亡情况。Western blot检测Caspase-8蛋白、Bcl-2蛋白的表达情况。结果:Hoechst 33342染色荧光显微镜下pLXSN-PIG11-HepG2细胞组可见核染色质浓缩,核碎片,荧光增强,以及凋亡小体。PI染色流式细胞仪检测结果显示:HepG2细胞、miR-PIG11-HepG2细胞、miR-HepG2细胞、pLXSN-PIG11-HepG2细胞、pLXSN-HepG2细胞的凋亡率分别为5.72%±0.81%、1.34%±0.71%、5.10%±0.40%、34.83%±2.29%、5.34%±0.60%。PIG11高表达的pLXSN-PIG11-HepG2细胞组凋亡率比其它各组增高(P<0.01),PIG11低表达的miR-PIG11-HepG2细胞组凋亡率降低(P<0.01)。Western blot检测结果显示PIG11高表达的pLXSN-PIG11-HepG2细胞Caspase-8蛋白表达上调,Bcl-2蛋白表达下调(P<0.01),PIG11低表达的miR-PIG11-HepG2细胞Caspase-8蛋白的表达下调,Bcl-2蛋白表达上调(P<0.01)。结论:PIG11蛋白高表达能诱导HepG2细胞凋亡,其机制可能与Caspase-8蛋白及Bcl-2蛋白表达相关。     

NS-398对人胃癌细胞系SGC-7901增殖、凋亡和COX-2表达的影响

目的 探讨环氧合酶-2(COX-2)抑制剂NS-398对人胃癌细胞系SGC-7901增殖、凋亡及COX-2表达的影响,并进一步探讨其作用的可能机制.方法 采用四甲基偶氮唑蓝(MTT)法检测NS-398对SGC -7901细胞的杀伤抑制作用;免疫细胞化学法检测SGC-7901细胞内COX-2的蛋白表达情况;ELISA法检测NS-398作用于SGC-7901细胞后PGE2释放水平;流式细胞仪检测SGC-7901细胞的凋亡情况.结果 NS-398对胃癌SGC-7901细胞具有较强的抑制作用,且这种抑制作用随浓度和时间的增加而增强,呈剂量-时间双效应关系(P＜0.05);不同浓度NS-398作用下的SGC-7901细胞中,COX-2的表达明显减弱,且呈剂量梯度下降(P＜ 0.05);NS-398可抑制PGE2释放,并且这种抑制作用呈剂量效应关系,与对照组相比差异有统计学意义(P＜ 0.05);NS-398作用于SGC-7901细胞48 h后,细胞凋亡率升高,且呈剂量效应(P＜0.05).结论 NS-398通过COX-2依赖途径抑制SGC-7901细胞增殖并促进其凋亡.     

环氧合酶-2选择性抑制剂NS-398诱导人肝癌BEL-7402细胞凋亡及其机制探讨

目的:探讨环氧合酶-2(cyclooxygenase-2,COX-2)选择性抑制剂NS-398对人肝癌BEL-7402细胞凋亡及凋亡抑制蛋白survivin、XIAP和c-IAP1表达的调节作用.方法:用不同浓度的NS-398作用BEL-7402细胞后,MTT法测定细胞增殖抑制情况,FCM法和TUNEL法检测细胞凋亡情况,免疫细胞化学法检测COX-2、survivin、XIAP和c-IAP1蛋白的表达情况.结果:NS-398 可以显著抑制BEL-7402细胞的增殖,诱导其凋亡.免疫细胞化学法检测结果显示,与未处理组相比,NS-398作用可使BEL-7402细胞中COX-2、survivin、XIAP和c-IAP1蛋白的表达明显下调(P<0.01).结论:NS-398对人肝癌细胞株BEL-7402有抑制细胞增殖和诱导细胞凋亡的作用,其机制可能与通过下调survivin、XIAP和c-IAP1的表达有关.     

选择性环氧合酶-2 抑制剂 NS-398 抑制多药耐药细胞株 P-糖蛋白表达

目的:探讨选择性环氧合酶-2(cyclooxygenase-2,COX-2)抑制剂NS-398对多药耐药细胞株K562/ADM细胞P-糖蛋白(P-glycoprotein,P-gp)表达的影响。方法:K562/ADM细胞经浓度分别为10μmol/L、20μmol/L、40μmol/L、80μmol/L、160μmol/L的NS-398处理,24h、48h、72h后用RT-PCR法检测MDR1mRNA的表达、用流式细胞仪检测mdr1蛋白表达。结果:随着NS-398浓度的升高以及作用时间延长,MDR1mRNA、p-gp表达降低,不同浓度的药物与测量时间之间存在着交互作用(P<0.05)。结论:选择性环氧合酶-2抑制剂NS-398可抑制K562/ADM细胞的MDR1/P-gp表达。     

Selective inhibition of cyclooxygenase-2 enhances mitomycin-C-induced apoptosis

Purpose: Cyclooxygenase-2 (COX-2) is involved in antiapoptosis signaling, and its induction may require activation of protein kinase C (PKC). Safingol (SAF), a PKC inhibitor, has been shown to enhance apoptosis induced by mitomycin-C (MMC) in human gastric cancer MKN-74 cells. The aim of this study was to identify the role of COX-2 in MMC-induced apoptosis in MKN-74 cells. Methods: Protein expression of COX-2 and Bcl-2 and activation of PKCα were examined by Western blot analysis. Apoptosis induction was examined by staining with bisbenzimide trihydrochloride (Hoechst-33258) of condensed chromatin, which characterizes the cells undergoing apoptosis. COX-2 mRNA levels were examined by Northern blot analysis. Results: After exposure for 1–2 h to 1 μg/ml MMC, upregulation of COX-2 and Bcl-2 protein expression was noted. The activation of PKCα occurred within 1 h of MMC exposure, and temporally preceded the induction of COX-2. Similar results were observed in cells exposed to the PKC activator, 3-phorbol 12-myristate 13-acetate. Cotreatment with SAF and MMC abolished the induction of COX-2 by MMC. Furthermore, NS-398, a selective COX-2 inhibitor, significantly enhanced MMC-induced apoptosis by fivefold from 4 ± 2% (MMC alone) to 20 ± 2% (MMC plus NS-398). There was no discernible change in COX-2 mRNA levels after a 2-h exposure to MMC but a twofold increase after a 24-h exposure. Conclusions: MMC upregulates COX-2 expression, which appears to be an antiapoptotic signal downstream of PKC. Selective inhibition of COX-2 can therefore provide a novel way to enhance MMC-induced apoptosis independent of inhibiting PKC. Received: 6 July 1999 / Accepted: 19 November 1999     

HGF和VEGFR-3在大肠癌中的表达及其在淋巴管生成和转移中的作用

目的观察肝细胞生长因子(HGF)和血管内皮生长因子受体3（VEGFR-3）在大肠癌组织中的表达,检测大肠癌组织中的微淋巴管密度(LMVD),探讨HGF和VEGFR-3 在大肠癌淋巴管生成及转移中的作用。方法应用免疫组织化学（SABC）法检测52例大肠癌、20例大肠息肉组织和20例健康对照组织中HGF和VEGFR-3的表达,并应用podoplanin标记淋巴管,检测各组组织中的淋巴管密度,结合大肠癌患者的临床病理资料,分析其相关性。结果(1)大肠癌组织中HGF和VEGFR 3均被染成棕褐色或棕黄色,阳性表达率分别为75%、67.3%,相对表达量分别为(0.36±0.07)、(0.41±0.10),均明显高于大肠息肉组[25%、30%; (0.24±0.06)、 (0.28±0.03）] 和正常大肠组织[15%、10%;(0.23±0.06)、(0.21±0.03）]的表达(P<0.01)。且微淋巴管密度(LMVD)也明显增多[(4.13±1.99) vs. (2.59±1.46) vs. (2.40±1.44),P<0.01]。(2)大肠癌组织中HGF、VEGFR 3的相对表达量,LMVD三者间呈两两正相关。39例HGF表达阳性的大肠癌,其LMVD明显大于HGF表达阴性者[(4.25±2.13) vs. (2.73±1.54),t=3.051,P=0.003];35例VEGFR-3表达阳性的大肠癌,其LMVD也明显大于VEGFR 3表达阴性者[(3.79±1.26) vs. (2.64±1.32),t=3.235,P=0.002]。(3)HGF、VEGFR 3和LMVD的表达与大肠癌患者年龄、性别以及肿瘤分化程度无关(P>0.05),但与Dukes分期(P=0.034,P=0.021,P=0.006)、淋巴管有无转移明显相关(P=0.015,P=0.012,P=0.001)。结论HGF与大肠癌的淋巴管生成及转移有一定的相关性,并可能通过VEGF-C、D/VEGFR-3 信号途径间接促进淋巴管增生,从而促进肿瘤细胞的淋巴转移。     

Selective cyclooxygenase-2 inhibitors inhibit growth and induce apoptosis of bladder cancer

Selective COX-2 inhibitors such as celecoxib and NS-398 are being evaluated as chemopreventive and therapeutic agents for bladder and other cancers. We investigated the effects of these nonsteroidal anti-inflammatory agents on a panel of bladder cancer cell lines, and assessed their effects on anchorage-dependent and -independent growth, cell cycle, apoptosis and morphology. The human bladder cancer cell lines UM-UC-1, -3, and -6 were assayed for COX-2 expression by Western analysis using a monoclonal antibody to COX-2. UM-UC-1, -3, and -6 cells were grown in the presence of increasing concentrations of NS-398 and celecoxib, and cell growth was quantitated over 7 days by crystal violet elution. The cell lines were treated with NS-398 and celecoxib for 48 h and analyzed by flow cytometry with propidium iodide staining and Br-dUTP staining for apoptosis. Anchorage-independent growth was assessed using an agarose growth assay. Western analysis demonstrated that COX-2 expression in UM-UC-1, -6, and -3 was high, low, and undetectable, respectively. NS-398 and celecoxib produced dose-dependent growth inhibition of UM-UC-1 and -6. Both NS-398 and celecoxib also inhibited anchorage-dependent and -independent growth of UM-UC-3 in a dose-dependent fashion, despite the low basal expression of COX-2 in this cell line. Cell cycle analyses of UM-UC-1 and -6 revealed a 50% reduction in S-phase in the presence of 100 microM NS-398 whereas a smaller reduction in S-phase was noted in UM-UC-3 cells. Furthermore, treatment with 100 microM celecoxib resulted in significant apoptosis in all three cell lines, which was associated with downregulation of Bcl-2. COX-2 selective inhibitors NS-398 and celecoxib produced dose-dependent growth inhibition of bladder cancer cells associated with a significant reduction in S-phase. Induction of apoptosis in all three cell lines by celecoxib was associated with downregulation of Bcl-2. These changes occur independently of COX-2 expression levels suggesting the presence of a COX-2 independent pathway.     

沉默Chk1基因对姜黄素诱导胃癌细胞SGC7901凋亡敏感度的影响

目的探讨siRNA沉默Chk1基因表达对姜黄素诱导胃癌细胞SGC7901凋亡和细胞周期的影响,评价其作为姜黄素治疗胃癌增敏靶点的有效性。方法采用RNAi技术在胃癌细胞SG-7901中将Chk1基因沉默,采用Western blot检测转染前后Chk1蛋白表达的变化,采用流式细胞术检测Chk1基因沉默对姜黄素诱导胃癌细胞凋亡及细胞周期变化的影响。结果转染Chk1 siRNA后,胃癌细胞SGC7901中Chk1蛋白表达受抑制,明显低于对照组(P＜0.05)。FCM检测结果显示,si-Chk1组较空白对照组G₂/M期百分比有所降低(P＜0.05),si-Chk1+Curcumin组G₂/M期比例明显低于Empty vector+Curcumin组(P＜0.05)。siRNA沉默Chk1基因使姜黄素诱导的细胞凋亡率由(14.7±1.1)%上升到(28.9±1.8)%。结论siRNA沉默Chk1基因可明显消除G₂/M期阻滞,并显著增强姜黄素诱导胃癌细胞SGC-7901凋亡的敏感度,提示Chk1可作为姜黄素治疗胃癌的有效增敏靶点。     

FEZ1蛋白和mRNA在胃癌组织中的表达及其意义

 目的 探讨肿瘤抑制基因FEZ1蛋白和mRNA在胃癌组织中的表达及其意义。 方法 采用免疫组织化学SP法及RT-PCR技术分别检测了36例胃癌及正常胃组织中FEZ1蛋白和mRNA的表达情况,分析其阳性表达与临床病理指标的关系。 结果 FEZ1蛋白在胃癌组织中的阳性表达率(55.6%)明显低于正常胃组织(86.1%),并且其在胃癌组织中的阳性表达率与分化程度密切相关(P＜0.05)。FEZ1 mRNA在胃癌组织中的表达水平为（0.677±0.120）,显著低于正常胃组织中的表达水平（0.746±0.119）,并且其在胃癌组织中的表达水平也与分化程度和淋巴结转移之间存在显著相关性（P＜0.05)。 结论 FEZ1的表达可能与胃癌的发生发展有关。     

Apoptosis induction and cyclooxygenase-2 regulation in human colorectal adenoma and carcinoma cell lines by the cyclooxygenase-2-selective non-steroidal anti-inflammatory drug NS-398

We determined the effect of the highly selective cyclooxygenase-2 (COX-2) inhibitor NS-398 on proliferation, apoptosis and COX-2 regulation in 3 pre-malignant human colorectal adenoma cell lines (RG/C2, AA/C1, RR/C1) and compared its effect on 3 colorectal carcinoma cell lines (HT29, KS, JW2). COX-2 protein was expressed in each cell line derived from an adenoma, thus providing evidence that COX-2 is expressed in the tumour cells themselves at an early stage in human colorectal adenoma formation. NS-398 (20 to 100 microM for 96 h) induced apoptosis and inhibited the proliferation of the adenoma cell lines. Of the 3 carcinoma lines, only HT29 expressed COX-2 protein, yet each line was similarly sensitive to NS-398. There was a positive correlation between overall sensitivity of the cell lines (determined by the attached cell yield) and sensitivity to NS-398-induced apoptosis, suggesting that apoptosis is the dominant anti-proliferative effect of NS-398. Two of the 3 adenoma cell lines (RG/C2, AA/C1) were less sensitive than the carcinoma cell lines. NS-398 up-regulated COX-2 protein expression in the HT29 and adenoma cell lines. This was studied further in HT29 cultures, where treatment with NS-398 inhibited COX-2 activity, reducing prostaglandin E(2) secretion. Here, neither the increase in COX-2 protein expression nor the anti-proliferative and apoptosis-inducing effect of NS-398 was prevented by addition of exogenous prostaglandin E(2). Apoptosis appears to be the dominant anti-proliferative effect of NS-398 and, in COX-2 expressing cells, may be mechanistically linked to the observed induction of COX-2 protein expression upon treatment with NS-398.     

c-IAP1和bax蛋白在甲状腺癌中的表达与细胞凋亡

目的探讨甲状腺癌中c-IAP1和bax蛋白的表达及其与细胞凋亡的关系。方法应用免疫组织化学SP法检测甲状腺肿瘤细胞中c-IAP1和bax蛋白的表达,用TUNEL法测定肿瘤细胞凋亡指数（AI）。结果20例甲状腺腺瘤中c-IAP1和bax阳性表达率分别为25.0%、60.0%,AI为0.33±0.21;47例甲状腺癌中c-IAP1和bax阳性表达率分别为87.2%、89.3%,AI为0.91±0.37。C-IAP1、bax和AI在腺瘤和癌组间比较差异均有统计学意义（P＜0.05）。在甲状腺癌中,c-IAP1阳性组AI低于阴性组,bax阳性组AI高于阴性组。结论c-IAP1和bax可能与甲状腺癌的发生发展密切相关;c-IAP1高表达抑制了甲状腺癌细胞凋亡,bax高表达促进了甲状腺癌细胞凋亡。     

Mechanism of growth inhibitory effects of cyclooxygenase-2 inhibitor-NS398 on cancer cells

Cyclooxygenase (COX)-2 appears to play an important role in gastrointestinal carcinogenesis, and COX-2 overexpression has been demonstrated both in esophageal adenocarcinomas and lymph nodes metastasis. The aim of our study was to investigate the mechanism of growth inhibitory effect of selective inhibition of COX-2 by NS-398 on human cancer cells. The esophageal cancer cell lines (EC9706) that express COX-2 permanently and hepatocellular carcinoma cell lines (SMMC7721) while no expression of COX-2 were studied. Two kinds of cell lines were treated with various concentrations of NS-398 (selective for COX-2 inhibition) at 0.01-0.1 mM for 24 h, 48 h and 72 h. Antiproliferation effect was measured by 3H-TdR incorporation. The cell apoptosis were determined by flow cytometry (FCM) and DNA fragmentation analysis. Survivin was detected by immunocytochemical technique. The growth inhibition could be induced by NS398 in a dose- and time-dependent manner in two kinds of cell lines. FCM analysis revealed a high sub-G1 cell peak in EC9706 group. Agarose electrophroesis showed marked apoptosis ladder pattern, but no apoptosis by NS-398 in SMMC7721. The difference of apoptosis percentage in EC9706 and SMMC7721 was (45.23 +/- 1.08)% and (3.05 +/- 0.15)% (p < 0.001). After 24 h incubation with NS-398 at concentration of 0.1 dmM, the expression of survivin was markedly reduced in EC9706, but not in SMMC7721. We conclude that the administration of a selective inhibitor of COX-2 significantly decreases cell growth in cancer cell lines by different mechanism. NS-398 could inhibit cell proliferation in cancer cells whether or no COX-2 expression. Nevertheless, apoptosis in the cancer cells expressing COX-2 protein increase more than those lacking COX-2.