奥沙利铂处理HepG2细胞后DR5、caspase-8及survivin、bcl-2表达的变化

目的：研究奥沙利铂作用于HepG2细胞后DR5、caspase-8、survivin、bcl-2的表达,对奥沙利铂诱导HepG2细胞凋亡的机制进行初步探讨。方法：实验分为对照组和奥沙利铂组,应用MTT法、流式细胞仪体外研究奥沙利铂对HepG2细胞增殖的影响;采用免疫细胞化学及western blot的方法,观察奥沙利铂作用于HepG2细胞24h后DR5、caspase-8、survivin、bcl-2的表达情况。结果：奥沙利铂对肝癌HepG2细胞的抑制作用呈时间依赖性和浓度依赖性;奥沙利铂作用于HepG2细胞24小时后细胞表面DR5及caspase-8的表达增强,而survivin和bcl-2的表达减弱。结论：奥沙利铂诱导肝癌HepG2细胞凋亡的机制可能与其上调DR5及caspase-8表达和下调survivin及bcl-2表达有关。     

奥沙利铂处理HepG2细胞后DR5、caspase-8及survivin、bcl-2表达的变化

目的:研究奥沙利铂作用于HepG2细胞后DR5、caspase-8、survivin、bcl-2的表达,对奥沙利铂诱导HepG2细胞凋亡的机制进行初步探讨.方法: 实验分为对照组和奥沙利铂组,应用MTT法、流式细胞仪体外研究奥沙利铂对HepG2细胞增殖的影响;采用免疫细胞化学及western blot的方法,观察奥沙利铂作用于HepG2细胞24h后DR5、caspase-8、survivin、bcl-2的表达情况.结果: 奥沙利铂对肝癌HepG2细胞的抑制作用呈时间依赖性和浓度依赖性;奥沙利铂作用于HepG2细胞24小时后细胞表面DR5及caspase-8的表达增强,而survivin和bcl-2的表达减弱.结论: 奥沙利铂诱导肝癌HepG2细胞凋亡的机制可能与其上调DR5及caspase-8表达和下调survivin及bcl-2表达有关.     

吉西他滨对人肝癌HepG2细胞增殖和凋亡影响的实验研究

目的:探讨吉西他滨对肝癌HepG2细胞株增殖和凋亡的影响及其可能的分子机制. 方法:MTT法测定吉西他滨不同浓度和时间作用后肝癌HepG2细胞的增殖抑制率;流式细胞仪检测吉西他滨作用HepG2细胞后细胞周期分布及凋亡情况;免疫细胞化学法、Western blot法分别检测吉西他滨作用后细胞凋亡相关因子Survivin及Bcl-2的表达. 结果:在0.3715-5mg/L 浓度范围内,吉西他滨对HepG2的生长具有明显的抑制作用,并呈时间和剂量依赖性;0.3715mg/L的吉西他滨可导致HepG2细胞G0/G1期阻滞,并引起细胞凋亡;免疫细胞化学和Western blot的结果显示吉西他滨作用后Survivin和Bcl-2的表达下调. 结论: 吉西他滨可抑制HepG2细胞增殖并诱导凋亡,其诱导凋亡的机制与Survivin和Bcl-2的表达下调有关.     

全反式维甲酸诱导人肝癌细胞HepG2凋亡的初步研究

[目的]研究全反式维甲酸（ATRA）体外诱导人肝癌细胞株HepG2的凋亡及其作用机制。[方法]ATRA处理HepG2细胞。MTT法分析细胞增殖反应;Hoechst染色法检测细胞凋亡情况;Western blot检测细胞中caspase-9、caspase-3和NF-κB蛋白表达情况。[结果]A-TRA可抑制HepG2细胞增殖并诱导细胞凋亡,可上调细胞中caspase-9、caspase-3表达水平（P〈0.05）。[结论]ATRA可抑制HepG2细胞增殖并诱导细胞凋亡,其作用机制可能与cas-pase-9、caspase-3表达上调有关。     

δ-生育三烯酚诱导人肝癌HepG2细胞凋亡的机制研究

目的:探讨δ-生育三烯酚诱导人肝癌HepG2细胞凋亡的作用机制.方法:应用MTT法检测δ-生育三烯酚对人肝癌HepG2细胞增殖的影响,应用高内涵活细胞成像系统检测δ-生育三烯酚对人肝癌HepG2细胞凋亡率、细胞周期以及线粒体膜电位的影响,Western印迹法检测δ-生育三烯酚对人肝癌HepG2细胞凋亡相关蛋白(如caspase-3、caspase-8、caspase-9、Bcl-2、Bax、tBid和cytochrome C)表达的影响.结果:δ-生育三烯酚呈浓度依赖性地抑制肝癌HepG2细胞生长并诱导其凋亡,其机制为δ-生育三烯酚降低线粒体膜电位,并诱导cytochrome C从线粒体释放到细胞质中,调控Bcl-2家族蛋白表达(如上调Bax及tBid蛋白的表达,下调Bcl-2蛋白的表达),继而引起caspase-3、caspase-8和caspase-9的活化,最终导致肝癌 HepG2细胞凋亡.结论:δ-生育三烯酚可能通过线粒体途径及膜死亡受体途径共同诱导人肝癌细胞 HepG2凋亡.     

恩度联合吉西他滨对肝癌HepG2细胞的抑制作用及对HIF-1α、VEGF表达的影响

目的:探讨恩度(ES)、吉西他滨(GEM)单药及联合作用在体外对人肝癌细胞系HepG2细胞的增殖抑制和诱导凋亡作用,以及加药前后HIF-1α、VEGF表达的变化。方法:MTT比色法观察不同浓度恩度、吉西他滨及联合应用对HepG2细胞生长的抑制作用。采用流式细胞仪检测上述药物单独或联合应用对HepG2细胞凋亡率的影响。免疫组织化学技术检测上述药物单独或联合应用时HIF-1α、VEGF的表达差异。结果:恩度单药对HepG2细胞无明显增殖抑制及诱导细胞凋亡作用;吉西他滨单药及联合恩度对HepG2细胞有明显抑制作用,且均呈明显的剂量依赖关系,均可诱导细胞凋亡,联用时有协同作用(P<0.05)。加药组与空白组相比、联合用药组与单药组相比,HIF-1α、VEGF的表达水平均显著降低(P<0.05)。结论:吉西他滨单药以及与恩度联合能够抑制人肝癌HepG2细胞并诱导凋亡。两药联合有协同作用。其机制可能与HIF-1α、VEGF有关。     

硒-甲基硒代半胱氨酸诱导肝癌HepG2细胞凋亡作用

[目的]探讨硒-甲基硒代半胱氨酸(MSC)对肝癌HepG2细胞的增殖抑制及诱导凋亡的作用.[方法]用不同浓度的MSC处理培养的HepG2细胞,MTT法和流式细胞仪分别检测其对细胞生长和细胞凋亡的影响,并检测半胱氨酸蛋白酶3,8,9(caspase-3,8,9)的活性.[结果]25μmol/L的MSC处理HepG2细胞24 h后,细胞生长受到明显抑制,出现细胞凋亡,呈现浓度和时间依赖关系.caspase-3,8,9的活性检测显示,25μmol/L MSC处理HepG2细胞24h,48 h后,caspase-3的活性分别升高38.50%和119.72%,caspase-8活性分别升高28.86%和89.42%,caspase-9活性分别升高31.94%和74.28%.50μmol/L的MSC处理24h,48h后,caspase-3活性分别升高82.56%和155.79%,caspase-8活性分别升高48.95%和167.84%,caspase-9活性分别升高55.94%和126.58%.[结论]MSC抑制HepG2细胞增殖,诱导其凋亡,其凋亡与caspase-3,8,9的活性增强有关.     

吉西他滨诱导人NK/T细胞淋巴瘤细胞株SNK-6凋亡的机制

目的探讨吉西他滨诱导人NK/T细胞淋巴瘤细胞株SNK-6产生凋亡的机制。方法应用MTT法、DNA电泳技术及流式细胞术观察吉西他滨诱导人SNK-6细胞凋亡情况,应用基因芯片技术分析加药前后凋亡相关基因的表达差异。结果吉西他滨作用后,MTT结果显示细胞生长抑制率随药物浓度的增加而逐渐增大;DNA断裂电泳可见典型的梯形DNA条带,随吉西他滨作用浓度的增加而逐渐增强;流式细胞术分析,2 μg/ml吉西他滨作用SNK-6细胞4、8、24、48 h后,凋亡细胞比例分别为2.1%、8.3%、23.9%、30.9%;吉西他滨作用48 h后,在88条有关凋亡的目的基因中共有17条基因表达发生大于3倍的显著变化,其中表达上调基因4条,下调基因13条。结论吉西他滨可以诱导人NK/T细胞淋巴瘤细胞产生凋亡,呈时间和剂量依赖性;吉西他滨可使SNK-6细胞中多个凋亡相关基因的表达发生改变,初步揭示了其诱导淋巴瘤细胞凋亡的作用机制。     

GS-Rg3联合GEM对肝癌HepG2细胞株及其VEGF的影响

目的:探讨GS-Rg3、吉西他滨及GS-Rg3与吉西他滨联合对肝癌Hep G2细胞增殖和凋亡情况的影响,研究GS-Rg3作用Hep G2细胞后VEGF表达的变化。方法:采用MTT法及流式细胞技术检测Hep G2细胞对GS-Rg3、吉西他滨及GS-Rg3联合吉西他滨的药物敏感性差异。免疫细胞化学法检测Hep G2细胞中VEGF的表达。结果:GS-Rg3和吉西他滨单药或联合用药对Hep G2细胞的增殖呈抑制作用且呈现时间与浓度的依赖性,并能诱导Hep G2细胞凋亡,联合组凋亡诱导作用强于单药组(P<0.05)。GS-Rg3能下调Hep G2细胞中VEGF的表达。结论:GS-Rg3与吉西他滨联合对肝癌Hep G2细胞具有协同抑制作用,可能通过抑制VEGF的表达发挥抗癌作用。     

青蒿琥酯对人肺腺癌A549细胞中caspase-9及caspase-3活性的影响

 目的 研究青蒿琥酯（artesunate,Art）体外诱导人肺腺癌A549细胞凋亡及对半胱天冬氨酸蛋白酶9（cysteine containing aspartate9,caspase-9）和caspase-3活性的影响。方法 Art处理A549细胞,流式细胞计数（Flow Cytometry,FCM）检测细胞周期和细胞凋亡,比色法检测caspase-9活性,westernblot检测caspase-3变化。结果 FCM显示A549细胞经100mg/L Art作用24h,出现S期细胞减少（P〈0.01）,G2/M期细胞数目增多（P〈0.01）,细胞凋亡率增加（P〈0.0）。不同浓度（10mg/L、25mg/L、50mg/L、100mg/L）的Art作用A549细胞24h,caspase-9活性呈浓度依赖性增加,分别为对照组的9.87倍、23.33倍（P〈0.01）、38.47倍（P〈0.01）和60.47倍（P〈0.01）。Western blot显示A549细胞经100mg/L Art作用6、12、24h后,细胞浆中caspase-3活化,分别为对照组1.2倍、1.6倍（P〈0.01）、1.8倍（P〈0.01）。结论 青蒿琥酯可通过增加caspase-9和caspase-3的活性,诱导A549细胞凋亡,为阐明Art的抗癌机理,指导青蒿琥酯用于肿瘤治疗提供实验依据。     

Downregulation of survivin expression and elevation of caspase-3 activity involved in pitavastatin-induced HepG 2 cell apoptosis

The aim of the present study was to research the apoptosis of human hepatocellular carcinoma cell line HepG 2 induced by pitavastatin. HepG 2 cells were treated with increasing doses of pitavastatin or with mevalonic acid for 48 h. The proliferation of cells was detected with WST-8. The morphology of the nucleus was observed under a microscope by Hoechst 33258 staining. The apoptosis peaks were examined by flow cytometry. The expression of survivin mRNA was examined with RT-PCR. The caspase-3 activity was detected with caspase-3 colorimetric protease assay. We found that growth inhibitory effects were observed for treatment with pitavastatin at 10-50 microM. Pitavastatin at 10 microM induced granular apoptotic bodies of HepG 2 cells. Furthermore, pitavastatin at 10 microM increased the appearance of sub-G1 population of HepG 2 cells. Finally, pitavastatin at 10 microM downregulated the expression of survivin mRNA and upregulated the caspase-3 activity, which was clearly related to the HMG-CoA reductase activity. These results suggest that pitavastatin at 10 microM induces apoptosis of HepG 2 cells, which is associated with the decreased expression of survivin mRNA and increased caspase-3 activity of HepG 2 cells.     

TRAIL cleaves caspase-8, -9 and -3 of AM-1 cells: a possible pathway for TRAIL to induce apoptosis in ameloblastoma.

Tumor-necrosis-factor-related apoptosis-inducing ligand (TRAIL/Apo-2L), a potent ligand in inducing apoptosis, has recently emerged as a novel anticancer agent based on its ability to induce apoptosis in tumor cells, while exhibiting no toxicity in most normal cells. Since no potent apoptosis-inducing factor has been found yet in ameloblastoma, the present study was conducted. In the present study, expressions of TRAIL receptors, death receptor 4 (DR4) and DR5, were detected in all ameloblastoma tissues by immunohistochemistry as well as in AM-1 cells by immunofluorescence. By applying TRAIL in AM-1 cells, ameloblastoma cell line, for 24 h, we found that TRAIL cleaved caspase-8, -9 and -3, and lowered mitochondrial membrane potential (Deltapsim), and markedly induced apoptosis in AM-1 cells (46%). These results suggested that TRAIL is a potent apoptosis-inducing ligand in ameloblastoma.     

Midkine protects hepatocellular carcinoma cells against TRAIL-mediated apoptosis through down-regulation of caspase-3 activity

BACKGROUND: It is believed that midkine (MK), a heparin-binding growth factor, plays an important role in carcinogenesis. However, the biologic mechanism of MK in hepatocellular carcinoma has not been clarified to date. The objective of the current study was to investigate the antiapoptotic role of MK in a human hepatoma cell line. METHODS: The human hepatoma cell line HepG2 was used to study the antiapoptotic effect of MK. Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)/actinomycin D (ActD)-induced apoptosis was detected using a 2-(2-methoxy-4-nitrophenyl)-3-(4-nitrophenyl)-5-(2,4-disulphophenyl)-2H-tetrazolium monosodium salt (WST-8) assay, a caspase-3 activity assay, a caspase-8 activity assay, and flow cytometric analysis. RESULTS: TRAIL had a potent, dose-dependent inductive effect on cell death in HepG2 cells, for which viable cell counts decreased to 6.3% of the control count at a TRAIL concentration of 100 ng/mL in the presence of 500 ng/mL ActD. Flow cytometry was used to demonstrate that apoptosis induced by TRAIL/ActD was in fact the cause of cell death. According to the WST-8 assay, MK pretreatment resulted in the suppression of TRAIL/ActD-mediated apoptosis in HepG2 cells, although cell viability did not increase when HepG2 cells were treated with MK alone. Caspase-3 activity was down-regulated when MK was added, but caspase-8 activity was high in both the absence and presence of MK. CONCLUSIONS: The results of the current study indicate that MK acts as an antiapoptotic factor in HepG2 cells through the down-regulation of caspase-3 activity.     

The roles of p38MAPK and caspase-3 in DADS-induced apoptosis in human HepG2 cells

Objectives

To explore the function of p38MAPK and caspase-3 in DADS-induced apoptosis in human HepG2 cells, and discuss the signal transduetion mechanism of HepG2 cells in the apoptosis process induced by DADS by using the inhibitors of p38MAPK (SB203580) and caspase-3 (Z-DEVD-FMK).

Methods

After the human HepG2 cells had been treated with the DADS and inhibitors for 24 h, cell viability was determined by the MTT method, apoptosis was evaluated by flow cytometry (FCM) and the expressions of p38MAPK and caspase-3 were measured by western-blot.

Results

Our results indicated that DADS activities the p38MAPK and caspase-3, but the inhibitors, SB203580 and Z-DEVD-FMK (for p38MAPKand for caspase-3, respectively), both have the effect of inhibitory activity on P38MAPK and caspase-3. Furthermore, a combination treatment with both DADS and inhibitor (SB203580 or Z-DEVD-FMK) decreases the inhibitory and apoptotic activity of HepG2 cells increased compared with DADS-treated.

Conclusions

Our data indicate that p38MAPK and caspase-3 are involved in the process of DADS-induced apoptosis in human HepG2 cells and interact with each other.