曲格列酮诱导胃癌MKN45细胞株凋亡

目的:研究不同浓度曲格列酮对胃癌MKN45细胞过氧化物酶体增殖激活受体γ(PPARγ)激活水平变化及细胞凋亡的作用.方法:胃癌MKN45细胞培养后分为4组,分别为生理盐水对照组和1、5、10μmol/L曲格列酮实验组.用EMSA测定不同浓度曲格列酮对胃癌MKN45细胞PPARγ激活水平的变化,用流式细胞术检测caspase-3蛋白的表达、细胞周期的变化及凋亡.结果:随曲格列酮浓度的增加,PPARγ活性明显升高,以对照组活性为100.1、5、10μmol/L曲格列酮组的PPARγ平均活性分别为155.8、21 8.7和307.6(P<0.01).流式细胞术证实MKN45细胞经1,5,10μmol/L曲格列酮的作用后,随着曲格列酮剂量的增加,Caspase-3蛋白的表达均值分别为4.51,10.95,20.49,33.56(P<0.01),G_0/G_1期细胞逐渐增加,S期细胞下降,凋亡细胞增多.结论:曲格列酮通过对胃癌MKN45细胞PPARγ的激活可引发胃癌MKN45细胞株细胞周期抑制及凋亡,可为胃癌的治疗提供新的靶点.     

曲古菌素A对血管平滑肌细胞p27kip1表达的调控机制研究

目的探讨组蛋白去乙酰化酶抑制剂曲古菌素A（Trichostatin A，TSA）对血管平滑肌细胞（VSMC）的p27kip1表达的影响和调控机制。方法半定量逆转录聚合酶链反应（RT—PCR）检测p27kip1的mRNA水平，蛋白印迹测定p27kip1和S-phase kinase—associated protein-2（skp2）蛋白表达，荧光分光光度法测定20S蛋白酶体活性。结果100ng／ml TSA不影响VSMC中p27kip1的mRNA水平。100ng／ml TSA显著抑制血清诱导的p27kip1蛋白下调，并延长p27kip1蛋白的半衰期。100ng／mlTSA抑制血清诱导的skp2表达上调，且skp2表达与相应时点p27kip1蛋白呈负相关。100ng／ml TSA对20S蛋白酶体活性物影响。结论TSA对VSMC的p27kip1表达调控不是在转录水平上，而是通过翻译后机制抑制血清诱导VSMC的p27kip1蛋白降解，其机制可能与TSA抑制泛素连接酶亚单侍skp2表达有关．     

结直肠腺癌中skp2、p27^kip1、ERK蛋白的表达及意义

目的研究细胞S期激酶相关蛋白2（skp2）、p27k ip1、细胞外调节蛋白激酶（ERK）蛋白在结直肠癌组织中的表达情况及在结直肠腺癌发生发展中的作用。方法应用免疫组化法检测60例结直肠癌组织（A组）、30例腺瘤组织（B组）、20例正常大肠组织（对照组）中skp2、p27k ip1、ERK蛋白的表达,分析其与临床病理因素的关系。结果 3组skp2、p27k ip1、ERK蛋白表达阳性率比较差异均有统计学意义（P〈0.05）;skp2、p27k ip1、ERK蛋白的表达与结直肠腺癌的分化程度、Dukes’分期及淋巴结转移有关（P〈0.05）;skp2、ERK与p27k ip1表达呈负相关（r=-0.723 7、P〈0.01;r=-0.695 2、P〈0.01）,而skp2与ERK表达呈正相关（r=0.652 2、P〈0.01）。结论 skp2、p27k ip1、ERK蛋白的表达可能与结直肠腺癌的发生发展有关,ERK可能参与了skp2-p27k ip1通路的调节。     

PPARγ配体对人肺癌细胞95-D增殖的影响及机制探讨

目的观察过氧化物酶体增殖体激活受体γ（PPARγ）的合成配体曲格列酮（TGZ）和天然配体15-脱氧前列腺素J2（15-PGJ2）对肺癌95-D细胞增殖活性及凋亡的影响,并探讨其机制。方法将对数生长期的95-D细胞分为TGZ组、15-PGJ2组、对照组,分别加入500μl的TGZ溶液、15-PGJ2溶液、DMSO混合溶液培养;采用MTT法检测95-D细胞的增殖能力,采用流式细胞仪检测95-D细胞凋亡率和细胞周期变化,采用免疫细胞化学法检测95-D细胞中的PPARγ。结果与对照组比较,TGZ、15-PGJ2组95-D细胞增殖抑制率显著增加（P均〈0.01）,且存在时相性;95-D细胞凋亡率增加,S期细胞比例升高,G1期细胞比例降低;95-D细胞中PPARγ表达水平增加。结论PPARγ配体TGZ、15-PGJ2可抑制95-D细胞增殖,诱导其凋亡;该作用与PPARγ表达增加有关。     

曲古霉素A对人胃癌细胞的抑制作用及其机制探讨

背景：组蛋白去乙酰基酶抑制剂（HDACi）是一类新型抗肿瘤药物。曲古霉素A（TSA）是目前研究最为广泛的HDACi之一,已发现其对多种肿瘤细胞具有明显抑制作用,但关于TSA对胃癌作用的研究尚少。目的：观察TSA对人胃癌细胞增殖、凋亡、细胞周期以及相关基因表达的影响,探讨其抑制人胃癌细胞的可能作用机制。方法：以不同浓度TSA（0—1μmol／L）处理人胃癌细胞株AGS和HGC-27。CCK-8实验检测细胞增殖抑制情况,流式细胞术检测细胞凋亡和细胞周期,realtimeRT-PCR和蛋白质印迹法检测细胞凋亡、细胞周期相关基因mRNA和蛋白水平的表达。结果：TSA能剂量依赖性地抑制AGS、HGC-27细胞增殖（P=0．000）,对两者的半数致死浓度分别约为0．25μmol／L和0．5μmol／L。TSA能诱导AGS、HGC-27细胞发生G0／G1期和G2／M期阻滞,以G0／G11期阻滞更为明显。TSA对AGS细胞的诱导凋亡作用强于HGC-27细胞（P〈0．05）。TSA尚能上调p21、p53、BaxmRNA和蛋白表达,下调Bel-2、CDK2、cyelinD1mRNA和蛋白表达,作用均呈时间依赖性（P〈0．05）。结论：TSA抑制人胃癌细胞增殖、诱导细胞凋亡的作用可能是通过调节细胞凋亡、细胞周期相关分子、激活多种肿瘤相关信号通路实现的。     

腺病毒介导的小鼠过氧化物酶体增殖剂活化受体γ基因过度表达对Raw264.7细胞小窝蛋白-1基因和蛋白表达影响的实验研究

目的比较腺病毒介导的小鼠过氧化物酶体增殖剂活化受体γ（PPARγ）基因过度表达与配体活化对小鼠Raw264.7巨噬细胞小窝蛋白-1（CAV-1）基因和蛋白表达的影响,探讨PPARγ基因对巨噬细胞CAV-1的调控作用及机制.方法首先构建表达小鼠PPARγ1基因的复制缺陷型腺病毒表达载体;将Raw264.7细胞随机分成对照组、PPARγ基因过度表达组、PPARγ活化剂曲格列酮干预组以及PPARγ基因过度表达和曲格列酮共刺激组进行干预;观察各组Raw264.7细胞PPARγ和CAV-1基因和蛋白的表达变化.结果RT-PCR检测对照组Raw264.7细胞有CAV-1基因的表达,免疫印迹法未发现CAV-1蛋白表达,但免疫细胞化学证实胞膜和核膜上均有少量CAV-1表达;经RT-PCR、免疫细胞化学和免疫印迹检测发现PPARγ基因过度表达组、曲格列酮干预组和二者共刺激组Raw264.7细胞CAV-1基因和蛋白表达明显增加（且共刺激组＞PPARγ基因过度表达组＞曲格列酮干预组,P〈0.05）.对照组Raw264.7胞浆内PPARγ表达量较低,而PPARγ基因过度表达组和共刺激组PPARγ表达均明显增加（P〈0.05）,而曲格列酮干预组无明显变化.结论PPARγ基因活化或过度表达均能上调Raw264.7细胞CAV-1基因和蛋白表达.曲格列酮活化PPARγ基因,增加CAV-1基因和蛋白表达,但不增加PPARγ基因和蛋白表达水平.与单一作用比较,同时活化和过度表达PPARγ基因对CAV-1基因和蛋白的表达有累积效应,说明PPARγ的这一作用在配体活化下增强.推测曲格列酮上调CAV-1表达依赖于PPARγ,非本身药理特性所致.     

吡格列酮对大鼠缺血再灌注诱导的内质网应激相关的心肌保护作用

目的观察吡格列酮对大鼠心肌缺血再灌注损伤（MIRI）时JNK、p-JNK及caspasc-12蛋白表达的影响,探讨吡格列酮通过JNK通路对内质网应激途径的心肌保护作用。方法Wistar大鼠40只随机分为假手术组（sham组）、缺血再灌注组（I／R组）、I／R＋Pio（吡格列酮）组及I／R＋Pi0＋sP600125组各10只。制作大鼠MIRI模型;TUNEL检测心肌细胞凋亡,免疫组织化学检测各组caspase-12表达变化,westernBlot法检测各组JNK、P-JNK的表达。结果吡格列酮预处理组大鼠心肌细胞凋亡、JNK磷酸化率及caspase-12蛋白表达水平明显比I／R组降低（P〈0．05）,加用JNK抑制剂（SP600125）后上述指标进一步下降,与吡格列酮组比较差异有统计学意义（P〈0．05）。结论缺血再灌注损伤可激活JNK通路,诱导过度的ERS,增加ER凋亡信号介导的细胞凋亡。吡格列酮预处理可减少ER凋亡信号介导的细胞凋亡,JNK信号途径在吡格列酮预处理抑制ER凋亡信号分子活化的机制中发挥重要作用。     

吡格列酮通过内质网应激致凋亡途径对大鼠血管平滑肌细胞钙化的影响

目的　探讨吡格列酮通过内质网应激致凋亡途径对大鼠血管平滑肌细胞钙化的影响及机制。方法　利用β-甘油磷酸钠联合丙酮酸钠制备钙化血管平滑肌细胞模型,予不同浓度（10、50、100　μmol/L）吡格咧酮干预。用Von　Kossa　染色、茜素红S染色测定钙含量以及碱性磷酸酶（ALP）活性观察细胞钙化程度。采用流式细胞术及Tunel法检测细胞凋亡率,实时荧光定量PCR及Western　Blot检测各组细胞GRP78、Caspase-12和Runx2的mRNA及蛋白表达。结果　钙化组其钙含量、ALP活性较对照组细胞增多（P<0.05）,而不同浓度吡格列酮呈剂量依赖性地减轻钙化大鼠血管平滑肌细胞的钙含量和ALP活性（P<0.05）;钙化组其细胞凋亡率较对照组明显升高,而不同浓度吡格列酮呈剂量依赖性地减轻钙化大鼠血管平滑肌细胞凋亡率（P<0.05）;钙化组GRP78、Caspase-12和Runx2　的mRNA及蛋白表达明显升高,而不同浓度吡格列酮呈剂量依赖性地下调钙化大鼠血管平滑肌细胞GRP78、Caspase-12和Runx2的mRNA及蛋白表达（P<0.05）。结论　吡咯列酮通过内质网应激致凋亡途径作用可减轻β-磷酸甘油诱导的血管平滑肌细胞钙化,其作用可能与GRP78、Caspase-12及Runx2表达下调有关。     

曲格列酮分化调节人单核细胞源性巨噬细胞Kv1.3和Kir2.1表达及其对膜电位的影响

目的 研究曲格列酮对人单核细胞源性巨噬细胞电压依赖性钾通道Kv1.3、内向整流钾通道Kir2.1表达及膜电位的影响.方法 以健康人外周血单核细胞源性巨噬细胞为研究对象,采用Real time RT-PCR及Western blot技术观察曲格列酮对巨噬细胞Kv1.3、Kir2.1表达的调节作用和电压敏感染料膜电位标测技术分析其对巨噬细胞膜电位的影响.结果 50 μmol/L曲格列酮显著抑制巨噬细胞Kv1.3的表达,mRNA和蛋白表达下降分别超过82%和60%（P＜0.05）,而对Kir2.1的表达没有明显影响（P＞0.05）;同时,巨噬细胞膜电位下降了约23%（P＜0.05）.结论 曲格列酮分化调节人单核细胞源性巨噬细胞Kv1.3和Kir2.1表达,降低巨噬细胞膜电位.     

阿奇霉素诱导淋巴细胞白血病Jurkat细胞凋亡作用的研究

目的：研究阿奇霉素诱导淋巴细胞白血病Jurkat细胞凋亡作用,及其相关的凋亡蛋白和细胞周期的变化,为临床治疗淋巴细胞白血病提供新的研究思路。方法：应用Annexin V-FITC/PI双染法流式细胞术检测细胞凋亡并用流式细胞术进行细胞周期分析,MTT法检测阿奇霉素对Jurkat细胞的增殖抑制作用,利用West-ern-blotting检测凋亡途径相关蛋白的表达。结果：用阿奇霉素处理Jurkat细胞48h后300mg/L剂量组早期凋亡率显著增高达到（88.0&#177;3.3）%,而25mg/L剂量组为（11.5&#177;2.7）%,与对照组（10.6%&#177;1.8）%无明显差异。MTT法检测结果IC50值为88.4mg/L,200mg/L抑制率达到89.27%。细胞周期显示150mg/L时G1期细胞增加,G2期和S期细胞下降。Western-blotting结果表明Bcl-2蛋白高表达,处理前后无明显变化,而Bax蛋白表达随药物浓度提高而上升,活化的Caspase3在100mg/L表达最高。结论：阿奇霉素可以有效的诱导Jurkat细胞凋亡并呈明显的浓度依赖性,其凋亡途径可能是通过Bax蛋白表达上升诱导下游效应分子Caspase3活化实现。细胞增殖抑制试验表明200mg/L以上时细胞增殖明显受抑制,细胞周期分析提示细胞增殖阻滞在了G1期。     

Troglitazone, a peroxisome proliferator-activated receptor γ ligand, induces growth inhibition and apoptosis of HepG2 human liver cancer cells

AIM: To examine the effect of troglitazone, a peroxisome proliferator-activated receptor γ (PPARγ) ligand, on the proliferation and apoptosis of human liver cancer cells.METHODS: Liver cancer cell line HepG2 was cultured and treated with troglitazone. Cell proliferation was detected by 3-(4-,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay; apoptosis was detected by flow cytometry and terminal deoxynucleotidyl transferasemediated nick end labeling of DNA fragmentation sites (TUNEL) assay; and apoptosis-related protein was detected by immunocytochemistry and Western blotting.RESULTS: Troglitazone inhibited growth and induced apoptosis of HepG2 cells in a dose-dependent manner,and induced activation of caspase-3 expression.Troglitazone not only drove apoptosis-inhibiting factor survivin to translocate incompletely from the nucleus to the cytoplasm, but also inhibited expression of survivin,while it did not affect expression of apoptosis-promoting factor Bax.CONCLUSION: PPARγ ligands inhibit growth and induce apoptosis of liver cancer cells, and may have applications for the prevention and treatment of liver cancer.     

Troglitazone, a peroxisome proliferator-activated receptor γ ligand, induces growth inhibition and apoptosis of HepG2 human liver cancer cells

AIM： To examine the effect of troglitazone, a peroxisome proliferator-activated receptor γ （PPARγ） ligand, on the proliferation and apoptosis of human liver cancer cells. METHODS： Liver cancer cell line HepG2 was cultured and treated with troglitazone. Cell proliferation was detected by 3-（4-,5-dimethylthiazol-2-yl）-2,5-diphenyl tetrazolium bromide （MTT） assay; apoptosis was detected by flow cytometry and terminal deoxynucleotidyl transferase- mediated nick end labeling of DNA fragmentation sites （TUNEL） assay; and apoptosis-related protein was detected by immunocytochemistry and Western blotting. RESULTS： Troglitazone inhibited growth and induced apoptosis of HepG2 cells in a dose-dependent manner, and induced activation of caspase-3 expression. Troglitazone not only drove apoptosis-inhibiting factor survivin to translocate incompletely from the nucleus to the cytoplasm, but also inhibited expression of survivin, while it did not affect expression of apoptosis-promoting factor Bax. CONCLUSION： PPARγ ligands inhibit growth and induce apoptosis of liver cancer cells, and may have applications for the prevention and treatment of liver cancer.     

S-腺苷蛋氨酸对活化人肝星状细胞增殖和凋亡的影响

背景:肝星状细胞(HSCs)的活化是肝纤维化发生的中心环节。S-腺苷蛋氨酸(SAM)是机体最重要的甲基供体,既往研究表明SAM具有一定的抗纤维化作用,能抑制HSCs的活化。目的:观察SAM对活化人肝星状细胞株LX-2增殖、凋亡的作用及其相关机制。方法:用不同浓度SAM培养LX-2细胞24 h,采用CCK-8法检测SAM对LX-2细胞增殖的影响,流式细胞术检测细胞周期和凋亡率,实时定量PCR法检测cyclin D1 mRNA表达,蛋白质印迹法检测α-SMA蛋白表达。结果:与对照组相比,3.0~8.0 mmol/L SAM能抑制LX-2细胞增殖,并呈剂量依赖性(P0.05);2.0、4.0 mmol/L组G1/G0期细胞比例显著降低(P0.05),S期细胞比例显著升高(P0.05);4.0、8.0 mmol/L组早期凋亡率和总体凋亡率显著升高(P0.05);2.0、4.0 mmol/L组cyclin D1 mRNA表达显著升高(P0.05);1.0、2.0、4.0 mmol/L组α-SMA蛋白表达显著降低(P0.05)。结论:SAM能抑制LX-2细胞增殖,其机制可能通过上调cyclin D1的表达而使细胞周期阻滞于S期;同时,SAM能诱导LX-2细胞的凋亡,并下调α-SMA的表达。     

Troglitazone, but not rosiglitazone, inhibits Na/H exchange activity and proliferation of macrovascular endothelial cells

Diabetes is associated with a high level of mortality due to cardiovascular disease resulting from accelerated coronary artery atherosclerosis. A current focus for investigation of atherosclerotic mechanisms is the vascular endothelium since physical or functional injury may represent an initiating step for atherogenesis. Thiazolidinediones (TZDs) are the newest class of drugs for the treatment of insulin resistance and its metabolic consequences; they are peroxisome proliferator-activating receptor (PPAR)-gamma ligands that act as insulin-sensitizing agents. We are interested in the contribution of direct vascular actions to the clinical utility of these agents. We investigated the effect troglitazone and rosiglitazone on endothelial cell proliferation in low- and high-glucose media and further explored their action on the ubiquitous membrane transport system, the Na/H exchanger (NHE), which has been implicated in regulating the growth of vascular cells. Experiments were conducted in cultured bovine aortic endothelial cells (BAECs). Cell proliferation was assessed by cell counting, and NHE activity was determined in cells loaded with the pH-sensitive fluorescent dye, 2',7'-bis-(2-carboxyethyl)-5-(and-6)-carboxyfluorescein, acetoxymethyl ester (BCECF-AM). Troglitazone caused a dose-dependent inhibition of endothelial cell proliferation with approximately 50% inhibition at 10 microM. Troglitazone inhibited endothelial cell proliferation with similar potency under low- (5 mM) and high-glucose (25 mM) concentrations. Rosiglitazone had no significant effect on endothelial cell proliferation at concentrations of up to 100 microM under low- or high-glucose concentrations. The NHE inhibitor, 3-metlylsulfonyl-4-piperidinobenzoyl guanidine (HOE 694), caused dose dependent inhibition of BAEC proliferation, which was independent of the media glucose concentration. Acute exposure of cells to troglitazone (10 microM) and rosiglitazone (30 microM) during recovery from acidosis showed slight but significant (P<.05) inhibition of NHE activity by troglitazone, but no significant (P>.05) effect by rosiglitazone. Exposure of cells to either drug for 24 h revealed no chronic regulation of NHE activity. Our data demonstrate that troglitazone has similar actions in endothelial cells as in vascular smooth muscle. The absence of rosiglitazone effects, a more potent PPAR-gamma activator, suggests that the observed actions of troglitazone may be at least partially independent of PPAR-gamma. The effects of troglitazone and rosiglitazone on endothelial cell proliferation and NHE activity, although contrasting, are consistent with a central signalling role of this transporter in cell proliferation.     

红景天苷对人恶性黑色素瘤细胞A375增殖和凋亡的影响

目的：观察红景天苷对人恶性黑色素瘤细胞A375增殖及凋亡的影响。方法分别用0、0．01、0．1、1、10、100μg/mL红景天苷处理人恶性黑色素瘤细胞A375后,MTT法检测各组细胞增殖率,Annexin V-FITC/PI双染色流式细胞术检测细胞凋亡率,RT-PCR检测各组细胞周期依赖性激酶CDk4和CDk2 mRNA、细胞周期素CyclinE和CyclinD1 mRNA的影响。结果与阴性对照组比较,各给药组细胞增殖抑制率明显增多（P＜0．05）。给药组细胞以G0/G1期为主,S期细胞增加,G2/M期细胞减少（P＜0．05）。给药组中的CDk2、 CDk4、CyclinD1和CyclinE mRNA表达较阴性对照组明显降低（P＜0．05）。结论红景天苷能够抑制人恶性黑色素瘤细胞A375增殖和促进其凋亡。     

A ligand for peroxisome proliferator activated receptor gamma inhibits cell growth and induces apoptosis in human liver cancer cells

BACKGROUND AND AIMS: Induction of apoptosis of cancer cells through ligands of nuclear hormone receptors (NHRs) is a new approach in cancer therapy. Recently, one of the NHRs, peroxisome proliferator activated receptor gamma (PPARgamma), has been shown to influence cell growth in certain cancer cells although its effect on hepatocellular carcinoma (HCC) has not been analysed. METHODS: Experiments were conducted using three human liver cancer cell lines, PLC/PRF/5, Hep G2 and HuH-7, in vitro. These cells were exposed to troglitazone, a synthetic ligand for PPARgamma, and the effects on cell growth were analysed. RESULTS: Expression of PPARgamma mRNA was detected in all three liver cancer cell lines. Activation of PPARgamma by troglitazone caused a marked growth inhibition in a dose dependent manner in three hepatoma cell lines. The DNA fragmentation ELISA assay and Hoechst 33258 staining revealed that the growth inhibitory effect by adding troglitazone was due to apoptosis of PLC/PRF/5, which strongly expressed PPARgamma. Troglitazone also induced activation of the cell death protease, caspase 3, but not caspase 8, in PLC/PRF/5 cells. However, expression levels of antiapoptotic factor bcl-2 and apoptosis inducing factor bax were not affected. CONCLUSION: Our study showed that PPARgamma was expressed in human liver cancer cells and that the ligand for PPARgamma, troglitazone, inhibited the growth of these cells by inducing apoptosis through caspase 3 activation, indicating that troglitazone could be potentially useful as an apoptosis inducer for the treatment of HCC.