鞘氨醇激酶1抑制剂和5-FU联合应用对体外胃癌细胞增殖与凋亡的影响

目的观察鞘氨醇激酶1(SphK1)抑制剂二甲基鞘氨醇(DMS)与化疗药物5-氟尿嘧啶(5-FU)联合应用对体外胃癌细胞SGC7901增殖与凋亡的影响。方法体外培养人胃癌细胞株SGC7901,分别单用不同浓度5-FU(1、5、25μg/ml)或5-FU与DMS(1μmol/L)联合应用。MTT比色法检测各组细胞生长抑制率,光镜下观察细胞形态变化,流式细胞术检测各组细胞凋亡率。通过SAS软件进行反应曲面分析,分析两药之间的关系。结果不同浓度的5-FU单用组及联用DMS组的抑制率差异有统计学意义(P<0.05),联用组抑制率均高于单用组,两者具有协同作用。单用DMS组及5-FU组的胃癌细胞凋亡率较空白对照组明显增高,联用组凋亡率较单用组明显增加(P<0.05)。结论 DMS可抑制SGC7901细胞的增殖;DMS和5-FU联用显示了较好的协同作用,提示抑制SphK1活性能够提高胃癌细胞对于化疗药物的敏感性。     

银杏叶提取物对胃癌SGC7901细胞增殖与凋亡的影响

目的:研究银杏叶提取物(GBE)对胃癌SGC7901细胞增殖与凋亡的影响。方法:0、5、10、20、50、100、200μg/ml GBE培养细胞48 h后,MTT法测定细胞活力并计算抑制率。0、10、50、200μg/ml GBE培养细胞48 h后,流式细胞仪检测细胞周期分布及凋亡率。结果:5、10、20、50、100、200μg/ml GBE培养细胞48 h后,对细胞生长有明显抑制作用,且呈剂量依赖关系。10、50、200μg/ml GBE培养细胞48 h后细胞凋亡率升高。结论:GBE可一定程度上抑制SGC7901细胞增殖,诱导其凋亡,以前者为主。     

伊立替康联合TRAIL对胃癌细胞SGC7901凋亡的影响

目的探讨伊立替康和肿瘤坏死因子相关凋亡诱导配体(TRAIL)对胃癌SGC7901细胞凋亡的影响并初步探讨其作用机制。方法不同浓度的伊立替康和/或200μg·L-1TRAIL作用于人胃癌细胞SGC7901细胞,MTT检测细胞增殖能力;流式细胞术检测细胞凋亡;TRAIL和/或伊立替康作用SGC7901细胞后,Western-blot检测蛋白表达。结果 200μg·L-1的TRAIL对胃癌细胞的增殖抑制率为18.46%,TRAIL(200μg·L-1)联合伊立替康(28.67mg·L-1)引起明显的增殖抑制和细胞凋亡(P<0.05)。TRAIL(200μg·L-1)单药和伊立替康(28.67mg·L-1)单药都没有改变Bax、Caspase-8蛋白的表达,而两者联用增加了Bax、Caspase-8蛋白的表达。结论伊立替康通过增加Bax、Caspas-8蛋白表达来增强TRAIL诱导的胃癌SGC7901细胞凋亡。     

丹参酮Ⅰ对人胃腺癌细胞SGC-7901 EIF2a和EIF3a基因表达的调控作用

目的分析丹参酮Ⅰ对人胃腺癌细胞SGC-7901真核翻译起始因子2a(EIF2a)、真核翻译起始因子3a(EIF3a)基因表达的调控作用。方法体外培养SGC-7901人胃腺癌细胞株,经丹参酮Ⅰ干预后,采用实时荧光定量聚合酶链反应(RT-PCR)法测定EIF2a和EIF3a mRNA水平;采用四甲基偶氮唑蓝(MTT)比色法测定丹参酮Ⅰ对SGC-7901细胞株增殖的影响,采用流式细胞术检测细胞周期及细胞凋亡率。结果不同质量浓度丹参酮Ⅰ干预后SGC-7901细胞株EIF2a mRNA和EIF3a mRNA降低,与空白对照组比较,差异有统计学意义(P<0.05);EIF2a mRNA与EIF3a mRNA比较,丹参酮Ⅰ1μg/mL>5μg/mL>10μg/mL(P<0.05)。丹参酮Ⅰ1,5,10μg/mL组细胞培养不同时间A值低于空白对照组(P<0.05),抑制率高于空白对照组(P<0.05);不同时间A值比较,丹参酮Ⅰ1μg/mL>5μg/mL>10μg/mL;不同时间抑制率比较,丹参酮Ⅰ1μg/mL<5μg/mL<10μg/mL(P<0.05)。丹参酮Ⅰ不同质量浓度组G1期细胞比例高于空白对照组(P<0.05),S期细胞比例低于空白对照组(P<0.05);G1期细胞比例丹参酮Ⅰ不同质量浓度组对比,丹参酮Ⅰ1μg/mL<5μg/mL<10μg/mL;S期细胞比例丹参酮Ⅰ不同质量浓度组对比,丹参酮Ⅰ1μg/mL>5μg/mL>10μg/mL(P<0.05),丹参酮Ⅰ1,5,10μg/mL组细胞凋亡率均高于空白对照组(P<0.05),不同质量浓度组丹参酮Ⅰ细胞凋亡率比较,丹参酮Ⅰ1μg/mL<5μg/mL<10μg/mL(P<0.05)。结论丹参酮Ⅰ可通过下调人胃腺癌细胞SGC-7901 EIF2a和EIF3a基因表达,抑制癌细胞增殖,促进肿瘤细胞凋亡。     

复合应用紫杉醇和顺铂对胃癌细胞SGC放疗的增敏作用

目的观察紫杉醇、顺铂及两者联合应用加放疗对胃癌细胞株SGC的细胞增殖与细胞周期的影响。方法将体外培养的胃癌细胞株SGC种于96孔板。实验分为P1组(紫杉醇0.1μg/ml)、P2组(紫杉醇0.01μg/ml)、C1组(顺铂0.1μg/ml)、C2组(顺铂0.01μg/ml)、PC1组(紫杉醇0.1μg/ml+顺铂0.1μg/ml)、PC2组(紫杉醇0.01μg/ml+顺铂0.01μg/ml)。无菌环境下实施4Gy照射。采用MTT法观察SGC细胞增殖抑制率;以流式细胞技术检测细胞凋亡及周期变化。结果 PC1组和PC2组胃癌SGC细胞抑制率分别为(76.6±7.7)%和(68.3±2.6)%,明显高于P1组的(46.7±4.5)%、P2组的(39.2±5.3)%、C1组的(41.4±0.2)%和C2组的(25.6±1.3)%(P<0.01)。联合应用紫杉醇和顺铂加放疗组的胃癌SGC细胞主要阻滞在G2/M期;而对照组的多数细胞处于G1期(P<0.05)。结论紫杉醇复合顺铂密集化疗对离体胃癌细胞放疗有明显增敏作用。     

四硫化四砷对人胃癌细胞SGC7901增殖的抑制作用

目的:研究四硫化四砷(As4S4)对人胃癌细胞SGC7901增殖的抑制作用及其作用机制。方法:体外培养SGC7901,取对数生长期的细胞分为空白对照组(不加药物)和20、40、60、80μmol/LAs4S4处理组,分别作用24、48、72 h。采用MTT法检测细胞增殖的抑制率,透射电镜观察细胞的形态,流式细胞仪分析细胞的周期分布,逆转录-聚合酶链式反应法和蛋白质印迹法检测作用48 h后细胞中凋亡相关基因Bcl-2、Bax mRNA和蛋白的表达。结果:与空白对照组比较,20(作用48、72 h)、40、60、80μmol/LAs4S4处理组细胞增殖的抑制率明显升高(P<0.01),与浓度和时间呈正相关;从40μmol/L As4S4处理组细胞开始出现凋亡,60μmol/L As4S4处理组细胞开始出现大量凋亡,细胞周期阻滞于S期;与空白对照组比较,As4S4处理组细胞中Bcl-2 mRNA和蛋白表达随As4S4浓度的增加而减弱,Bax mRNA和蛋白表达随As4S4浓度的增加而增强。结论:As4S4具有抑制SGC7901细胞增殖的作用,其机制可能与诱导细胞凋亡、下调Bcl-2表达、上调Bax表达有关。     

DAB2IP过表达对人胃癌细胞SGC7901增殖、迁移及对E-cad-herin、Snail、Twist表达的影响

摘要：目的:研究失活蛋白-2相互作用蛋白基因(DAB2IP)过表达对人胃癌细胞SGC7901增殖、迁移及对上皮间质转化(EMT)相关上皮细胞-钙黏蛋白基因(E-cadherin)、Snail、Twist蛋白表达的影响。方法:采用慢病毒介导DAB2IP过表达转染并筛选稳定人胃癌细胞SGC7901细胞株(过表达组),另设慢病组对照液转染的人胃癌细胞SGC7901作为慢病毒对照组,无转染人胃癌细胞SGC7901为空白对照组,采用实时定量PCR(RT-qPCR)检测各组人胃癌细胞SGC7901 DAB2IP基因表达水平,采用噻唑蓝法(MTT)及平板克隆形成试验检测过表达DAB2IP对人胃癌细胞SGC7901增殖的影响采用细胞划痕试验检测过表达DAB2IP对人胃癌细胞SGC7901迁移的影响,采用免疫印迹(Western Blot,WB)法检测过表达DAB2IP对人胃癌细胞SGC7901中EMT相关蛋白表达水平。结果:同一时间及不同时间,空白对照组和慢病毒对照组人胃癌细胞SGC7901中DAB2IP mRNA表达水平、细胞增殖抑制率差异无统计学意义(P>0.05)。与空白对照组和慢病毒对照组比较,24,48,72 h过表达组人胃癌细胞SGC7901中DAB2IP mRNA表达水平、细胞增殖抑制率均显著升高(P<0.05)。与24 h比较,48和72 h过表达组人胃癌细胞SGC7901中DAB2IP mRNA表达水平、细胞增值抑制率显著升高(P<0.05),与48 h比较,72 h过表达组人胃癌细胞SGC7901中DAB2IP mRNA表达水平、细胞增殖抑制率差异无统计学意义(P>0.05)。提示48 h过表达效果最佳,可用于下游试验。空白对照组和慢病毒对照组平板克隆形成率、细胞迁移距离、E-cadherin、Snail、Twist蛋白水平比较差异无统计学意义(P>0.05)。与空白对照组和慢病毒对照组比较,过表达组人胃癌细胞SGC7901平板克隆形成率、细胞迁移距离、Snail、Twist蛋白水平显著降低(P<0.05),E-cadherin蛋白水平显著增加(P<0.05)。结论:DAB2IP过表达可抑制人胃癌细胞SGC7901增殖、迁移,可能与上调E-cadherin蛋白表达,下调Snail、Twist蛋白表达有关。     

藤茶蛇葡萄素抗人胃癌细胞作用的实验研究

目的:探讨藤茶蛇葡萄素的体外抗肿瘤作用。方法:采用MTT法、生长曲线法、细胞集落形成法观察蛇葡萄素对人胃癌SGC-7901细胞的抑制作用。结果:蛇葡萄素能明显抑制体外培养的SGC-7901细胞的生长,MTT法IC50为11.19μg/mL;细胞生长曲线法提示其对SGC-7901细胞的生长也有明显的抑制作用;集落形成法,当药物浓度在9.90μg/mL以上时抑制率为100%,当药物浓度为6.60μg/mL时抑制率为72.3%,当药物浓度为4.40μg/mL时抑制率为36.0%。结论:蛇葡萄素对体外SGC-7901细胞的生长有明显的抑制作用。     

苦参碱和氧化苦参碱对胃癌细胞株SGC7901/VCR耐药性的作用

目的研究苦参碱和氧化苦参碱对人胃癌细胞株SGC7901/VCR耐药性的作用。方法以SGC7901/VCR为研究对象,用SRB法测定苦参碱和氧化苦参碱对SGC7901/VCR耐药细胞的增殖抑制率,计算IC50和IC10,并进一步计算其耐药倍数和逆转倍数。流式细胞术检测罗丹明123的荧光强度变化。结果苦参碱和氧化苦参碱对SGC7901/VCR均存在抑制作用,且呈剂量依赖。VCR耐药倍数为33.4倍;0.78 mg/ml苦参碱逆转倍数为1.92倍;0.71 mg/ml氧化苦参碱逆转倍数为3.39倍;细胞内罗丹明123浓度较明显增加(P<0.01)。结论低毒浓度的苦参碱和氧化苦参碱对人胃癌耐药细胞株SGC7901/VCR具有一定的耐药逆转作用,且氧化苦参碱优于苦参碱。     

二氢丹参酮对人肺癌GLC-82细胞的抑制作用及其机制研究

目的:研究二氢丹参酮(DTS)对人肺癌GLC-82细胞的抑制作用及其作用机制。方法:以质量浓度为0(空白对照)、5、10、20、40、80、100μg/ml的DTS作用细胞24、48 h后,采用MTT法测定细胞的增殖抑制率和半数抑制浓度(IC50);流式细胞术检测17.85μg/ml DTS作用12、24、48 h后细胞的凋亡情况,计算凋亡率;Western blot法检测Bcl-2、Bax和半胱氨酸天冬氨酸蛋白激酶3(Caspase-3)蛋白的表达。结果:与空白对照组比较,DTS组细胞的增殖受到抑制,作用24、48 h后最大细胞抑制率分别为54.48%、64.95%,IC50分别为62.36、33.94μg/ml;DTS可诱导细胞的凋亡且与作用时间呈正相关,凋亡率为5.6%~29.6%;Western blot检测结果表明,DTS能下调细胞中Bcl-2蛋白的表达、上调Caspase-3蛋白的表达(P<0.01或P<0.05)。结论:DTS对人肺腺癌GLC-82细胞有较强的抑制作用,并诱导其凋亡,其机制可能与下调Bcl-2蛋白的表达、上调Caspase-3蛋白的表达有关。     

Distribution of carbon‐14 labeled C60 ([14C]C60) in the pregnant and in the lactating dam and the effect of C60 exposure on the biochemical profile of urine

This study was conducted to determine the distribution of [¹⁴C]C60 in the pregnant rat and fetuses, and in the lactating rat and offspring. Pregnant rats were dosed on gestation day (gd) 15 and lactating rats were dosed on postnatal day (pnd) 8 via tail vein injection with a suspension of ～0.3 mg [¹⁴C]C60 kg^?1 body weight prepared in polyvinylpyrrolidone (PVP), or with PVP alone. Tissues were collected at 24 and 48 h after dosing. The largest portion of the administered dose was detected in the liver (～43%, pregnant dam; ～35%, lactating dam) and lung (～25%, lactating dam). Radioactivity (～6%) was distributed to the reproductive tract, placenta and fetuses of the pregnant dam. Lactating rats had radioactivity distributed to the milk (3140 dpm g^?1 tissue, 24 h; 1620 dpm g^?1 tissue, 48 h), and to the pups' GI tract (2.8%, 24 h; 4.4% 48 h) and liver (<1%). Blood radioactivity was significant at 24 h (14–19%) and at 48 h (7%) after dosing; largely accounted for in the plasma fraction. Less that 4% of the dose was recovered in the maternal spleen, heart, brain, urine or feces. Metabolomics analysis of urine indicated that dams exposed to [¹⁴C]C60 had decreased metabolites derived from the Krebs cycle and increased metabolites derived from the urea cycle or glycolysis, as well as alterations in the levels of some sulfur‐containing amino acids and purine/pyrimidine metabolites. This study demonstrated that [¹⁴C]C60 crosses the placenta and is transmitted to offspring via the dam's milk and subsequently systemically absorbed. Copyright © 2009 John Wiley & Sons, Ltd.     

Role of Complements C3 and C5 in the Phagocytosis of Liposomes by Human Neutrophils

During the course of a previous investigation, we noticed that the uptake of liposomes by human polymorphonuclear neutrophils (PMNs) was significantly lower in the presence of heat-inactivated serum compared to that in intact whole serum (Scieszka et al., Pharm. Res. 5:352, 1988). This observation suggested the participation of heat-labile complement components in the phagocytic process. In this report we conclude that complement C3bi is the component responsible for opsonization of the liposome surface. Phagocytosis was not supported by C3-deficient serum, and phagocytosis in whole serum was blocked by the antibody to the receptor for C3bi (CR3) but not by the antibody to the receptor for C3b (CR1). We also found that with C5-deflcient serum the level of uptake was minimal but slightly higher than without any serum. When exogenous C5a was added along with C5-deficient serum, uptake levels similar in magnitude to those observed with intact serum were obtained. We conclude that C5a enhances phagocytosis of opsonized liposomes by activating the phagocytic capacity of CR3 on the PMN.     

Blockade of long-term potentiation and of NMDA receptors by the protein kinase C antagonist calphostin C

Summary We have studied the effects of calphostin C, an antagonist of the regulatory subunit of protein kinase C, on the induction and expression of long-term potentiation (LTP) and on responses mediated by activation of N-methyl-d-aspartate (NMDA) receptors in rat hippocampal slices. No effect of calphostin C was observed on preestablished LTP, even at concentrations of 2–3 mol/l. In contrast, the drug was found to prevent LTP induction. This effect was concentration-dependent, although high concentrations were needed (1–2 mol/l), and, at the lower concentrations, it could be partially antagonized by using coactivation of two pathways instead of single input activation. While calphostin C did not alter synaptic transmission mediated by activation of -amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA) receptors, it considerably interfered with the function of NMDA receptors. The drug blocked the NMDA receptor-mediated component of burst responses, significantly antagonized the NMDA receptor-mediated synaptic responses recorded in the presence of an AMPA receptor antagonist, and blocked the effect of iontophoretic application of NMDA on regular synaptic transmission. These results are consistent with the idea that calphostin C prevents the induction of long-term potentiation by interfering with the function of NMDA receptors.