TROP2 shRNA真核表达载体转染胃癌BGC-823细胞的沉默作用

目的:构建TROP2特异性短发夹环RNA(shRNA)真核表达载体, 抑制人胃癌BGC-823细胞TROP2基因的表达.方法:构建TROP2短发夹环RNA, 产生重组质粒转染胃癌BGC-823细胞, 转染24 h后用G418(浓度400 mg/L)筛选, 待细胞稳定后收集, 分别命名为W组(未处理组), HK组(随机阴性对照质粒组), KB组(空质粒组), T1组, T2组, T3组. 并运用实时荧光定量PCR和Western blot检测TROP2的表达.结果:TROP2特异性shRNA片段被成功克隆进pGensil1.1质粒中, 重组质粒shRNA编码序列与设计片断的序列完全一致. 与未转染细胞组、随机阴性对照组、空质粒组相比, 转染shRNA重组质粒的人胃癌BGC-823细胞TROP2表达在mRNA和蛋白水平都受到抑制.与T1、T2组相比, T3组对TROP2 mRNA和蛋白抑制作用最明显, 差异具统计学意义(8.79±0.23 vs 9.54±0.20, 9.57±0.23; 3.66±0.11vs 6.46±0.36, 9.31±0.11, 均P<0.05).结论:成功构建了针对TROP2 的特异性shRNA真核表达载体并抑制了TROP2的表达,为进一步研究其基因功能打下了基础.     

姜黄素联合奥沙利铂对人胃癌BGC-823细胞的作用

目的观察姜黄素联合奥沙利铂增强对人胃癌BGC823细胞生长抑制及杀伤作用,并探讨其与Fas蛋白的关系。方法采用不同浓度姜黄素和奥沙利铂单独或联合作用于BGC-823胃癌细胞,分别应用CCK-8法检测细胞生长抑制率,Annexin V-FITC/PI双染色检测BGC-823细胞凋亡率,流式细胞术检测Fas蛋白表达及采用分光光度法检测Caspase-3酶活性变化。结果姜黄素和奥沙利铂明显抑制细胞的增殖,呈剂量依赖性,联合作用组显著高于单独用药组;两药均可增强胃癌BGC-823细胞凋亡率,联合作用组显著高于单独用药组;两药均可增强Fas蛋白表达。联合作用组显著高于单独用药组;两药均可增强Caspase-3酶活性,联合作用组显著高于单独用药组。结论姜黄素联合奥沙利铂可显著增强对BGC823胃癌细胞的增殖抑制作用,并可增强诱导细胞凋亡作用,其机制可能与上调Fas蛋白的表达、增强Caspase-3活性有关。     

舒林酸诱导胃癌BGC-823细胞凋亡的研究

目的 探讨舒林酸诱导人胃癌BGC-823细胞株凋亡的作用及其机制。方法将舒林酸作用于人胃癌BGC-823细胞,并设置不同的作用浓度和作用时间,应用流式细胞术、TUNEL法检测胃癌细胞的凋亡率;免疫组化（S-P）法检测凋亡基因蛋白bcl-2、Sru—vivin的表达以及环氧合酶-2（COX-2）蛋白的表达情况。结果 流式细胞仪检测出凋亡峰;其凋亡检测率及TUNEL法检测的细胞凋亡率均高于对照组（P〈0.05）;免疫组化结果显示凋亡基因蛋白bcl-2、survivin等在胃癌细胞表达下降,COX-2蛋白的表达阳性率也显著低于对照组,均呈时间和剂量依赖性（P〈O.05）。结论舒林酸可诱导胃癌BGC-823细胞凋亡,其机制与抑制凋亡抑制基因bcl-2和survivin的表达及下凋COX-2蛋白的表达有关。     

叶酸对胃癌细胞凋亡的影响

目的胃癌的发生与发展中有细胞凋亡的变化,叶酸抗肿瘤的机理涉及到维持ＤＮＡ甲基化水平等,其与凋亡的关系尚未明了。方法以高低两种浓度的叶酸干预培养的人胃癌ＭＫＮ－４５和ＭＫＮ－２８细胞系７２小时后,以原位ＤＮＡ断端切口标记法和ＤＮＡ琼脂糖凝胶电泳检测凋亡形态学改变和ＤＮＡ断裂情况。结果未加干预者两种细胞系的凋亡指数均低于５％,不同分化细胞系间比较差异无显著性;低浓度叶酸可诱导ＭＫＮ－４５细胞凋亡,而高浓度者使ＭＫＮ－２８细胞凋亡率增加。结论胃癌细胞自然凋亡率较低。叶酸干预可影响凋亡的发生。     

EGCG诱导人胃癌BGC-823细胞凋亡及钙稳态失衡对其的影响

目的探讨表没食子儿茶素没食子酸酯(EGCG)对人胃癌BGC-823细胞的促凋亡作用及钙稳态失衡对该作用的影响。方法对体外培养的BGC-823细胞采用EGCG干预。采用MTT比色法检测细胞活性;光镜、倒置显微镜观察细胞形态变化;DNA琼脂糖凝胶电泳检测细胞凋亡情况;流式细胞光度仪分析细胞内游离钙水平。结果 EGCG作用后BGC-823细胞核染色质固缩,核碎裂,凋亡细胞率明显升高,呈时间和剂量依赖性。EGCG作用24 h后BGC-823细胞DNA凝胶电泳出现典型梯形条带;细胞内游离钙水平呈浓度依赖性上升。用细胞内游离钙特异性阻断剂BAPT A-AM预处理细胞后,细胞内游离钙水平不再升高,且EGCG诱导的凋亡明显受抑。结论EGCG能诱导胃癌BGC-823细胞凋亡;钙稳态失衡可抑制EGCG诱导的胃癌BGC-823细胞凋亡。     

槲皮素对胃癌细胞SGC-7901和BGG-823生长的影响

目的 观察槲皮素对胃癌细胞SGC-7901和BGC-823生长和增殖的影响。方法 以台盼蓝拒染法计数胃癌细胞的生长抑制率，荧光显微镜了解凋亡的发生，流式细胞术检测细胞周期变化。结果 台盼蓝拒染法计数显示槲皮素抑制SGC-7901和BGC-823细胞增殖的作用明显，呈浓度和时问依赖性，槲皮素处理48h后的Ic50为14．12μm(SGC-7901)和28．13μm(BGC-823)。形态学检测显示出细胞凋亡的特征变化，流式细胞仪检测表明经10～20μm／L的槲皮素处理，SGC-7901细胞周期阻滞于G0／G1期，BGC-823细胞周期阻滞于S期。结论 槲皮素能抑制胃癌细胞的生长并诱导其发生凋亡，是有效的抗癌药。     

奥沙利铂联合rmhTNF对胃癌BGC-823细胞凋亡的影响

目的观察奥沙利铂（OXA）联合重组改构人肿瘤坏死因子（rmhTNF）对胃癌BGC-823细胞系凋亡的影响。方法将胃癌BGC423细胞随机分为A、B、c、D组,分别加入含500U／ml rmhTNF、12．5μg／ml OXA、500U／ml rmhTNF＋12．5μg／ml OXA及不加药物的培养液培养72h,用流式细胞仪检测各组的细胞周期分布及凋亡率。结果A组细胞处于G0／1期占25．49％±0．83％,S期31．37％±0．68％,G2／M期45．32％±0．97％,细胞凋亡率39．52％±0．95％;B组分别为47．29％±0．98％、30．02％±0．53％、23．44％±0．93％、15．29％±0．91％,C组分别为19．45％±0．94％、10．60％±0．79％、71．47％±1．32％、71．47％±1．32％,D组分别为55．28％±1．24％、19．55％±0．70％、26．71％±0．43％、3．42％±0．64％。A、B、C组与D组比较,P均〈0．05;C组与A、B、D组比较,P均〈0．05。结论OXA联合rmhTNF可协同阻滞胃癌细胞处于G2／M期诱导细胞凋亡。     

胃腺癌BGC-823细胞总RNA转染人树突状细胞分泌exosomes的抗肿瘤效应研究

目的研究人外周血树突状细胞（DC）体外经人胃腺癌BGC-823细胞系总RNA转染后,提取培养上清液中DC分泌的外泌体（exosomes）,诱导出特异性抗胃癌效应。方法分离外周血单核细胞,经GM-CSF、IL-4培养5d后,获得未成熟DC（imDC）;体外以脂质体转染BGC-823细胞总RNA。第7天收集上清,利用超速离心法提取exosomes。分别将DC以及exosomes与T淋巴细胞共培养3d,获得细胞毒T淋巴细胞（CTL）,检测CTL对BGC-823细胞的杀伤作用。结果与未转染组相比,转染BGC-823总RNADC来源的exosomes明显促进T细胞对BGC-823的杀伤活性（P〈0．05）。结论应用BGC-823总RNA转染DC分泌exosomes能够诱导出强烈的抗肿瘤免疫反应。     

异欧前胡素对人胃癌BGC-823细胞的凋亡诱导作用的研究

目的探讨异欧前胡素对人胃癌BGC-823细胞的凋亡诱导作用。方法以体外培养人胃癌BGC-823细胞和裸鼠荷人胃癌模型为观察对象,采用MTT法和Annexin V-FITC/PI双染法观察异欧前胡素对人胃癌BGC-823细胞的增殖存活率及诱导凋亡能力的影响,并且通过裸鼠成瘤实验观察异欧前胡素对BGC-823细胞的增殖生长情况。结果人胃癌BGC-823细胞系的增殖存活率随着异欧前胡素浓度的提高或者处理时间的增加呈下降趋势,增殖存活率与异欧前胡素呈剂量-时间依赖性;异欧前胡素可以明显诱导BGC-823细胞发生凋亡,且在一定范围内随着异欧前胡素浓度的提高,凋亡率也随之升高;有效剂量的异欧前胡素瘤体内注射能够缩小裸鼠瘤体体积,增加瘤体抑制率,与对照组相比较,差异具有统计学意义(P0.05)。结论异欧前胡素能够有效抑制人胃癌BGC-823细胞的增殖并诱导其凋亡,抑制胃癌细胞移植瘤的生长,但对于其具体的调控机制有待进一步研究。     

大蒜素对人胃癌细胞SGC-7901及BGC-823 G2/M期的阻滞调节机制

目的:研究大蒜素对人胃癌细胞SGC-7901及BGC-823G2/M期阻滞作用及其调节机制.方法:应用MTT法测定大蒜素对人胃癌细胞株SGC-7901和BGC-823细胞增殖抑制率及72h的IC50.通过流式细胞仪检测IC50浓度的大蒜素对SGC-7901和BGC-823细胞周期的影响.应用免疫组化染色检测大蒜素作用前后SGC-7901和BGC-823细胞CDC2和CyclinB蛋白表达.结果:不同浓度的大蒜素可以抑制人胃癌细胞株SGC-7901和BGC-823的增殖,且随着大蒜素浓度的增大,抑制率逐渐增高.大蒜素抑制SGC-7901细胞增殖50%的药物浓度(IC50):72h为23mg/L;大蒜素抑制BGC-823细胞增殖50%的药物浓度(IC50):72h为35mg/L.大蒜素作用于两种细胞,其细胞周期均发生了明显的变化,主要表现为G0/G1期细胞减少,G2/M期细胞增多(SGC-7901细胞24,48hvs对照:26.47±2.54%,28.88±2.75%vs24.30±2.74%,P<0.01;BGC-823细胞24,48hvs对照:22.78±1.45%,24.87±1.61%vs20.32±1.34%,P<0.01),S期细胞无明显变化.未经大蒜素处理的两种细胞,CDC2和CyclinB蛋白表达均为阳性,大蒜素处理后,CDC2和CyclinB蛋白表达下降.SGC-7901细胞经23mg/L大蒜素处理后,CDC2蛋白相对阳性表达率为87.2%;CyclinB蛋白相对阳性表达率为59.3%.BGC-823细胞CDC2蛋白在35mg/L大蒜素作用后,相对阳性表达率为84.4%;CyclinB蛋白相对阳性表达率为62.8%,与对照组相比均有显著性差异(P<0.01).结论:大蒜素使人胃癌细胞株SGC-7901和BGC-823停滞于G2/M期,其机制是通过CDC2和CyclinB蛋白表达下降实现的.     

SN-38载药纳米微球对人胃癌细胞BGC-823的抑制作用

目的:检测喜树碱活性代谢产物SN-38载药纳米微球(SN-38-np)的各项特征,比较该栽药纳米微球与裸药抗人胃癌肿瘤细胞BGC-823的效果.方法:用溶剂分散法制备SN-38/PCL-PEG纳米微球.原子力显微镜和透射电子显微镜观察纳米微球形态,采用高效液相色谱法(HPLC)测定SN-38浓度并计算该栽药微球载药量、包封率及描绘其体外释放曲线.采用MTT法观察该微球对人胃癌细胞株BGC-823的生长抑制效果,荧光显微镜检测细胞内活性氧(ROS)水平.结果:微球为不规则的圆形,平均粒径小于100nm.载药量11%左右,包封率80%左右;SN-38纳米微球可稳定溶解于水中且具有良好的缓释特性:MTT结果显示,较低浓度的SN-38载药纳米微球在72 h抑制肿瘤效果明显优于SN-38裸药,同时计算IC50发现SN-38载药纳米微球在24 h和72 h的IC50明显低于SN-38裸药(P<0.05),两者48 h时间点的IC50相当;细胞内活性氧(ROS)检测结果显示:裸药和载药微球均可明显诱导ROS产生,在较低作用浓度时,SN-38载药纳米微球可比裸药诱导产生更多的细胞内ROS产物.结论:SN-38载药纳米微球可使细胞内达到并维持有效药物浓度,即使在较低作用浓度下亦可持续有效的抑制肿瘤细胞生长,效果明显优于相同浓度下SN-38裸药.     

衣霉素诱导胃癌细胞内质网应激介导的细胞凋亡

目的:观察衣霉素(tunicamycin,TM)诱导胃癌BGC-823细胞发生内质网应激介导的细胞凋亡.方法:以浓度为10 mg/L的TM分别处理胃癌BGC-823细胞0、24、36和48 h.Annexin V-PI染色法检测细胞凋亡,应用RT-PCR、Western blot检测CHOP的表达水平.结果:PI染色法检测凋亡细胞且随时间增加凋亡细胞增多,细胞凋亡率分别为0.0%、11.8%、16.3%、20.4%,具有时间依赖性(P<0.01).RT-PCR及Western blot结果显示,CHOP的表达明显高于对照组,随着处理时间的增加表达量呈上调趋势,差异均有统计学意义(P<0.01).结论:TM可诱导胃癌细胞内质网应激介导的细胞凋亡.     

Effects of tachyplesin and n-sodium butyrate on proliferation and gene expression of human gastric adenocarcinoma cell line BGC-823

AIM: To investigate the effects of tachyplesin and n-so-dium butyrate on proliferation and gene expression of human gastric adenocarcinoma cell line BGC-823. METHODS: Effects of tachyplesin and n-sodium butyrate on proliferation of BGC-823 cells were determined with trypan blue dye exclusion test and HE staining. Effects of tachyplesin and n-sodium butyrate on cell cycle were detected by flow cytometry. Protein levels of c-erbB-2, c-myc, p53 and pl6 were examined by immu-nocytochemistry. RESULTS: The inhibiting effects were similar after 2.0 mg/L tachyplesin and 2.0 mmol/L n-sodium butyrate treatment, the inhibitory rate of cellular growth was 62.66% and 60.19% respectively, and the respective maximum mitotic index was decreased by 49.35% and 51.69% respectively. Tachyplesin and n-sodium butyrate treatment could markedly increase the proportion of cells at G0/G1 phase and decrease the proportion at S phase. The expression levels of oncogene c-erbB-2, c-myc, and mtp53 proteins were down-regulated while the expression level of tumor suppressor gene pl6 protein was up-regulated after the treatment with tachyplesin or n-sodium butyrate. The effects of 1.0 mg/L tachyplesin in combination with 1.0 mmol/L n-sodium butyrate were obviously superior to their individual treatment in changing cell cycle distribution and expression of c-erbB-2, c-myc, mtp53 and pl6 protein. The inhibitory rate of cellular growth of BGC-823 cells after combination treatment was 62.29% and the maximum mitotic index was decreased by 51.95%. CONCLUSION: Tachyplesin as a differentiation inducer of tumor cells has similar effects as n-sodium butyrate on proliferation of tumor cells, expression of correlative oncogene and tumor suppressor gene. It also has a syn-ergistic effect on differentiation of tumor cells.     

Co-expression of heat shock protein 70 and glucose-regulated protein 94 in human gastric carcinoma cell line BGC-823

AIM:To investigate the co-expression and significance of heat shock protein 70 (HSP70) and glucose-regulated protein 94 (grp94) in human gastric carcinoma cell line BGC-823. METHODS: The expression and localization of HSP70 and grp94 in human gastric carcinoma cell line BGC-823 were determined by immunocytochemistry and indirect immunofluorescence cytochemical staining. Flow cytometry was used to analyze the correlation between expression of HSP70, grp94 and cell cycle in BGC-823 cell line. RESULTS: Gastric cancer cell line BGC-823 expressed high level of HSP70 and grp94. The positive rate of HSP70 and grp94 was 84.9±4.94% and 79.6±5.16%, respectively. Both of them were stained in cell plasma. There was a significant difference compared with control group (1.9±0.94%, P<0.01). During the cell cycle, HSP70 and grp94 were continuously expressed in BGC-823. CONCLUSION: HSP70 and grp94 are highly expressed in human gastric carcinoma BGC-823 cells through the whole cell cycle. There is no relationship between expression of HSP70, grp94 and cell cycle.     

MTA1基因表达与人胃癌的浸润和转移

目的:探讨MTA1基因在胃癌及癌周组织中的表达及其表达水平与胃癌浸润和转移潜能的相关性.方法:采用荧光定量PCR及Western印迹技术,分别在mRNA和蛋白水平检测42例手术切除的人胃癌组织及癌旁组织中MTA1的表达,结合胃癌的临床生物学特征分析MTA1表达与胃癌病理类型、淋巴结转移的关系.结果:胃癌组织中MTA1mRNA相对量的表达显著高于癌旁胃黏膜组织(0.6711vs0.3940,P<0.01),蛋白水平表达与mRNA一致.低分化胃腺癌组织中的MTA1mRNA的相对量表达显著高于中高分化胃腺癌组织(0.7475vs0.3460,P<0.01),而伴有淋巴结转移的胃癌组织中MTA1mRNA的相对量表达明显高于不伴有淋巴结转移的胃癌组织(0.8128vs0.4933,P<0.01).结论:MTA1的表达与促进胃癌的转移相关,检测MTA1表达可作为预测胃癌生物学行为、判断胃癌患者预后的一个参考指标.     

Inhibitory effects of apigenin on the growth of gastric carcinoma SGC-7901 cells

AIM: To explore the growth inhibition and apoptosis-inducing effect of apigenin on human gastric carcinoma SGC-7901 cells. METHODS: The effects of apigenin on the growth, clone formation and proliferation of human gastric carcinoma SGC-7901 cells were observed by MTT, clone-forming assay, and morphological observation. Fluorescent staining and flow cytometry analysis were used to detect apoptosis of cells. RESULTS: Apigenin obviously inhibited the growth, clone formation and proliferation of SGC-7901 cells in a dosedependent manner. Inhibition of growth was observed on d 1 at the concentration of 80 μmol/L, while after 4 d, the inhibition rate (IR) was 90%. The growth IRs at the concentration of 20, 40, and 80 μmol/L were 38%, 71%, and 99% respectively on the 7~(th) d. After the cells were treated with apigenin for 48 h, the number of clone-forming in control, 20, 40, and 80 μmol/L groups was 217±16.9, 170±11.1 (P<0.05), 98±11.1(P<0.05), and 25±3.5 (P<0.05) respectively. Typical morphological changes of apoptosis was found by fluorescent staining. The cell nuclei had lost its smooth boundaries, chromatin was condensed, and cell nuclei were broken. Flow cytometry detected typical apoptosis peak. After the cells were treated with apigenin for 48 h, the apoptosis rates were 5.76%, 19.17%, and 29.30% respectively in 20, 40, and 80 μmol/L groups. CONCLUSION: Apigenin shows obvious inhibition on the growth and clone formation of SGC-7901 cells by inducing apoptosis.