紫杉醇对TRAIL诱导胃癌SGC7901细胞凋亡的影响

目的探讨紫杉醇对TRAIL诱导的胃癌SGC7901细胞凋亡的影响。方法采用MTT法测定细胞活力、采用流式细胞仪检测细胞凋亡、Western blot检测蛋白表达。结果在胃癌SGC7901细胞中,100 ng/ml的TRAIL导致轻度的增殖抑制和细胞凋亡,TRAIL（100 ng/ml）联合紫杉醇（7.19μg/ml,24 h的IC50剂量）引起明显的细胞增殖抑制和诱导凋亡作用（P〈0.05）。TRAIL单药没有改变死亡受体5（DR5）的蛋白表达,而7.19μg/ml紫杉醇作用于胃癌SGC7901细胞后明显上调了DR5的蛋白表达。TRAIL和紫杉醇联合作用后,也有DR5蛋白的明显上调。结论紫杉醇通过上调DR5的蛋白表达增强了TRAIL诱导的胃癌SGC7901细胞凋亡。     

紫杉醇增强TRAIL诱导的胃癌BGC823细胞凋亡的机制

目的 探讨紫杉醇增强TRAIL诱导的胃癌BGC823细胞凋亡的机制。方法胃癌BGC823细胞传代堵养后,取对数生长期细胞用于实验。采用MTT法测定细胞活力,流式细胞仪检测细胞凋亡,Westernblot检测Akt、p-Akt蛋白表达。结果在胃癌BGC823细胞中,100ng／ml的TRAIL可致少量的细胞凋亡,同时检测到Akt的磷酸化。紫杉醇作用胃癌BGC823细胞24h,IC50剂量为8．97μg／ml。与单药TRAIL和紫杉醇相比,TRAIL（100ng／m1）联合紫杉醇（8．97μg／ml,24h的IC50剂量）对细胞的诱导凋亡作用明显增强（P〈0．05）。免疫印迹结果显示,TRAIL（100ng／ml）作用BGC823细胞24h,活化了Akt蛋白,而8．97μg／ml的紫杉醇抑制了Akt的磷酸化。TRAII（100ng／ml）联合紫杉醇（8．97μg/ml）作用后,TRAIL引起的Akt磷酸化被抑制。结论紫杉醇通过抑制TRAIL引起的Akt磷酸化,从而增强了TRAIL诱导的胃癌BGC823细胞凋亡。     

HCTB006联合5-FU对胃癌细胞系MKN28、7901的作用及其机制

目的:探讨肿瘤坏死因子相关诱导配体受体(DR5)的单克隆抗体HCTB006联合5-FU对人胃癌细胞系7901、MKN28的作用以及机制.方法:用ATPlite法检测HBCT006单药组、5-FU单药组及两药物合用对胃癌细胞存活率的影响,研究两者之间的关系;采用流式细胞技术检测胃癌细胞系7901以及MKN28表面DR5的表达水平;Westernblot检测上述3组用药后胃癌细胞内XIAP,caspase3的变化.结果:胃癌细胞系7901、MKN28对HCTB006不敏感;5-FU对二者的增殖抑制作用具有时间以及浓度依赖效应;联合用药组具有很好的协同抑制胃癌细胞系增殖的效果,且具有浓度依赖效应,与给药次序无关.流式细胞技术检测胃癌细胞系7901,MKN28表面死亡受体DR5的表达依次为:93.8%以及87.7%.免疫迹印结果表明,联合用药组可以引发胃癌细胞内凋亡抑制蛋白XIAP的降解,激活最终凋亡执行蛋白caspase3,引起细胞死亡.结论:HTB006与5-FU联合应用具有协同杀伤胃癌细胞的作用.胃癌细胞7901、MKN28对于HCTB006的敏感程度与细胞表面DR5的表达量不相关;联合用药作用机制可能与细胞内抑制凋亡蛋白XIAP降解有关.     

CIK联合紫杉醇对胃癌细胞株SGC-7901的杀伤作用观察

目的观察由细胞因子诱导的杀伤细胞（CIK）联合紫杉醇对胃癌细胞株SGC-7901的杀伤作用。方法将健康人外周血单核细胞（PBMC）在体外诱导形成CIK。取SGC-7901,分别加入CIK、紫杉醇、CIK＋紫杉醇培养,采用MTT法分别检测各组细胞的杀伤率。结果5μg/ml的紫杉醇作用于SGC-7901细胞4 h后,分别加入效靶比为10∶1和20∶1的CIK细胞作用24 h,SGC-7901杀伤效率明显高于单用紫杉醇及单用CIK时的杀伤率,P均〈0.01。结论CIK联合紫杉醇对胃癌细胞株SGC-7901的杀伤作用明显增强。     

三氧化二砷协同肿瘤坏死因子相关细胞凋亡诱导配体抗胃癌细胞的作用及其机制

目的研究三氧化二砷（As2O3）联合肿瘤坏死因子相关细胞凋亡诱导配体（TRAIL）对胃癌细胞生长和凋亡的影响及其机制。方法人胃腺癌细胞株SGC7901以As2O3、rsTRAIL及两者联用处理；用MTT法检测细胞生长；用双染色流式细胞仪检测细胞凋亡；用间接免疫荧光染色结合流式细胞技术检测细胞表面TRAIL R1／DR4和TRAIL R2／DR5分子表达；RT—PCR方法检测TRAIL R1／DR4和TRAIL R2／DR5 mRNA表达。结果As2O3和rsTRAIL在单用或联用时均可以抑制胃癌细胞SGC7901生长，并在一定范围内呈时间、剂量依赖性；联合用药组抑制率显著高于单用As2O3或rsTRAIL组（P〈0．01），金正均方法分析提示两药联用有协同抑制细胞生长效应。As2O3和rsTRAIL在单用或联用时均可以诱导胃癌细胞SGC7901凋亡，联合用药组细胞凋亡率显著高于单用As2O3或rsTRAIL组（P〈0．01）。As2O3单独或联合rsTRAIL作用于SGC7901细胞24h后，死亡受体TRAIL R1／DR4和TRAIL R2／DR5在细胞表面的表达明显上调（P〈0．01），其mRNA表达水平亦相应增加（P〈0．01）。结论As2O3联合rsTRAIL可以协同抑制胃癌细胞SGC7901生长并显著增强两药诱导胃癌细胞凋亡的作用，其机制可能是As2O3增加细胞TRAIL R1／DR4和TRAIL R2／DR5 mRNA表达、上调细胞表面TRAIL死亡受体从而增加胃癌细胞SGC7901对rsTRAIL的敏感性。     

白藜芦醇增敏TRAIL对肺癌细胞PC9的凋亡机制研究

目的观察白藜芦醇(resveratrol,RES)增敏肿瘤坏死因子相关凋亡诱导配体(TNF-related apoptosis-inducting ligand,TRAIL)对人肺癌细胞PC9细胞株的促凋亡作用,并探讨其机制。方法取对数生长期的人肺癌细胞PC9细胞,MTT法检测不同浓度的RES和TRAIL对PC9细胞的增殖抑制率,流式细胞术检测不同浓度的RES和TRAIL对PC9细胞的凋亡,Western blot法检测不同浓度的RES作用PC9细胞后死亡受体4(Death receptor 4 DR4)的表达变化。结果 RES对人肺癌细胞PC9细胞有明显增殖抑制作用,且呈剂量依赖性,联合TRAIL后可显著促进PC9的凋亡率,不同浓度的RES作用24h后,可显著上调DR4的表达。结论 RES增敏TRAIL对人肺癌PC9细胞的抑制作用明显,其凋亡机制可能是与上调DR4有关。     

敲低DR5表达对rmhTRAIL联合5-FU干预结肠癌细胞增殖及凋亡的影响

目的 探讨敲低死亡受体5(DR5)表达对重组变构人肿瘤坏死因子相关凋亡诱导配体(rmhTRAIL)联合5氟尿嘧啶(5-FU)抑制人结直肠癌(CRC)HCT116细胞增殖及凋亡的影响.方法 体外培养人CRC HCT116细胞,用DR5 shRNA质粒转染,构建敲低DR5的CRC HCT116/shRNA细胞系(HCT11...     

As2O3对TRAIL抑制人肺癌A549细胞增殖及调节DR4 mRNA、DR5 mRNA表达作用的影响

目的观察三氧化二砷（As2O3）对人肿瘤坏死因子相关凋亡诱导配体（TRAIL）抑制人肺癌A549细胞增殖作用的影响及机制。方法体外培养A549细胞至对数生长期后随机分为As2O3组、TRAIL组、联合组及对照组,As2O3组分别加入1、10μmol／LAs2O3,TRAIL组加入100μg／LTRAIL,联合组分别加入1μmol／LAs2O3＋100μg/LTRAIL、10μmol／LAs2O3＋100μg／LTRAIL,对照组加入DMEM培养液。四组均继续培养24、48、72h,采用四甲基偶氮唑蓝（MTT）比色法检测细胞生长情况,计算细胞增殖抑制率（IR）;用RT-PCR法检测死亡受体4（DR4）mRNA、死亡受体5（DR5）mRNA表达变化。结果 联合组IR显著高于As2O3,组及TRAIL组,尤以作用48h和72h为著（P均〈0．05）;联合组DR4 mRNA和DR5 mRNA表达均明显强于As2O3组及TRAIL组（P均〈0.05）。结论 As2O3,可增强TRAIL对A549细胞增殖的抑制作用,机制可能为上调DR4m RNA和DR5 mRNA表达;此为肺癌的临床靶向治疗根供了依据．     

硼替佐米抑制PI3K/Akt通路增强胃癌细胞对TRAIL诱导凋亡的敏感性

目的:研究硼替佐米对TRAIL诱导胃癌细胞凋亡的影响, 探讨PI3K/Akt通路在TRAIL诱导凋亡中的作用.方法:不同浓度的TRAIL和/或硼替佐米作用于人胃癌细胞系MGC803细胞, MTT法检测细胞存活率, 流式细胞术PI染色检测细胞凋亡.Western blot法检测caspase裂解及p-Akt表达水平的变化.结果:50 nmol/L硼替佐米预处理细胞2 h, 之后予100 μg/L TRAIL继续作用24 h, 细胞存活率明显低于TRAIL单独处理组(35.1%±2.7% vs71.0%±4.3%, P <0.01); 细胞凋亡率明显高于TRAIL单药组(31.3%±2.0% vs 8.2%±0.8%,P <0.01). 20 nmol/L硼替佐米预处理未能增强细胞对TRAIL的敏感性. 进一步研究发现,TRAIL可活化PI3K/Akt通路, 硼替佐米预处理可阻止PI3K/Akt通路的活化, 进而增强细胞对TRAIL诱导凋亡的敏感性.结论:硼替佐米通过抑制TRAIL诱导的PI3K/Ak t通路活化, 增强胃癌MGC803细胞对TRAIL诱导凋亡的敏感性.     

TRAIL联合顺铂诱导胶质瘤细胞凋亡的机制

作为新型的抗肿瘤药物,肿瘤坏死因子相关凋亡诱导配体(TRAIL)已进入临床Ⅱ期试验阶段[1].研究发现,TRAIL可以诱导包括胶质瘤在内的多种肿瘤细胞发生凋亡,但大多恶性胶质瘤细胞对TRAIL耐药[2].前期研究的实验发现,原代培养的胶质瘤细胞对TRAIL诱导凋亡的敏感性不同,检测发现死亡受体(DR)5的表达量不同,并当TRAIL与化疗药物联合作用后可发挥协同作用[3～5].因此,本文进一步对TRAIL与化疗药物联合作用诱导胶质瘤细胞凋亡的机制进行研究,为TRAIL作为肿瘤治疗新药提供新的实验依据.     

5-FU增强TRAIL诱导的胃癌BGC823细胞凋亡的实验研究

目的 观察5-FU对TRAIL诱导的胃癌BGC823细胞凋亡的影响,明确死亡受体5(DR5)在5-FU和TRAIL诱导凋亡中的作用.方法 采用MTT法测定细胞活力、流式细胞仪检测细胞凋亡、免疫印迹检测蛋白表达.结果 TRAIL可导致BGC823细胞轻度的增殖抑制和少量的细胞凋亡.与单药TRAIL和5-FU相比,TRAIL联合5-FU对细胞的增殖抑制和诱导凋亡作用明显增强(P＜0.05).免疫印迹结果显示,TRAIL没有改变DR5的蛋白表达,而5-FU作用BGC823细胞48 h后,DR5蛋白表达上调(P＜0.05).TRAIL和5-FU联合作用后,DR5蛋白表达同样明显上调(P均＜0.05).结论 5-FU通过上调DR5蛋白表达提高了BGC823细胞对TRAIL的敏感性.     

抗人DR5单克隆抗体诱导肝癌细胞株SMMC-7721凋亡实验研究

目的探讨抗人DR5单克隆抗体对肝癌细胞株SMMC-7721致凋亡作用。方法常规培养肝癌细胞SMMC-7721,通过MTT法检测细胞抑制作用,流式细胞术定量分析凋亡细胞率。结果抗人DR5单抗能够诱导肝癌SMMC-7721细胞凋亡,在抗人DR5单抗浓度2μg/ml作用48h,对肝癌SMMC-7721细胞的杀伤率可达50.10%,增加抗人DR5单抗浓度细胞凋亡作用无明显增加。结论抗人DR5单抗能够诱导肝癌细胞SMMC-7721凋亡,以死亡受体为靶点的抗体制剂为肝癌治疗提供新途径。     

Differential display of vincristine-resistance-related genes in gastric cancer SGC7901 cells

AIM: To isolate and clone the vincristine-resistine-relatedgenes in gastric cancer SGC7901 cell line and to clarify themultidrug-resistant molecular mechanism of gastric cancercells.METHODS: The modified differential-display polymerasechain reaction (DD-PCR) was used to examine thedifferences in the mRNA composition of Vincristine-resistantgastric cancer SGC 7901 cells (SGC7901/VCR), induced byvincristine sulfate versus SGC7901cells. The differentiallyexpressed cDNA fragments were confirmed byreverseNorthern analysis, sequencing, BLAST analysis andNorthern bolt analysis.RESULTS: DD-PCR identified that 54 cDNA fragments werepreferentially expressed in SGC 7901/VCR cells. When thesecDNA fragments were analyzed by reverseNorthern blot, 20were reproducibly expressed at a high level in SGC7901/VCR. Sequencing and BLAST analysis revealed that sevenof the genes were known genes: ADP-ribosylation factor 4,cytochrorne oxidase subunit Ⅱ, Ss-A/Ro ribonucleoprteinautoantigen 60kd subunit, ribosomal protein S13, galaectin-8 gene, oligophrenin 1 mRNA, and ribosomal protein L23mRNA; and thirteen of the genes were unknown genes. Thelength and abundance of the four unknown genes mRNAwere further confirmed by Northern blot analysis.CONCLUSION: The twenty differential known and unknowngenes may be related to the vincristine-resistant mechanismin human gastric cancer SGC7901 cell line.     

Anti-proliferation effects of Twist gene silencing in gastric cancer SGC7901 cells

AIM:To study the role of Twist gene in gastric cancer by gene silencing,including the potential of induction of apoptosis,cell cycle arrest,and proliferation inhibition in human malignant gastric SGC7901 cells.METHODS:The expression level of Twist in gastric cancer samples was measured by immunohistochemistry.The effects of Twist gene silencing were detected at both m RNA and protein levels by RT-PCR and Western blot.We also evaluated the cell proliferation and apoptosis by CCK-8 assay and flow cytometry.We determined the activity of caspase-3 and caspase-9 with a caspase activity assay kit.Cell cycle distribution was analyzed by flow cytometry.Cell migration and invasion ability was evaluated by wound scratch assay and Boyden chamber assay.RESULTS:Twist protein was highly expressed in gastric cancer samples.Twist gene silencing significantly induced apoptosis,cell cycle arrest at G0/G1 phase,proliferation inhibition,and reduced the ability of migration and invasion in human gastric cancer SGC7901 cells.Meanwhile,both caspase-3 and caspase-9 were activated.CONCLUSION:The Twist gene could serve as a potential molecular target for gene therapy of gastric cancer with targeted small interfering RNA.     

抗Fas单克隆抗体诱导人胃癌细胞系SGC-7901细胞

目的探讨抗Ｆａｓ单克隆抗体诱导胃癌细胞凋亡的规律及在胃癌治疗中的意义．方法应用细胞形态观察、琼脂糖凝胶电泳、流式细胞光度术检测抗Ｆａｓ单克隆抗体对胃癌细胞ＳＧＣ７９０１增殖周期的影响以及对细胞杀伤作用的方式,并检测了ＳＧＣ７９０１细胞表面Ｂｃｌ２的表达情况．．结果抗Ｆａｓ单克隆抗体有阻滞细胞周期、通过诱发凋亡而抑制肿瘤细胞生长的作用．经抗Ｆａｓ单克隆抗体处理后,ＳＧＣ７９０１细胞表面Ｂｃｌ２蛋白表达无明显变化．．结论抗Ｆａｓ单克隆抗体可以诱导胃癌细胞系ＳＧＣ７９０１细胞凋亡．抗Ｆａｓ单克隆抗体诱导胃癌细胞凋亡与Ｂｃｌ２表达无关     

miR495、miR551a靶向干扰SGC7901细胞PRL-3基因的表达

目的:构建靶向PRL-3基因的miRNA495和miRNA551a真核表达载体,观察其转染胃癌SGC7901细胞后对胃癌细胞PRL-3基因表达的影响.方法:设计并合成两条针对PRL-3基因的特异性miRNA495和miRNA551a干扰序列,分别与pcDNA6.2-GW/Em GFP-miR载体连接,转化大肠杆菌,纯化并鉴定后利用LipofectamineTM2000转染胃癌SGC7901细胞,实时定量PCR及Western blot技术鉴定重组体对PRL-3基因表达的干扰效果.结果:针对PRL-3基因的miRNA495和miRNA551a干扰质粒构建成功,胃癌SGC7901细胞分别转染两种质粒后miRNA495及miRNA551a的表达明显升高,并且明显抑制了PRL-3基因mRNA及蛋白的表达.结论:靶向PRL-3基因的miRNA495和miRNA551a真核表达载体构建成功,其可有效提高胃癌SGC7901细胞miRNA495和miRNA551a的表达,并抑制PRL-3mRNA及PRL-3蛋白的表达.     

转染Zbtb7a基因对人胃癌SGC7901细胞增殖、凋亡的影响及其机制

目的 观察转染Zbtb7a基因对人胃癌细胞系SGC7901增殖及凋亡的影响,并探讨其机制.方法 将pcDNA3.1-Zbtb7a和pSilencer 3.1-H1-mk用Lipofectamine2000转染SGC7901细胞,采用RT-PCR和Western Blot法检测MK mRNA及蛋白表达,CCK-8试剂盒和平板克隆法检测细胞增殖,流式细胞仪Annexin V-PI染色检测细胞凋亡.结果 转染Zbtb7a后,SGC7901细胞中MK表达水平明显升高,细胞增殖能力明显增强（P＜0.05）,并且0.5ng/mL TRAIL诱导的细胞凋亡受到抑制（P＜0.05）.Zbtb7a高表达后干扰MK的表达,细胞增殖及克隆能力则明显降低（P＜0.05）,TRAIL诱导的细胞凋亡数也明显增加（P＜0.05）.结论 Zbtb7a可以通过上调MK的表达,促进SGC-7901细胞增殖以及抑制TRAI诱导的细胞凋亡.     

Effect of silencing Bcl-2 expression by small interfering RNA on radiosensitivity of gastric cancer BGC823 cells

ObjectiveTo explore the influence of silencing Bcl-2 expression by small interfering RNA (siRNA) on Bcl-2 protein expression, cell apoptosis rate and radiosensitivity of gastric cancer BGC823 cells.MethodssiRNA segment for Bcl-2 gene was designed and synthesized, then was induced into gastric cancer BGC 823 cells by liposome transfection. Bcl-2 protein expression was detected by Western Blotting. After X radiation, flow cytometry and clone forming assay were used to determine the effects of RNA interference on BGC823 cell apoptosis rate and radiosensitivity.ResultAfter the transfection of Bcl-2 siRNA, the positive expression rate of Bcl-2 protein in BGC823 cells was (35.45±2.35)%. Compared with the control group and negative siRNA transfection group, the rate was significantly decreased (P<0.01). The apoptosis rate of BGC823-RNAi cell was (10.81±0.91)%, which was significantly higher than the control group and negative siRNA transfection group (P<0.01). After 48h X radiation, the apoptosis rate of BGC823-RNAi was (28.91±1.40)%, which was significantly higher than the control group and the group without radiation (P<0.01). During clone forming assay D₀, D_q and SF₂ values in Bcl-2 siRNA1 transfection group were all lower than those in the control group. The radiosensitivity ratio was 1.28 (the ratio of D₀) and 1.60 (the ratio of D_q).ConclusionsSpecific siRNA of Bcl-2 gene can effectively inhibit the expression of Bcl-2 gene, enhance the radiosensitivity and apoptosis of gastric cancer BGC823 cells, having good clinical application perspective.     

Foxo3a对胃癌细胞SGC7901凋亡的促进作用

目的:观察转录因子Foxo3a对胃癌细胞SGC7901凋亡的影响,并初步探讨其促进凋亡的分子机制.方法:构建Foxo3a真核表达质粒,转染培养的胃癌细胞系SGC7901 4-6 h,在FBS完全培养基培养24 h后,换成0.1%无血清的培养基中培养8 h,TUNEL染色观察对胃癌细胞凋亡的影响,Western blo检测切割的caspase-3和PARP水平.结果:成功构建了Foxo3a真核表达质粒.转染胃癌细胞后,与对照组相比,1和2 μg Foxo3a处理组胃癌细胞凋亡率达到了5.8%±2.3%和11.1%±3.4%.是对照组的近2和4倍.caspase-3和PARP活性明显增高.结论:Foxo3a是一种肿瘤抑制因子,可通过促进caspase-3和PARP的活性来诱导癌细胞凋亡,从而抑制肿瘤细胞的生长.     

Study on biological characters of SGC7901 gastric cancer cell-dendritic cell fusion vaccines

AIM: To detect the biological characters of the SGC7901 gastric cancer cell-dendritic cell fusion vaccines. METHODS: The suspending living SGC7901 gastric cancer cells and dendritic cells were induced to be fusioned by polyethylene glycol. Pure fusion cells were obtained by selective culture with the HAT/HT culture systems. The fusion cells were counted at different time points of culture and their growth curves were drawn to reflect their proliferative activities. The fusion cells were also cultured in culture medium to investigate whether they could grow into cell clones. MTT method was used to test the stimulating abilities of the fusion cells on T lymphocytes' proliferations. Moreover, the fusion cells were planted into nude mice to observe whether they could grow into new planted tumors in this kind of immunodeficiency animals. RESULTS: The fusion cells had weaker proliferative activity and clone abilities than their parental cells. When they were cultured, the counts of cells did not increase remarkably, nor could they grow into cell clones in culture medium. The fusion cells could not grow into new planted tumors after planted into nude mice. The stimulating abilities of the fusion cells on T lymphocytes' proliferations were remarkably increased than their parental dendritic cells. CONCLUSION: The SGC7901 gastric cancer cell-dendritic cell fusion vaccines have much weaker proliferative abilities than their parental cells, but they keep strong abilities to irritate the T lymphocytes and have no abilities to grow into new planted tumors in immunodeficiency animals. These are the biological basis for their anti-tumor biotherapies.