胃癌细胞 herg mRNA、HERG 蛋白表达及 HERG 电流强度变化

目的探讨胃癌细胞herg mRNA、HERG蛋白表达及HERG电流强度的变化的临床意义。方法培养胃癌细胞(胃癌细胞系SGC7901、MGC803、AGS、MKN45)及永生化胃上皮细胞(GES),取对数生长期细胞用于实验。采用RT-PCR法检测herg mRNA表达,Western blot法检测HERG蛋白表达,采用全细胞膜片钳技术测定SGC7901及GES的HERG电流强度。结果 herg mRNA及其蛋白在4种胃癌细胞系中均有表达,AGS中HERG蛋白表达量低于其他三种细胞系(P均<0.05);GES中无herg mRNA及其蛋白表达。在SGC7901中检测到HERG电流,GES中未记录到HERG电流。结论 herg mRNA及其蛋白在胃癌细胞系SGC7901、MGC803、AGS、MKN45表达增高,SGC7901中存在HERG电流。HERG蛋白可能参与了胃癌的发生,并与胃癌恶性程度有关。     

凋亡相关蛋白在胃癌细胞凋亡中的作用研究

目的　研究核转录因子 (NF) κB、生存素 (survivin)、Bcl 2和Caspase3在肿瘤坏死因子相关凋亡诱导配体 (TRAIL)诱导的胃癌细胞凋亡中的作用。方法　应用细胞培养和流式细胞仪检测的方法 ,观察胃癌细胞SGC 790 1、MKN2 8、AGS、MKN45经TRAIL作用后的细胞凋亡率 ,Westernblot方法分析 4种胃癌细胞中NF κB、生存素、Bcl 2和Caspase3的表达。结果　TRAIL 50ng/ml作用于胃癌细胞 2 4h后 ,MKN2 8、MKN 45、AGS和SGC 790 1细胞的凋亡率分别为 2 4.0 5% ,7.83 % ,8.0 5%和3 .17%。TRAIL 3 0 0ng/ml作用于胃癌细胞 2 4h后 ,MKN2 8、MKN 45、AGS和SGC 790 1细胞的凋亡率分别为 3 6.0 5% ,2 0 .2 7% ,16.50 %和 11.80 %。Westernblot结果显示 ,SGC 790 1细胞NF κB、生存素的表达高于MKN2 8细胞 (P <0 .0 5) ,与Bcl 2的表达无明显差异。MKN2 8细胞Caspase3的表达高于SGC 790 1细胞 (P <0 .0 5)。结论　TRAIL具有选择性诱导肿瘤细胞凋亡的特性 ,肿瘤细胞对TRAIL的耐药现象可能与凋亡抑制因子生存素和NF κB的表达增强以及Caspase3 的表达抑制有关     

联合抑制环氧合酶-2与5-脂氧合酶对胃癌细胞增殖凋亡的影响

目的:通过单独及联合应用选择性COX-2抑制剂尼美舒利和5-LOX抑制剂AA861处理胃癌细胞系AGS,比较各实验组的增殖凋亡率,探讨联合抑制COX-2和5-LOX两条通路对胃癌细胞系AGS增殖凋亡的影响.方法:AGS细胞在含100 mL/L小牛血清 100kU/L青、链霉素的RPMI1640培养基中培养,取对数生长期细胞做为实验组.以相差显微镜观察药物处理前后的细胞形态改变;设立AA861(25,50,100 μmol/L)组,尼美舒利(50,100,200 μmol/L)组,及AA861联合尼美舒利处理组(50 μmol/L AA861 100 μmol/L尼美舒利),用四氮唑蓝(MTT)法在24,48,72 h测量细胞吸光度,以此检测单用及联用AA861与尼美舒利对细胞生长增殖的影响;实验通过脱氧核糖核酸末端转移酶介导的dUTP缺口末端标记法(TUNEL)和吖啶橙/溴化乙啶(AO/EB)染色法检测细胞凋亡率,以DNA-LADDER法观察凋亡.结果:相差显微镜观察,药物处理组细胞与对照组相比,形态发生明显改变.MTT显示,除尼美舒利200μmol/L的24,48 h处理组及AA861 25 μmol/L的24 h处理组外,尼美舒利和AA861基本呈时间、剂量依赖性抑制AGS细胞增殖.TUNEL染色法表明,尼美舒利或AA861处理组的细胞凋亡率随着剂量的增加而升高.药物处理48 h后,MTT法表明,细胞增殖在AA861组和尼美舒利组与两药联用组间相比差异显著(0.240±0.002 vs 0.207±0.001,P＜0.01;0.211±0.002 vs 0.207±0.001,P＜0.05);TUNEL染色法表明,单药组与两药联用组细胞凋亡率相比差异明显(AA861组:1 8.67%±0.03%,尼美舒利组:20.94%±0.48%vs两药联用组:23.76%±0.92%,P＜0.01);AO/EB染色法也同时表明,细胞凋亡单药组与两药联用组相比差异明显(AA861组:18.17%±0.28%、尼美舒利组:19.35%±0.74% vs两药联用组:23.78%±0.04%,P＜0.01).DNA琼脂糖凝胶电泳法显示,两药联合处理AGS细胞组与单药处理组比较,癌细胞增殖被抑制,凋亡明显增加.结论:COX-2抑制剂尼美舒利和5-LOX抑制剂AA861对胃癌AGS细胞的增殖抑制以及促凋亡作用基本呈时间浓度依赖性.联用尼美舒利和AA861抑制COX-2与5-LOX两条通路,与单独抑制其中一条通路比较,能更有效抑制胃癌细胞增殖,促进凋亡.     

尼美舒利和5-氟尿嘧啶联用对胃癌细胞的协同抑制作用及机制

目的 体外研究选择性环氧合酶-2（COX-2）抑制剂尼美舒利和5-氯尿嘧啶（5-FU）对胃癌细胞的抑制作用及机制。方法 以胃癌细胞株MKN45、MKN28为研究对象．观察尼美舒利和5-FU单独或联合应用对细胞增殖、凋亡和细胞周期的影响。应用MTT法检测细胞增殖，流式细胞仪检测细胞凋亡（FITC-Annexin-V/PI双标记）和细胞剧期，RT-PCR观察朋药前后COX-2 mRNA在两株细胞中的表达，Western免疫印迹法观察经两种药物单独和联合作用48h后细胞内凋亡相关蛋白Bax和Bcl-2的表达。结果 在MKN45和MKN28细胞中均可观察到不同水平的COX-2 mRNA表达，尼美舒利和5FU联合应用可明显抑制COX-2 mRNA表达。尼美舒利可抑制两株细胞的增殖并诱导凋亡。尼美舒利和5-FU具有协同抑制细胞增殖及诱导凋亡的作用，该作用与两种药物作用顺序无关，但在联用时作用最强。两药协同抑制增殖的作用主要通过协同杀伤和诱导凋亡而实现。5-FU增强了凋亡诱导蛋白Bax的表达，而尼美舒利则减少凋亡抑制蛋白Bcl-2的表达。两药联用可明显抑制胃癌细胞株生长。结论 选择性环氧合酶-2抑制剂尼美舒利和5-FU通过抑制COX-2 mRNA的表达硬增强Bax／Bcl-2的表达比率诱导胃癌细胞凋亡．从而对胃癌细胞起到协同抑制增殖的作用。     

核抗原Mina53在人胃癌细胞中的作用及其意义探讨

背景:核抗原Mina53基因为原癌基因Myc的下游直接靶基因之一,在一些消化系统恶性肿瘤中呈高表达,并与肿瘤增殖、侵袭、转移或患者生存期相关。目的:研究Mina53在人胃癌细胞中的作用及其对胃癌发生、发展的意义。方法:选择Mina53表达水平较高的人胃癌细胞株SGC7901和AGS,应用RNA干扰技术下调其Mina53表达,以转染无关序列siRNA的细胞作为对照组。采用CCK-8实验检测细胞增殖,流式细胞术检测细胞周期和细胞凋亡,细胞侵袭和迁移实验检测细胞侵袭、迁移能力。结果:与相应对照组相比,Mina53 siRNA转染组SGC7901、AGS细胞增殖受抑(96 h相对增殖率:60%和68%),并发生明显细胞周期G1期阻滞(SGC7901细胞G1/G2:2.76±0.12对1.86±0.06,P<0.05;AGS细胞G1/G2:1.78±0.13对1.34±0.05,P<0.05),细胞凋亡率分别增加9.8%±1.2%和10.6%±1.5%(P<0.05),穿透Transwell小室基质胶细胞数(SGC7901细胞:11.67±0.88对24.33±1.45,P<0.05;AGS细胞:8.00±1.15对20.33±1.73,P<0.05)和穿透Transwell小室微孔膜细胞数(SGC7901细胞:7.00±1.53对14.67±2.03,P<0.05;AGS细胞:8.00±1.16对15.33±1.45,P<0.05)均显著减少。结论:Mina53对人胃癌细胞的增殖、细胞周期、细胞凋亡以及侵袭、迁移能力具有调控作用,可能影响胃癌的生长、浸润和转移,有望作为胃癌基因治疗的靶点。     

羟基喜树碱诱导胃癌细胞凋亡的作用机制初步研究

目的：研究羟基喜树碱（HCPT）诱导胃癌细胞的凋亡作用及对凋亡相关基因p53,c-myc,bcl-2,bcl-xl和bcl-xs表达的影响,探讨其诱导胃癌细胞凋亡的作用机制。方法：应用TUNEL染色、流式仪、免疫组化和RT－PCR技术等研究HCPT对胃细胞SGC－7901和MKN－45的诱导凋亡作用和对凋亡相关有达的影响。结果：HCPT作用于细胞后,可看到较为典型的细胞凋亡的形态学变化;细胞核固缩,染色质凝集,呈新月型紧核膜周边,核碎裂,染色质片段化,凋亡小体形成等。流式细胞仪DNA直方图上出现典型的亚二倍体的“凋亡峰”。流式细胞仪计数显示,10μg/ml的HCPT诱导胃癌细胞SGC－7901和MKN－45的凋亡率为21．88％和12．34％。TUNEL染色法显示,细胞凋亡指数在1．865－9．54％之间。免疫组化和RT－PCR结果显示：HCPT能够明显下调SGC－7901细胞的P53和bcl-2基因的蛋白和mRNA表达,对SGC－7901细胞的c-myc,bcl-xl和bcl-xs基因的蛋白表达无影响。HCPT作用后MKN－45细胞的p53蛋白和mRNA的表达增加,对MKN－45细胞的bcl-2,c-myc,bcl-xl和bcl-xs基因的表达无影响。结论：HCPT能够诱导胃癌细胞凋亡,可能是通过调控胃癌细胞的P53和bcl-2的表达而诱导胃癌细胞凋亡。     

胃癌细胞对细小病毒H-1敏感性差异的实验研究

目的 探讨不同胃癌细胞株对细小病毒细胞毒作用的敏感性差异及可能的机制。方法共选用HGC27(未分化)、BGC823(未分化)、MKN45(低分化)、AGS(低分化)、SGC7901(中分化)和MKN28(高分化)等6株不同分化状态的胃癌细胞株，用流式细胞仪分析其各自的细胞周期，H-1病毒感染后采用MTT方法检测不同胃癌细胞株对其细胞毒作用的敏感性差异，用RT-PCR来检测H-1病毒中的非结构蛋白基因(NS-1)在6株不同胃癌细胞中的表达。结果 HGC27、BGC823、MKN45、AGS、SGC7901和MKN28等不同分化状态细胞株中，S期细胞的比率分别为24．72％，30．15％，27．10％，29．03％，31．82％和33．73％。其中HGC27细胞对H-1病毒的细胞毒作用敏感；SGC7901细胞其次；MKN45、AGS细胞对H-1病毒的细胞毒作用中等敏感；MKN28细胞对H-1病毒的细胞毒作用不敏感；而BGC823则对H-1病毒的细胞毒作用抵抗。病毒NS-1的mRNA在HGC27、BGC823、MKN45和SGC7901等细胞中的表达水平较高，而在AGS和MKN28中的表达水平却较低。结论 H-1病毒的细胞毒作用在不同的胃癌细胞株中的差异显著。总体上，与高分化细胞株MKN28细胞相比，分化差的细胞对细小病毒H-1的细胞毒作用敏感性增加。其机制至少部分与分化差细胞中病毒NS-1蛋白的产生和积聚能力增高相关。未分化的BGC823细胞对H-1病毒的细胞毒作用抵抗，进一步证实并非所有的肿瘤细胞都对细小病毒的溶胞性作用敏感。     

RNA干扰FLOT2基因表达下调NF-κB信号对胃癌细胞凋亡诱导作用研究

目的 探讨RNA干扰FLOT2基因表达对胃癌细胞凋亡及NF-κB信号的影响。方法 Western blotting检测人胃癌BGC823、SGC7901和MKN28细胞中FLOT2蛋白表达。BGC823细胞分为空白组、阴性组和si-FLOT2组,参照脂质体Lipofectamine~(TM)2000将siRNA转染细胞,细胞转染48 h,Western blotting检测FLOT2、NF-κB p65、IKK-β、p-IKK-β和Bax的蛋白表达。流式细胞术检测细胞凋亡率。结果 BGC823、SGC7901和MKN28胃癌细胞中FLOT2蛋白表达均显著高于人正常胃黏膜上皮细胞GES1(P0.05)。转染si-FLOT2的BGC823细胞FLOT2蛋白表达显著低于空白组(P0.05)。与空白组比较,si-FLOT2组细胞凋亡率显著升高,NF-κB p65、IKK-β和p-IKK-β蛋白表达显著降低,Bax蛋白表达显著升高(P0.05)。结论 RNA干扰FLOT2基因表达可诱导胃癌细胞凋亡,机制可能与下调NF-κB信号通路有关。     

异甘草素通过PI3K/Akt通路诱导人胃癌SGC7901细胞凋亡

目的:初步研究异甘草素(isoliquiritigenin ISL)对人胃癌SGC7901细胞凋亡诱导作用的影响,并探讨信号通路中蛋白质丝氨酸苏氨酸激酶(protein kinase B,Akt)、磷酸化Akt(PAkt)及下游凋亡蛋白Bax表达水平的变化.方法:取对数生长期人胃癌SGC7901细胞分为对照组、ISL实验组,培养24、48、72 h后采用MTT实验检测ISL对细胞生长的抑制情况,摸索后续实验药物浓度和作用时间;应用流式细胞仪检测各组细胞凋亡情况;应用Western blot法检测凋亡调节蛋白Bax、Ak和P-Akt的表达.结果:10mmol/L ISL不能抑制胃癌细胞株SGC7901的生长,而25、50、100mm o l/LISL可明显抑制其生长,且呈时间和浓度依赖性.与对照组凋亡率3.23%±0.45%相比,25mmol/L组(6.13%±0.61%)、50mmol/L组(11.70%±0.75%)、100mmol/L组(26.60%±1.51%)凋亡率逐渐增高(P0.05)随ISL浓度的增加,P-Akt蛋白表达水平逐渐降低,凋亡蛋白Bax表达水平逐渐增加(均P0.05),各组间A k t蛋白水平差异无统计学意义.结论:ISL能够诱导SGC7901细胞凋亡,其机制可能与下调PI3K/AKT信号转导通路蛋白的表达以及上调其下游的凋亡蛋白Bax有关.     

PFKFB3基因增强阿帕替尼对胃癌凋亡的影响及机制

[目的]探讨沉默PFKFB3基因对阿帕替尼处理的胃癌细胞凋亡的影响及机制。[方法]通过Western blotting检测人胃黏膜上皮细胞株GES1及SGC-7901、BGC823和MKN45胃癌细胞PFKFB3蛋白表达。将PFKFB3特异性siRNA(si-PFKFB3)转染SGC-7901细胞,Western blotting检测转染效果。MTT法检测转染siPFKFB3或不同浓度(10、20、30、40μmol/L)阿帕替尼处理SGC-7901细胞48h的细胞活力。流式细胞术检测转染si-PFKFB3或/和40μmol/L阿帕替尼处理SGC-7901细胞48h的细胞凋亡率,Western blotting检测Bcl-2、Bax、PI3K、AKT和p-AKT蛋白表达。[结果]与对照GES1细胞相比,PFKFB3在SGC-7901、BGC823和MKN45胃癌细胞中的表达均明显升高(P0.05)。si-PFKFB3转染SGC-7901细胞后,PFKFB3蛋白表达明显降低(P0.05)。转染si-PFKFB3及不同浓度阿帕替尼均可抑制SGC-7901细胞活力,阿帕替尼对细胞活力抑制呈现浓度依赖性(P0.05)。转染si-PFKFB3及阿帕替尼均可诱导SGC-7901细胞凋亡,下调Bcl-2、PI3K和p-AKT表达,上调Bax表达,二者合用对SGC-7901细胞凋亡诱导更明显(P0.05)。[结论]沉默PFKFB3基因表达可明显增强阿帕替尼对胃癌细胞的凋亡诱导作用,机制可能与下调PI3K/AKT信号通路有关。     

Investigation of the sensitivities of distinct gastric cancer cells to parvovirus H‐1 induced cytotoxicity

OBJECTIVE: To investigate the sensitivities of distinct gastric cancer cells to parvovirus H‐1 induced cytotoxicity and the possible mechanism(s). METHODS: There were six distinct differentiated gastric cancer cell lines: HGC27 (undifferentiated), BGC823 (undifferentiated), MKN45 (poorly differentiated), AGS (poorly differentiated), SGC7901 (moderately differentiated) and MKN28 (well differentiated). The cell cycle distributions were measured by flow cytometry and the differential sensitivities of the six distinct gastric cancer cells after H‐1 virus infection were detected by MTT assay. RT‐PCR was used to detect viral NS1 gene expression in all six gastric cancer cell lines. RESULTS: The S phase ratios of HGC27, BGC823, MKN45, AGS, SGC7901 and MKN28 were 24.72%, 30.15%, 27.10%, 29.03%, 31.82% and 33.73%, respectively. HGC27 cells were sensitive to H‐1 virus induced cytotoxicity, followed by SGC7901 cells. MKN45 and AGS cells were moderately sensitive and MKN28 cells were insensitive. However, BGC823 cells were resistant to H‐1 virus induced cytotoxicity. The expressions of viral NS1 were higher in HGC27, BGC823, MKN45 and SGC7901 cells, and lower in AGS and MKN28 cells. CONCLUSIONS: The sensitivities of the distinct gastric cancer cells to H‐1 virus induced cytotoxicity were markedly different. In general, the poorly differentiated cells showed an enhanced sensitivity to H‐1 virus attack compared with well‐differentiated ones. The enhanced sensitivity of poorly versus well‐differentiated gastric cancer cells to H‐1 virus is related in part to the enhanced capacity of the former for NS1 protein production and accumulation. The undifferentiated BGC823 cells were resistant to H‐1 virus triggered cytotoxicity. It may further verify that not all tumor cells are sensitive to H‐1 virus lytic effects.     

Effect of NF-κB, survivin, Bcl-2 and Caspase3 on apoptosis of gastric cancer cells induced by tumor necrosis factor related apoptosis inducing ligand

AIM: To study the effect of NF-κB, survivin, Bd-2 and Caspase3 on tumor necrosis factors related apoptosis inducing ligand (TRAIL) induced apoptosis of gastric cancer cells. METHODS: Gastric cancer cells of SGC-7901, MKN28, MKN45 and AGS lines were cultured in PRMI-1640 medium and the apoptosis rates of the cells of 4 lines were observed after treatment of tumor necrosis factors related apoptosis indudng ligand (TRAIL) with a flow cytometer. The expression of NF-κB, survivin, Bcl-2 and Caspase3 in gastric cancer cells of 4 lines was analyzed with Western blot. RESULTS: After the gastric cancer cells were exposed to TRAIL 300 ng/ml for 24 hours, the apoptosis rate was 36.05%, 20.27%, 16.50% and 11.80% in MKN28, MKN45,AGS and SC-C-7901cells respectively. Western blot revealed that the expressions of NF-EB and survivin were lower in MKN28 cells than in MKN45, AGS and SGC-7901 cells. In contrast, the expression of Caspase3 was higher in MKN28 cells than in MKN45, AGS and SGC-7901 cells. CONCLUSION: There is a selectivity of TRAIL potency to induce apoptosis in gastric cancer cells of different cell lines.The anticancer potency of TRAIL is associated with the decreased expression of NF-κB and survivin and increased expression of Caspase3 of gastric cancer cells.     

Effect of NF-κB, survivin, Bcl-2 and Caspase3 on apoptosis of gastric cancer cells induced by tumor necrosis factor related apoptosis inducing ligand

AIM: To study the effect of NF-κB, survivin, Bcl-2 and Caspase3 on tumor necrosis factors related apoptosis inducing ligand (TRAIL) induced apoptosis of gastric cancer cells.METHODS: Gastric cancer cells of SGC-7901, MKN28,MKN45 and AGS lines were cultured in PRMI-1640 medium and the apoptosis rates of the cells of 4 lines were observed after treatment of tumor necrosis factors related apoptosis inducing ligand (TRAIL) with a flow cytometer. The expression of NF-κB, survivin, Bcl-2 and Caspase3 in gastric cancer cells of 4 lines was analyzed with Western blot.RESULTS: After the gastric cancer cells were exposed to TRAIL 300 ng/ml for 24 hours, the apoptosis rate was 36.05%, 20.27%, 16.50% and 11.80% in MKN28, MKN45,AGS and SGC-7901cells respectively. Western blot revealed that the expressions of NF-κB and survivin were lower in MKN28 cells than in MKN45, AGS and SGC-7901 cells. In contrast, the expression of Caspase3 was higher in MKN28 cells than in MKN45, AGS and SGC-7901 cells.CONCLUSION: There is a selectivity of TRAIL potency to induce apoptosis in gastric cancer cells of different cell lines.The anticancer potency of TRAIL is associated with the decreased expression of NF-κB and survivin and increased expression of Caspase3 of gastric cancer cells.     

&beta;-elemene enhances the radiosensitivity of gastric cancer cells by inhibiting Pak1 activation

AIM: To explore the potential of β-elemene as a radiosensitizer for gastric cancer cells and the underlying mechanisms. METHODS: SGC7901, MKN45, MKN28, N87, and AGS human gastric cancer cell lines were used to screen for radioresistant gastric cancer cell lines. A 3-(4,5-dimeth-ylthiazol-2-yl)-2,5-diphenyltetrazolium (MTT) assay was used to determine the effects of β-elemene and IPA-3 on cell viability in MKN45 and SGC7901 gastric cancer cell lines. A clonogenic survival assay and annexin V-FITC/PI apoptosis detection assay were used to evaluate cellular radiosensitivity and radiation-induced cell death, respectively. A proteomic method, isobaric tags for relative and absolute quantitation (iTRAQ), was employed to screen the proteins regulated by β-elemene pretreatment prior to ionizing radiation (IR) in SGC7901 gastric cancer cell line. IPA-3 was used as a specific small molecule inhibitor of p21-activated protein kinase 1 (Pak1) to target Pak1 signaling. Protein levels of PAK1IP1 (p21-activated protein kinase-interacting protein 1), total Pak1 (t-Pak1), phospho-Pak1 (T423), phospho-ERK1/2 (Thr202/Tyr204), and cleaved caspase-3 (17 kDa) were assessed by western blotting. RESULTS: MKN45 and SGC7901 gastric cancer cell lines were relatively more resistant to IR. β-elemene pretreatment decreased clonogenic survival following IR in MKN45 and SGC7901 gastric cancer cell lines. Additionally, β-elemene pretreatment prior to IR increased radiation-induced cell death compared with IR alone in MKN45 (10.4% ± 0.9% vs 34.8% ± 2.8%, P < 0.05) and SGC7901 (11.6% ± 0.9% vs 46.7% ± 5.2%, P < 0.05) human gastric cancer cell lines, respectively, consistent with the level of cleaved caspase-3 (17 kDa). Through iTRAQ analysis and western blot validation, we found that β-elemene upregulated PAK1IP1 and downregulated phospho-Pak1 (T423) and phospho-ERK1/2 in SGC7901 gastric cancer cells. IR increased the level of phospho-Pak1 (T423). Pretreatment with β-elemene decreased radiation-induced Pak1 and ERK1/2 phosphorylation. Inhibition of Pak1 using IPA-3 decreased clonogenic survival following IR. In addition, IPA-3 increased radiation-induced cell death in MKN45 (13.4% ± 0.3% vs 26.6% ± 1.0%, P < 0.05) and SGC7901 (16.0% ± 0.6% vs 37.3% ± 1.7%, P < 0.05) gastric cancer cell lines, respectively, consistent with the level of cleaved caspase-3 (17 kDa). Western blotting showed that IPA-3 decreased radiation-induced Pak1 and ERK1/2 phosphorylation. CONCLUSION: This is the first demonstration that β-elemene enhances radiosensitivity of gastric cancer cells, and that the mechanism involves inhibition of Pak1 signaling.     

扶正抗癌冲剂对体外胃癌细胞的抑制作用研究

目的研究中药扶正抗癌冲剂对体外胃癌细胞有无直接抑制或杀伤作用．方法采用体外培养的ＭＫＮ４５，ＭＫＮ２８及ＳＧＣ７９０１三种胃癌细胞株，以扶正抗癌冲剂配制药液（１６１５ｍｇ／ｍｌ含量）的不同稀释度，对３种胃癌细胞体外作用观察，并设丝裂霉素阳性对照组及单纯培养液加生理盐水阴性对照组．结果扶正抗癌冲剂对３种胃癌细胞株均有一定抑制作用，对低分化ＭＫＮ４５胃癌细胞抑制作用最明显，在１∶２稀释度４８ｈ抑制作用最强，抑制率达７４７％，持续到１２０ｈ抑制率仍在７１０％，与正常对照组比较有显著差异（Ｐ＜００５）．在电镜下观察被抑制的ＭＫＮ４５胃癌细胞发生线粒体肿胀、内质网水肿、胞浆脂肪空泡样变性、核仁缩小等变化．结论扶正抗癌冲剂对ＭＫＮ４５低分化胃癌细胞有较强的抑制和杀伤作用，并能使胃癌细胞结构改变．     

核糖体蛋白L5在胃癌中的表达及功能

目的:探讨核糖体蛋白L5(ribosomal protein L5,RPL5) 在胃癌细胞中的表达及对胃癌细胞生长的影响．方法:Western blot检测RPL5在胃癌细胞系中的表达, 构建RPL5特异性siRNA载体,转染细胞,Western blot进行鉴定,MTT方法和流式细胞术检测转染细胞的生长变化．结果:RPL5在胃癌细胞系AGS、MKN45、SGC7901、 MGC803中的表达均明显强于在GES-1和正常胃黏膜上皮中的表达．成功构建RPL5特异siRNA载体U6- RPL5A和U6-RPL5B,转染AGS细胞,进行稳定筛选,发现U6-RPL5A能显著抑制RPL5的表达,其相应的细胞系AGS-U6-RPL5A的生长速度减慢．细胞周期检测结果显示AGS-U6-RPL5A细胞中处于增殖期的细胞减少了约5％．结论:对RPL5功能的进一步深入研究可能会有助于胃癌的诊断和治疗．