Capsaicin-induced cell death in a human gastric adenocarcinoma cell line

AIM: Capsaicin, a pungent ingredient found in red pepper, has long been used in spices, food additives, and drugs. Cell death induced by the binding of capsaicin was examined in a human gastric adenocarcinoma cell line (AGS cells). METHODS: By using XTT-based cytotoxicity assay, flow cytometry using the TUNEL method, and quantitation of DNA fragmentation, both cell death and DNA fragmentation were detected in AGS cells treated with capsaicin. By using Western blotting methods, capsaicin reduced the expression of Bcl-2, the antiapoptotic protein, in AGS cells in a concentration-dependent manner. RESULTS: After incubation of AGS cells with capsaicin for 24 h, cell viability decreased significantly in a dose-dependent manner. After incubation of AGS cells with capsaicin for 24 h, apoptotic bodies also significantly increased, and were again correlated with the dose of capsaicin. When the concentration of capsaicin was 1 mmol/L, the amount of DNA fragments also increased. Similar results were also in the lower traces. CONCLUSION: These results suggest that capsaicin-induced cell death might be via a Bcl-2 sensitive apoptotic pathway. Therefore, capsaicin might induce protection from gastric cancer.     

Nimesulide inhibits proliferation via induction of apoptosis and cell cycle arrest in human gastric adenocarcinoma cell line

AIM: To evaluate the potential role of Nimesulide, a selective COX-2 inhibitor, in proliferation and apoptosis of gastric adenocarcinoma cells SGC7901. METHODS: Cell counts and MTT assay were used to quantify the influence of Nimesulide in the proliferation of SGC7901 cells. Transmission electron microscopy and flow cytometry were used to observe the induction of Nimesulide the apoptosis of SGC7901 cells and influence in the distribution of cell cycle. The expression of P27(kip1) protein was observed by immunocytochemical staining. RESULTS: SGC-7901 Cells treated with Nimesulide at various concentrations exhibited a profound dose- and time-dependent reduction in the proliferation rate over the 72 h test period. The highest survival rate of the cells was 78.7 %, but the lowest being 22.7 %. Nimesulide induced apoptosis of the cells in a dose-dependent and non-linear manner and increased the proportion of cells in the G(0)/G(1) phase and decreased the proportion in the S and G(2)/M phase of the cell cycle. Meanwhile, Nimesulide could up-regulate the expression of P27(kip1) protein. CONCLUSION: The induction of apoptosis and cell cycle arrest are both anti-proliferative responses that likely contribute to the antineoplastic action of nimesulide on SGC-7901 cells. The up-regulation of P27(kip1) gene may contribute to the accumulation of these cells in the G(0)/G(1) phase following treatment with Nimesulide. Selective COX-2 inhibitor may be a new channel of the chemoprevention and chemotherapy for gastric carcinoma.     

人子宫内膜腺癌细胞系的建立

目的构建人子宫内膜腺癌细胞系。方法将1例高分化子宫内膜腺癌手术切除的肿瘤组织制成单细胞悬液,用含10%胎牛血清的DMEM/F-12培养基进行原代培养,倒置显微镜下观察细胞形态,并用免疫荧光染色法检测其角蛋白。结果体外培养细胞传至50代以上,传代后细胞单层贴壁,散在生长,密度增加时见堆积现象,失去接触抑制,细胞质中角蛋白表达阳性。结论成功建立了人子宫内膜腺癌细胞系。     

塞来昔布对胃癌细胞株LRP表达的影响

目的探讨塞来昔布对胃癌细胞株LRP表达的影响。方法采用MTT法检测塞来昔布不同剂量对胃腺癌细胞株SGC-7901生长的影响,在此基础上采用免疫组化及ELISA方法检测塞来昔布在一定剂量范围内某一时间点对SGC-7901细胞COX-2、LRP表达的影响。结果不同浓度的塞来昔布均对胃腺癌细胞株SGC-7901有抑制作用,并且这种影响呈时间和剂量依赖性;胃癌细胞株LRP的表达也随着塞来昔布浓度的增加而减少。结论选择性COX-2抑制剂塞来昔布可以下调胃癌细胞株中耐药基因LRP的表达,逆转多药耐药作用。     

人胃癌顺铂耐药细胞系的建立过程

目的:建立人胃癌顺铂耐药细胞系方法:采用逐步递增顺铂浓度,间歇作用体外诱导法建立人胃癌顺铂耐药细胞系SGC7901/ DDP,每月作相关检测;MTT法测定药物敏感性:光镜、电镜、MTT法计数活细胞、流式细胞仪等方法观察其生物学特征的改变.结果:历时4 mo建成人胃癌顺铂耐药细胞系SGC7901/DD P,1,2,3,4mo的耐药指数分别为2.13,5.32,12.60,12.93,并且与5-氟尿嘧啶、丝裂霉素等多种抗癌药有不同程度的交叉耐药性:SGC7901/DDP的细胞形态逐渐发生改变;体外群体倍增时间较亲代细胞逐渐延长:细胞周期分析发现其S期与G_2/M期细胞逐渐减少,G_0/G_1期细胞逐渐增多.结论:SGC7901/DDP细胞具有耐药表型特征,耐药性能稳定,增殖能力逐渐下降.     

质子泵抑制剂提高人胃腺癌细胞化学治疗敏感性研究

目的 探讨质子泵抑制剂(PPI)泮托拉唑(PPZ)是否通过抑制空泡型质子泵来逆转细胞内外pH梯度,从而增加肿瘤细胞化学治疗敏感性,并探讨PPZ最佳预处理时间、剂量及机制.方法 免疫印迹及免疫荧光法比较PPZ处理前、后人胃低分化腺癌细胞株SGC7901空泡型质子泵的表达及胞内分布变化.用BCECF-AM荧光探针检测不同浓度PPZ作用不同时间对细胞内pH值的影响.用四甲基偶氮唑盐比色法和膜联蛋白V-异硫氰酸荧光素-碘化丙啶试剂盒检测化学治疗药物联合PPZ的细胞毒性和细胞凋亡变化.用阿霉素检测PPZ对细胞内药物蓄积和潴留量的影响.结果 10和100μg/ml PPZ作用24 h后,空泡型质子泵表达的相对吸光度值(1.19±0.03和0.70±0.03)明显低于空白对照组(1.53±0.05),而1μg/ml PPZ可促进其表达(2.29±0.06).在10μg/ml PPZ作用第6和12小时,可见其对空泡型质子泵表达的抑制作用(相对吸光度值分别为0.32±0.02和0.13±0.02),在作用24 h后可改变空泡型质子泵的细胞内分布.10和100 ttg/ml PPZ作用24 h可使细胞内pH值(7.44±0.09和7.31±0.06)明显低于空白对照组(7.51±0.05),10μg/ml及以上浓度的PPZ可逆转细胞内外pH梯度.PPZ预处理24 h后予化学药物治疗的细胞存活率(58.71%±1.18%)低于单用化学治疗药物(74.33%±1.77%,P<0.05),其总凋亡率(80.81%±1.16%)和早期凋亡率(77.52%±1.13%)显著高于单用化学治疗药物(26.42%±1.19%和23.18%±0.92%,P值均<0.01).20、50和100 μg/ml PPZ作用24 h后的阿霉素释放指数(0.164±0.013、0.162±0.015、0.152±0.012)低于空白对照组(0.277±0.011,P值均<0.01).结论 PPZ预处理可提高人胃腺癌细胞的化学治疗敏感性.     

雌激素受体在胃腺癌细胞株和胃癌高侵袭转移细胞系中的表达

目的 测定雌激素受体(ER)在人胃腺癌细胞系SGC-7901以及高转移株OCUM-2MD3上的表达.方法 用免疫细胞化学方法、RT-PCR和免疫印迹方法检测ER在人胃腺癌细胞上的表达,并对其表达量进行相对定量分析.结果 ER在人胃腺癌细胞上有表达;ERα在OCUM-2MD3细胞系的表达强于SGC-7901;而ERβ表达在SGC-7901和OCUM-2MD3中相同,并且ERα/ERβ比值在胃癌高侵袭转移细胞系OCUM-2MD3中升高.结论 雌激素有可能通过它的受体对人胃腺癌细胞产生一定的影响,ERα/ERβ比值的改变在胃腺癌发生和转移过程中可能起一定作用.     

Identification of laminin binding proteins in cell membranes of a human colon adenocarcinoma cell line.

The invasion of malignant cells through the basement membrane is a critical step in local infiltration and metastasis. Adhesion and invasion of malignant cells may be modulated by their receptor mediated binding to the basement membrane glycoprotein laminin. We studied the specific adhesion of human colon adenocarcinoma derived HT 29 cells to laminin and its proteolytic fragments. The major cell adhesion domain of laminin was localised in the central part of the cross shaped molecule. Immunoblotting experiments on separated HT 29 cell membranes using specific antibodies or radiolabelled laminin fragments revealed two major laminin-binding cell surface components with Mr of 67,000 and 69,000 D similar to the putative laminin receptor described for other tissues. Using a nitrocellulose filter disk assay, the specific interaction between cell surface binding proteins and proteolytic fragments originating from the central core of the laminin molecule could be further corroborated. In contrast, interaction of HT 29 cell membranes with the pentapeptide YIGSR (tyr-ile-gly-ser-arg), a sequence domain of the B1-chain of the laminin molecule, thought to be responsible for cell adhesion, was significantly weaker.     

Establishment of a new human pancreatic adenocarcinoma cell line, MDAPanc-3.

A new cell line was established from a liver metastasis of a human pancreatic adenocarcinoma. The cell line, MDAPanc-3, which arose from a moderately differentiated adenocarcinoma, produces carbonic anhydrase II mRNA, but no detectable levels of insulin or alpha amylase mRNA. The stem line chromosome number was determined to be 43, with six marker chromosomes. Growth of MDAPanc-3 is stimulated by cholecystokinin (CCK) fragment 26-33. The cell line will be useful in further studies on the mechanism(s) by which CCK stimulates growth of certain human pancreatic adenocarcinomas and normal human pancreatic exocrine tissue.     

Protection of gastric epithelial cell monolayers from a human cell line by omeprazole in vitro

Omeprazole has an anti-ulcerogenic effect and protects rat gastric mucosa against drug-induced damage in vivo. We have evaluated omeprazole protection against damage induced by sodium taurocholate to gastric epithelial cell monolayers, an experimental model that completely excludes the influence of systemic factors. Furthermore, since our model consists of mucus-producing cells, the acid inhibitory effect of the drug in any protection is negligible. The role of prostaglandin and sulfhydryls in any such protection has also been evaluated. Monolayers of gastric cells from a well-differentiated human cell line were studied. A chromium-51 release assay was used to assess cell damage. Sodium taurocholate damaged cells dose-dependently (r = 0.97, p less than 0.01). Pretreatment with omeprazole significantly reduced the amount of cell damage brought about by sodium taurocholate (p less than 0.001). Indomethacin did not prevent the protection afforded by omeprazole, nor did incubation with omeprazole increase the amount of prostaglandin E2 produced by cultured cells. Omeprazole did not increase the amount of sulfhydryl compounds in cultured cells. These results indicate that omeprazole protects gastric cells independently of systemic factors and of inhibition of gastric acid secretion. This protection is not related to stimulation of prostaglandin synthesis nor is it associated with an increase of endogenous sulfhydryl compounds.     

幽门螺杆菌致胃上皮细胞株GES-1和胃癌细胞株SGC-7901的氧化性损伤

目的: 探讨H pylori对人正常胃黏膜上皮细胞永生细胞株GES-1和人淋巴结转移胃腺癌细胞株SGC-7901的氧化性DNA损伤作用.方法: 采用细菌-细胞共培养的方法, 比较H pylori作用前后GES-1和SGC-7901细胞株的形态学变化;采用激光扫描共聚焦显微镜方法, 比较H pylori作用前后GES-1和SGC-7901细胞株8-羟基脱氧鸟苷(8-OhdG)的表达.结果: H pylori对GES-1和SGC-7901细胞株均具有损伤作用;8-OHdG表达升高, 加菌组与对照组相比差别具有统计学意义(64.9396±17.8142 vs 32.3010±7.3620;102.8344±30.2632 vs 77.1336±32.3223, 均P = 0.000);而且8-OHdG表达的变化程度GES-1细胞显著高于SGC-7901细胞.结论: H pylori能够诱导GES-1和SGC-7901细胞DNA氧化性损伤显著增加;在H pylori氧化损伤的相关研究中, 更适宜选择对损伤作用敏感的GES-1细胞株作为研究对象.     

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.     

人肺腺癌A549细胞系培美曲塞耐药细胞株模型的建立

目的建立人肺腺癌A549细胞培美曲塞耐药细胞株模型。方法以人肺腺癌A549细胞为亲本株,应用高浓度反复间歇法模拟临床给药模式建立人肺腺癌A549细胞培美曲塞耐药细胞株。MTT法绘制生长曲线、计算倍增时间,同时检测耐药株细胞对顺铂、依托泊苷、紫杉醇、长春新碱的药物敏感性。结果亲本株IC_50为(181.75±12.56)ng/ml,耐药株IC_50为(4930.40±129.71)ng/ml,最终获得耐药指数为27.18±1.16的人肺腺癌A549细胞培美曲塞耐药细胞株,命名为A549/PEM。A549和A549/PEM增殖速度接近,倍增时间分别为(62.78±1.06)h和(62.35±0.89)h(P=0.773)。A549/PEM同时对顺铂、依托泊苷耐药,耐药指数分别为(1.93±0.02)、(8.26±1.55);对紫杉醇、长春新碱敏感,耐药指数分别为(0.89±0.10)、(0.95±0.11)。结论本研究成功建立的人肺腺癌A549细胞培美曲塞耐药细胞株模型。     

Effects of mifepristone on invasive and metastatic potential of human gastric adenocarcinoma cell line MKN-45 in vitro and in vivo

AIM： To investigate the effects of mifepristone on the invasive and metastatic potential of human gastric adenocarcinoma cell line MKN-45 and its mechanisms. METHODS: After incubation with various concentrations of mifepristone (5, 10, 20 umol/L), the adhesion to artificial basement membrane, Matrigel, and the migration of MKN-45 cells were assayed using MTT assay and Transwell cell culture chambers, respectively. Enzyme- linked immunoabsorbent assay (ELISA) and flow cytometry were used to determine the expression of vascular endothelial growth factor (VEGF) and integrin 133 in the cells. After subcutaneous transplantation of MKN-45 cells in nude mice, mifepristone (50 mg/kg.d) was administrated subcutaneously for 8 wk to assess its effects on tumor metastasis. Immunohistochemical analysis was used to detect the expression of VEGF and microvascular density (MVD) in xenografted tumors. RESULTS: Mifepristone dose-dependently inhibited the heterotypic adhesion to Matrigel of MKN-45 cells. The inhibition was accompanied by a significant down-regulation of integrin 133 expression in the cells. After incubation with 5, 10, 20 umol/L mifepristone, the number of migrated MKN-45 cells was 72+8, 50+6, 41+5 in experiment group, and 94+16 in control group (P&lt;0.01). Meanwhile, secreted VEGF protein of MKN-45 cells in mifepristone-treated group (14.2+2.9, 8.9+3.1, 5.4+2.1 ng/g per liter) was significantly lower than that in control group (22.7+4.3 ng/g per liter, P&lt;0.01). In vivo, mifepristone decreased the number of metastatic foci in lungs of nude mice and down-regulated the expression of VEGF and MVD in the xenograted tumors. CONCLUSION: Mifepristone can effectively inhibit the invasive and metastatic potential of human gastric adenocarcinoma cell line MKN-45 in vitro and in vivo through inhibition of heterotypic adhesion to basement membrane, cell migration and angiogenesis.     

胃癌MKN-28肿瘤细胞系SP细胞亚群初步分析

目的:分析胃癌细胞株MKN-28中是否包含肿瘤干细胞相关的SP(side population)细胞亚群.方法:采用免疫荧光方法检测干细胞标记ABcG2在胃癌细胞株MKN-28的表达;制备MKN-28细胞悬液,经Hoechst33342染色,流式细胞仪分析SP亚群.结果:ABCG2在胃癌细胞系MKN-28中有少量表达,ABCG2阳性细胞约占1.7%.SP亚群占MKN-28细胞的0.25%,维拉帕米阻断后减少为0.05%.结论:人胃癌细胞株MKN-28中存在SP细胞亚群,提示胃癌干细胞的存在.     

桩蛋白表达下调对结直肠癌细胞SW480侵袭力的影响

目的:探讨下调桩蛋白(paxillin)的表达对结直肠癌细胞SW480体外侵袭的影响.方法:筛选常见结直肠癌细胞株中paxillin 的表达,发现SW480中表达最多.构建干扰paxillin表达的特异性短发夹RNA(shRNA),转染结直肠癌细胞SW480.将SW480细胞分为3组:正常SW480组、阴性对照组及pa...