FoxM1通过促进肿瘤干细胞化参与骨肉瘤细胞对顺铂的耐药

目的探讨FoxM1是否通过促进肿瘤干细胞化参与骨肉瘤细胞对顺铂的耐药。方法利用骨肉瘤亲本细胞MG-63,采用递增药物浓度筛选建立顺铂耐药细胞MG-63R;运用慢病毒转染FoxM1建立稳定过表达MG-63F细胞及空载体对照MG-63V细胞。MTT法检测细胞对顺铂药物的敏感性。Western blot法检测FoxM1及肿瘤干细胞相关标志物Sox-2、Oct-4、Nanog蛋白水平表达。无血清培养悬浮克隆球实验检测微球形成能力。检测FoxM1抑制剂Thiostrepton处理后对肿瘤干细胞相关标志物表达水平、微球形成能力和对顺铂药物敏感性的影响。结果在2μg/mL顺铂浓度下稳定生长和传代的耐药细胞MG-63R的半数有效抑制浓度IC_(50)由亲本细胞中1.27上升为7.36,FoxM1蛋白水平在MG-63R中表达较MG-63明显增高;MG-63R中肿瘤干细胞相关标志物Sox-2、Oct-4、Nanog蛋白水平表达明显升高,同时平均悬浮克隆球数量明显增多。成功构建FoxM1过表达细胞MG-63F,其FoxM1蛋白表达水平较空载体对照MG-63V明显增高,肿瘤干细胞相关标志物也明显升高,平均悬浮克隆球数量由14增加至25,差异有统计学意义。MG-63F细胞对顺铂耐药性明显升高,IC_(50)由对照组0.96升高为31.23;MG-63F细胞经4μmol/L Thiostrepton处理后,FoxM1蛋白表达明显降低,对顺铂的敏感性明显增加,同时肿瘤干细胞相关标志物表达明显降低,平均悬浮克隆球数目也明显减少。结论 FoxM1过表达可能通过促进肿瘤干细胞化参与骨肉瘤细胞对顺铂的耐药,FoxM1抑制剂可能通过逆转肿瘤干细胞化而增强骨肉瘤耐药细胞对顺铂的敏感性。     

信号通路对胃癌干细胞及胃癌发生的影响

背景：Hedgehog与Wnt/β-catenin信号通路对胃癌干细胞的影响及在胃癌发生发展中的作用机制少见报道。 目的：探讨Hedgehog与Wnt/β-catenin信号通路在胃癌发生发展中的作用机制。 方法：采用肿瘤球悬浮分选法从胃癌组织标本中分选胃癌干细胞。采用免疫组化SP法检测Hedgehog 及Wnt/β-catenin信号通路主要分子SHH、GLI1、Wnt2 及β-catenin在胃癌干细胞中的表达。Spearman相关分析各细胞因子间的相关性分析。 结果与结论：SHH、GLI1、Wnt2及β-catenin 在胃癌干细胞中的阳性表达率分别为74.7%,78.3%,85.5%和83.3%,均显著高于癌旁组织的阳性表达率(P < 0.05)。各细胞因子间在胃癌干细胞中的表达均呈正相关(P < 0.05)。说明在胃癌干细胞中Hedgehog及Wnt/β-catenin信号通路均被激活,二者互相作用可能参与了胃癌的发生发展,为胃癌的干细胞治疗提供了新的研究方向。     

高质量浓度肿瘤坏死因子α对骨髓间充质干细胞的损伤作用

BACKGROUND:Stem cell transplantation has achieved good results in the treatment of cerebral ischemia, and how to reduce apoptosis of transplanted cells has become the focus of the therapy. OBJECTIVE:To investigate the injured effect of tumor necrosis factor alpha (TNF-α) on bone marrow mesenchymal stem cells and its mechanism. METHODS:Primary cultured bone marrow mesenchymal stem cells from Sprague-Dawley rats were treated with 200 μg/L TNF-α for 6 hours. Cell vitality was assayed by MTT, and cell apoptosis was observed by Hoechst33342 staining. Apoptotic rate was detected by Annexin-V/PI double staining. Level of oxidative stress was evaluated by determination of malondialdehyde and superoxide dismutase levels. The protein expressions of phosphorylated-Akt, Akt, phosphorylated-FoxO1, FoxO1 were detected by western blot analysis. RESULTS AND CONCLUSION:After treatment with TNF-α, the cell vitality of bone marrow mesenchymal stem cells decreased, the apoptotic rate increased, and the cells were arrested in the S phase. Moreover, the oxidative stress level was elevated, and the protein expression of phosphorylated-Akt and phosphorylated-FoxO1 was significantly reduced compared with the control group (P < 0.05). These results suggest that TNF-α at high level contributes to the S-stage arrest, responsible for the apoptosis processes of bone marrow mesenchymal stem cells via the Akt-FoxO1 pathway.     

胃癌干细胞表面标记物的研究与最新进展

背景:最近人们研究发现,肿瘤的复发与肿瘤干细胞密切相关。肿瘤干细胞理论为研究胃癌的发病机制以及诊治开辟了新的途径,确定的表型有利于锁定胃癌干细胞,这有助于探讨胃癌干细胞在自我更新和分化过程中的作用,并为治疗胃癌提供新思路,但其表型仍存在争议。目的:综述胃癌干细胞表面标志物的研究进展。方法:由第一作者分别以"Gastric Cancer Stem Cells"为英文关键词检索PubM ed英文数据库(http://www.ncbi.nlm.nih.gov/pubmed)中1965年1月至2015年10月的文献,共保留68篇文献进行综述。结果与结论:通过分析整理,传统上的肿瘤干细胞表型不适合于标记胃癌干细胞。研究发现CD90在胃癌原发性肿瘤中有表达,分离后经无血清肿瘤球培养法培养可获得肿瘤球。CD24的表达有助于提高胃癌细胞的黏附、侵袭、迁移能力。此外研究证实CD44及CD54共表达的细胞会大量出现在胃癌复发早期患者的体内而不是晚期,表达CD44及CD54的肿瘤细胞很可能是导致胃癌发生以及复发的重要原因。综上所述,CD44^+CD24^+CD90^+CD54^+很可能是胃癌干细胞的表型。     

人原代胃癌细胞中肿瘤干细胞的分化培养

BACKGROUND:There is a close relationship between tumor stem cells and tumor occurrence and recurrence, but there are still some disputes in the presence of tumor stem cells in all tumors. OBJECTIVE:To investigate the differentiation and culture of tumor stem cells in human primary gastric cancer cells. METHODS:Primary gastric cancer cells isolated from fresh gastric cancer tissues were stained with hematoxylin-eosin and identified by immunohistochemical detection of carcinoembryonic antigen. The CD44 expression of the cells was detected using immunofluorescence method. Magnetic activated cell sorting was used to isolate CD44⁺ gastric cancer cells that were then seeded subcutaneously behind the armpit of mice. Growth of implanted tumor cells was observed. RESULTS AND CONCLUSION:Human primary gastric cancer cells were isolated in serum-free medium. Compared with the routine culture group, the number of CD44⁺ cells (P < 0.05) and the tumor volume were significantly increased in the spheroid culture group. Furthermore, at 90 days after transplantation, the tumor volume of mice in spheroid culture group was significantly higher than that in the routine culture group. These experimental findings indicate that gastric cancer cells with certain tumorigenicity can be successfully isolated from gastric cancer cells using serum-free culture method and magnetic activated cell sorting method.     

骨髓间充质干细胞联合还原型谷胱甘肽对肺损伤小鼠的保护

背景：大量实验证明骨髓间充质干细胞治疗肺部疾病或改善肺损伤方面具有良好的效果,其治疗作用主要以减少炎性反应为主。 目的：观察骨髓间充质干细胞移植联合还原型谷胱甘肽对博来霉素诱导的小鼠肺损伤的保护效果。 方法：取1只雄性NOD/SCID小鼠制备骨髓间充质干细胞,并观察其形态、表型。将64只雌性NOD/SCID小鼠按随机数字表法分为对照组、模型组、骨髓间充质干细胞组和骨髓间充质干细胞+还原型谷胱甘肽组,每组16只。对照组气管内注入生理盐水,模型组气管内注入博来霉素,骨髓间充质干细胞组气管内注入博来霉素2 h后尾静脉内注入培养的骨髓间充质干细胞,骨髓间充质干细胞+还原型谷胱甘肽组气管内注入博来霉素2 h后尾静脉注入培养的骨髓间充质干细胞与还原型谷胱甘肽,7 d后处死动物,按照试剂盒说明测定肺组织匀浆肿瘤坏死因子α、白细胞介素1β、丙二醛水平,同时留取肺组织进行病理检查,确认骨髓间充质干细胞联合还原型谷胱甘肽对肺损伤的保护效果。 结果与结论：雄性小鼠骨髓间充质干细胞呈上皮细胞样,其CD34、CD45阴性表达,CD10、CD13、CD44阳性表达。雌性小鼠中,与对照组相比,模型组肿瘤坏死因子α、白细胞介素1β及丙二醛水平上升,骨髓间充质干细胞组和骨髓间充质干细胞+还原型谷胱甘肽组肿瘤坏死因子α、白细胞介素1β及丙二醛水平下降(P < 0.05),骨髓间充质干细胞+还原型谷胱甘肽组较骨髓间充质干细胞组下降更明显(P < 0.05)。病理切片显示,骨髓间充质干细胞+还原型谷胱甘肽组肺损伤较模型组及骨髓间充质干细胞组轻。以上结果表明骨髓间充质干细胞联合还原型谷胱甘肽能更有效保护博来霉素诱导的肺损伤。 中国组织工程研究杂志出版内容重点：干细胞;骨髓干细胞;造血干细胞;脂肪干细胞;肿瘤干细胞;胚胎干细胞;脐带脐血干细胞;干细胞诱导;干细胞分化;组织工程     

miR-126调节骨髓间充质干细胞对游离皮瓣组织学活性的作用

BACKGROUND:MicroRNA has tissue and cell specificity, and high expression of endothelial cell-specific microRNA-126 (miR-126) plays an important role in angiogenesis. OBJECTIVE:To explore the effect of miR-126 on transplanted free flap survival and histological activity as well as its mechanism in angiogenesis. METHODS:Transient transfection technology was used to enhance the expression of miR-126 in bone marrow mesenchymal stem cells. Expression levels of macrophage inflammatory protein-1α, tumor necrosis factor-α and vascular cell adhesion molecule-1 mRNA were detected by real-time PCR, and expression levels of ERK1/2, AKT, pERK1/2, pAKT protein were measured by western blot assay. Forty-eight Sprague-Dawley rats were randomly divided into three groups (n=16 per group), followed by preparation of abdominal free flap models. Rats in the three groups were given injection of miR-126 mimics-transfected cells, miR-126 mimics control-transfected cells and PBS 1 cm and 3 cm distal to the free flap, respectively. RESULTS AND CONCLUSION: Expression levels of macrophage inflammatory protein-1α, tumor necrosis factor-α and vascular cell adhesion molecule-1 mRNA in the cells transfected with miR-126 mimics were decreased by 36, 3.5 and 14 times compared with those in the PBS group, respectively. Expressions levels of ERK1/2, AKT, pERK1/2, pAKT protein in the distal free flap increased significantly in the miR-126 mimics group than the other two groups, as did the ratios of pAKT/AKT and pERK1/2/ERK1/2. In addition, the expression levels of macrophage inflammatory protein-1α, tumor necrosis factor-α and vascular cell adhesion molecule-1 protein in the flap tissue fluid were significantly lower in the miR-126 mimics transfection group than the other two group. All these findings suggest that miR-126 can promote free flap survival by creating favorable conditions for angiogenesis in the free flap tissue.     

多聚赖氨酸修饰γ-Fe2O3纳米颗粒标记不影响神经母细胞瘤干细胞的活化和增殖

BACKGROUND: Retinoic acid is the most promising inducer for neuroblastoma minimal residual lesion, and it can induce cell differentiation in vivo, accompanied by reducing tumor cell proliferation. OBJECTIVE: To study the effect of nanoparticle labeling on biological characteristics of neuroblastoma stem cells, and the role of 13-cis retinoic acid to induce differentiation of neuroblastoma stem cells. METHODS: Neuroblastoma stem cells were isolated and cultured in vitro using serum-free suspension culture method, labeled with polylysine-modified γ-Fe2O3 nanoparticles and induced in culture medium containing 13-cis retinoic acid. RT-PCR was used to detect the expression of Oct-4 before and after labeling as well as before and after induction. Immunofluorescence method was used to detect the expression of nestin before and after labeling as well as before and after induction. RESULTS AND CONCLUSION: Neuroblastoma stem cells were successfully cultured in the bone marrow samples from 5 of 20 cases. Polylysine-modified γ-Fe2O3 nanoparticle labeling did no influence the viability and proliferation ability of neuroblastoma stem cells, and also had no effect on Oct-4 mRNA and nestin expression. After cultured in the culture medium containing 13-cis retinoic acid, the cell shape changed and the growth rate slowed down. Moreover, the expression of Oct-4 mRNA and nestin was gradually reduced. These findings indicate that polylysine-modified gamma-Fe2O3 nanoparticles can be used to label neuroblastoma stem cells, and 13-cis retinoic acid can induce the differentiation of neuroblastoma stem cells.      

肿瘤干细胞表面标记物CD44在胃癌组织中的表达及意义

BACKGROUND:Studies have shown that CD44 expression is closely associated with malignant transformation of gastric cancer. OBJECTIVE:To study the expression of CD44 in gastric cancer tissues and its clinical significance. METHODS:Gastric cancer specimens from 94 cases of gastric cancer after surgery and normal gastric tissue specimens from 30 cases undergoing gastroscope examination were collected and detected using S-P method. The positive expression rate of CD44 protein in these two groups was compared, and the relationship between CD44 and prognosis was analyzed. RESULTS AND CONCLUSION:The positive expression rate of CD44 protein in the gastric cancer group (73%) was significantly higher than that in the normal group (3%) (P < 0.05). The positive expression rate of CD44 protein in gastric cancer patients was remarkably associated with TNM stage, differentiation degree, invasion depth and lymph node metastasis (P < 0.05). The 3-year survival rate of gastric cancer patients positive for CD44 protein was significantly lower than that of negative patients (P < 0.05). The higher TNM staging indicated the lower differentiation degree, and lymph node metastasis and CD44 positive expression were independent risk factors (P < 0.05). To conclude, the expression of CD44 protein is related to the clinical pathological features and prognosis of gastric cancer patients to some extents.     

肿瘤坏死因子α刺激骨髓间充质干细胞表达及分泌肝细胞生长因子

背景：有研究表明,肿瘤坏死因子α可以刺激骨髓间充质干细胞发挥免疫抑制功能,并促进骨髓间充质干细胞表达肝细胞生长因子。 目的：观察肿瘤坏死因子α刺激大鼠骨髓间充质干细胞是否可以促进肝细胞生长因子的表达及分泌。 方法：全骨髓贴壁法分离、纯化SD大鼠骨髓间充质干细胞,传代至第三四代使用。以100 µg/L肿瘤坏死因子α预刺激骨髓间充质干细胞 5 h后弃去培养基,换上新鲜培养基作为实验组,以正常培养的骨髓间充质干细胞为空白组。采用倒置相差显微镜观察细胞形态;流式细胞仪鉴定骨髓间充质干细胞表面标记物CD29、CD34、CD44、CD45的表达;RT-PCR 、Western blot检测细胞肝细胞生长因子mRNA及蛋白表达;ELISA测定细胞上清液中肝细胞生长因子水平。 结果与结论：获得的骨髓间充质干细胞形态均一,呈典型的旋涡样生长。骨髓间充质干细胞表达CD29⁺99.45%,CD34^-97.91%、CD44⁺99.52%、CD45^-98.42%;骨髓间充质干细胞中肝细胞生长因子 mRNA及蛋白与上清液中肝细胞生长因子表达量呈时间依赖性增加,实验组肝细胞生长因子 mRNA及蛋白与上清液中肝细胞生长因子的表达量明显高于空白组(P < 0.01)。说明肿瘤坏死因子α刺激骨髓间充质干细胞可以有效促进肝细胞生长因子的表达及分泌。     

槲皮苷通过抑制PI3K/AKT信号通路诱导胃癌SGC7901细胞凋亡

目的:探讨槲皮苷是否通过抑制PI3K/AKT信号通路诱导人胃癌SGC7901细胞凋亡。方法:选取SGC7901细胞作为研究对象,采用MTT法检测槲皮苷对SGC7901细胞的毒性作用并测定IC50值。实验分为对照组(不加药处理)、槲皮苷组(采用200μmol/L槲皮苷处理)、PI3K/AKT通路激动剂胰岛素样生长因子1(IGF-1)组(采用100μg/L IGF-1处理)和槲皮苷+IGF-1组(采用200μmol/L槲皮苷+100μg/L IGF-1共处理)。处理48 h后,采用流式细胞术检测细胞凋亡,Western blot法检测cleaved caspase-3、p-AKT(Ser473)、AKT、p-PI3K(Tyr508)和PI3K的蛋白水平。结果:从100μmol/L开始,随着槲皮苷处理浓度的逐渐升高,SGC7901细胞活力显著降低(P 0. 05),槲皮苷作用48 h的IC50值为275. 40μmol/L。200μmol/L槲皮苷作用SGC7901细胞48 h后,与对照组比较,细胞凋亡率和cleaved caspase-3蛋白水平显著上升(P 0. 05),p-AKT和p-PI3K蛋白水平显著降低(P 0. 05),然而IGF-1与槲皮苷共同作用时,IGF-1可逆转槲皮苷对SGC7901细胞的作用效果。结论:槲皮苷能够诱导胃癌SGC7901细胞凋亡,其作用机制可能与抑制PI3K/AKT信号通路的激活有关。     

Nucleostemin基因在姜黄素抑制胃癌SGC-7901细胞增殖中的意义

目的探讨NS基因在姜黄素抑制胃癌SGC-7901细胞株增殖和诱导凋亡中的作用。方法不同浓度姜黄素作用于胃癌SGC-7901细胞株,利用MTT法检测细胞增殖抑制率,RT-PCR法检测姜黄素作用前后NS基因表达量的变化,流式细胞仪法检测细胞周期和细胞凋亡情况。结果姜黄素能显著抑制体外培养的胃癌SGC-7901细胞株增殖,并呈量效和时效关系;流式细胞术显示G0/G1期细胞增加,S期细胞减少,检出亚二倍体凋亡峰;RT-PCR显示NS基因表达量下降。结论姜黄素显著抑制胃癌SGC-7901细胞株增殖,并促进凋亡,其发生可能与NS基因表达下降有关。     

姜黄素抑制ox-LDL诱导HUVECs凋亡

目的研究姜黄素对氧化低密度脂蛋白(ox-LDL)诱导的人脐静脉内皮细胞(HUVECs)凋亡的保护作用及其可能机制。方法体外培养HUVECs,实验分为:对照组、ox-LDL组、ox-LDL加内质网应激(ERS)抑制剂PBA组、姜黄素组、ox-LDL加姜黄素组和ox-LDL加姜黄素加PI3K抑制剂LY294002组。CCK-8法检测细胞存活率;流式细胞仪检测细胞凋亡;激光共聚焦显微镜观察活化转录因子6(ATF6)转位;Western bolt检测ERS相关蛋白:糖调节蛋白78(GRP78)、蛋白激酶样内质网激酶(PERK)和肌醇激酶-1(IRE-1)以及相关通路蛋白:LOX-1、AKT和p-AKT的表达。结果与对照组相比,ox-LDL可增加细胞凋亡,提高ERS相关蛋白的表达(P0.01),促使ATF6向核内转位,以及提高LOX-1(P0.01)和降低p-AKT的表达(P0.01);与ox-LDL组相比,PBA可抑制ox-LDL诱导的细胞凋亡(P0.01),姜黄素可抑制ox-LDL诱导的ERS相关蛋白和LOX-1的表达(P0.01),ATF6的核转位,内皮细胞的凋亡(P0.01),同时它还可提高ox-LDL引起的p-AKT表达下调(P0.01);LY294002可部分削弱姜黄素抑制ox-LDL诱导ERS相关蛋白表达的作用(P0.05)。结论姜黄素可降低ox-LDL诱导HUVECs的凋亡,其可能机制是通过抑制LOX-1的表达和激活AKT通路减轻细胞ERS来实现的。     

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目的:氧化苦参碱联合5-FU 对人胃癌SGC-7901 细胞生长的协同抑制作用及相关机制研究。方法:通过不同浓度的氧化苦参碱单独及联合应用5-FU 作用于SGC-7901 细胞24、48、72 h,采用MTT 法检测细胞活力,HOECHST 染色法检测细胞凋亡,免疫细胞法检测胃癌SGC-7901 细胞内血管内皮生长因子(VEGF)蛋白的表达,以逆转录聚合酶链式反应RT-PCR 法观察SGC-7901 细胞VEGF mRNA 的转录情况。结果:与空白组比,氧化苦参碱中剂量、高剂量组及其联合5-FU 组均能显著抑制人胃癌SGC-7901 细胞生长,并诱导其凋亡(P<0.01);与单独使用5-FU 组相比,联合用药组细胞增殖抑制率和凋亡率均显著增高(P<0.05);氧化苦参碱及联合5-FU 组中人胃癌SGC-7901 细胞的VEGF mRNA 转录及其蛋白表达显著降低(P<0.01)。结论:氧化苦参碱对5-FU 的胃癌SGC-7901 细胞的增殖抑制和诱导凋亡具有协同作用;促进氧化苦参碱对VEGF 的基因和蛋白表达抑制作用可能是其机制之一。     

白细胞介素8对宫颈癌细胞增殖和侵袭转移的影响及其机制*

目的：探讨白细胞介素8（ IL-8） 对宫颈癌细胞Caski 增殖、侵袭转移的影响及其机制。方法：将 体外培养的宫颈癌Caski细胞分为对照组、IL-8 组（20、40、60、80、100 ng/mL）、IL-8+LY294002 组 （80 ng/mL IL-8+20 μmol/L LY294002）以及LY294002 组（20 μmol/L）,采用MTT 实验检测Caski 细胞的增殖能力, 采用划痕实验检测Caski 细胞的侵袭能力,采用Transwell 实验检测Caski 细胞的迁移能力。免疫印迹法检测蛋白 激酶B（ PKB）、磷酸化蛋白激酶B（ p-AKT）、波形蛋白、β-连环蛋白、上皮-钙黏蛋白（ E-cadherin）的表达情 况。结果： IL-8 呈剂量依赖性促进细胞增殖,80 ng/mL 与100 ng/mL 组之间差异无统计学意义。IL-8 组划痕愈合 能力和细胞迁移能力均增强,IL-8+LY294002 组及LY294002 组划痕愈合能力和细胞迁移能力均低于IL-8 组。各 组AKT总蛋白表达量差异无统计学意义,IL-8 组中p-AKT、波形蛋白和β- 连环蛋白表达均增加,E-cadherin 减少, AKT通路特异性抑制剂LY294002 可阻断上述作用。结论：IL-8 可能通过PI3K/AKT 通路影响波形蛋白、β- 连环 蛋白和E-cadherin 蛋白的表达,促进宫颈癌细胞的增殖、侵袭和转移。     

小分子化合物P-275抑制胃癌细胞增殖及机制研究

目的研究小分子化合物P-275对人胃癌细胞BGC823、SGC7901、MKN-45增殖的抑制作用及其机制。方法分别用不同浓度的化合物P-275处理人胃癌细胞BGC823、SGC7901和MKN-45,MTT法检测化合物对细胞增殖的影响,流式细胞术检测化合物对细胞周期的影响,Western Blot检测化合物对周期调控蛋白Cyclin D1、CDK4表达的影响。结果化合物P-275能够以剂量依赖的方式抑制人胃癌细胞BGC823、SGC7901及MKN-45的增殖,同时能够抑制上述细胞G1期向S期的转化。Western Blot结果显示P-275能够以剂量依赖的方式下调胃癌细胞SGC7901中周期调控蛋白Cyclin D1、CDK4的表达。结论化合物P-275能够通过下调胃癌细胞中周期调控蛋白Cyclin D1、CDK4的表达,从而抑制胃癌细胞G1期向S期的转化,进而抑制胃癌细胞的增殖。     

SN50 enhances the effects of LY294002 on cell death induction in gastric cancer cell line SGC7901

Introduction

In the previous study, we found that the inhibition of phosphatidylinositol 3-kinase (PI3K) by {"type":"entrez-nucleotide","attrs":{"text":"LY294002","term_id":"1257998346","term_text":"LY294002"}}LY294002 induced SGC7901 cell death in vitro. We did not know whether SN50, which is a specific inhibitor of nuclear factor κB (NF-κB), could increase the cell death induction of gastric cancer of {"type":"entrez-nucleotide","attrs":{"text":"LY294002","term_id":"1257998346","term_text":"LY294002"}}LY294002 in vitro, and we also wanted to know the mechanism of it, which might be applied to clinical tumor therapy.

Material and methods

The 3-(4,5-dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide (MTT) assay was used to determine the cytotoxic effects of the drugs. Mitochondrial membrane potential was measured using the fluorescent probe JC-1. Hoechst 33258 staining was used to detect apoptosis and necrosis morphological changes after {"type":"entrez-nucleotide","attrs":{"text":"LY294002","term_id":"1257998346","term_text":"LY294002"}}LY294002 and/or SN50 treatment. Expression of p53, PUMA and Beclin1 were determined with real-time polymerase chain reaction (RT-PCR) analysis. We used transmission electron microscopy to identify ultrastructural changes in SGC7901 cells after {"type":"entrez-nucleotide","attrs":{"text":"LY294002","term_id":"1257998346","term_text":"LY294002"}}LY294002 and/or SN50 treatment.

Results

In this study, we found that treating the human gastric cancer cells SGC7901 with SN50 could significantly enhance the effects of {"type":"entrez-nucleotide","attrs":{"text":"LY294002","term_id":"1257998346","term_text":"LY294002"}}LY294002 on inducing cell death after 24 h, compared to the control group (p < 0.05). Detection of mitochondrial potential and transmission electron microscopic examination indicated that the rate of cell death increased progressively. The expression of p53, PUMA and Beclin1 was up-regulated.

Conclusions

The NF-κB inhibitor SN50 could enhance the role of {"type":"entrez-nucleotide","attrs":{"text":"LY294002","term_id":"1257998346","term_text":"LY294002"}}LY294002 on inducing cell death of human gastric cancer cells SGC7901, which might be a promising new approach to gastric cancer therapy.     

PPZ与5-FU对胃癌细胞生长、自我更新能力的影响及相互作用

目的 探讨泮托拉唑（PPZ）、5-氟尿嘧啶（5-FU）在调控胃癌细胞及胃癌干细胞生长、自我更新能力中的影响及其相互作用。方法 将SGC-7901和HGC-27细胞分为3组实验:5-Fu处理组、PPZ处理组和5-Fu+PPZ组。通过细胞成球实验检测PPZ加药前后胃癌细胞系（SGC7901、HGC-27）中胃癌细胞及胃癌干细胞自我更新能力的变化,观察PPZ对胃癌细胞系成球能力干扰情况;MTT法检测PPZ、5-FU对胃癌细胞及胃癌干细胞增殖能力的影响,观察PPZ对5-FU药物敏感性的调节作用。结果 PPZ加入后胃癌细胞系（SGC7901、HGC-27）和胃癌干细胞系（SGC7901-SP、 HGC-27-SP）自我更新率比PPZ加入前的自我更新率下降（P＜0.01）;PPZ、5-FU对胃癌细胞（SGC7901、HGC-27）增殖均有抑制作用,而5-Fu+PPZ联合组抑制最为明显,抑制增殖的作用在24 h开始出现,96 h最低,均低于0 h。PPZ对胃癌干细胞（SGC7901-SP、HGC-27-SP）增殖均有抑制作用,在48 h逐渐明显;加入PPZ后,胃癌干细胞（SGC7901-SP、HGC-27-SP）两个细胞系酶标仪检测到的吸光值在48 h、72 h、96 h时均下降。72 h和96 h时,加与不加PPZ的吸光值比较,统计学意义显著（P＜0.01）。不同浓度（0~50 μg/ml）5-FU对胃癌干细胞（SGC7901-SP、HGC-27-SP）增殖抑制的差异不显著;而加入PPZ 100 μg/ml后,随着5-FU浓度的增加增殖抑制作用逐渐增强,在40~50 μg/ml浓度的5-FU对胃癌干细胞（SGC7901-SP、HGC-27-SP）增殖抑制更加明显;加入PPZ 后,40 μg/ml及50 μg/ml浓度的5-FU作用下胃癌干细胞（SGC7901-SP、HGC-27-SP）酶标仪检测到的吸光值均降低。结论 PPZ能有效抑制胃癌细胞及胃癌干细胞的自我更新能力,抑制其增殖,并可提高其对5-FU的化疗敏感性。PPZ有望成为逆转胃癌耐药的一类联合治疗药物应用于临床。     

甲基莲心碱对耐长春新碱人胃癌细胞多药耐药性的逆转

目的:研究甲基莲心碱(Nef)逆转耐长春新碱人胃癌细胞多药耐药性(MDR)的作用及机制。方法:采用噻唑蓝(MTT)比色法检测长春新碱(VCR)的细胞毒性;PI染色流式细胞计数测定VCR诱导细胞凋亡;间接免疫荧光流式细胞术检测细胞P-gp和MRP的表达。结果:Nef(5、10μmol·L^-1)对人胃癌细胞(SGC7901)和耐长春新碱人胃癌细胞(SGC7901/VCR)无显著毒性作用,VCR对敏感株SGC7901的IC₅₀为0.06mg·L^-1,而对MDR细胞株SGC7901/VCR的IC₅₀为2.32mg·L^-1,SGC7901/VCR较SGC7901对VCR耐药39倍,Nef(2.5、5、10μmol·L^-1)能使VCR对SGC7901/VCR细胞的IC₅₀从2.32mg·L^-1依次下降至0.34、0.12、0.05mg·L^-1,逆转倍数分别为6.8、18.1、43.8。Nef(2.5、5、10μmol·L^-1)能降低SGC7901/VCR细胞对VCR的凋亡抗性,其作用强于维拉帕米(VRP)。SGC7901/VCR细胞较SGC7901细胞高表达P-gp、MRP,Nef(10μmol·L^-1)处理24h后,SGC7901/VCR细胞P-gp、MRP的表达明显低下。结论:Nef具有逆转耐长春新碱人胃癌细胞的MDR作用,其作用机理与下调P-pg和MRP表达有关。     

MicroRNA-17-92基因对胃癌干细胞更新和增殖的影响

背景：研究表明,miRNA对肿瘤干细胞的更新分化有调节作用,有关miRNA-17-92在胃癌干细胞更新及增殖中的作用尚未完全阐明。 目的：分析miRNA-17-92在胃癌干细胞自我更新及增殖中的作用。 方法：①利用细胞培养使胃癌干细胞贴壁分化并送miRNA芯片检测,寻找并验证不断缺失的miRNA。②构建并转染miRNA-17-92分子慢病毒稳定转染细胞。③通过tumorsphere实验研究miRNA-17-92与胃癌细胞更新的关系。④通过MTT、平板克隆试验检测miRNA-17-92与胃癌干细胞增殖的关系。 结果与结论：①miR-19b/20a/92a在胃癌干细胞贴壁分化过程中表达逐渐减低。②慢病毒携带的miRNA-17-19基因在MKN28细胞和CD44-/EpCAM-细胞中的表达均明显增加;瞬时转染pre-miR-19b/20a/92a能使CD44-/EpCAM-和MKN28的miRNA表达增高,瞬时转染pre-miR-19b/20a/92a拮抗剂能使SGC7901和CD44+/EpCAM+的miRNA表达降低;过表达lenti-miR-19b/20a/92a能显著增加胃癌细胞形成肿瘤球的能力;在化疗药的作用下,lenti-miR-19b/20a/92a感染细胞的生存时间延长;瞬时转染pre-miR-19b/20a/92a 能够显著增加CD44+/EpCAM+细胞数,转染其拮抗剂可以降低CD44+/EpCAM+细胞数。③miR-19b/20a/92a稳定表达组的胃癌细胞增殖速度较对照组快。瞬间转染miR-19b/20a/92a前体组加快胃癌细胞的增殖速度,而瞬时转染其拮抗物组减慢胃癌细胞的增殖速度;瞬间转染 miR-19b/20a/92a前体组的克隆数较对照组多,而瞬时转染miR-19b/20a/92a拮抗物组的克隆数较对照组少。结果表明miR-19b/20a/92a基因在胃癌干细胞分化过程中不断缺失,miR-17-92基因能够促进胃癌干细胞的更新和增殖。 中国组织工程研究杂志出版内容重点：干细胞;骨髓干细胞;造血干细胞;脂肪干细胞;肿瘤干细胞;胚胎干细胞;脐带脐血干细胞;干细胞诱导;干细胞分化;组织工程