TP53INP1高表达在砷剂杀伤肺腺癌细胞中的增敏作用

目的构建TP53INP1高表达的肺腺癌A549细胞,初步研究提高TP53INP1的表达能否提高砷剂对肺腺癌细胞的杀伤作用。方法构建TP53INP1重组真核表达质粒,以慢病毒为载体将其转染到A549细胞,建立稳定高表达TP53INP1基因的A549-TP53INP1细胞株,以流式细胞术和MTT实验检测As_2O_3处理后A549-TP53INP1细胞的凋亡和存活率。结果成功构建稳定A549-TP53INP1细胞株。流式细胞术结果显示,相同剂量As2O3作用下(5~40μmol/L),A549-TP53INP1细胞凋亡率[(15.6±3.5)%]显著高于A549细胞[(10.0±2.5)%](P<0.05)。MTT实验显示,As_2O_3处理后A549-TP53INP1细胞的IC50值[(44.64±6.84)μmol/L]显著低于A549细胞[(54.25±6.13)μmol/L](P<0.05)。结论 TP53INP1高表达可增加砷剂对肺腺癌细胞的杀灭作用,提示TP53INP1可作为砷剂治疗肺癌的增敏靶点。     

苯并(a)芘通过活化蛋白-1非依赖性通路诱导细胞中p53蛋白过表达及高磷酸化

目的探讨苯并(a)芘[B(a)P]诱导的人胚肺成纤维细胞(HELF)中p53蛋白、p53磷酸化水平及亚细胞分布和活化蛋白-1(AP-1)活性的改变,以及p53与AP-1的上下游关系。方法转染p53小干扰RNAp53 siRNA质粒(p53-H)、载体CMV的HELF细胞(HELF/CMV)和转染AP-1荧光报告质粒的HELF细胞(AP-H)无血清培养48h后,加入2μmol/L B(a)P作用24h,用Western blot及免疫荧光法检测细胞中p53蛋白及p53磷酸化的改变,利用细胞核、细胞浆分离技术观察其亚细胞定位,用荧光检测法检测AP-1的相对活性。用AP-1的化学抑制剂curcumin抑制其活性,用p53的化学抑制剂pifithrin-α(PFT)抑制其表达,观察了二者的上下游关系。结果2μmol/L B(a)P作用24h后细胞内p53蛋白及p53蛋白20位丝氨酸磷酸化水平增加,并且主要分布在细胞核内;AP-1的活性增加。抑制AP-1活性后,对B(a)P诱导的p53蛋白含量增加没有明显的影响;抑制p53表达后,对B(a)P诱导的AP-1活性的增加没有明显影响。结论B(a)P通过AP-1非依赖的信号通路引起人胚肺成纤维细胞p53蛋白含量的增加。     

RNA干扰Grp78蛋白对肺癌细胞A549的作用研究

目的 探讨采用RNA干扰Grp78蛋白表达,观察对肺癌细胞A549的作用.方法 通过转染Grp78的siRNA质粒到肺癌细胞A549并进行表达,观察A549细胞的Grp78蛋白的表达及细胞的侵袭和转移能力的变化.结果 RNA干扰肺癌细胞A549的Grp78的表达,能够显著地抑制癌细胞的黏附、伸展,以及MMP-2,MMP-9蛋白的表达,甚至诱导细胞凋亡.结论 siRNA特异性下调Grp78蛋白,可以抑制肺癌细胞A549的侵袭和转移,甚至导致细胞凋亡.     

TRIM28磷酸化对人肺上皮细胞高致病性禽流感病毒感染过程中IFN-β和促炎细胞因子的表达

目的探究TRIM28磷酸化对人肺上皮细胞高致病性禽流感病毒感染过程中IFN-β和促炎细胞因子表达的影响。方法以人肺癌上皮细胞(human lung carcinoma cells A549,ATCC)及人肺腺癌细胞系PAa为研究对象。将细胞进行高致病性禽流感病毒ⅣAnhui/112005(H5N1)转染。将病毒转染后的细胞进行siRNA转染,对转染后的细胞的总RNA进行提取,检测各组细胞中mRNA的表达量,细胞内的蛋白表达量,细胞活性及细胞凋亡率。结果转染均siRNA2与siRNA3后能有效抑制TRIM28蛋白的磷酸化;TRIM28的磷酸化可促进IFN-β、IL-1β在细胞内的表达;与转染TRIM28 siRNA2、TRIM28 siRNA3后的对照组GAPDH和对照组scrambled siRNA中PAa细胞的G0/G1期比例(即50.02%和53.46%)相比,转染后的PAa细胞在G0/G1期的比例(60.13%和59.38%)增加(P0.05)。但转染TRIM28 siRNA2、TRIM28 siRNA3的PAa细胞的G2/M期与S期的比例均下降。结论 TRIM28磷酸化增强了人肺上皮细胞高致病性禽流感病毒感染过程中IFN-β和促炎细胞因子的表达。     

N-乙酰半胱氨酸抑制亚砷酸钠诱导心肌细胞凋亡和自噬作用的研究

目的:探讨N-乙酰半胱氨酸(NAC)抑制亚砷酸钠诱导H9C2细胞凋亡和自噬作用及机制。方法:用亚砷酸钠诱导H9C2细胞构建凋亡和自噬模型。采用CCK-8比色法检测细胞的存活率,Hoechst 33258核染色法观察凋亡细胞的形态和数量改变.双氯荧光素染色法检测细胞内活性氧(ROS)水平,Western Blot法测定蛋白P53、Bcl-2、Bax及LC3的表达水平,以及磷酸化ERK1/2蛋白及ERK1/2蛋白总量的表达水平。结果:与对照组相比,15μM亚砷酸钠处理的H9C2细胞存活率显著降低.细胞内ROS水平明显增加.凋亡细胞数量明显增多,自噬标志蛋白LC3-Ⅱ与LC3-Ⅰ比值明显增大(P0.01)。1 mM NAC预处理后显著减少H9C2细胞内ROS的生成和促凋亡蛋白P53和Bax的表达,诱导抗凋亡蛋白Bcl-2表达升高,同时降低自噬相关蛋白LC3-Ⅱ与LC3-Ⅰ的比值。亚砷酸钠处理诱导ERK1/2蛋白磷酸化(P0.01),而NAC和亚砷酸钠共处理抑制了ERK1/2蛋白的磷酸化。结论:亚砷酸钠降低H9C2细胞的存活率,增加细胞内ROS的生成,诱导细胞凋亡和自噬。NAC通过降低H9C2细胞内的ROS水平和抑制ERK1/2蛋白的磷酸化拮抗亚砷酸钠诱导的细胞凋亡和自噬。     

姜黄素增强紫杉醇诱导HeLa细胞凋亡的作用及机制研究

目的探讨姜黄素对紫杉醇诱导He La细胞凋亡的影响及其相关机制。方法将He La细胞分为对照组(未加任何药物刺激)、紫杉醇组(10μM)、姜黄素(5μM)+紫杉醇(10μM)组,噻唑蓝(MTT)法检测He La细胞活力,Annexin VFITC/PI法检测细胞凋亡,Western blot检测p53、Cleaved caspase-3及NF-κB信号通路激活情况。结果与对照组比较,紫杉醇组细胞活力降低(P0. 01),细胞凋亡率提高(P0. 01),p53和Cleaved caspase-3蛋白表达显著增加(P0. 01),IκB-α蛋白和NF-κB p65磷酸化水平显著降低(P0. 01);与紫杉醇组比较,姜黄素+紫杉醇组细胞活力降低(P0. 01),细胞凋亡率提高(P0. 01),p53和Cleaved caspase-3蛋白表达显著增加(P0. 01),IκB-α蛋白和NF-κB p65磷酸化水平显著降低(P0. 01)。结论黄素增强紫杉醇诱导宫颈癌He La细胞凋亡的作用,该过程可能通过NF-κB信号通路的进一步抑制,并增强其下游蛋白Cleaved caspase-3及p53的表达实现。     

油酸对3T3-L1脂肪细胞脂联素及CDK5、PPARγ表达的调节作用

目的探讨不同浓度油酸对3T3-L1脂肪细胞脂联素及细胞周期性依赖激酶5(CDK5)、过氧化物酶体增殖物激活受体经(PPARy)表达的调节作用。方法用不同浓度(25、50、100、200、400μmol/L)油酸处理诱导成熟的3T3-L1脂肪细胞24h,用实时荧光定量PCR及Western-blotting法测定各处理组胞内脂联素、CDK5、PPARy mRNA和蛋白表达水平,并在油酸浓度为100、400μmol/L时用Western-blotting法测定PPARγ~(ser273)磷酸化水平。结果50~100μmol/L范围内,油酸可促进脂联素、PPARy mRNA表达,100μmol/L油酸可显著上调脂联素和PPAR;mRNA及蛋白表达;之后随浓度增加,油酸对脂联素和PPARy的促进作用下降,在400μmol/L时显著降低脂联素mRNA和蛋白表达,但对PPARγ蛋白无明显作用。100μmol/L油酸对PPARγ~(ser273)磷酸化水平无明显影响,但在400μmol/L时可显著升高PPARγ~(ser273)磷酸化水平。各浓度油酸对CDK5 mRNA及蛋白均无明显影响。结论50~100μmol/L油酸可促进脂联素、PPARγ表达,400μmol/L油酸抑制脂联素的表达并升高PPARγ~(ser273)磷酸化水平。提示50~100μmol/L油酸可能通过上调PPARγ而促进脂联素表达,400μmol/L油酸可能通过异常激活CDK5介导的PPARγ~(ser273)磷酸化抑制脂联素表达。     

p53在苯并[a]芘诱导所致p21和细胞周期蛋白改变中的作用

目的探讨在苯并[a]芘(B[a]P)诱导的人胚肺成纤维细胞(HELF)中p53蛋白对p21、cyclin D1和CDK4蛋白间相互作用的影响。方法向转染p53小干扰RNA(p53siRNA)质粒的HELF细胞即p53-H细胞组、载体CMV的HELF细胞即HELF/CMV细胞组中分别加入2μmol/L B[a]P作用24 h,向p53化学抑制剂Pifithrin-α(PFT-α)组即HELF/CMV+PFT-α细胞组中同时加入2μmol/L B[a]P和20μmol/L PFT-α作用24 h,各组同时设立不做任何处理的对照组。用免疫印迹(Western blot)法检测细胞中p53、p53-ser20以及p21、cyclin D1和CDK4蛋白水平的变化,同时利用免疫沉淀方法分析p53蛋白对p21、cyclin D1以及CDK4蛋白间相互作用的影响。结果利用PFT-α或p53 siRNA技术抑制p53蛋白后,B[a]P诱导的p53蛋白20位丝氨酸磷酸化水平和p21蛋白水平的增高受抑制,B[a]P诱导的cyclin D1水平的增加不受影响,CDK4的水平不受B[a]P的影响;免疫沉淀实验结果表明,B[a]P引起的p21和CDK4结合的增加受到抑制,B[a]P引起的p21与cyclin D1结合的增加不受影响,cyclin D1和CDK4的结合不受B[a]P的影响。结论B[a]P通过p53-ser20影响人胚肺成纤维细胞p21和CDK4的结合。     

青蒿琥酯联合热疗诱导肺腺癌A549细胞凋亡作用

目的 探讨青蒿琥酯联合热疗诱导肺腺癌A549细胞凋亡的线粒体途径作用机制.方法 150μmol/L青蒿琥酯、青蒿琥酯联合热疗(43℃,1 h)作用A549细胞24 h,流式细胞技术检测细胞周期和凋亡率情况.荧光显微镜观察线粒体膜电位变化.免疫组化、western blot检测细胞色素c、Bcl-2和caspase-3表达,CaspACE<'TM>检测试剂盒检测活性caspase-3表达.结果 青蒿琥酯、青蒿琥酯联合热疗作用A549细胞24 h后,G0/G1期细胞数增多,S期和G2/M期细胞数减少(P<0.01);凋亡率分别是16.77%和28.90%(P<0.01).线粒体膜电位下降率分别为18.05%,50.98%(P<0.01).细胞色素c蛋白、caspase-3表达增加而Bcl-2蛋白表达减少(P<0.01).活性caspase-3蛋白水平增加A值分别为0.2641±0.0027,0.3613±0.0019,与对照组相比,差异有统计学意义(P<0.01).结论 青蒿琥酯、青蒿琥酯联合热疗可诱导肺腺癌A549细胞凋亡,激活线粒体途径可能是诱导凋亡重要作用机制.     

Orai1和STIM1在姜黄素诱导人肺腺癌A549细胞凋亡中的作用

目的探讨不同浓度姜黄素诱导人肺腺癌A549细胞凋亡中Orai1和STIM1mRNA水平的改变。方法 A549细胞分别暴露于5、10、15、20、25和30μmol/L姜黄素12、24和48 h后,应用四甲基偶氮唑蓝(MTT)比色法测定细胞增殖活力;将不同浓度姜黄素孵育A549细胞24 h后,流式细胞仪检测细胞凋亡率;real-time PCR确定25μmol/L姜黄素处理24 h后,Orai1和STIM1mRNA表达水平。结果姜黄素对A549细胞的抑制作用呈剂量依赖性和时间依赖性,不同浓度姜黄素处理A549细胞24 h细胞存活率分别为96.5%、95.0%、77.4%、63.9%、57%、39.6%,与对照组相比,差异有统计学意义(P0.05或P0.01)。姜黄素处理后,流式细胞仪分析结果显示,细胞凋亡率呈明显剂量依赖关系(P0.05或P0.01)。经姜黄素处理后A549细胞Orai1和STIM1mRNA表达量均明显低于对照组(P0.01)。结论姜黄素可能引起A549细胞Orai1和STIM1 mRNA表达水平发生改变,通过下调Orai1和STIM1mRNA表达量引起细胞凋亡。     

Comparison of neurosphere cells with cumulus cells after fusion with embryonic stem cells: reprogramming potential

Embryonic stem cells (ESCs) are the pluripotent cells that also have the capacity to induce the genomic reprogramming of differentiated somatic cells. The progressively restricted genomic potential of somatic cells observed during embryonic development can be reverted to a pluripotent state by the formation of cell hybrids with ESCs. To assess the reprogramming potential of ESCs, we investigated the reprogramming of one of two different somatic cell populations, neurosphere cells (NSCs) and cumulus cells (CCs), after fusion with ESCs. Specifically, hybrid cells were produced by cell fusion of E14 ESCs with either NSCs or CCs containing the neo/lacZ and Oct4-GFP transgenes. The first reprogramming event, observed by the presence of Oct4-GFP in the hybrid cells, could be identified on Day 2, at approximately 45 h after fusion in both ESC-NSC and ESC-CC hybrids. In addition, the two ESC-somatic cell hybrids exhibit a similar reprogramming rate and share characteristics with the E14 ESC line: (1) expression of pluripotent markers (Oct4, Rex-1 and nanog); (2) inactivation of differentiated tissue-specific gene expression; and (3) the capacity to differentiate into all three germ layers. Taken together, our results suggest that the ESC-somatic cell hybrids have fully acquired ESC characteristics and that somatic cells of different tissue origin have the same potential to be reprogrammed after fusion with ESCs.     

树突状细胞激活效应细胞作用的初步研究

目的探讨树突状细胞（DC）对肿瘤浸润淋巴细胞（TIL）和小鼠脾淋巴细胞（小鼠脾LC）的最佳激活作用比例.方法联合应用GM-CSF、IL-4和小鼠H22肝癌细胞全细胞性抗原致敏从荷瘤小鼠四肢长骨提取的DC,依据不同的激活比例用致敏DC体外激活TIL和小鼠脾LC,采用乳酸脱氢酶（LDH）4小时释放法测定、观察被不同程度激活的TIL和小鼠脾LC对小鼠H22肝癌细胞的杀伤活性.结果当E/T为1：400和1：200时,所激活的TIL或小鼠脾LC的杀伤活性较弱,线性关系不明显,P＞0.05;当E/T为1：100时,杀伤活性有较明显的提高,与前两者比较,P＜0.05;当E/T=1：50时,杀伤活性徒增,与前三者比较均有显著性差异;而当E/T=1：25,1：12.5和1：6.25时,杀伤活性与E/T=1：50时基本没变化,P＞0.05.结论当E/T=1：50时,DC能使小鼠脾LC和TIL充分激活,显著提高其对小鼠H22肝癌细胞的体外杀伤活性.     

肝实质细胞和肝非实质细胞及非肝细胞的共培养

生物人工肝有望成为肝衰竭患者有效的体外肝支持治疗手段,而建立生物人工肝的前提是要获得足够数量高活性和良好功能的肝细胞.大量研究发现,肝细胞共培养能明显增强肝细胞功能,保持肝细胞的表型.此文就近年来肝细胞和非实质细胞、非肝细胞共培养的效果、方法和可能的机制作了综述.     

Generation and functional assessment of antigen-specific T cells stimulated by fusions of dendritic cells and allogeneic breast cancer cells

We have reported that fusions of patient-derived dendritic cells (DC) and autologous breast cancer cells induce T-cell responses against autologous tumors. However, the preparation of fusion cells requires patient-derived tumor cells, and these are not always available in the clinical setting. In the present study, we explore an alternative approach to constructing DC-breast cancer fusion vaccine by using breast cancer-cell lines. DC generated from HLA-A*0201-positive donor were fused to HLA-A*0201+ allogeneic MCF7 breast cancer cells. These fusion cells co-expressed tumor-associated antigens and DC-derived costimulatory and MHC molecules. Both CD4 and CD8 T cells were activated by the fusion cells as demonstrated by the production of IFN-gamma. The fusion cells induced strong antigen-specific cytotoxic T lymphocytes (CTL) activity against their parent cells. The lysis of targets was restricted by HLA-A*0201, since killing was blocked by the anti-HLA-A2 mAb. Similar CTL activity against HLA-A*0201-positive targets was induced when T cells were cocultured with fusions of DC and HLA-A*0201-negative allogeneic BT20 breast cancer cells. In addition, administration of T cells stimulated by DC-breast cancer fusion cells regressed 7-day-old tumors and rendered mice free of disease up to 90 days. These results suggest that tumor-cell lines can be used as a fusion partner in the construction of DC-tumor fusion vaccine. Such fusion cells hold promise since they can be used as a vaccine for active immunotherapy or as stimulators to activate and expand T cells for adoptive immunotherapy.     

Influence of glutamine-supplemented Caco-2 cells on cytokine production of mononuclear cells

BACKGROUND: Caco-2 cells, cultured with mononuclear cells, were used as an in vitro model of human intestinal cell function. This study shows the effect of glutamine (Gln) supplementation on the production of tumor necrosis factor alpha, interleukin-10 (IL-10), and interleukin-6 (IL-6). METHODS: Confluent Caco-2 cells were cultured in media with Gln at 0 mmol/L, 4 mmol/L, or 10 mmol/L +/- 1 microg/mL lipopolysaccharide (LPS), treated with fluorescein isothiocyanate- (FITC-) conjugated intercellular adhesion molecule-1 (ICAM-1) mononuclear antibody, and assessed for ICAM-1 expression levels via flow cytometry. Confluent Caco-2 cells alone in apical inserts, or mononuclear cells (MNCs) alone in basal chambers of transwells, were cultured in media with 0 mmol/L, 4 mmol/L, or 10 mmol/L Gln. Supernatants were taken to assess cytokine and endotoxin levels. Confluent Caco-2 cells in apical inserts of transwells were cultured in media containing Gln at 0 mmol/L, 4 mmol/L, or 10 mmol/L, whereas MNCs were cultured in the basal chamber in media containing Gln at 4 mmol/L +/- LPS. Supernatants were collected to determine cytokine levels in each chamber. RESULTS: With Gln supplementation of the media at 10 mmol/L, enterocytes displayed a decrease in ICAM-1 expression. MNCs showed a decrease in tumor necrosis factor alpha and IL-6 production and an increase in IL-10 production when incubated with Caco-2 cells in media supplemented with Gln at 10 mmol/L. CONCLUSIONS: Although cytokine production by Caco-2 or mononuclear cells incubated alone was not influenced by the Gln concentration of the media, cultured together, Gln levels affected cytokine production by mononuclear cells, which suggests that Caco-2 cells produce mediators in Gln-rich conditions that can influence mononuclear cell cytokine production.     

人子宫内膜细胞原代培养与间质细胞MTS比较

目的探究原代人子宫在位内膜细胞分离及培养的简易方法,比较分离培养单一间质细胞和混合培养间质细胞之间的差异。方法采用单纯胰蛋白酶,分段消化人子宫内膜组织,经过两次筛网过滤、离心纯化技术,分离、纯化人子宫内膜间质细胞(ESC)和腺上皮细胞(EEC),采用免疫荧光方法对细胞进行鉴定,采用Cell Titer96~ Aqueous One Solution Reagent(MTS)方法监测细胞之间增长速度。结果间质细胞多呈梭形或多角形,纯度可达97%以上。腺上皮细胞多似蝌蚪形或多角形,纯度可达93%以上。混合培养细胞比单一培养细胞增殖能力强。结论采用单纯胰蛋白酶分段消化法和二次筛网过滤法可成功分离子宫内膜腺上皮细胞和间质细胞,具有获得细胞成活率高、生长稳定的优点,混合培养间质细胞,保留细胞间整体性,可为进一步研究子宫内膜细胞提供一定的实验基础。     

胚胎干细胞在心肌样环境中向心肌样细胞的分化情况

目的探讨心肌细胞促进胚胎干细胞(embryonic stem cells,ESCs)分化为心肌样细胞的诱导作用。方法收集小鼠3.5d胚龄的囊胚,将其培养在小鼠胚胎成纤维细胞饲养层上,4～5d后取内细胞团接种在饲养层上分离培养出ESCs。取3～5代ESCs,先将ESCs悬浮培养形成2～3d的拟胚体(embryoid bodies,EBs),再与新生大鼠心肌细胞共培养诱导向心肌细胞分化,相差显微镜下观察分化细胞的形态学变化,免疫细胞荧光技术检测心肌细胞特异性肌钙蛋白T(TnT)、а-肌动蛋白(а-Actin)的表达。结果诱导d3起可见自发性、有节律跳动的拟胚体出现,12d时共培养组约有93%的拟胚体出现节律性收缩,显著高于对照组,均表达心肌细胞特异性蛋白cTnT、а-actin,心肌细胞直接接触诱导组其分化比率达56.5%,分化的细胞形态较单一。结论心肌细胞与胚胎干细胞直接接触能促进胚胎干细胞向心肌细胞分化。     

Differentiation of embryonic and adult stem cells into insulin producing cells

Replacement of insulin producing cells represents an almost ideal treatment for patients with diabetes mellitus type 1. Transplantation of pancreatic islets of Langerhans is successful in experienced centers. The wider application of this therapy, however, is limited by the lack of donor organs. Insulin producing cells generated from stem cells represent an attractive alternative. Stem cells with the potential to differentiate into insulin producing cells include embryonic stem cells (ESC) as well as adult stem cells from various tissues including the pancreas, liver, bone marrow and adipose tissue. The use of human ESC is hampered by ethical concerns but research with human ESC may help us to decipher important steps in the differentiation process in vitro since almost all information available on pancreas development are based on animal studies. The present review summarizes the current knowledge on the development of insulin producing cells from embryonic and adult stem cells with special emphasis on pancreatic, hepatic and human mesenchymal stem cells.     

奈达铂对宫颈癌Hela及Siha细胞的作用

目的:比较奈达铂(NDP)体外对人宫颈腺癌细胞Hela细胞及鳞癌细胞Siha的抑制作用并探讨其作用机制。方法:以2.5～40μg/ml NDP分别作用于Hela及Siha细胞24 h,48 h,72 h,MTT法检测抑制率,计算半数抑制浓度(IC50);利用流式细胞术(FCM)观察细胞凋亡率及周期变化;半定量PCR法分析基因半胱氨酸天门冬氨酸蛋白酶3(Caspase 3,Caspase 9)及基质金属蛋白酶2(MMP-2)的表达变化。结果:NDP对宫颈癌Hela细胞及Siha细胞均有抑制作用,呈时间-剂量依赖性,NDP对Hela细胞的抑制率大于Siha细胞;FCM显示,随时间、浓度增加,Hela及Siha细胞凋亡率增加,相同浓度和作用时间下,Hela细胞的凋亡率大于Siha细胞(P<0.05),S期细胞的比例增加,G0/G1期比例减少,G2/M期比例变化不明显;与对照组相比,Caspase 3,Caspase 9表达增加,MMP-2表达减少。结论:NDP可抑制宫颈腺癌细胞Hela及鳞癌细胞Si-ha的增殖,NDP体外对Hela细胞的抑制作用更强。NDP的作用机制与诱导细胞凋亡、细胞周期阻滞、上调Caspase3和Caspase9的表达有关;下调MMP-2的表达可能有利于降低宫颈癌细胞的侵袭力。