早期B细胞因子3在肝癌中的表达及对HepG2细胞株作用的研究

目的 研究肝癌及远端非痛肝组织中早期B细胞因子3(EBF3)mRNA与蛋白质表达差异及临床意义,并研究EBF3-EGFP(增强型绿色荧光蛋白)融合蛋白表达对肝癌细胞株HepG2细胞增殖的影响.方法 采用荧光定量PCR技术检测20例配对肝癌及远端非癌肝组织EBF3 mRNA水平,Western blot检测5例配对标本EBF3蛋白表达.将EBF3与EGFP融合蛋白表达载体pEGFP/EBF3转染HepG2细胞株,倒置荧光显微镜观察EBF3-EGFP融合蛋白表达,流式细胞术测定转染后不同时间S期细胞分数(SPF)和增殖指数(PI).结果 20例肝癌和配对远端非癌肝组织中EBF3mRNA与β2M mRNA的埘数比值分别为0.55±0.12和0.22±0.23,差异有统计学意义(t=5.69,P<0.001);Western blot结果表明EBF3蛋白主要表达于细胞核中,5例肝癌组织核蛋白中EBF3条带平均灰度值为26.35±14.06,与远端非癌肝组织(7.86±8.47)相比差异有统计学意义(t=2.52,P=0.036);将pEGFP/EBF3导入HepG2细胞株24 h后,可观察到EBF3-EGFP融合蛋白主要表达于核内.转染pEGFP/EBF3后48 h和72 h,SPF和PI均显著高于pEGFP转染细胞组.结论 肝癌组织中EBF3 mRNA及其蛋白表达均上调,EBF3基因导入HepG2促进细胞株增殖,EBF3在肝癌中的作用有待进一步研究.     

早期B细胞因子3在肝癌中的表达及对HepG2细胞株作用的研究

Objective To investigate the expression and clinical significance of early B-cell factor 3 (EBF3) mRNA and protein in hepatocellular carcinoma(HCC) and the effect of EBF3 overexpression on HepG2 cell proliferation. Methods The expression levels of EBF3 mRNA in 20 pairs surgical specimens of HCC and their distant noncancerous tissues were detected by fluorescence quantitative real-time polymerase chain reaction(FQ-RT-PCR). Western blot was used to detect the expression levels of EBF3 protein in 5 pairs surgical specimens of HCC and distant noncancerous tissues. The fusion protein EBF3-EGFP was ex-pressed in HepG2 cells by transfection of pEGFP/EBF3 into the synchronized HepG2 cells using lipo-fectAMINE 2000 regent. Expression of EBF3-EGFP fusion protein was observed under the inverted fluores-cence microscope. S-phase fraction(SPF) and proliferating index(PI) were analyzed with flow cytometry (FCM). Results The ratio of EBF3 mRNA to β2 mRNA in HCC tissues was significantly higher than that in distant liver non-cancerous tissues(0.55 ±0.12 versus 0. 22 ± 0.23, t = 5.69, P < 0.001 ). EBF3 protein in nuclear extracts of HCC tissues was about 4 fold that in distant non-cancerous tissues (26.35 ±14.06 versus 7.86 ± 8.47, t = 2.52, P = 0.036). Fluorescence microscopy revealed that 24 h after trans-fection of pEGFP/EBF3 into hepatoma HepG2, the fluorescence of EBF3-EGFP fusion protein was mainly observed in the nucleus. After transfection for 24 h and 48 h, SPF and PI were markedly increased in HepG2 cells transfected by pEGFP/EBF3 as compared with that in pEGFP-N1 transfeeted cells. Conclusion The expression of EBF3 at both mRNA and protein levels was up-regulated in HCC tissues. EBF3 promotes HepG2 cells proliferation through DNA replication, effect of EBF3 in ttCC needs to be further investigated.     

稳定过表达的HLrg蛋白对HepG2细胞周期和细胞形态的影响

目的在肝癌细胞系HepG2中稳定过表达HLrg，观察过表达的HLrg蛋白对HepG2的细胞周期和细胞形态等生物学影响。方法构建真核重组表达质粒pcDNA3．1（＋）-hlrg，转染到HepG2细胞并进行稳定筛选；对稳定过表达pcDNA3．1（＋）空载体的对照组、pcDNA3．1（＋）-hlrg的实验组进行观察。Westernblot进行HLrg蛋白的鉴定。流式细胞仪测定细胞周期、MTT法测定生长曲线、透射电子显微镜观测细胞形态的改变。结果获得了稳定过表达pcDNA3．1（＋）-hlrg的HepG2细胞株。与对照组相比，过表达HLrg蛋白的细胞株出现G1阻滞，微绒毛减少，分裂相减少，生长趋缓。结论稳定过表达的Hk蛋白对细胞周期有调节作用，对肝癌细胞HepG2具有生长阻滞的作用。     

EBF3与EGFP融合蛋白表达载体的构建及其在HepG2中的表达

目的:构建早期B细胞因子3(EBF3)与增强型绿色荧光蛋白(EGFP)的融合基因真核表达载体pEGFP/EBF3, 使EBF3-EGFP融合蛋白在人肝癌细胞株HepG2中得到表达.方法:采用RT-PCR技术, 从人胎盘组织总RNA中逆转录并扩增出EBF3全长编码基因, 构建EBF3与EGFP的融合基因真核表达载体pEGFP/EBF3, 用脂质体转染技术将pEGFP/EBF3导入HepG2, 使EBF3-EGFP融合蛋白得到表达.结果:经转化细菌、抽提质粒、酶切鉴定和DNA序列分析证实, EBF3基因已正确插入pEGFP-N1中EGFP基因的上游, 获得融合基因表达载体pEGFP/EBF3.将pEGFP/EBF3导入HepG2细胞24 h后, 在倒置荧光显微镜下可观察到EBF3-EGFP融合蛋白主要表达于核内, 转染pEGFP/EBF3和pEGFP-N1后48 h的转染效率分别为52%和59%.Western blot证实转染pEGFP/EBF3后24 h和48 h细胞质和细胞核中均检出相对分子质量(Mr)为87 000的EBF3-EGFP融合蛋白, 转染pEGFP/EBF3后48 h和72 h, S期细胞比例均明显高于pEGFP-N1转染细胞组和未转染细胞组, 表明EBF3基因的导入可诱导细胞从G1期向G2期发展, 从而促进细胞增殖.结论:成功构建了真核表达载体pEGFP/EBF3, 并在HepG2细胞中进行了表达, 为进一步研究EBF3的功能提供实验基础.     

Runx3对人肝癌HepG2细胞增殖、凋亡及侵袭的影响

目的探讨siRNA干扰Runx3对人肝癌Hep G2细胞增殖、凋亡和侵袭能力的影响。方法以人肝癌Hep G2细胞为研究对象,构建Runx3-siRNA,转染入细胞。将细胞分为对照组、脂质体组、NC-siRNA组和Runx3-siRNA组。用RT-PCR法检测Runx3 mRNA表达,用Western blot检测Runx3蛋白表达。用MTT法、流式细胞法和Transwell小室法观察Runx3对Hep G2细胞增殖、凋亡和侵袭的影响。结果 Runx3-siRNA可抑制Hep G2细胞的增殖(P0.05);Runx3-siRNA可促进Hep G2细胞凋亡(P0.05);Runx3-siRNA可抑制Hep G2细胞的侵袭(P0.05)。结论Runx3基因在肝癌的发生发展中发挥一定的促进作用,有可能成为肝癌治疗的新靶点。     

Fas配体对HepG2细胞凋亡的影响

细胞凋亡 (apoptosis)与肿瘤的发生、增殖与转移有着较为密切的关系 ,而Fas Fas配体 (FasLigand ,FasL)被认为是传导细胞凋亡信号的“死亡信号传递分子”。其中FasL主要存在于免疫活性细胞 ,通过与靶细胞膜Fas结合 ,导致靶细胞凋亡。为研究FasL在肝癌细胞凋亡过程中的作用 ,我们首先采用ELISA法对慢性乙型肝炎、肝硬化与肝癌患者血清中Fas及可溶性FasL(sFasL)水平进行了初步检测 ,结果显示肝癌患者血清中sFas明显升高 ,而FasL的浓度又明显低于慢性肝炎及肝硬化者 ,提示在肝癌的发生中 ,FasL及Fas与肝癌细胞凋亡有重要关系。我们…     

基因芯片筛选HepG2与HepG2.2.15细胞中的差异表达基因

目的 探讨HepG2细胞及HepG2.2.15细胞中差异表达的基因并对其基因表达谱进行生物学信息分析.方法 用Trizol一步法提取HepG2细胞及HepG2.2.15细胞的总RNA,并纯化mRNA,反转录合成荧光分子(Cy3/Cy5)标记的cDNA探针,与基因芯片杂交;采用LuxScan3.0图像分析软件对芯片图像进行分析,把图像信号转化为数字信号,最后以差异为2倍的标准来确定差异表达基因.结果 在54614个基因表达谱的筛选中,发现有4462个基因表达水平显著上调,2592个基因表达水平显著下调.结论 HBV基因组及其表达产物对于肝细胞基因表达谱有显著影响,可能参与了肝癌的发生发展.     

丙型肝炎病毒核心蛋白对HepG2细胞生长周期的影响

目的: 构建丙型肝炎病毒核心蛋白(HCV-core-1b)真核重组质粒,获得稳定表达HCV-core-1b的HepG2细胞株,观察HCV-core-1b对HepG2细胞株生长周期及cyclin D1 和pRb/p130表达的影响,探讨丙型肝炎病毒慢性感染的可能机制。方法: 将HCV-core-1b亚克隆入pBabe-Flag-puro载体,获得重组质粒pBabe-Flag-HCV-core-1b;将重组质粒转染病毒包装细胞Pheonix 293T,筛选获得分泌HCV-core-1b的病毒包装细胞株。利用包装细胞产生的病毒上清感染靶细胞,筛选后获得稳定表达HCV-core-1b的HepG2细胞株,流式细胞仪检测靶细胞生长周期的变化,Western blotting检测cyclin D1 和pRb/p130蛋白的表达。结果: 基因测序确认HCV-core-1b亚型基因编码区完整无移位,与标签蛋白Flag形成融合蛋白。HepG2-HCV-core细胞株成功表达Flag-HCV-core-1b蛋白,并导致细胞cyclin D1 和 pRb/p130的水平下调,显著改变了HepG2细胞生长周期,使细胞阻滞在G₀/G₁期。结论: 成功构建了pBabe-Flag-HCV-core-1b真核表达质粒,获得稳定表达Flag-HCV-core-1b融合蛋白的HepG2细胞。由于HCV-core-1b蛋白的表达,下调了HepG2细胞 cyclin D1和pRb/p130的表达,显著抑制HepG2细胞生长周期。     

棕榈酸刺激的巨噬细胞对HepG2细胞侵袭和迁移的影响

目的:研究棕榈酸刺激的巨噬细胞对肝癌细胞侵袭和迁移能力的影响,并进一步探讨其作用机制。方法:应用棕榈酸(0.16 mmol/L)刺激人急性单核细胞白血病细胞系THP-1来源的巨噬细胞,并取其上清液处理HepG2细胞。细胞迁移实验检测巨噬细胞的迁移能力,侵袭实验和划痕实验分别观察HepG2细胞的纵向迁移能力和横向迁移能力;RT-qPCR检测巨噬细胞和HepG2细胞的炎症/趋化因子及HepG2细胞上皮-间充质转化标志蛋白(E-cadherin和N-cadherin)的mRNA表达水平。结果:棕榈酸促进了巨噬细胞迁移,显著上调巨噬细胞白细胞介素1β(IL-1β)、白细胞介素6(IL-6)、肿瘤坏死因子α(TNF-α)和单核细胞趋化蛋白1(MCP-1)的mRNA表达;用棕榈酸刺激巨噬细胞的上清液处理HepG2细胞,其纵向迁移能力和横向迁移力明显强于未经棕榈酸处理组,且HepG2细胞的多种炎症因子和N-cadherin表达上调,E-cadherin表达下调。结论:棕榈酸可以增强巨噬细胞的迁移能力,刺激巨噬细胞产生大量炎症因子/趋化因子,进一步通过旁分泌/内分泌作用于HepG2细胞,促进HepG2细胞的上皮-间充质转化,增强HepG2细胞的侵袭与迁移能力。     

丙型肝炎病毒核心区蛋白对HepG2细胞凋亡的影响

已有越来越多的证据表明肝细胞和外周血淋巴细胞凋亡在丙型肝炎的发生和慢性化过程中起着重要作用。ＨＣＶ核心区 (ＨＣＶ Ｃ)具有较强的免疫调节功能 ,但ＨＣＶ Ｃ蛋白究竟是促进细胞凋亡还是抑制细胞凋亡目前还有争论。目前尚未见有关ＴＲＡＩＬ(ＴＮＦｒｅｌａｔｅｄａｐｏｐｔｏｓｉｓｉｎｄｕｃｉｎｇｌｉｇａｎｄ)所介导细胞凋亡在丙型肝炎致病过程中所起作用的研究报道。本实验主要研究ＨＣＶ Ｃ蛋白对ＨｅｐＧ2细胞凋亡的影响。通过基因重组技术构建包括ＨＣＶ Ｃ的重组真核表达质粒 ,将重组真核表达质粒经脂质体介导稳定转染肝癌细…     

Fas Ligand转染人肝癌细胞株HepG2细胞后的生物学效应

目的：将FasL-peDNA3．1 hisB转染至人肝癌细胞株HepG2并检测其生物学效应。方法：转染采用脂质体转染方法，HepG2细胞FasL的表达采用免疫组化检测，培养液上清sFasL的检测采用EIA，细胞凋亡采用Annexin V／P1双染后双变量流式细胞仪检测及荧光显微镜和共聚焦激光扫描显微镜观察。结果：转染后HepG2细胞FasL表达呈阳性，培养液上清检测出微量sFasL，转染后HepG2细胞与HepG2．2．15共同培养后，细胞凋亡率为36．30％，未转染FasL的对照组细胞凋亡率11．53％。结论：将FasLcDNA转染入肝癌细胞系HepG2，可使肝癌细胞发生细胞毒性T细胞（CTL）非依赖Fas-FasL介导的细胞凋亡。     

Apoptosis in dengue virus infected liver cell lines HepG2 and Hep3B

While both in vivo and in vitro evidence has suggested that liver cells undergo apoptosis in response to dengue virus infection, little is known about the mechanism of induction. Given that the p53 tumour suppressor gene is a key mediator of apoptosis, we sought to define the role of this gene in response to dengue virus infection. After infection, a p53 wild type liver cell line (HepG2) showed changes consistent with apoptosis including alterations of cell morphology, cellular detachment and DNA laddering. However, p53 was neither up-regulated, nor showed any evidence of complexing with dengue virus proteins as determined by immunoprecipitation. Infection of a p53 null liver cell line (Hep3B) also produced changes consistent with the induction of apoptosis. While the profile of the cells undergoing apoptosis in each cell line was similar as determined by flow cytometry, the absolute levels were markedly different with up to 90% of Hep3B cells undergoing apoptosis compared to only 20% of HepG2 cells at day 5 post infection. By day 7, all Hep3B infected cells were dead. In contrast, it proved possible to culture dengue virus infected HepG2 cells for 3 months. Viral progeny released from the p53 null cell line were nine-fold higher per attached cell than from the p53 wild type cell line. These results suggest that, while induction of apoptosis in liver cells is mediated by a non-p53 regulated pathway, p53 may play a role in restricting the level of viral progeny to below a critical level at which apoptosis is triggered.     

The effect of bleeding on hematopoietic stem cell cycling and self-renewal

Hematopoietic stem cells (HSCs) divide and give rise to more committed progenitors, which ultimately produce all lineages of blood cells. HSCs can be induced to enter the cell cycle in vitro and in vivo by stimulatory cytokines and in vivo by ablation of bone marrow (BM) cells with irradiation or chemotherapeutic agents. Although it has been postulated that rates of HSC proliferation increase with normal hematopoietic stresses, such as infection or hemorrhage, this hypothesis has never been directly tested. The ability to analyze HSCs prospectively by cell-surface phenotype c-kit(+), Thy1.1(lo), Sca-1(+), Linage(neg/lo) has allowed us to perform a detailed examination of the effects of bleeding on the cell cycle kinetics of HSCs. Our results demonstrate for the first time that HSCs in both the BM and the spleen proliferate and self-renew in response to tail-vein bleeding in mice. This response was suppressed when red blood cells, but not when white blood cells, were transferred after bleeding. Thus, regulators of HSC proliferation can sense and respond to red blood cell levels.     

白藜芦醇对人肝癌HepG2细胞周期影响的实验研究

目的:探讨白藜芦醇(Resveratrol,Res)对体外培养的人肝癌细胞(HepG2)细胞周期分布的影响,为Res抗癌作用提供实验依据.方法:人肝癌细胞系HevG2细胞经不同浓度Res(0、25、50、100μmol/L)培养24、48、72 h.在相差显微镜下观察细胞的形态变化.将作用于Res的细胞经PBS洗涤,70%冷乙醇同定,PI染色,流式细胞仪检测(FCM)细胞周期时相分布以及细胞周期素蛋白依赖性激酶CDK2,周期素Cyclin E水平的变化.结果:白藜芦醇可抑制肝癌HepG2细胞增殖,其作用具有一定的时间和浓度依赖性,伴随细胞周期分布变化,G0/G1期比例下降,s期、G2/M期比例上调,且与对照组相比,实验组CDK2及Cyclin E表达增加.结论:白藜芦醇可能通过影响CDK2及Cyclin E的活性使HepG2细胞阻滞在S期,从而抑制肝癌HepG2细胞的增殖.     

B7-H3在人肝癌细胞株HepG2对外周血CD8+T细胞活化、周期及分泌IL-17调节中的作用

目的 研究B7-H3在人肝癌细胞株HepG2对人外周血CD8+T细胞活化、周期及IL-17分泌等调节中的作用.方法 RT-PCR及FCM检测B7-H3在HepG2细胞上的表达;应用脂质体法将PGPU6/GFP/neo-B7-H3shRNA质粒转入肝癌细胞株HepG2,阻断B7-H3的表达;免疫磁珠分选健康人外周血CD8+T细胞;FCM分析B7-H3分子在HepG2细胞对PHA刺激下CD8+T细胞活化、周期及PMA刺激下CD8+T细胞分泌IL-17调节中的作用.结果 肝癌细胞株HepG2高表达B7-H3分子,PGPU6/GFP/neo-B7-H3 shRNA质粒能有效阻断B7-H3在HepG2细胞上的表达;FCM分析结果显示,肝癌细胞株HepG2对CD8+T细胞活化及周期均有抑制作用;阻断B7-H3的表达后,明显减弱HepG2细胞对CD8+T细胞早期活化表型CD69表达的抑制作用,且能够通过下调CD8+T细胞Go/G1期细胞数量,上调S期细胞数量逆转HepG2细胞对CD8+T细胞周期的阻滞作用;在HepG2存在条件下,CD8+T细胞对IL-17的分泌明显增加,阻断B7-H3的表达后,IL-17的分泌被进一步上调.结论 HepG2细胞高表达B7-H3分子;B7-H3能够协同HepG2细胞对CD8+T细胞活化表型CD69的表达及细胞周期的抑制作用;HepG2细胞上调CD8+T细胞对IL-17的分泌作用,但B7-H3可抑制该上调作用.     

Sulindac对人肝癌细胞HepG2增殖及β-catenin表达的影响

目的　观察Sulindac对人肝癌细胞HepG2增殖、凋亡及β-catenin蛋白表达的影响,探讨Sulindac抗肝癌的可能机制。 方法　不同浓度的Sulindac作用HepG2细胞后,采用MTT实验检测细胞增殖抑制作用;采用Hoechst33258染色法检测Sulindac对HepG2细胞凋亡的影响;利用RT-PCR及Western blotting检测HepG2细胞在Sulindac作用后Wint通路中β-catenin的表达变化。 结果　Sulindac对人肝癌细胞HepG2有增殖抑制作用,且呈剂量时间依赖关系;Hoechst33258结果显示,Sulindac作用24 h后HepG2细胞凋亡数目明显增多;随着Sulindac浓度的增加,β-catenin mRNA及蛋白表达量逐渐下降。 结论　Sulindac能够抑制人肝癌细胞HepG2增殖,通过阻断Wnt信号传导通路,降低β-catenin表达,诱导人肝癌细胞HepG2的凋亡。