Snail增强乳腺癌细胞MCF-7中P-gp介导的多药耐药

目的探讨乳腺癌细胞中Snail过表达与P-gp之间的关系,揭示EMT对乳腺癌细胞多药耐药的影响。方法构建Snail真核表达载体pCDNA3.1-Snail,将载体转染人乳腺癌细胞MCF-7后用阿霉素对细胞进行诱导。利用细胞毒性实验(MTT)、阿霉素外排实验对耐药细胞系的耐药状况进行评价;通过流式细胞术和Real-time PCR分别测量耐药细胞系中P-gp和MDR1 mRNA,Snail mRNA的表达。结果由细胞毒性实验和阿霉素外排实验的结果显示,MCF-7/Snail细胞经阿霉素诱导后相对耐药指数升高至109.2,细胞内荧光强度降至7.1(P<0.05);Real-time PCR显示相对于MCF-7,MCF-7/Snail细胞中的MDR1 mRNA,Snail mRNA的表达明显升高与流式细胞术显示的P-gp升高相一致。结论转染Snail真核表达载体后,MCF-7/Snail细胞的耐药性较MCF-7细胞明显升高。     

nmhaFGF对人乳腺癌细胞增殖的影响及相关机制

目的比较nmhaFGF和haFGF对恶性肿瘤细胞的促增殖作用及其机制，探讨nmhaFGF临床应用的安全性。方法以haFGF和nmhaFGF分别处理人乳腺癌细胞(MCF-7)，用MTT法检测其细胞增殖活性；用流式细胞技术分析细胞周期；用蛋白免疫印迹法半定量检测MAPK通路中的信号蛋白Grb2和ERK1/2在MCF-7中的表达。结果nmhaFGF对MCF-7细胞的促增殖作用明显低于haFGF；haFGF组G₁/G₀和G₂/M期细胞比例均低于nmhaFGF组和对照组，S期细胞比例显著高于nmhaFGF组和对照组；nmhaFGF组的Grb2和ERK1/2信号蛋白表达水平均低于haFGF组，亦接近对照组。结论nmhaFGF的促增殖活性显著下降，其机制是通过下调MAPK信号通路中的Grb2和ERK1/2信号分子的表达来实现的。     

Id1 miRNA表达载体构建与转染乳腺癌细胞

目的构建正义、反义Id1真核表达载体,并成功转染乳腺癌MDA．MB-231细胞系,筛选稳定表达细胞株。方法设计针对Id1基因的mRNA效的干扰序列。将干扰序列插入pcDNA6．2-GW／EmGFP-miR表达载体,构建Id1 miRNA真核表达载体,脂质体转染法转染乳腺癌MDA-MB-231细胞系,杀稻瘟霉素筛选稳定表达的细胞株。结果Id1 mRNA真核表达载体的构建后,经酶切及测序鉴定正确后。转染乳腺癌MDA-MB231细胞系。经过2周杀稻瘟霉素筛选,获得稳定表达的细胞系。经RT-PCR鉴定,转染Id1 mRNA真核表达载体的细胞系M1表达水平低于对照组。未转染组与阴性对照转染组无明显差异。     

凝血因子Ⅷ野生型pIRES2-ZsGreen1真核表达载体的构建及鉴定

目的本研究以含有凝血因子Ⅷ(FⅧ)cDNA的pCI/FⅧ质粒为模板构建真核表达载体pIRES2-ZsGreen1/FⅧ并进行鉴定,在HEK-293细胞中表达。方法以pCI/FⅧ质粒为模板,扩增出FⅧ的开放阅读框(ORF)区,使用Infusion酶对线性pIRES2-ZsGreen1双酶切产物及FⅧORF扩增产物进行连接,连接产物进行转化后筛选阳性克隆,对阳性克隆进行DNA测序及凝胶电泳鉴定。野生型pIRES2-ZsGreen1/FⅧ转染HEK-293细胞后,采用实时定量聚合酶链反应(PCR)检测野生型FⅧ基因mRNA表达水平。结果成功构建pIRES2-ZsGreen1/FⅧ并转染入HEK-293细胞中,实时定量PCR检测FⅧmRNA在HEK-293细胞中的表达,激光共聚焦显微镜观察转染情况。结论为实时观察FⅧ真核表达载体在HEK-293细胞中的表达及FⅧ基因突变导致血友病A的分子发病机制的研究奠定实验基础。     

SARI基因真核表达载体的构建及稳定转染HeLa细胞系的建立

目的构建人SARI基因真核表达载体,并建立稳定转染的HeLa细胞系。方法采用RT-PCR技术从正常人外周血单个核细胞cDNA文库中扩增SARI基因序列,连接插入至pCMV-N-Flag真核表达载体,并对重组质粒进行酶切及测序鉴定;阳离子聚合物介导重组质粒转染HeLa细胞后,用G418抗生素筛选稳定转染的细胞系。间接免疫荧光检测Flag-SARI融合蛋白在HeLa细胞系中的表达定位。RT-PCR及Western blot检测SARI mRNA及蛋白的表达变化。结果双酶切和DNA测序表明pCMV-Flag-SARI真核表达质粒构建成功。经G418筛选后,RT-PCR和Western blot表明,转染重组质粒的HeLa细胞系中SARI mRNA及蛋白的表达明显升高。间接免疫荧光结果显示,Flag-SARI融合蛋白在HeLa细胞系的胞质和胞核中均有表达,且胞质荧光信号强于胞核。结论成功构建pCMV-Flag-SARI真核表达载体,表达的FlagSARI蛋白主要定位于HeLa细胞系的胞质中。     

人雌激素受体β绿色荧光蛋白真核表达载体的构建与表达

目的构建人雌激素受体β(ERβ)绿色荧光蛋白(GFP)真核表达载体,并稳定转染乳腺癌MCF-7细胞。方法通过双酶切将pCMV5-hERβ中的人ERβcDNA克隆到pEGFP-C3中,构建并鉴定重组质粒pEGFP-hERβ,然后转染乳腺癌MCF-7细胞,采用G418(500μg/mL)筛选出稳定转染的细胞系,在荧光显微镜下观察融合蛋白质在真核细胞内的表达分布,并采用逆转录-聚合酶链反应(RT-PCR)检测ERβ的mRNA转录水平。结果成功构建重组表达载体pEGFP-hERβ,有效转染并筛选出稳定转染ERβ基因的MCF-7细胞系,外源性ERβ基因在MCF-7细胞中获得了有效转录,并在细胞质和细胞核中均广泛分布。结论建立了稳定表达ERβ的MCF-7细胞系,为筛选ERβ调节剂和进一步研究ERβ在乳腺癌中的作用及其机制奠定基础。     

中介素真核表达质粒的构建及其在大鼠近端肾小管上皮细胞中的表达

目的构建带有绿色荧光蛋白的中介素(IMD)真核表达质粒pIRES2-EGFP/IMD,并转染大鼠近端肾小管上皮细胞系(NRK-52E)。方法合成带有IMD基因片段的pMD19-TSimple/IMD质粒,将pMD19-TSimple/IMD质粒和pIRES2-EGFP载体双酶切之后进行高效连接,将IMD亚克隆至pIRES2-EGFP上,对重组表达载体进行酶切、测序鉴定。采用FuGENEHD转染试剂转染NRK-52E细胞,荧光显微镜下观察绿色荧光蛋白。提取细胞mRNA和蛋白,反转录-聚合酶链反应(RT-PCR)方法检测基因表达,Western检测IMD蛋白表达。结果经限制性酶切鉴定及测序分析证实pIRES2-EGFP/IMD载体序列正确;荧光显微镜下可见转染的NRK-52E细胞有绿色荧光蛋白的表达,经RT-PCR和Western测定分析,转染细胞IMD基因及蛋白的表达增加。结论pIRES2-EGFP/IMD载体构建成功,并在NRK-52E细胞内成功表达。     

肝素寡糖通过抑制PKC-α影响血管平滑肌细胞增殖的作用(英文)

为考察肝素寡糖对血管平滑肌细胞增殖的抑制作用,并探索其相关细胞内信号转导机制,采用cell-based ELISA法、RT-PCR法、Western blotting法和免疫细胞化学法检测细胞内PKC-α蛋白水平和mRNA水平;采用RT-PCR法检测c-jun、c-myc和c-fos等3种原癌基因的mRNA水平。结果显示,肝素寡糖可以抑制新生牛血清诱导的PKC-α和原癌基因的表达,这可能是肝素寡糖抑制血管平滑肌细胞增殖的机制之一;流式细胞实验结果显示,肝素寡糖能将细胞阻滞于G0/G1期,从而阻断细胞周期进程。综上所述,肝素寡糖可能通过抑制PKC-α表达,进而抑制原癌基因的表达,阻断细胞G1/S期转换,从而抑制血管平滑肌细胞的增殖。     

血管内皮生长因子过表达载体和干扰载体的构建及其对Lewis肺癌细胞的干预

目的:探讨血管内皮生长因子(VEGF)过表达载体和干扰载体对Lewis肺癌细胞的干预作用。方法:构建VEGF过表达载体pIRES2-VEGF-GFP和干扰载体psiRNA-VEGF-GFP,脂质体法介导转染Lewis肺癌细胞;荧光显微镜观察细胞GFP蛋白的表达状态;MTT法和流式细胞术分别检测各组细胞生长差异和细胞周期变化;Western-Blot检测细胞转染前后VEGF蛋白表达量的变化。结果:送检测序的质粒图谱正确,经转染Lewis肺癌细胞后建立了稳定表达模型;过表达VEGF组可见稳定的绿色荧光蛋白表达;过表达VEGF进入S期的细胞达到45.3%,未转染组为29.1%;干扰其表达后细胞的生长受阻,细胞周期阻滞在G0/G1期的比率达74.5%。过表达VEGF组VEGF蛋白的表达量约为未转染Lewis肺癌细胞的3倍;干扰VEGF表达后VEGF蛋白的表达下调。结论:本实验成功构建了VEGF过表达载体和干扰载体,并在Lewis肺癌细胞中建立了稳定表达模型,初步证实VEGF能够促进肺癌细胞恶性进展。     

小鼠p27~(kip1)真核表达载体的构建及其对单个核细胞周期的影响

目的构建小鼠p27kip1真核表达载体,探讨其对单个核细胞生长情况和细胞周期的影响,为进一步研究p27kip1在疾病防治中的作用奠定基础。方法将小鼠p27kip1基因克隆至pcDNA3.0真核表达载体上,并经脂质体介导转染至小鼠单个核细胞中,应用MTT法和流式细胞仪分析转染细胞生长情况和细胞周期。结果经酶切分析和测序鉴定,成功构建了小鼠pcDNA3.0/p27kip1重组质粒;经pcDNA3.0/p27kip1转染的单个核细胞中p27蛋白表达增多,其生长增殖不仅受到明显抑制,而且处于G1/G0期的细胞明显增加,处于S期的细胞明显减少。结论构建的pcDNA3.0/p27kip1真核表达载体能够在单个核细胞中表达,且高表达的pcD-NA3.0/p27kip1可以通过抑制细胞周期的方式抑制单个核细胞的生长。     

Transforming growth factor-β1 upregulates the expression of CXC chemokine receptor 4 （CXCR4） in human breast cancer MCF-7 cells

Aim:

To investigate whether rhTGF-β1 or a recombinant vector encoding a fusion protein comprising an extracellular domain of TGF-β receptor II and an IgG Fc fragment) affects the regulation of CXC chemokine receptor 4 (CXCR4) expression in MCF-7 human breast cancer cells.

Methods:

MCF-7 breast cancer cells were treated with rhTGF-β1 or transfected with a recombinant vector, pIRES2-EGFP-TβRII-Fc. Expression of CXCR4 in these cells was then analyzed at the mRNA and protein levels by quantitative RT-PCR and flow cytometry assay, respectively. A transwell assay was used to measure the chemotactic response of these cells to SDF-1α.

Results:

CXCR4 mRNA and protein expression were upregulated in TGF-β1-treated MCF-7 cells. These cells also demonstrated an enhanced chemotactic response to SDF-1α. In MCF-7 cells transiently transfected with pIRES2-EGFP-TβRII-Fc, a fusion protein named TβRII-Fc (approximately 41 kDa) was produced and secreted. In these transfected cells, there was a reduction in CXCR4 expression and in the SDF-1α-mediated chemotactic response.

Conclusion:

TGF-β1 upregulated CXCR4 expression in MCF-7 cells, which subsequently enhanced the SDF-1α-induced chemotactic response. The results suggest a link between TGF-β1 and CXCR4 expression in MCF-7 human breast cancer cells, which may be one of the mechanisms of TGF-β1-mediated enhancement of metastatic potential in breast cancer cells.     

Regulation of c-fos and c-jun gene expression by lipopolysaccharide and cytokines in primary cultured astrocytes: effect of PKA and PKC pathways

The effects of lipopolysaccharide (LPS) and several cytokines on the c-fos and c-jun mRNA expression were examined in primary cultured astrocytes. Either LPS (500 ng/mL) or interferon-gamma (IFN-gamma; 5 ng/mL) alone increased the level of c-fos mRNA (1 h). However, tumor necrosis factor-alpha (TNF-alpha; 10 ng/mL) or interleukin-1beta (IL-1beta; 5 ng/mL) alone showed no significant induction of the level of c-fos mRNA. TNF-alpha showed a potentiating effect in the regulation of LPS-induced c-fos mRNA expression, whereas LPS showed an inhibitory action against IFN-gamma-induced c-fos mRNA expression. LPS, but not TNF-alpha, IL-1beta and IFN-gamma, increased the level of c-jun mRNA (1 h). TNF-alpha and IFN-gamma showed an inhibitory action against LPS-induced c-jun mRNA expression. Both phorbol 12-myristate 13-acetate (PMA; 2.5 mM) and forskolin (FSK; 5 mM) increased the c-fos and c-jun mRNA expressions. In addition, the level of c-fos mRNA was expressed in an antagonistic manner when LPS was combined with PMA. When LPS was co-treated with either PMA or FSK, it showed an additive interaction for the induction of c-jun mRNA expression. Our results suggest that LPS and cytokines may be actively involved in the regulation of c-fos and c-jun mRNA expressions in primary cultured astrocytes. Moreover, both the PKA and PKC pathways may regulate the LPS-induced c-fos and c-jun mRNA expressions in different ways.     

氨氯地平对人乳腺癌细胞MCF-7细胞的抑制作用及机制研究

目的观察氨氯地平对人乳腺癌细胞MCF-7周期、周期蛋白相关基因及产物表达的影响,探讨氨氯地平对人乳腺癌MCF-7细胞周期的影响及其机制。方法MTT检测细胞增殖;流式细胞仪分析细胞周期;RT-PCR技术检测细胞周期相关基因cyclinD1、p21mRNA的表达;Western blot检测细胞周期蛋白cyclinD1、p21的蛋白表达。结果氨氯地平剂量和时间依赖性的抑制人乳腺癌MCF-7细胞增殖,IC50为14.439μmol.L-1。经7.22μmol.L-1(1/2IC50)、14.439μmol.L-1(IC50)、28.88μmol.L-1(2IC50)的氨氯地平作用人乳腺癌MCF-7细胞48h,G0/G1期细胞较对照组明显增高(P<0.05);并使人乳腺癌MCF-7细胞中cyclinD1mRNA及蛋白表达降低;p21mRNA及蛋白表达升高。结论氨氯地平对人乳腺癌MCF-7细胞具有抗增殖作用,并使细胞阻滞于G1期。其G1阻滞机制可能与调控细胞周期相关基因cyclinD1、p21mRNA及蛋白的表达相关。     

宫颈癌中激活蛋白 1 通路的活化及临床意义

目的：探讨激活蛋白1（AP-1）信号通路的重要组分c-jun和c-fos在宫颈癌中的表达及临床意义。方法免疫组织化学（ SP）法检测c-jun和c-fos在70例宫颈鳞状细胞癌、30例宫颈上皮内瘤变及20例慢性宫颈炎中的表达情况,同时分析其与宫颈癌临床病理特征和预后的关系。结果70例宫颈癌中c-jun和c-fos的阳性表达率分别为57.1％（40/70）、60.0％（42/70）,在30例宫颈上皮内瘤变的表达阳性率分别为53.3％（16/30）、63.3％（19/30）,而在20例慢性宫颈炎的表达阳性率均为0;宫颈癌组与宫颈炎组相比差异有统计学意义（P＜0.01）,宫颈癌组与宫颈上皮瘤病变组相比差异无统计学意义（P＞0.05）。 c-jun和c-fos表达与宫颈癌的临床分期、组织学分级、淋巴结转移等分组中差异具有统计学意义（P＜0.05）,但与患者年龄及肿瘤的大小等分组中的表达差异无统计学意义（P＞0.05）。 c-jun和c-fos在宫颈癌的表达呈正相关（r＝0.67,P＜0.05）。结论 AP-1信号通路活化可能与宫颈鳞状细胞癌发生发展相关,c-jun和c-fos在致瘤过程中可能起协同作用。     

Activations of c-fos/c-jun signaling are involved in the modulation of hypothalamic superoxide dismutase (SOD) and neuropeptide Y (NPY) gene expression in amphetamine-mediated appetite suppression

Amphetamine (AMPH) is known as an anorectic agent. The mechanism underlying the anorectic action of AMPH has been attributed to its inhibitory action on hypothalamic neuropeptide Y (NPY), an appetite stimulant in the brain. This study was aimed to examine the molecular mechanisms behind the anorectic effect of AMPH. Results showed that AMPH treatment decreased food intake, which was correlated with changes of NPY mRNA level, but increased c-fos, c-jun and superoxide dismutase (SOD) mRNA levels in hypothalamus. To determine if c-fos or c-jun was involved in the anorectic response of AMPH, infusions of antisense oligonucleotide into the brain were performed at 1 h before daily AMPH treatment in freely moving rats, and the results showed that c-fos or c-jun knockdown could block this anorectic response and restore NPY mRNA level. Moreover, c-fos or c-jun knockdown could partially block SOD mRNA level that might involve in the modulation of NPY gene expression. It was suggested that c-fos/c-jun signaling might involve in the central regulation of AMPH-mediated feeding suppression via the modulation of NPY gene expression.     

含绿色荧光蛋白及人胰岛素基因的真核表达载体的构建

目的构建含绿色荧光蛋白(GFP)基因与人胰岛素基因的重组真核表达载体。方法将人胰岛素基因插入到真核表达载体pIRES2-EGFP的EcoRⅠ和BamHⅠ位点中,构建重组质粒pIRES2-EGFP-INS。酶切鉴定,测序证实。结果重组真核表达载体pIRES2-EGFP-INS经限制性内切酶EcoRⅠ和BamHⅠ酶切,电泳后显示360bp的INS的目的片段和5.3kb的pIRES2-EGFP载体片段,进一步测序并证明重组质粒连接正确。结论成功构建了pIRES2-EGFP-INS重组质粒,为简便快速了解胰岛素基因的转染效率奠定了基础。