转染kiss-1基因对人食管癌EC9706细胞裸鼠移植瘤的抑制作用

目的:研究转染kiss-1基因对人食管癌EC9706细胞裸鼠皮下移植瘤的作用,探讨其在食管癌基因治疗中的可行性和特异性.方法:在食管癌细胞系EC9706中转染kiss-1基因,经G418筛选,建立稳定高表达Kiss-1蛋白的细胞系.稳定表达该基因的细胞为转染kiss-1基因组,转染空质粒细胞及未处理细胞为对照组,建立裸鼠荷瘤模型;监测肿瘤生长变化,HE染色观察肿瘤病理学变化,RT-PCR、Western blot方法检测kiaa-1 mRNA和蛋白变化.结果:转染kiss-1基因组肿瘤生长受到显著抑制:HE染色显示转染kiss-1基因组及转染空质粒纽肿瘤组织内坏死均较空白对照组多;RT-PCR、Western blot结果表明转染kiss-1基因组裸鼠肿瘤组织kiss-1 mRNA和蛋白表达均显著升高,三组间比较差异具有统计学意义(F=72.685,24.807,均P<0.05).结论:转染kiss-1基因能抑制人食管癌EC9706细胞裸鼠皮下移植瘤的形成,且能有效上调kiss-1 mRNA和蛋白的表达,可为食管癌的基因治疗提供新的靶点、开辟新的思路.     

xCT,component of cysteine/glutamate transporter,as an independent prognostic factor in human esophageal squamous cell carcinoma

Background

xCT is a component of the cysteine/glutamate transporter, which plays a key role in glutathione synthesis. The objectives of the present study were to investigate the role of xCT in the regulation of genes involved in cell cycle progression and the clinicopathological significance of its expression in esophageal squamous cell carcinoma (ESCC).

Methods

xCT expression in human ESCC cell lines was analyzed by Western blotting and immunofluorescent staining. Knockdown experiments were conducted with xCT siRNA, and the effect on cell cycle was analyzed. The cells’ gene expression profiles were analyzed by microarray analysis. An immunohistochemical analysis of 70 primary tumor samples obtained from ESCC patients that had undergone esophagectomy was performed.

Results

xCT was highly expressed in TE13 and KYSE170 cells. In these cells, the knockdown of xCT using siRNA inhibited G₁-S phase progression. Microarray analysis identified 1652 genes whose expression levels in TE13 cells were altered by the knockdown of xCT. Pathway analysis showed that the top-ranked canonical pathway was the G₁/S checkpoint regulation pathway, which involves TP53INP1, CDKN1A, CyclinD1/cdk4, and E2F5. Immunohistochemical staining showed that xCT is mainly found in the nuclei of carcinoma cells, and that its expression is an independent prognostic factor.

Conclusions

These observations suggest that the expression of xCT in ESCC cells might affect the G₁/S checkpoint and impact on the prognosis of ESCC patients. As a result, we have a deeper understanding of the role played by xCT as a mediator and/or biomarker in ESCC.     

Construction of Eukaryotic Expression Vector with mBD1-mBD3 Fusion Genes and Exploring Its Activity against Influenza A Virus

Influenza (flu) pandemics have exhibited a great threat to human health throughout history. With the emergence of drug-resistant strains of influenza A virus (IAV), it is necessary to look for new agents for treatment and transmission prevention of the flu. Defensins are small (2–6 kDa) cationic peptides known for their broad-spectrum antimicrobial activity. Beta-defensins (β-defensins) are mainly produced by barrier epithelial cells and play an important role in attacking microbe invasion by epithelium. In this study, we focused on the anti-influenza A virus activity of mouse β-defensin 1 (mBD1) and β defensin-3 (mBD3) by synthesizing their fusion peptide with standard recombinant methods. The eukaryotic expression vectors pcDNA3.1(+)/mBD1-mBD3 were constructed successfully by overlap-PCR and transfected into Madin-Darby canine kidney (MDCK) cells. The MDCK cells transfected by pcDNA3.1(+)/mBD1-mBD3 were obtained by G₄₁₈ screening, and the mBD1-mBD3 stable expression pattern was confirmed in MDCK cells by RT-PCR and immunofluorescence assay. The acquired stable transfected MDCK cells were infected with IAV (A/PR/8/34, H1N1, 0.1 MOI) subsequently and the virus titers in cell culture supernatants were analyzed by TCID₅₀ 72 h later. The TCID₅₀ titer of the experimental group was clearly lower than that of the control group (p < 0.001). Furthermore, BALB/C mice were injected with liposome-encapsulated pcDNA3.1(+)/mBD1-mBD3 through muscle and then challenged with the A/PR/8/34 virus. Results showed the survival rate of 100% and lung index inhibitory rate of 32.6% in pcDNA3.1(+)/mBD1-mBD3group; the TCID₅₀ titer of lung homogenates was clearly lower than that of the control group (p < 0.001). This study demonstrates that mBD1-mBD3 expressed by the recombinant plasmid pcDNA3.1(+)/mBD1-mBD3 could inhibit influenza A virus replication both in vitro and in vivo. These observations suggested that the recombinant mBD1-mBD3 might be developed into an agent for influenza prevention and treatment.     

The expression and role of Aquaporin 5 in esophageal squamous cell carcinoma

Background

Aquaporins (AQPs) are water channel proteins that facilitate transcellular water movements. Recent studies have shown that AQP5 is expressed in various cancers, and plays a role in tumor progression. However, its expression and role in esophageal squamous cell carcinoma (ESCC) have not been investigated. We examined the pathophysiologic role of AQP5 in cell proliferation and survival, and also investigated its expression and effects on the prognosis of ESCC patients.

Methods

AQP5 expression in human ESCC cell lines was analyzed by Western blot testing. Knockdown experiments with AQP5 siRNA were conducted, and the effects on cell proliferation, cell cycle progression, and cell survival were analyzed. The cells’ gene expression profiles were analyzed by microarray analysis. Immunohistochemistry of AQP5 for 68 primary tumor samples obtained from ESCC patients undergoing esophagectomy was performed.

Results

AQP5 expression was high in TE2 and TE5 cells. In these cells, the knockdown of AQP5 using siRNA inhibited cell proliferation and G₁-S phase progression, and induced apoptosis. The AQP5 siRNA transfected TE5 cells showed significant increase in p21 and decrease in CCND1 mRNA expression, respectively. The expression pattern of AQP5 and p21 protein was sharply contrasted, but AQP5 and CCND1 protein expression showed a similar pattern in ESCC tissue. These findings agree with the microarray results. Immunohistochemical staining of 68 ESCC patients showed the AQP5 expression is associated with tumor size, histological type, and tumor recurrence.

Conclusion

The AQP5 expression in ESCC cells may affect cell proliferation and survival, and impact on the prognosis of ESCC patients.     

重组转化生长因子β3基因对大鼠肝星状细胞Ⅰ型胶原表达的影响

目的观察转化生长因子D3基因（TGFβ3）对大鼠肝星状细胞株（HSC—T6）Ⅰ型胶原合成的影响。方法TGFβ3表达质粒[pcDNA3．1（＋）-TGFβ31和TGFβ1表达质粒[pcDNA3．1（＋）-TGFD11的构建。通过脂质体介导方法，将pcDNA3．1（＋）-TGFβ1、pcDNA3．1（＋）-TGFβ3分别及共同转染体外培养的HSC—T6细胞，荧光定量PCR法及Westernblot法分别检测转染后TGFβ1、TGFD3、Ⅰ型胶原mRNA及蛋白质的表达。将pcDNA3．1（＋）-TGFD1转染HSC—T6细胞，经G418筛选建立高表达TGFD1的HSC～T6细胞克隆，pcDNA3．1（＋）-TGFD3转染克隆细胞，荧光定量PCR法检测转染后TGFβ3、TGFβ1及Ⅰ型胶原mRNA的表达，Westernblot法检测TGFβ1、Ⅰ型胶原蛋白的表达情况。结果构建的pcDNA3．1（＋）TGFD3、pcDNA3．1（＋）-TGFD1质粒可转染HSC—T6细胞，转染率28．2％。pcDNA3．1（＋）TGF侈3转染细胞后，Ⅰ型胶原mRNA及蛋白的表达较空白组及对照组增加，以72h增高最为明显（P〈0．05）；共转染组Ⅰ型胶原mRNA及蛋白质的表达较pcDNA3．1（＋）-TGFβ1转染组明显降低（P〈0．05）。TGF侈3转染克隆细胞后，TGFD1mRNA表达较克隆组无明显改变（P〉0．05），而蛋白质表达明显下降（P〈0．05），Ⅰ型胶原mRNA及蛋白质表达均较克隆组明显降低（P〈0．05）。结论TGFD3基因转染正常培养的HSC—T6细胞，增加Ⅰ型胶原的表达；转染高表达TGFβ1的克隆组HSC—T6细胞，Ⅰ型胶原表达明显降低，提示TGFβ3对肝纤维化的发生有抑制作用。     

家蝇抗菌肽基因Cecropin在COS-7细胞中的表达及产物活性初步研究

目的初步研究家蝇抗菌肽Cecropin cDNA在非洲绿猴肾细胞株COS-7中的表达及其产物的抗菌作用。方法以Cecropin基因为模板设计2条特异引物,扩增在C端含6×His标签的Cecropin开放阅读框序列,将此序列与真核表达载体pcDNA3.1(+)进行重组,构建重组质粒pcDNA3.1(+)/Cecropin-His_6。以脂质体LipofectamineTM2000为载体,对COS-7细胞进行重组质粒pcDNA3.1(+)/Cecropin-His_6和空载体pcDNA3.1(+)的转染,72h后收集细胞培养上清液,表达产物经His-TrapHP亲合层析柱分离纯化和Tricine-SDS-PAGE电泳鉴定后,进行杀菌活性的初步检测。结果转染了重组质粒pcDNA3.1(+)/Cecropin-His_6细胞培养上清液的纯化物,行Tricine-SDS-PAGE电泳得到与预期分子量大小相符的单一目的条带,该纯化物对大肠杆菌E.coli K12D31具有一定的杀菌活性。结论家蝇抗菌肽Cecropin cDNA在COS-7中得到了正确表达。     

HIV-1B亚型核心蛋白gag基因真核表达载体的构建及其在HepG2细胞中的表达

目的克隆人类免疫缺陷病毒Ⅰ型B亚型核心蛋白gag基因,构建真核表达载体,并在真核细胞中表达,为进一步制备自行设计的以λ噬菌体作为载体的HIV核酸疫苗奠定基础。方法以克隆好的HIV1B亚型U26942全基因质粒DNA作为模板,根据Genbank中gag基因的核苷酸序列设计引物,并在引物的5’端分别引入BamHⅠ及XhoⅠ酶切位点,特异性的扩增gag基因。TA克隆后经双酶切、测序等鉴定重组质粒,再经双酶切、连接构建含gag编码基因的真核表达载体,并进行酶切鉴定分析pcDNA3.1(+)/gag。在脂质体介导下转染HepG2细胞,经G418压力筛选建立稳定转染gag基因的细胞系,用RT PCR及Western印迹检测其在HepG2细胞中的表达。结果重组质粒经BamHⅠ、XhoⅠ双酶切成5.4kb与1.5kb的片断,表明表达载体pcDNA3.1(+)中插入了gag基因片断,测序结果表明编码框正确。RT PCR及Western印迹证实稳定转染gag基因的HepG2细胞系中有该基因的表达。结论成功构建了HIV1B亚型核心蛋白gag基因的真核表达载体pcDNA3.1(+)/gag,并在HepG2细胞中获得稳定表达。     

miR-21 targets and inhibits tumor suppressor gene PTEN to promote prostate cancer cell proliferation and invasion: An experimental study

Objective: To study whether miR-21 targets and inhibits tumor suppressor gene PTEN can promote prostate cancer cell proliferation and invasion,Methods: Prostate cancer cell lines PC-3 were cultured and divided into negative control group(NC group),miR-21 group,pc DNA3.1 group,miR-21+pc DNA3.1 group and miR-21+PTEN group that were transfected with different mi R and plasmid,respectively,After 12 h and 24 h of transfection,the cell viability and invasive cell number were determined; after 24 h of transfection,Bcl-2,Survivin,MMP2,MMP9,PTEN,PI3 K,and AKT expression in cells were determined,Results: After 12 h and 24 h of transfection,OD value and invasive cell number of miR-21 group were significantly higher than those of NC group; after 24 h of transfection,Bcl-2,Survivin,MMP2,MMP9,PI3 K and AKT expression levels were significantly higher than those of NC group while PTEN expression level was significantly lower than that of NC group; after 12 h and 24 h of transfection,OD value and invasive cell number of mi R-21+pcDNA3.1 group were significantly higher than those of pc DNA3.1 group,and the OD value and invasive cell number of mi R-21+PTEN group were significantly lower than those of mi R-21+pcDNA3.1 group; after 24 h of transfection,Bcl-2,Survivin,MMP2 and MMP9 content of mi R-21+pc DNA3.1 group were significantly higher than those of pcDNA3.1 group,and Bcl-2,Survivin,MMP2 and MMP9 content of miR-21+PTEN group were significantly lower than those of mi R-21+pcDNA3.1 group,Conclusions: miR-21 can target and inhibit tumor suppressor gene PTEN expression to promote prostate cancer cell proliferation and invasion.     

Analysis of gene expression profile induced by EMP-1 in esophageal cancer cells using cDNA Microarray

AIM: To obtain human esophageal cancer cell EC9706 stably expressed epithelial membrane protein-1 (EMP-1) with integrated eukaryotic plasmid harboring the open reading frame (ORF) of human EMP-1, and then to study the mechanism by which EMP-1 exerts its diverse cellular action on cell proliferation and altered gene profile by exploring the effect of EMP-1. METHODS: The authors first constructed pcDNA3.1/myc-his expression vector harboring the ORF of EMP-1 and then transfected it into human esophageal carcinoma cell line EC9706. The positive clones were analyzed by Western blot and RT-PCR. Moreover, the cell growth curve was observed and the cell cycle was checked by FACS technique. Using cDNA microarray technology, the authors compared the gene expression pattern in positive clones with control. To confirm the gene expression profile, semi-quantitative RT-PCR was carried out for 4 of the randomly picked differentially expressed genes. For those differentially expressed genes, classification was performed according to their function and cellular component. RESULTS: Human EMP-1 gene can be stably expressed in EC9706 cell line transfected with human EMP-1. The authors found the cell growth decreased, among which S phase was arrested and G1 phase was prolonged in the transfected positive clones. By cDNA microarray analysis, 35 genes showed an over 2.0 fold change in expression level after transfection, with 28 genes being consistently up-regulated and 7 genes being down-regulated. Among the classified genes, almost half of the induced genes (13 out of 28 genes) were related to cell signaling, cell communication and particularly to adhesion. CONCLUSION: Overexpression of human EMP-1 gene can inhibit the proliferation of EC9706 cell with S phase arrested and G1 phase prolonged. The cDNA microarray analysis suggested that EMP-1 may be one of regulators involved in cell signaling, cell communication and adhesion regulators.     

HIF-1α induces VE-cadherin expression and modulates vasculogenic mimicry in esophageal carcinoma cells

AIM: To investigate whether hypoxia inducible factor (HIF)-1α modulates vasculogenic mimicry (VM) by upregulating VE-cadherin expression in esophageal squamous cell carcinoma (ESCC).METHODS: Esophageal squamous cancer cell lines Eca109 and TE13 were transfected with plasmids harboring small interfering RNAs targeting HIF-1α or VE-cadherin. The proliferation and invasion of esophageal carcinoma cells were detected by MTT and Transwell migration assays. The formation of tubular networks of cells was analyzed by 3D culture in vitro. BALB/c nude mice were used to observe xenograft tumor formation. The relationship between the expression of HIF-1α and VE-cadherin, ephrinA2 (EphA2) and laminin5γ2 (LN5γ2) was measured by Western blot and real-time polymerase chain reaction.RESULTS: Knockdown of HIF-1α inhibited cell proliferation (32.3% ± 6.1% for Eca109 cells and 38.6% ± 6.8% for TE13 cells, P < 0.05). Both Eca109 and TE13 cells formed typical tubular networks. The number of tubular networks markedly decreased when HIF-1α or VE-cadherin was knocked down. Expression of VE-cadherin, EphA2 and LN5γ2 was dramatically inhibited, but the expression of matrix metalloproteinase 2 had no obvious change in HIF-1α-silenced cells. Knockdown of VE-cadherin significantly decreased expression of both EphA2 and LN5γ2 (P < 0.05), while HIF-1α expression was unchanged. The time for xenograft tumor formation was 6 ± 1.2 d for Eca109 cells and Eca109 cells transfected with HIF-1α Neo control short hairpin RNA (shRNA) vector, and 8.4 ± 2.1 d for Eca109 cells transfected with an shRNA against HIF-1α. Knockdown of HIF-1α inhibited vasculogenic mimicry (VM) and tumorigenicity in vivo.CONCLUSION: HIF-1α may modulate VM in ESCC by regulating VE-cadherin expression, which affects VM formation through EphA2 and LN5γ2.     

MORF4基因诱导HeLa细胞衰老

目的建立MORF4基因高表达诱导HeLa细胞衰老模型,探索MORF4基因对HeLa细胞衰老的影响。方法分别将pcDNA3.1(+)/Flag-MORF4和pcDNA3.1(+)空载质粒转染人宫颈癌HeLa细胞株。SA-β-Gal染色检测细胞衰老,MTT法及流式细胞术检测细胞周期变化及细胞的增殖活力,两者共同确定MG-132处理的最适条件。Western印迹检测MORF4、PCNA基因的表达。结果质粒经酶切和测序鉴定,证明pcD-NA3.1(+)/Flag-MORF4质粒中含有目的基因序列;经浓度梯度1.25、2.5、5、10μmol/L MG-132处理转染细胞2、4、24、48 h后,SA-β-Gal染色和MTT检测结果显示10μmol/L MG-132处理24 h的转染细胞明显衰老,细胞活力降低;细胞周期被阻滞在G0/G1期,S期细胞明显减少,增殖受到抑制;Western印迹检测结果显示MORF4蛋白在细胞中的含量明显升高,而与增殖相关基因PCNA表达下调。结论构建的pcDNA3.1(+)/Flag-MORF4质粒在HeLa细胞中表达;并在MG-132作用下,使MORF4基因的表达产物积累,从而影响PCNA蛋白的表达量,抑制HeLa细胞的增殖活性,阻滞细胞周期的进行,导致细胞进入衰老状态。     

乙型肝炎病毒表面抗原基因启动子Ⅰ结合蛋白1反式调节基因的筛选

目的应用表达谱基因芯片技术，研究乙型肝炎病毒(HBV)表面抗原基因启动子DNA结合蛋白1(SBP1)反式调节基因，阐明SBP1蛋白可能的分子生物学功能。方法设计并合成SBP1基因序列特异性的引物，应用聚合酶链反应(PCR)技术扩增SBP1基因片段，以常规的分子生物学技术将获得的SBP1编码基因片段克隆到TA载体中进行核苷酸序列测定，构建真核表达载体pcDNA3．1(-)-SBP1。以脂质体转染肝母细胞瘤细胞系HepG2，提取mRNA，逆转录为cDNA，与转染空表达载体pcDNA3．1(-)的HepG2细胞进行cDNA芯片分析。结果构建的表达载体经过限制性内切酶分析和DNA序列测定，证实准确无误。提取高质量的mRNA，逆转录为cDNA，进行cDNA芯片分析。在1152个基因容量的表达谱芯片的筛选中，发现有12个基因表达水平显著上调，6个基因表达水平显著下调。结论应用基因表达谱芯片成功筛选了SBP1转染细胞后差异表达基因，为进一步阐明SBP1蛋白可能的生物学功能提供依据。     

霍乱肠毒素ctxA基因真核表达重组质粒的构建及表达

目的 构建霍乱肠毒素A亚单位基因（ctxA）真核表达重组质粒，并在NIH3T3细胞中进行表达。方法 用限制性核酸内切酶从重组质粒pET32a—ctxA上切下ctxA基因，导入真核表达载体peDNA3．1（＋）．重组子pcDNA3．1-ctxA经限制性酶切分析、PCR鉴定和序列测定正确后，用脂质体法将重组质粒pcDNA3．1-ctxA转染NIH3T3细胞，采用免疫荧光法和Westernblot对peDNA3．1-ctxA的瞬时表达产物和稳定表达产物进行鉴定。结果 重组质粒peD—NA3．1-ctxA成功转入NIH3T3细胞。利用免疫荧光技术在NIH3T3细胞膜和细胞浆中检测到了瞬时表达，用Westernblot检测到转染的阳性细胞克隆稳定表达出约29ku的蛋白。结论 成功构建霍乱肠毒素A亚单位基因真核表达重组质粒peDNA3．1-ctxA，并在NIH3T3细胞中表达出29ku的CTA蛋白。     

血管内皮细胞生长因子真核表达质粒的构建及其在心肌细胞中的表达

目的 :构建血管内皮细胞生长因子 （ VEGF1 65）真核表达质粒 pc DNA3 .1（ -） /h VEGF1 65,并通过转染心肌细胞来验证其生物活性。方法 :应用 DNA重组方法 ,将编码 h VEGF1 65全长 c DNA克隆于真核表达载体 pc DNA3 .1（ -）中 ,构建 pc DNA3 .1（ -） /h VEGF1 65真核表达质粒 ;应用阳性脂质体介导的基因转染技术 ,将真核表达质粒 pc D-NA3 .1（ -） /h VEGF1 65瞬时转染培养的大鼠心肌细胞中 ;采用 RT-PCR,ELISA,Western blot及免疫组化染色等方法检测 VEGF1 65基因在心肌细胞中的表达情况 ;应用 MTT法检测转染后细胞上清液中 VEGF1 65的生物活性。结果 :将构建好的真核表达质粒 pc DNA3 .1（ -） /h VEGF1 65转染心肌细胞后 ,VEGF m RNA及蛋白表达水平明显增高 ,转染后的心肌细胞培养上清液具有促使内皮细胞增殖的生物活性。结论 :成功构建了真核表达质粒 pc DNA3 .1（ -） /h VEGF1 65,其转染心肌细胞后可获得较高水平 VEGF蛋白的表达 ,所表达出 VEGF蛋白具有生物学活性     

Construction of targeted plasmid vector pcDNA3.1-Egr.1p-p16 and its expression in pancreatic cancer JF305 cells induced by radiation in vitro

To construct pcDNA3.1-Egr.1p-p16 recombinant plasmid and investigate the expression of p16 in pancreatic cancer JF305 cells induced by radiation and the feasibility of gene radiotherapy for pancreatic carcinoma.