调控胃癌BGC823细胞PTEN和Livin基因表达的生物学效应

目的 观察在体外培养胃癌BGC823细胞中增加FTEN基因表达,同时沉默Livin基因表达,对胃癌细胞增殖、细胞凋亡以及侵袭转移能力的影响.方法 将已构建的表达FTEN基因的真核表达载体pCL-neo-PTEN、沉默Livin基因的siRNA载体pRNAT-U6.1-Livin、既表达PTEN又沉默Livin重组载体pCL-neo-PTEN-siLivin脂质体包裹后分别转染入胃癌BGC823细胞.逆转录-聚合酶链反应(RT-PCR)和Western blot检测PTEN和Livin mRNA和蛋白表达;测定细胞生长曲线和Caspase-3、9活性;检测细胞凋亡和体外侵袭能力.结果 转染pCL-neo-PTEN-siLivin的胃癌BGC823细胞PTENmRNA(0.897±0.112)和蛋白都呈高表达,Livin mRNA(0. 071±0.009)和蛋白都呈表达沉默.调控组细胞增殖速度减缓、穿透Matrigel的细胞数下降(23.1±3.5);凋亡率(16.72±1.84)、Caspase-3、9活性增加(1.88±0.21、1.07±0.18),与对照组比较差异均有统计学意义(P＜0.05);对BGC823细胞增殖和转移的抑制效果均优于单独增加PTEN基因表达和单独沉默Livin基因表达的效果.结论 同时增加PTEN基因表达和沉默Livin基因表达可有效抑制胃癌BGC823细胞的生长和转移.     

纳米磁流体-单纯疱疹病毒胸苷激酶重组质粒的构建及其对胃癌细胞增殖的影响

目的研究hTERT启动子调控下单纯疱疹病毒胸苷激酶（HSV-tk）重组质粒的构建、在人胃癌细胞BGC823中的表达及对胃癌细胞BGC823增殖的影响。方法构建重组质粒pGL3-hTERT-tk和相应的荧光报告质粒pGL3-hTERT-tk-Luc＋：经纳米磁流体PEG-PEI／Fe304转染胃癌细胞BGC823．荧光显微镜观察细胞形态变化和转染效率．免疫组织化学（免疫组化）方法检测目的基因在胃癌细胞BGC823中的表达．M1Tr法检测胃癌细胞BGC823的增殖能力．以上实验均以正常肝细胞L02为对照。结果重组质粒pGL3-hTERT-tk构建成功,其长度为1100bp。荧光素酶标记的阳性、阴性对照及治疗报告质粒pGL3-hTERT-TK-Luc＋均能有效转染高表达端粒酶活性的胃癌细胞BGC823,转染效率为（28．1±2．3）％。免疫组化结果显示,重组质粒组胃癌细胞BGC823的细胞质中可见大量HSV-tk基因编码的表达。MqT检测结果示．转染pGL3．hTERT-tk质粒4d后．BGC823细胞增殖受抑制．其A,,值为0．254±0．011,低于L02细胞的0．322±0．013;亦低于pGL3-basic-tk转染的BGC823细胞（0．357±0．014）（均P〈0．05）。结论纳米磁流体能将重组质粒pGL3-hTERT．tk转染BGC823细胞并获得表达,PEG-PEI／Fe3O4纳米磁流体-tk可显著抑制BGC823细胞增殖。有望成为胃癌基因治疗的新型生物制剂之一。     

circ_0009910在胃癌细胞中作用机制初步研究

目的通过检测分析胃癌细胞中circ_0009910表达,初步探讨其在胃癌细胞中的作用机制。方法用qRT-PCR检测胃癌细胞系BGC823、SGC7901、AGS、MGC803、MKN45中的circ_0009910表达水平,在BGC823、AGS细胞中采用circ_0009910 siRNA转染敲降circ_0009910,验证转染效果;在circ_0009910敲降的BGC823、AGS细胞中,用MTT法检测细胞增殖、平板法检测集落形成、Transwell检测迁移和侵袭、western-blotting检测上皮间质转化(EMT),采用SPSS 18.0软件进行统计学分析。结果BGC823、SGC7901、AGS、MGC803、MKN45中的circ_0009910相对表达水平为(7.238±0.895)、(5.023±0.786)、(4.184±0.356)、(8.561±1.026)、(3.478±0.301),较正常胃癌显著升高(P<0.01),siRNA转染敲降circ_0009910后,BGC823、AGS细胞活力、集落形成数目、迁移和侵袭能力与对照组相比均明显降低(P<0.01),N-cadherin、Snail蛋白的相对表达降低,而E-cadherin表达增加。结论circ_0009910在胃癌细胞中高表达,可促进胃癌细胞增殖、集落形成、迁移和侵袭及EMT。     

shRNA-CXCR4对人胃癌BGC823细胞增殖迁移的影响

目的 构建针对人CXCR4基因的shRNA干扰表达载体,观察CXCR4基因表达对人胃癌细胞株BGC823细胞增殖和迁移能力的影响.方法 根据人CXCR4序列设计并构建CXCR4基因的shRNA真核表达载体,以脂质体转染的方法将CXCR4干扰质粒转染至人胃癌细胞株BGC823,经G418筛选出稳定转染的阳性细胞,应用流式细胞仪技术检测其细胞周期变化,噻唑蓝(MTT)比色法检测CXCR4干扰对胃癌细胞增殖的影响,采用Trans-well小室法检测细胞体外迁移能力.结果 经测序证明CXCR4的shRNA基因已成功插入Psilencer4.1质粒中,构建的干扰质粒能够显著抑制CXCR4的表达,CXCR4 mRNA被抑制了(2.7±0.2)倍(P＜0.01).CXCR4基因的表达下调将胃癌细胞阻滞在G1期(由84.2％升至94.1％),MTT法检测CXCR4-shRNA干扰细胞增殖(P＜0.05),且穿过Trans -well小室膜的细胞数显著下降(P＜0.05).结论 干扰CXCR4的表达可显著抑制胃癌细胞的增殖和迁移能力.     

莪术醇对胃癌细胞凋亡的影响及机制研究

目的 观察莪术醇对胃癌细胞株BGC823细胞凋亡的影响,并探讨其作用机制.方法 体外培养BGC823细胞,分别加入12.5、25、50、100 mg/L莪术醇培养液,对照组加入10 ml/L无水乙醇培养液,分别孵育24 h和48 h,采用MTT法分析增殖率;应用流式细胞仪检测各浓度莪术醇处理BGC823细胞48 h的凋亡率及细胞周期的分布;分光光度法检测Caspase-3活性;100 mg/L莪术醇孵育BGC823细胞48 h后,用RT-PCR和Western blot法检测Caspase-3、Bcl-2、Bax和Survivin mRNA和蛋白的表达水平.结果 莪术醇抑制BGC823细胞增殖,并且随浓度的增加和时间的延长而加强;不同浓度莪术醇处理BGC823细胞,均使处于G0/G1期的细胞显著增加,S期细胞明显减少(P＜0.05);细胞凋亡率随莪术醇浓度增加而升高(P＜0.05);Caspase-3活性呈浓度依赖性增加(P＜0.05);100 mg/L莪术醇孵育BGC823细胞48 h后,Caspase-3、Bax表达均显著升高(P＜0.05),Survivin、Bcl-2表达均显著下降(P＜0.05),Bcl-2/Bax比值显著降低(P＜0.05).结论 莪术醇对胃癌BGC823细胞生长具有抑制作用,阻滞细胞周期于G0/G1期,并促进其凋亡.其作用与增强Caspase-3的活性,上调Caspase-3、Bax表达,下调Survivin、Bcl-2表达及降低Bcl-2/Bax比值有关.     

纳米磁流体-单纯疱疹病毒胸苷激酶重组质粒的构建及其对胃癌细胞增殖的影响

目的 研究hTERT启动子调控下单纯疱疹病毒胸苷激酶(HSV-tk)重组质粒的构建、在人胃癌细胞BGC823中的表达及对胃癌细胞BGC823增殖的影响.方法 构建重组质粒pGL3 -hTERT-tk和相应的荧光报告质粒pGL3-hTERT-tk-Luc+;经纳米磁流体PEG-PEI/Fe3O4转染胃癌细胞BGC823,荧光显微镜观察细胞形态变化和转染效率,免疫组织化学(免疫组化)方法检测目的基因在胃癌细胞BGC823中的表达,MTT法检测胃癌细胞BGC823的增殖能力,以上实验均以正常肝细胞LO2为对照.结果 重组质粒pGL3-hTERT-tk构建成功,其长度为1100 bp.荧光素酶标记的阳性、阴性对照及治疗报告质粒pGL3-hTERT-TK- Luc+均能有效转染高表达端粒酶活性的胃癌细胞BGC823,转染效率为(28.1±2.3)％.免疫组化结果显示,重组质粒组胃癌细胞BGC823的细胞质中可见大量HSV -tk基因编码的表达.MTT检测结果示,转染pGL3-hTERT-tk质粒4d后,BGC823细胞增殖受抑制,其A570值为0.254±0.011,低于L02细胞的0.322±0.013;亦低于pGL3-basic-tk转染的BGC823细胞(0.357±0.014)(均P＜0.05).结论 纳米磁流体能将重组质粒pGL3-hTERT-tk转染BGC823细胞并获得表达,PEG-PEI/Fe3O4纳米磁流体-tk可显著抑制BGC823细胞增殖,有望成为胃癌基因治疗的新型生物制剂之一.     

腺相关病毒载体介导p27Kip1基因转染骨肉瘤MG-63细胞的研究

目的 观察p27Kip1基因转染后对骨肉瘤MG-63细胞增殖和生存能力的影响.方法 重组质粒在内的三质粒共转染包装、收集腺相关病毒颗粒,检测病毒滴度并感染MG-63细胞,细胞免疫组织化学检测p27Kip1基因的表达,并行细胞增殖实验、细胞周期分析,探讨p27Kip1基因对骨肉瘤MG-63细胞的体外作用.结果 三质粒成功共转染293细胞,X-gal染色观察转染率为60%;采用CPE法(微量全细胞病变法)检测病毒滴度1.6×108 PFU/ml;细胞免疫细胞化学鉴定p27Kip1基因高表达;细胞生长曲线显示转染组细胞增殖明显减慢;流式细胞仪观察转染AAV-p27Kip1组细胞周期见S、G2期细胞比例明显降低,G0/G1期细胞比例增高.结论 p27Kip1基因重组腺相关病毒感染骨肉瘤MG-63细胞后能高表达目的 基因,并阻滞细胞于G1/S期,从而显著抑制骨肉瘤MG-63细胞增殖.     

穿心莲内酯体外对人胃腺癌BGC823细胞增殖凋亡的影响

目的探讨穿心莲内酯（andrographolide,AD）对人胃癌细胞株BGC-823细胞增殖、细胞周期以及细胞凋亡的影响。方法分别采用MTT法、流式细胞术和流式细胞仪AnnexinV／PI双染色法检测AD对BGC-823细胞体外增殖、细胞周期和细胞凋亡的影响：应用光镜和透射电镜观察不同浓度的AD作用后BGC．823细胞形态学改变。结果各浓度组AD均对人低分化胃癌细胞株BGC-823的增殖有抑制作用。并具有时间和浓度依赖关系（均P〈0．05）。浓度7．5μg／ml以下的AD抑制效果较弱,而15．0-60．0μg／ml抑制效果显著提高（P〈0．05）,60．0μg／ml以上抑制率增高不显著（P〉0．05）。24、48和72h的IC50分别为（35．3±4．3）、（25．5±3．5）和（18．2±2．7）μg／ml。BGC-823细胞经AD作用后,G0／G1期细胞的比例增加,S期和G2/M期细胞的比例下降,细胞被阻滞在G0／G1期,呈浓度依赖关系。AD浓度为7．5、10．0和15．0μg／ml组作用24h后,早期凋亡率分别为（19．3±4．7）％、（29．4±4．1）％和（52．7±6．7）％,晚期凋亡率为（10．8±1．8）％、（10．9±4．7）％和（14．7±4．8）％,均显著高于阴性对照组的早期凋亡率[（3．4±1．0）％]和晚期凋亡率[（4．1±0．7）％],差异有统计学意义（均P〈0．05）,并呈浓度依赖关系。结论AD能抑制BGC-823细胞增殖、阻滞其细胞周期在G0／G1期和诱导其细胞凋亡．是潜在的胃癌抗肿瘤中药制剂成分。     

5-氮胞苷对EB病毒阳性胃癌细胞的影响

目的体外建立EB病毒阳性胃癌细胞系并探讨去甲基化试剂5-氮胞苷对EB病毒阳性胃癌的辅助治疗作用。方法用cell to cell感染法建立EB病毒阳性胃癌细胞系。用逆转录-聚合酶链反应（RT-PCR）和PCR-southem检测不同剂量5-azacytidine处理前后EB病毒启动子的活性，并用Western blot检测EB病毒相关基因的表达。结果体外感染后筛选的细胞克隆为EB病毒阳性，EBNA免疫荧光染色为阳性。EB病毒相关蛋白的免疫印记显示核蛋白除EBNA1阳性外EBNA2 EBNA3s均为阴性。膜蛋白LMP1也为阴性。5-azacytidine处理后EB病毒阳性胃癌细胞系中被甲基化失活的C启动子重新活化，并表达潜伏性膜蛋白1（LMP1）。且呈剂量依赖性。结论体外通过cell to cell感染方式，可成功建立EB病毒阳性胃癌细胞系。建立的EB病毒阳性胃癌细胞系AGS／EB病毒和NUGC3／EB病毒体外培养呈Ⅰ型潜伏感染。5-azacytidine可能对EB病毒阳性胃癌的特异性治疗有帮助。     

RhoC基因转染对人胆管癌QBC 939细胞增殖和侵袭性的影响

目的研究RhoC（ras homolog gene family，member C）基因对胆管癌QBC939细胞株增殖和侵袭能力的影响。方法以脂质体将RhoC cDNA真核表达载体转染人胆管癌QBC939细胞。应用克隆形成试验检测细胞增殖活性的变化，流式细胞仪检测转染前后细胞周期的变化，Boyden小室侵袭实验检测侵袭能力的变化。结果RhoC基因能促进胆管癌QBC939细胞增殖，流式细胞仪分析结果显示转染后细胞出现G1期细胞减少，侵袭实验显示转染后细胞侵袭能力较转染前有显著加强。结论RhoC基因能够促进胆管癌QBC939细胞株的体外增殖和侵袭能力。     

Molecular characterization of Epstein-Barr virus and oncoprotein expression in nasopharyngeal carcinoma in Korea

BACKGROUND: We evaluated the characteristics of nasopharyngeal carcinoma in Korea, including its clinical, pathologic, and molecular features, especially emphasizing on the EBV strains involved, latent membrane protein 1 (LMP1) expression, and the alterations of matrix metalloproteinase 9 (MMP9) and E-cadherin expression. METHODS.: The presence of EBV was evaluated by EBER in situ hybridization, and the expression of LMP1, MMP9, and E-cadherin by immunohistochemistry. The characterization of EBV type and LMP1 variant was performed by PCR. RESULTS: EBER was detected in 55 of 57 cases (96%) of nonkeratinizing carcinoma (NKC) and undifferentiated carcinoma, but in only four of nine cases (44%) of squamous cell carcinoma (SCC). EBER positivity was much higher in the group with nodal metastases (p =.003). The predominant strain of EBV infection was type A (81%) and a 30-bp deletion LMP1 variant (77%). All EBER-positive SCCs were infected with EBV type A. LMP1 expression was detected in 36 of 59 (61%) patients with latent EBV infection and MMP9 in 41 of these 59 (69%). LMP1 positivity was much higher among the patients aged 50 years and younger. MMP9 expression was associated with LMP1 expression (p =.008), and nodal and distant metastasis (p =.019, p =.045). Loss of E-cadherin expression was correlated with MMP9 and nodal metastasis. The survival rate was much lower in patients with a higher TNM classification, stage, and a histology of SCC. EBER positivity was associated with a better prognosis in the Kaplan-Meier test, but had no prognostic value by Cox regression analysis. Loss of E-cadherin expression and nodal metastasis were also correlated with local recurrence and distant metastasis. CONCLUSION: EBV type and LMP1 variant had no significant influence on the clinicopathologic properties of tumor. However, there was a tendency toward a better survival in the EBV type B group. Histology and clinical staging were the two most important prognostic factors.     

Lymphoproliferative disorder of fetal origin presenting as oligohydramnios

Lymphoma involving the placenta or fetus remains a very rare event. All cases reported to date have shown the lymphoma cells to be of maternal origin in that the tumor cells have preferentially involved the intervillous spaces with sparing of the villi and fetal circulation. We report a novel case of a monoclonal primary placental Epstein-Barr virus (EBV)-associated B-cell lymphoma of fetal origin. The placenta of a 20-week stillborn fetus born to a 19-year-old gravida 1 para 0 woman, presenting with oligohydramnios, showed a large cell infiltrate confined within villi and sparing the intervillous spaces, indicative of preferential involvement of the fetal circulation. Necropsy did not show any other site of involvement by malignant lymphoma or other abnormalities. Immunophenotypic studies showed the tumor cells to be of B-cell phenotype with a relatively high proliferation rate. EBV EBER1 RNA was identified in more than 95% of tumor cells, and polymerase chain reaction studies showed EBV EBNA1 strain type A and wildtype EBV LMP1. Analysis of the immunoglobulin heavy chain by polymerase chain reaction showed a monoclonal B-cell population. In situ hybridization studies using a commercially available probe directed at repeated sequences on the human Y chromosome showed a single intense signal within trophoblastic epithelium and lymphoma cells, indicative of male origin. The mother remains in good health 11 months after delivery.     

Vitamin E inhibits cyclosporin A and H2O2 promoted Epstein-Barr virus (EBV) transformation of human B cells as assayed by EBV oncogene LMP1 expression

BACKGROUND: We have previously shown that oxidative stress induced by H2O2 or cyclosporin A (CsA) can promote Epstein-Barr virus (EBV) transformation of human B cells as analyzed by colony formation, cell number, and by 3H-thymidine incorporation. In this report, we used EBV oncogene LMP1 as a marker to analyze H2O2 or CsA promotion of EBV transformation of human B cells and to test whether antioxidant vitamin E could inhibit H2O2 or CsA promoted LMP1 expression in the EBV-infected cells. MATERIALS AND METHODS: Human splenocytes were prepared by centrifugation and plating technique to provide a greater than 80% pure preparation of B cells and were used for EBV infection. The EBV infected cells were treated with H2O2 (0.1 mM, 10 min), or with CsA (500 ng/ml) with or with out vitamin E (40 microM). The cells were cultured for up to 4 weeks. Samples were taken every week and were stained with phycoerythrin-conjugated mouse anti-LMP1 monoclonal antibody to assay LMP1 positive population by flow cytometry. RESULTS: In EBV-infected cells, the LMP1-positive cell population reached 14% after 4 weeks of culture. CsA or H2O2 treatment promoted LMP1 positive population to 43% and 41% after 4 weeks of culture. Vitamin E (40 microM) completely inhibited LMP1 expression in EBV-infected cells and in CsA- or H2O2-treated cells. CONCLUSION: In agreement with our previous observation, CsA or H2O2 can promote EBV transformation of human B cells. This oxidative stress induced promotion of EBV transformation can be blocked by antioxidant Vitamin E. This finding may have future therapeutic implications for post-transplant lymphoproliferative disorder.     

The Epstein–Barr virus DNA load in the peripheral blood of transplant recipients does not accurately reflect the burden of infected cells

Transplant recipients frequently exhibit an increased Epstein–Barr virus (EBV) load in the peripheral blood. Here, we quantitated the EBV‐infected cells in the peripheral blood of these patients and defined the mode of viral infection, latent or lytic. These data indicated that there is no strong correlation between the number of infected cells and the EBV load (EBVL). This can be explained by a highly variable number of EBV copies per infected cell and by lytic replication in some cells. The plasma of these patients did not contain any free infectious viruses, but contained nevertheless EBV DNA, sometimes in large amounts, that probably originates from cell debris and contributed to the total EBVL. Some of the investigated samples carried a highly variable number of infected cells in active latency, characterized by an expression of the Epstein–Barr nuclear antigens (EBNA2) protein. However, a third of the samples expressed neither EBNA2 nor lytic proteins. Patients with an increased EBVL represent a heterogeneous group of patients whose infection cannot be characterized by this method alone. Precise characterization of the origin of an increased EBVL, in particular, in terms of the number of EBV‐infected cells, requires additional investigations including the number of EBV‐encoded small RNA‐positive cells.     

Posttransplant lymphoproliferative disorder associated with an Epstein-Barr-related virus in cynomolgus monkeys

BACKGROUND: Human posttransplant lymphoproliferative disorder (PTLD) has been shown to be associated with Epstein-Barr virus (EBV) infection. Primate animal models of PTLD and the use of molecular markers in its diagnosis have not been reported. This study was designed to evaluate the frequency, pathology, and molecular characteristics of PTLD in cynomolgus kidney allograft recipients. METHODS: Over a 5-year period (January 1995 to November 2000), 160 primate renal transplants were performed at the Massachusetts General Hospital (MGH). Of these, all cases (n=9) that developed PTLD were included. H&E stained paraffin sections of all available tissue samples from the cases were evaluated for the presence of PTLD. Immunoperoxidase staining for T cells (CD3), B cells (CD20), kappa and lambda light chains as well as EBV nuclear antigens (EBNA2) and latent membrane proteins (EBV LMP-1) was done on paraffin sections using standard immunohistochemical (IHC) methods. In situ hybridization for EBV encoded RNA (EBER) was performed in all tissue samples with atypical lymphoid proliferations, using a novel EBER nucleotide probe based on consensus gene sequences from EBV and the related herpes lymphocryptoviruses (LCV) infecting baboons and rhesus macaques. RESULTS: Of 160 consecutive primate renal transplants performed at MGH, 5.6% developed PTLD 28-103 days after transplantation. In all cases, the lymph nodes were involved and effaced by an atypical polymorphous lymphoid proliferation of EBER+ B cells, diagnostic for PTLD. Focal staining for EBNA-2 was noted in tumor cells. In 67% (six of nine) the PTLD infiltrates were present in extra nodal sites, notably liver (56%), lung (44%), heart (44%), renal allograft (44%), and native kidney (22%). The spleen was involved by PTLD in all four animals that had not undergone a pretransplant splenectomy. The PTLD morphology was similar in all cases and predominantly of the polymorphous type, however, some of these showed areas that appeared minimally polymorphous. No cases of monomorphic PTLD were seen. CONCLUSIONS: By in situ hybridization, expression of the RNA product, homologous for EBV-encoded RNA (EBER) was identified in the PTLD tumor cells of all cases, indicating latent primate EBV- related infection. This report identifies a novel animal model of EBV associated PTLD in the setting of kidney transplantation, with valuable implications for managing and understanding human PTLD and oncogenesis.     

Gene Expression Profiling Reveals Clear Differences Between EBV‐Positive and EBV‐Negative Posttransplant Lymphoproliferative Disorders

Posttransplant patients are at risk of developing a potentially life‐threatening posttransplantation lymphoproliferative disorder (PTLD), most often of diffuse large B cell lymphoma (DLBCL) morphology and associated with Epstein–Barr Virus (EBV) infection. The aim of this study was to characterize the clinicopathological and molecular‐genetic characteristics of posttransplant DLBCL and to elucidate whether EBV(+) and EBV(?) posttransplant DLBCL are biologically different. We performed gene expression profiling studies on 48 DLBCL of which 33 arose posttransplantation (PT‐DLBCL; 72% EBV+) and 15 in immunocompetent hosts (IC‐DLBCL; none EBV+). Unsupervised hierarchical analysis showed clustering of samples related to EBV‐status rather than immune status. Except for decreased T cell signaling these cases were inseparable from EBV(?) IC‐DLBCL. In contrast, a viral response signature clearly segregated EBV(+) PT‐DLBCL from EBV(?) PT‐DLBCL and IC‐DLBCL cases that were intermixed. The broad EBV latency profile (LMP1+/EBNA2+) was expressed in 59% of EBV(+) PT‐DLBCL and associated with a more elaborate inflammatory response compared to intermediate latency (LMP1+/EBNA2?). Inference analysis revealed a role for innate and tolerogenic immune responses (including VSIG4 and IDO1) in EBV(+) PT‐DLBCL. In conclusion we can state that the EBV signature is the most determining factor in the pathogenesis of EBV(+) PT‐DLBCL.     

Epstein-Barr virus latency in kidney specimens from transplant recipients.

BACKGROUND: Epstein-Barr virus (EBV) infection is common in immunosuppressed patients and can lead to life threatening lymphoproliferative diseases. Small numbers of cells infected by EBV have been detected in human tissues, transplanted or non-transplanted. Little is known about EBV latency in the allograft kidneys of patients without post-transplant lymphoproliferative disease (PTLD). The aims of this study were to look for the presence of EBV-encoded small RNAs (EBER) in allograft kidneys and to quantify their expression. METHODS: We analysed 62 allograft nephrectomies and 20 native kidneys to determine the presence of EBV; we also quantified its expression and calculated its ratios to CD45 and CD20 cells. The techniques used were: tissue microarray, EBER-1- and 2-specific in situ hybridization and immunohistochemistry. RESULTS: EBER expression was detected in 30.6% of transplanted kidneys and 5% of non-transplanted kidneys. In the positive specimens, a mean of 8.2 cells/1.57 mm(2) expressed the EBERs (range 1-38 cells). The ratios of EBER-positive (+) cells to CD45 or CD20 cells were 1.7 +/- 2.4% (range 0.1-8.1%) and 8.4 +/- 10.9% (range 0.5-34.4%), respectively. No relationship was found between anti-T-cell treatment and EBER expression in the failed allografts. CONCLUSIONS: In failed kidney allografts, a small number of lymphocytes can express EBV latency. The number of EBER+ cells is smaller than in PTLD. Studies of functioning grafts are necessary to better understand the clinical relevance of this expression.     

Tiam1基因在胃癌细胞的表达及其生物学行为研究

目的构建Tiam1基因的真核表达载体,评估其转染人胃癌细胞株MKN45细胞后对胃癌细胞功能的影响。方法实时荧光定量PCR分析Tiam1基因在胃癌细胞中的表达;将外源性重组真核表达载体Tiam1基因(N1/Tiam1)转染到人胃癌细胞株MKN45内,经G418筛选并建立稳定表达Tiam1基因的胃癌MKN45细胞株,为:N1/Tiam1组,转染空质粒细胞(N1)组和未处理细胞(MKN45)组的两个对照组分别为:N1组和MKN45组;通过细胞增殖、划痕和侵袭实验分别观察上调Tiam1基因表达后的胃癌细胞功能。结果与N1组相比,N1/Tiam1组中Tiam1蛋白表达明显上调[(0.36±0.05)vs.(2.67±0.14),P<0.01];与对照组相比较,N1/Tiam1实验组较N1对照组细胞增殖数量明显增加(P=0.000);与转染N1空载体的MKN45细胞对照组相比,转染了N1/Tiam1高表达质粒的MKN45细胞促进胃癌细胞的迁移和侵袭。结论 Tiam1基因真核表达载体的筛选成功,为继续深入的研究Tiam1基因在胃癌中的功能奠定了基础。     

Epstein-Barr virus DNA detection in the diagnosis of nasopharyngeal carcinoma

OBJECTIVES: This study examines the presence of Epstein-Barr virus (EBV) in nasopharyngeal carcinoma (NPC) by using polymerase chain reaction (PCR). STUDY DESIGN: Eighty-six postnasal biopsy samples and 71 fine-needle aspirate samples of neck masses were obtained from patients who were clinically suspect for NPC. Genomic DNA was extracted from the samples, and EBNA1, EBNA2, and LMP genes of EBV were detected by PCR. PCR results were compared with NPC histopathology findings. RESULTS: The sensitivity of PCR to detect EBNA1 (97.14%), EBNA2 (88.57%), and LMP (91.43%) genes of EBV in nasopharyngeal biopsy samples were higher than those in fine-needle aspirate samples. CONCLUSION: Detection of EBV by PCR in tissue obtained from nasopharyngeal biopsy and fine-needle aspirate samples of neck masses is a relatively inexpensive, reliable, and accurate method of diagnosing NPC. Detection of EBV genes is on par with histopathological examination (HPE) and superior to fine-needle aspirate cytology. SIGNIFICANCE: PCR is an ideal tool for suggesting NPC and guiding the diagnostic workup in occult primary tumors, facilitating earlier diagnosis and reducing morbidity and mortality.