~(131)I照射对分化型甲状腺癌细胞摄碘水平及NISmRNA表达的影响

目的分析131I照射对分化型甲状腺癌细胞摄碘水平及钠/碘转运体(NIS)mRNA表达的影响。方法收集50例分化型甲状腺癌(DTC)患者的临床资料,所有患者均应用同一活度的131I进行照射治疗,治疗前后应用γ计数仪测定125I摄取率,采用RT～PCR法检测甲状腺癌细胞的NISmRNA表达,对其相关性进行分析。结果随着照射时间的延长,甲状腺癌患者对125I摄取率出现下降,凝胶电泳显示甲状腺癌细胞组细胞NISmRNA表达降低,前后比较差异明显,有统计学意义(P<0.05)。结论131I照射可降低分化型甲状腺癌患者125I摄取率,可能与甲状腺癌细胞NISmRNA表达降低有关。     

Melanoma Differentiation-Associated Gene 5 Regulates the Expression of a Chemokine CXCL10 in Human Mesangial Cells: Implications for Chronic Inflammatory Renal Diseases

Mesangial cells play an important role in inflammatory reactions in kidney. Although viral infections often trigger the worsening of chronic inflammatory renal diseases, the mechanisms are largely unknown. Melanoma differentiation-associated gene 5 (MDA5) is a member of RNA helicase family with a conserved Asp-Glu-x-His (DExH) box. In the present study, we examined the effect of polyinosinic-polycytidylic acid (poly IC), an authentic double-stranded RNA (dsRNA) that mimics viral dsRNAs, on MDA5 expression using primary culture of human mesangial cells. The cells were simply treated or transfected with poly IC; the former procedure is a model of cells exposed to viral dsRNA released from dying cells, and the latter is a model of entry of RNA virus into the cytoplasm. Expression levels of MDA5 mRNA in mesangial cells were increased about 70-100 fold in response to either treatment or transfection with poly IC. MDA5 protein expression was significantly induced as well. RNA interference experiments revealed that poly IC treatment induced MDA5 expression via Toll-like receptor 3 (TLR3) and interferon (IFN)-β, and that poly IC trasnfection induced MDA5 expression via another DExH box RNA helicase, retinoic acid-inducible gene-I (RIG-I), and IFN-β. Moreover, MDA5 induced by poly IC, in turn, increased the expression of a chemokine CXCL10. In addition, immunohistochemical staining demonstrated a high level of MDA5 expression in glomeruli, mainly in mesangial cells, of patients with severe lupus nephritis or proteinuric IgA nephropathy. MDA5 may be involved not only in physiological antiviral reactions but also in chronic inflammation in glomerular mesangial cells.     

Glucose Uptake and Its Effect on Gene Expression in Prochlorococcus

The marine cyanobacteria Prochlorococcus have been considered photoautotrophic microorganisms, although the utilization of exogenous sugars has never been specifically addressed in them. We studied glucose uptake in different high irradiance- and low irradiance-adapted Prochlorococcus strains, as well as the effect of glucose addition on the expression of several glucose-related genes. Glucose uptake was measured by adding radiolabelled glucose to Prochlorococcus cultures, followed by flow cytometry coupled with cell sorting in order to separate Prochlorococcus cells from bacterial contaminants. Sorted cells were recovered by filtration and their radioactivity measured. The expression, after glucose addition, of several genes (involved in glucose metabolism, and in nitrogen assimilation and its regulation) was determined in the low irradiance-adapted Prochlorococcus SS120 strain by semi-quantitative real time RT-PCR, using the rnpB gene as internal control. Our results demonstrate for the first time that the Prochlorococcus strains studied in this work take up glucose at significant rates even at concentrations close to those found in the oceans, and also exclude the possibility of this uptake being carried out by eventual bacterial contaminants, since only Prochlorococcus cells were used for radioactivity measurements. Besides, we show that the expression of a number of genes involved in glucose utilization (namely zwf, gnd and dld, encoding glucose-6-phosphate dehydrogenase, 6-phosphogluconate dehydrogenase and lactate dehydrogenase, respectively) is strongly increased upon glucose addition to cultures of the SS120 strain. This fact, taken together with the magnitude of the glucose uptake, clearly indicates the physiological importance of the phenomenon. Given the significant contribution of Prochlorococcus to the global primary production, these findings have strong implications for the understanding of the phytoplankton role in the carbon cycle in nature. Besides, the ability of assimilating carbon molecules could provide additional hints to comprehend the ecological success of Prochlorococcus.     

Impedance of Novel Therapeutic Technologies: The Case of Stem Cells

Embryonic stem cell (ES) technology has advanced considerably within the past three decades and has gained prominent distinction within the emerging field of regenerative medicine. As it now enters the nascent stages of clinical application, many hopes and expectations arise along with questions as to where the technology will go. This paper evaluates the technical and practical obstacles that must be overcome before it can fully translate into the clinical context, the existence of strong opposition to the technology, political and legal barriers that have impeded its progression, and the role of healthcare reform in creating new social and economic priorities. In contrast to the technological imperative, a driving force seeking to implement the most recent scientific advances into medical practice, we refer to such translational obstacles as “technological impedance.” Rather than expending inordinate effort to preserve existing systems that continue to possess major hurdles, we advocate fostering interdisciplinary approaches in the development of new generation platforms and embracing disruptive innovations that create solutions to technological impedance and move us forward in healthcare delivery. Clin Trans Sci 2012; Volume 5: 422–427     

A Novel Cancer Therapeutic Using Thrombospondin 1 in Dendritic Cells

Induction of thrombospondin 1 (TSP-1) is generally assumed to suppress tumor growth through inhibiting angiogenesis; however, it is less clear how TSP-1 in dendritic cells (DCs) influences tumor progression. We investigated tumor growth and immune mechanism by downregulation of TSP-1 in dendritic cells. Administration of TSP-1 small hairpin RNA (shRNA) through the skin produced anticancer therapeutic effects. Tumor-infiltrating CD4⁺ and CD8⁺ T cells were increased after the administration of TSP-1 shRNA. The expression of interleukin-12 and interferon-γ in the lymph nodes was enhanced by injection of TSP-1 shRNA. Lymphocytes from the mice injected with TSP-1 shRNA selectively killed the tumor cells, and the cytotoxicity of lymphocytes was abolished by depletion of CD8⁺ T cells. Injection of CD11c⁺ TSP-1–knockout (TSP-1-KO) bone marrow–derived DCs (BMDCs) delayed tumor growth in tumor-bearing mice. Similarly, antitumor activity induced by TSP-1-KO BMDCs was abrogated by depletion of CD8⁺ T cells. In contrast, the administration of shRNAs targeting TSP-2, another TSP family member, did not extend the survival of tumor-bearing mice. Finally, TSP-1 shRNA functioned as an immunotherapeutic adjuvant to augment the therapeutic efficacy of Neu DNA vaccination. Collectively, the downregulation of TSP-1 in DCs produces an effective antitumor response that is opposite to the protumor effects by silencing of TSP-1 within tumor cells.     

Ahi-1基因导入Jurkat细胞中表达及功能的研究

本研究目的是探讨Ahi-1基因及其编码蛋白在人T淋巴细胞白血病Jurkat细胞中的表达、细胞内定位以及Ahi-1基因对Jurkat细胞生长的调控作用。分别应用Northernblot、Werstemblot检测Ahi-1基因的mRNA及蛋白表达水平。构建Ahi-1的真核表达质粒并导入Jurkat细胞,用G418筛选获得稳定过表达Ahi-1基因的Jurkat-A细胞,用XTT法检测细胞的增殖活性,半固体培养法检测细胞集落形成能力。结果表明：正常人外周血淋巴细胞（PBL）、Jurkat细胞以及HUT78细胞均表达6．5、4．2以及2kb的Ahi-1基因mRNA转录本。PBL及Jurkat细胞均表达140kD的Ahi-1蛋白且主要定位于细胞浆内,但在细胞核内未见表达。PBL尚表达120kD的Ahi-1蛋白,主要存在于细胞核内,Jurkat细胞中120kD的Ahi-1蛋白表达水平低下。甲异靛、阿糖胞苷（Ara-C）、高三尖杉酯碱（HHT）、甲氨喋呤（MTX）以及鬼臼乙叉甙（VP16）可诱导Jurkat细胞核内140kD的Ahi-1蛋白表达增强,甲异靛降低细胞浆内Ahi-1蛋白表达。与转染质粒对照Jurkat细胞（Jurkat-C）相比,高表达外源性Ahi一1的Jurkat—A细胞的生长及集落形成能力显著低于Jurkat—C细胞;细胞总c-myb蛋白表达水平无改变,但Jurkat-A细胞中磷酸化c-myb蛋白表达增强;细胞中AKT磷酸化水平无明显变化。结论：Jurkat细胞表达6．5、4．2以及2kb的Ahi-1转录本;140kD的Ahi-1蛋白主要定位于细胞浆中,多种化疗药物可诱导细胞核内140kD的Ahi．1蛋白表达增强;过表达外源性全长Ahi-1可抑制Jurkat细胞的生长及集落形成能力,并诱导c-myb蛋白磷酸化。     

LRP15基因的表达谱分析及其在白血病细胞中的表达

为检测LRP15基因在肿瘤细胞以及处于不同发育阶段造血细胞的表达状况 ,探讨其在肿瘤发生、发展以及在白血病分型预后中可能具有的作用 ,利用NCBI提供的SAGE文库及NCI提供的正常组织及肿瘤细胞基因表达数据库 ,分析比较了LRP15基因在多种肿瘤组织、细胞系和正常组织中的表达谱 ;采用RT PCR方法检测了该基因在正常血细胞及原代白血病细胞中的表达状况。结果显示 ,LRP15在人类多种正常组织及肿瘤细胞中有表达 ;在幼稚细胞中表达阳性率高于成熟细胞 (P <0 .0 1) ,在急性髓细胞白血病中M1、M2 和M3 表达的阳性率高于其它亚型 (P <0 .0 1) ;难治组LRP15表达的阳性率有高于初治组的趋势。结论 ,LRP15基因与急性白血病及其它多种肿瘤的发生、发展密切相关 ,对急性白血病的临床分型具有重要的意义 ,可能对判断急性白血病的预后具有一定价值。     

Metagenomic Analysis of Lysogeny in Tampa Bay: Implications for Prophage Gene Expression

Phage integrase genes often play a role in the establishment of lysogeny in temperate phage by catalyzing the integration of the phage into one of the host's replicons. To investigate temperate phage gene expression, an induced viral metagenome from Tampa Bay was sequenced by 454/Pyrosequencing. The sequencing yielded 294,068 reads with 6.6% identifiable. One hundred-three sequences had significant similarity to integrases by BLASTX analysis (e≤0.001). Four sequences with strongest amino-acid level similarity to integrases were selected and real-time PCR primers and probes were designed. Initial testing with microbial fraction DNA from Tampa Bay revealed 1.9×10⁷, and 1300 gene copies of Vibrio-like integrase and Oceanicola-like integrase L⁻¹ respectively. The other two integrases were not detected. The integrase assay was then tested on microbial fraction RNA extracted from 200 ml of Tampa Bay water sampled biweekly over a 12 month time series. Vibrio-like integrase gene expression was detected in three samples, with estimated copy numbers of 2.4-1280 L⁻¹. Clostridium-like integrase gene expression was detected in 6 samples, with estimated copy numbers of 37 to 265 L⁻¹. In all cases, detection of integrase gene expression corresponded to the occurrence of lysogeny as detected by prophage induction. Investigation of the environmental distribution of the two expressed integrases in the Global Ocean Survey Database found the Vibrio-like integrase was present in genome equivalents of 3.14% of microbial libraries and all four viral metagenomes. There were two similar genes in the library from British Columbia and one similar gene was detected in both the Gulf of Mexico and Sargasso Sea libraries. In contrast, in the Arctic library eleven similar genes were observed. The Clostridium-like integrase was less prevalent, being found in 0.58% of the microbial and none of the viral libraries. These results underscore the value of metagenomic data in discovering signature genes that play important roles in the environment through their expression, as demonstrated by integrases in lysogeny.     

c-fes基因在白血病细胞中的表达及其临床意义

本研究观察了c—fes基因在急、慢性白血病患者骨髓细胞中的表达情况,并探讨其临床意义。采用实时定量逆转录-聚合酶链反应（RQ—PCR）方法,分别检测121例急、慢性白血病患者骨髓和20例正常人外周血单个核细胞中c-fesmRNA的表达水平。结果表明,急性髓系白血病（aML）患者组c-fes基因相对表达量（48．017±57．170）×10^-3高于正常对照组（0．152±0．398）×10^-3（P〈0．0001）;急性淋巴细胞白血病（ALL）患者组c—fes基因相对表达量（0．047±0．068）×10^-3。与正常对照组相比无差异（P=0．178）;慢性髓系白血病（CML）患者组c—fes基因相对表达量（21．605±24．818）×10^-3高于正常对照纽（P〈0．0001）。CML慢性期阳性率（80％）高于加速期（66．7％）和急变期（28．6％）,AML患者中C-fes基因阳性率最高的亚型是M2和M3,分别为80．77％、92．86％。初治AML（非M3）患者中,c-fes基因表达阳性患者的CR率（81．08％）高于不表达患者（40．00％）。结论：C-fes基因主要在髓系表达,在淋系中无表达或低表达;c-fes基因在髓系分化方面具有一定的作用,c-fes基因表达高的除M,外的AML患者CR率高,预后好。     

Induction of Immune Tolerance to a Therapeutic Protein by Intrathymic Gene Delivery

The efficacy of recombinant enzyme therapy for genetic diseases is limited in some patients by the generation of a humoral immune response to the therapeutic protein. Inducing immune tolerance to the protein prior to treatment has the potential to increase therapeutic efficacy. Using an AAV8 vector encoding human acid α-glucosidase (hGAA), we have evaluated direct intrathymic injection for inducing tolerance. We have also compared the final tolerogenic states achieved by intrathymic and intravenous injection. Intrathymic vector delivery induced tolerance equivalent to that generated by intravenous delivery, but at a 25-fold lower dose, the thymic hGAA expression level was 10,000-fold lower than the liver expression necessary for systemic tolerance induction. Splenic regulatory T cells (Tregs) were apparent after delivery by both routes, but with different phenotypes. Intrathymic delivery resulted in Tregs with higher FoxP3, TGFβ, and IL-10 mRNA levels. These differences may account for the differences noted in splenic T cells, where only intravenous delivery appeared to inhibit their activation. Our results imply that different mechanisms may be operating to generate immune tolerance by intrathymic and intravenous delivery of an AAV vector, and suggest that the intrathymic route may hold promise for decreasing the humoral immune response to therapeutic proteins in genetic disease indications.     

用基因芯片表达谱筛选恶性黑色素瘤差异基因的研究

目的 用基因芯片表达谱筛选出恶性黑色素瘤的差异基因。方法 用Agilent Human 1A OligoDNA芯片对恶性黑色素瘤和色素痣组织中基因表达情况进行检测，提取总RNA，进行荧光标记探针、杂交、洗涤后分析。结果 恶性黑色素瘤和正常色素痣组织共有1596个差异表达基因，其中上调基因733个，下调基因863个。结论 基因芯片技术可筛选出恶性黑色素瘤相关基因。     

丙型肝炎病毒E1基因在COS-7中的表达

目的：了解丙型肝炎病毒（HCV）E1基因在真核细胞中的表达情况。方法：采用基因重组技术,构建含HCVE1基因的重组表达质粒pEE1/HisC-E1,经酶切和PCR鉴定后,用脂质体转染法将重组质粒导入COS-7进行表达,经蛋白印迹实验鉴定表达产物。结果：重组表达载体pEF1/HisC-E1在COS-7中获得表达,表达的E1糖蛋白约29kD,具有抗原性,结论：HCVE1基因在真核细胞高效表达,为进一步研究HCVE1糖蛋白的生物学特性奠定基础。     

Stathmin表达水平与乳腺癌细胞侵袭能力相关性研究

目的 探讨乳腺癌细胞MDA-MB-231和MCF-7中Stathmin基因表达水平与细胞生长、黏附、侵袭等生物学行为之间的关系,为进一步研究乳腺癌转移机制奠定实验基础。方法 应用RT-PCR和Western Blot方法检测MDA-MB-231和MCF-7细胞中Stathmin基因的表达水平,同时利用细胞增殖试验、细胞黏附试验和细胞侵袭试验检测MDA-MB-231和MCF-7细胞的生长、黏附、侵袭能力,分析Stathmin表达与细胞的生长、黏附、侵袭能力之间的关系。结果 RT-PCR和Western Blot检测结果显示,Stathmin基因在MDA-MB-231和MCF-7细胞中表达均高于正常对照细胞(F=10.173,P<0.05),且MDA-MB-231细胞中的表达水平明显高于MCF-7细胞中的表达水平(t=4.562,P<0.05)。而MDA-MB-231细胞在生长、黏附和侵袭能力方面均强于MCF-7细胞(P<0.05)。结论 Stathmin表达水平高的乳腺癌细胞相应的生长、黏附、侵袭能力较强,Stathmin表达水平与细胞侵袭能力密切相关。     

同源盒HOXA1基因在髓系白血病细胞内的表达

目的研究HOXA1基因在髓系白血病细胞内的表达及药物对其表达的影响. 方法采用半定量逆转录-聚合酶链反应(RT-PCR)技术,研究全反式维甲酸(ATRA)对HL-60细胞内同源盒HOXA1基因表达的影响.同时对9例髓系白血病患者的HOXA1基因表达进行了检测. 结果①ATRA可上调HL-60细胞内HOXA1基因的表达.②所有受检白血病患者的HOXA1基因表达水平均比正常对照组高(P＜0.01). 结论 ATRA可能通过增强HOXA1基因表达使癌细胞朝良性细胞分化.     

Expression of the Elm1 Gene, a Novel Gene of the CCN (Connective Tissue Growth Factor, Cyr61/Cef10, and Neuroblastoma Overexpressed Gene) Family, Suppresses In Vivo Tumor Growth and Metastasis of K-1735 Murine Melanoma Cells

We previously isolated a partial cDNA fragment of a novel gene, Elm1 (expressed in low-metastatic cells), that is expressed in low-metastatic but not in high-metastatic K-1735 mouse melanoma cells. Here we determined the full-length cDNA structure of Elm1 and investigated the effect of Elm1 expression on growth and metastatic potential of K-1735 cells. The Elm1 gene encodes a predicted protein of 367 amino acids showing ~40% amino acid identity with the CCN (connective tissue growth factor [CTGF], Cyr61/Cef10, neuroblastoma overexpressed gene [Nov]) family proteins, which consist of secreted cysteine-rich proteins with growth regulatory functions. Elm1 is also a cysteine-rich protein and contains a signal peptide and four domains conserved in the CCN family proteins. Elm1 was highly conserved, expressed ubiquitously in diverse organs, and mapped to mouse chromosome 15. High-metastatic K-1735 M-2 cells, which did not express Elm1, were transfected with an Elm1 expression vector, and several stable clones with Elm1 expression were established. The in vivo growth rates of cells expressing a high level of Elm1 were remarkably slower than those of cells expressing a low level of Elm1. Metastatic potential of transfectants was reduced in proportion to the level of Elm1 expression. Thus, Elm1 is a novel gene of CCN family that can suppress the in vivo growth and metastatic potential of K-1735 mouse melanoma cells.     

黑色素瘤抗原基因3在K562细胞内质网应激反应性凋亡中的表达及意义

本研究旨在探讨黑色素瘤抗原基因-3（melanoma antigen gene-3,MAGE-3）在内质网应激反应性凋亡中的表达及意义.应用Ca^2＋荧光指示剂Fura-2/AM通过荧光分光光度计测定白血病细胞系K562及其多药耐药细胞株K562/A02经thapsigargin作用前后细胞内Ca^2＋浓度（[Ca^2＋]i）变化;Western blot检测GRP78蛋白表达变化;荧光显微镜观察细胞凋亡形态变化;TUNEL法检测细胞凋亡率;RT-PCR检测MAGE-3基因mRNA水平表达变化.结果显示：①毒胡萝卜素（thapsigargin）诱导K562和K562/A02细胞[Ca^2＋]i出现不同程度的升高并呈一定的浓度依赖性,同时诱导GRP78蛋白表达增加以及K562和K562/A02细胞典型的凋亡改变,细胞凋亡率亦呈一定的浓度依赖性;在静息状态下K562/A02细胞[Ca^2＋]i较K562细胞明显增高;②毒胡萝卜素诱导K562和K562/A02细胞凋亡过程中,MAGE-3 mRNA表达明显下调;此外,与K562细胞比较,K562/A02细胞MAGE-3 mRNA表达明显上调.结论：①毒胡萝卜素在一定浓度范围内可诱导K562及其多药耐药细胞株K562/A02发生内质网应激反应性凋亡,并可能与MAGE-3表达下调有关或MAGE-3基因可能参与此凋亡途径的调控;②MAGE-3可能具有抗凋亡活性,K562/A02细胞多药耐药性可能与细胞[Ca^2＋]i增高和MAGE-3表达上调有关.     

RHD基因的克隆及其在K562细胞中的表达

本研究目的在于克隆人类红细胞RHD基因，构建RhD表达载体，观察其在K562细胞中的表达。从脐血网织红细胞中提取总RNA，采用逆转录聚合酶链反应扩增RHD／CE基因，扩增产物通过TA连接克隆到pGEM-T质粒，采用测序方法筛选多个克隆获得RHD基因。将获得的RHD基因进一步亚克隆构建pcDNA3．1(-)表达载体。重组表达载体通过superfect试剂盒转染K562细胞，最后观察K562细胞中RHD基因的转录和表达。结果表明：成功分离克隆到RHD基因，构建的pcDNA3.1(-)重组表达载体经酶切和测序证实RHD cDNA序列及插入方向正确。转染后的K562细胞内有相应的mRNA转录，细胞表面有RhD抗原表达。结论：RHD cDNA转染的K562细胞能表达RhD抗原，该表达体系有助于进一步研究各种RhD变异型的分子基础。     

p53基因对HL-60细胞端粒酶活性和人端粒酶逆转录酶基因表达的影响

为了研究野生型p53基因转染的HL-60细胞端粒酶活性和人端粒酶逆转录酶（hTERT)基因表达的变化，采用脂质体法将野生型p53基因转染HL-60细胞，用TUNEL检测细胞凋亡。用端粒重复扩增法（TRAP）-酶联免疫吸附试验（ELISA）检测端粒酶活性变化，以及用RT-PCR方法检测hTERTmRNA表达的变化。结果显示：转染野生型p53基因的HL-60细胞在32.5℃培养24小时和72小时后，凋亡率分别为8.3%和21.0%,hTERTmRNA和端粒酶活性分别下降至对照组的68.4%和55.8%及27.3%和8.9%。结论：p53基因能下调HL-60细胞hTERTmRNA和端粒酶活性。这可能是野生型p53基因诱导细胞凋亡机制之一。