慢病毒载体介导端粒酶逆转录酶小干扰RNA治疗肝癌的实验研究

目的 探讨慢病毒介导的端粒酶逆转录酶(hTERT)小干扰RNA(siRNA)对肝癌细胞生长的影响.方法 构建携带hTERT siRNA的慢病毒表达载体,在体外转染人肝癌HepG2细胞系,以MTT法测定细胞生长变化,半定量逆转录聚合酶链反应(RT-PCR)检测hTERT mRNA的表达.将转染hTERT siRNA的HepG2细胞,接种于裸鼠腋窝皮下,观察移植瘤生长情况.取移植瘤组织,常规HE染色,行组织学观察,应用原位末端标记(TUNEL)技术检测细胞凋亡情况.结果 hTERT siRNA转染HepG2细胞后,随着时间的延长,对细胞增殖的抑制作用逐渐增强,到第8天,干扰组细胞抑制率为57.5%,与对照组比较,差异有统计学意义(P<0.01).RT-PCR产物凝胶电泳图显示,hTERT siRNA转染后,肿瘤细胞的端粒酶活性明显下降.转染后72 h,干扰组hTERT mRNA的表达水平为0.035±0.007,明显低于空载体对照组(0.151±0.016)和空白对照组(0.155±0.014,均P<0.01).转染细胞皮下接种后,干扰组的肿瘤生长速度明显慢于两个对照组,随着时间的延长,差异越来越明显.移植瘤组织常规HE染色显示,组织坏死增多,周围炎性细胞浸润.TUNEL检测结果显示,细胞凋亡增多,增殖减慢.结论 慢病毒介导的hTERT siRNA转染能明显抑制肝癌细胞的生长.     

RNA干扰抑制Hep-2细胞人端粒酶逆转录酶基因表达对放射敏感性的影响

目的构建人端粒酶逆转录酶(hTERT)基因特异性短发夹样RNA(shRNA)真核表达载体,观察其联合射线对人喉癌Hep-2细胞端粒酶活性和细胞存活的影响,研究hTERT基因在放射增敏中的作用。方法根据hTERT mRNA编码序列设计RNA干扰(RNAi)靶点,构建重组表达质粒pshRNA-hTERT,构建成功后,转染Hep-2细胞并作射线处理,用端粒重复序列扩增方法(TRAP-PCR- EHSA)检测端粒酶活性的动态变化,采用克隆形成分析方法观察质粒pshRNA-hTERT对Hep-2细胞放射敏感性的影响,计算放射增敏比SER_(SF2)。结果转染质粒pshRNA-hTERT后,Hep-2细胞的hTERT mRNA表达抑制率为60.8%,质粒pshRNA-hTERT不仅能够抑制Hep-2细胞的端粒酶活性(P<0.05),而且还可以抑制辐射诱导的端粒酶活性上升(P<0.05)。照射前经pshRNA-hTERT处理24h,明显降低了2Gy照射后Hep-2细胞的存活分数(85.7%),与单纯放射组(67.7%)相比,差异有统计学意义(P<0.05),pshRNA-hTERT的放射增敏比SER~(SF2)为1.27。结论RNAi显著抑制了靶基因hTERT的表达,质粒pshRNA-hTERT能明显抑制2Gy照射诱导的Hep-2细胞端粒酶活性升高,并显著提高其体外放射敏感性;质粒pshRNA-hTERT的放射增敏作用可能与端粒酶活性受抑制有关。     

端粒酶抑制剂叠氮胸苷对HeLa细胞放射性DNA损伤修复的影响

背景与目的:研究端粒酶抑制剂叠氮胸苷(Azidothymidine,AZT)对人宫颈癌HeLa细胞DNA放射性损伤修复的影响,探讨端粒酶在放射诱导的DNA损伤修复中的作用.材料与方法:实验分为空白组,AZT组(400 μmol/L AZT处理HeLa细胞24 h),放射组(2 Gy 60Co γ射线照射),AZT放疗组(400 μmol/L AZT处理HeLa细胞24 h后,用2 Gy 60Co γ射线照射).照射后于0、5、10、30、60、180及360 min分别收集细胞,用端粒重复序列扩增法(PCR-based telomeric repeat amplification protocol,TRAP)-联合酶联免疫吸附法(enzyme linked immunosorbent assay,ELISA)即TRAP-ELISA法检测端粒酶的活性.用单细胞凝胶电泳法检测DNA单链断裂损伤,以彗尾DNA百分含量表示DNA单链断损伤量.结果:HeLa细胞受2 Gy 60Co γ射线照射后10 min,端粒酶活性即开始增加,60 min后增加明显,360 min时达到最高.AZT处理HeLa细胞后,能使端粒酶活性下降约50%,而且能抑制HeLa细胞照射后端粒酶活性的增加(P＜0.05).单细胞凝胶电泳实验表明,2 Gy 60Co γ射线照射HeLa细胞后0～10 min,AZT放疗组与放射组的彗尾DNA百分含量无明显差异(P＞0.05),照后30～360 min AZT放疗组彗尾DNA百分含量均高于放射组(P均＜0.05).结论:AZT能阻抑照射后30～360 min DNA单链断裂的修复,说明端粒酶可能在放射性DNA损伤修复中具有重要作用.     

端粒酶逆转录酶小干扰RNA对结肠癌SW480细胞体外抑制作用的观察

目的:探讨RNA干扰(RNAi)对结肠癌SW480细胞人端粒酶逆转录酶(hTERT)基因的抑制效应。方法:化学合成靶向于hTERT基因的4个小分子干扰RNA(siRNA)序列,用阳离子脂质体为载体转染SW480细胞,分为siRNA1～4、siRNA阴性对照和空白对照6组。通过RT-PCR和蛋白质印迹法分别检测结肠癌细胞转染后细胞hTERT mRNA和蛋白水平,并用MTS法检测细胞生长增殖。结果:siRNA1～4组hTERT mRNA相对表达量分别为0.54±0.18、0.56±0.19、0.46±0.10和0.84±0.18,端粒酶相对活性分别为0.57±0.18、0.56±0.19、0.09±0.08和0.70±0.19,siRNA1～4组hTERT蛋白相对表达量分别为0.41±0.18、0.45±0.17、0.08±0.07和0.82±0.16,其中siR-NA1～3组的hTERT mRNA表达量、端粒酶活性和蛋白表达量与空白对照组的差异有统计学意义,P<0.05。SW480细胞在转染后48h时的细胞增长平均抑制率分别为42.14%、39.12%、48.05%和35.85%。提示不同siRNA序列对SW4...     

沉默EC9706核干细胞因子基因对裸鼠移植瘤生长的作用

观察由RNAi诱导的EC9706核干细胞因子（NS）基因沉默对裸鼠移植瘤生长的抑制作用。方法:BALB/c裸鼠15只,分为3组,siRNA干预组皮下注入pRNAT-U6.1-siNS2转染的EC9706细胞,无关siRNA对照组皮下注入pRNAT-U6.1-siC转染的EC9706细胞,空白对照组皮下注入正常EC9706细胞,接种5周分别测定各组裸鼠移植瘤体积,并应用RT-PCR技术检测裸鼠移植瘤组织中NS mRNA的表达。结果:无关siRNA对照组及空白对照组于第4天在接种部位出现肉眼可见的肿块,siRNA干预组于第6天在接种部位发现肉眼可见肿块。第5周各组裸鼠成瘤率均为100%。空白对照组、无关siRNA对照组和siRNA干预组瘤体大小分别为（1 806.40±77.75） mm3、（1 702.20±88.60） mm3和（847.00±82.25） mm3,3组相比差异有统计学意义（P<0.05）。空白对照组、无关siRNA对照组和siRNA干预组移植瘤组织中NS mRNA的表达量分别为0.681±0.033、0.685±0.034和0.497±0.056,3组相比差异有统计学意义（P<0.05）。结论:沉默EC9706细胞的NS基因可抑制裸鼠移植瘤生长,降低裸鼠体内NS mRNA的表达。沉默NS基因有可能成为治疗食管癌的新策略。      

RNA干扰Bcl-2基因表达对人胆管癌细胞及胆囊癌细胞株裸鼠移植瘤生长的抑制

目的:探讨Bcl-2基因的小干扰RNA(siRNA)真核表达载体干扰Bcl-2基因表达对人胆管癌细胞QBC939、胆囊癌细胞GBC-SD裸鼠体内移植瘤生长的抑制作用.方法:分别制作人胆管癌细胞QBC939、胆囊癌细胞GBC-SD细胞株移植瘤模型,随机分为3组,pSilencerTM-EGFP sh515组(实验组)、pSilencerTM-EGFP shCon组(空载体阴性对照组)和对照组.实验组用Bcl-2基因的小干扰RNA(siRNA)真核表达载体多点注射于移植瘤周围,空载体阴性对照组用空载体多点注射于移植瘤周围,对照组不作处理,观察其生长情况,计算肿瘤生长体积、生长率.6周后,处死裸鼠,剥离瘤体组织进行称重,并采用免疫组化检测Bcl-2蛋白的表达.结果:成功建立裸鼠人胆管癌细胞QBC939,胆囊癌GBC-SD细胞的动物模型.胆管癌细胞实验组、空载体阴性对照组、对照组瘤体平均体积(mm3)分别为:801.776±59.6,1383.980±78.2,1490.235±89.0.瘤体平均瘤体重量(g)为:0.90±0.11,1.49±0.31,1.63±0.22.平均生长率为:20.558%,35.587%,38.211%.人胆囊癌细胞实验组、空载体阴性对照组、对照组瘤体平均体积(mm3)分别为:729.736±66.6,1493.162±98.9,1548.668±101.0.瘤体平均瘤体重量(g)为:0.82±0.10,1.68±0.21,1.90±0.25.平均生长率为:18.711%,38.286%,39.709%.两组实验组分别和空载体阴性对照组、对照组比较有统计学意义(P<0.05),空载体阴性对照组和对照组比较无统计学意义(P>0.05).结论:针对Bcl-2基因siRNA真核表达载体通过局部多点注射于移植瘤周围可以有效降低Bcl-2基因的表达,该基因沉默后肿瘤细胞增殖受到抑制,体内瘤体生长减慢.     

三氧化二砷和5-氟脲嘧啶对人结肠癌裸鼠移植瘤端粒酶及其催化亚单位的影响

目的：研究三氧化二砷(As2O3)注射液、5-氟脲嘧啶(5-Fu)注射液单用和两药联合使用埘人结肠癌裸鼠移植瘤端粒酶活性及其催化亚单位表达的影响：方法：建立人类结肠癌裸鼠移植瘤模型,随机分为4组：牛理盐水组;As2O3组(2．5mg／kg);As2O3(2．5mg／kg) 5-Fu组(20mg／kg);5-Fu组(20mg／kg)。采用腹腔注射给药。利用银染-端粒重复扩增(TRAP)法测定人结肠癌裸鼠移植瘤端粒酶活性、RT—PCR法检测端粒酶催化亚基(human telomerase reverse transeriptases,hTERT)的表达：结果：生理盐水组和5-Fu组的端粒酶活性及其催化亚单位表达不受影响．As2O3单药组和联合用药组均明显抑制端粒酶活性及其催化亚单位表达。结论：As2O3单用以及联合5-Fu对于人结肠癌裸鼠移植瘤细胞的端粒酶活性及其催化亚单位的表达均具有明显的抑制作用。     

RNA干扰靶向抑制胃癌细胞株SGC7901 hTERT基因表达

背景与目的：胃癌是全人类常见恶性肿瘤之一。在我国，胃癌居各种癌症死亡之首，其总体五年生存率仅15％～20％。在目前尚无有效一级预防措施的情况下，积极探讨有效防治胃癌的方法成为必然趋势。本研究利用RNA干扰稳定筛选-抑制技术，抑制人端粒酶逆转录酶（hTERT）基因表达，探讨靶向hTERT基因RNAi对胃癌细胞增殖的抑制效应。方法：设计靶向hTERT基因的小干扰RNA，构建重组表达质粒pGenesil—shRNA—hTERT并导入人胃癌细胞系SGC7901细胞株，经G418筛选，建立稳定表达siRNA—hTERT的细胞株。采用real time RT—PCR、MTT和PCR—TRAP法同时检测pGenesil-shRNA—hTERT稳定抑制组和未处理SGC7901细胞组hTERT基因表达、端粒酶活性及细胞增殖变化。结果：在稳定表达pGenesil—shRNA—hTERT的SGC7901细胞株中，RNAi效力持续、稳定存在，hTERT mRNA表达、端粒酶活性明显降低，瘤细胞增殖被抑制。结论：RNA干扰能持续、稳定地抑制靶基因hTERT mRNA表达及肿瘤细胞增殖，是潜在的肿瘤基因治疗新方法。     

外泌体在肿瘤发展中的研究进展

外泌体是细胞经过"内吞-融合-外排"等一系列调控过程而形成的细胞外纳米级小囊泡。外泌体可以携带蛋白,运送RNA,在细胞间物质和信息转导中起重要作用。外泌体可能通过调控免疫功能,促进肿瘤血管新生和肿瘤转移,以及直接作用于肿瘤细胞等途径,影响肿瘤的进展。外泌体可应用于肿瘤的诊断。本文总结了近年来有关外泌体在肿瘤发展中作用的研究进展。     

Inhibitory effect of suramin in rat models of angiogenesis in vitro and in vivo

The aim of the present study was to test the ability of the chemotherapeutic agent suramin to inhibit angiogenesis in experimental models in vitro and in vivo. In the culture of rat aortic rings on fibronectin, suramin dose-dependently inhibited vascular cell growth, achieving the maximal effect (mean − 88% versus controls, P < 0.05) at 400 μg/ml. Image analysis showed that suramin could inhibit microvessel sprouting in fibrin from rat aortic rings as evaluated by the ratio between the cellular area and the mean gray value of the sample (sprouting index); suramin at 50 μg/ml significantly reduced the sprouting index from the control value of 0.35 ± 0.04 to 0.14 ± 0.02 mm²/gray level (P < 0.05). Likewise, the area occupied by cells was 19.2 ± 1.8 mm² as compared with 41.8 ± 4.2 mm² in controls (P < 0.05). In the rat model of neovascularization induced in the cornea by chemical injury, suramin at 1.6 mg/eye per day reduced the length of blood vessels (0.7 ± 0.1 mm as compared with 1.5 ± 0.1 mm in controls, P < 0.05). In the same model the ratio between the area of blood vessels and the total area of the cornea (area fraction score) was decreased by suramin from 0.19 ± 0.02 in controls to 0.03 ± 0.003 (P < 0.05). Suramin given i.p. at 30 mg/kg per day markedly inhibited the neovascularization induced in the rat mesentery by compound 48/80 or conditioned medium from cells secreting the angiogenic protein fibroblast growth factor-3 (FGF-3). The area fraction score in control rats treated with compound 48/80 was 0.31 ± 0.03, and this was reduced to 0.07 ± 0.01 by suramin (P < 0.05). After i.p. administration of FGF-3 the area fraction score was reduced by suramin from 0.29 ± 0.03 to 0.05 ± 0.01 (P < 0.05). These results provide evidence that suramin exerts inhibitory effects on angiogenesis in both in vitro and in vivo models. Received: 9 January 1998 / Accepted: 29 June 1998     

重组人血管内皮抑制素治疗恶性肿瘤的研究进展

重组人血管内皮抑制素(恩度)是一种广谱的抗血管生成分子靶向药物,主要循证证据为联合化疗治疗晚期非小细胞肺癌(NSCLC).近年来,重组人血管内皮抑制素用于治疗多种恶性肿瘤的研究逐渐增多,并取得了较好的疗效.此外,有关重组人血管内皮抑制素联合治疗手段、给药途径、给药方法的研究逐渐开展,有利于其合理应用.     

Effect of trauma of implantation of metastatic tumor in bone in mice

We studied the influence of surgical trauma to the iliac bone on the implantation of I. V. injected tumor cells, which formed tumor in the surgical wounds of 27/84 mice (32%). None of these mice or nonsurgical mice developed tumor in the opposite or uninjured pelvic bone (P < 0.0001). When different numbers (10⁵, 5 × 10⁵, and 10 × 10⁵) of TA3Ha cells were injected I. V. immediately after surgery, the frequency of tumor formation showed an increase (respectively, 32%, 63%, 71%). As the interval between induction of trauma and tumor cell injection was increased from 0 to 15 days, the frequency of tumor formation declined from 32% to 0%. These results suggest that the healing wound is a privileged site for experimental metastasis, particularly in the early stages. It is likely that the proteins in the blood clotting cascade are involved in local tumor implantation. © 1994 Wiley-Liss, Inc.     

胶质瘤中微RNA研究进展

微RNA(microRNA,miR)可在转录后水平负调控靶基因表达,miR异常表达与肿瘤生成密切相关.对胶质瘤中多个miR异常表达及其机制的研究将对进一步探讨胶质瘤的分子病理及其诊治开拓新途径.     

Evaluation of the antitumoral effect of dihydrocucurbitacin-B in both in vitro and in vivo models

Aims  We evaluated both in vitro and in vivo antitumoral properties of an isolated compound from Wilbrandia ebracteata, dihydrocucurbitacin-B (DHCB), using B16F10 cells (murine melanoma). Materials and methods  We made use of MTT and ³H-Thymidine assays to investigate the cell viability and cell proliferation, flow cytometry analysis to monitor cell cycle and apoptosis, western blot analysis to evaluate the expression of cell cycle proteins, imunofluorescence analysis and in vivo tumor growth and metastasis. Results  Dihydrocucurbitacin-B significantly reduced cell proliferation without important effects on cells viability. DHCB lead cells to accumulate in G2/M phases accompanied by the appearance of polyploid cells, confirmed by fluorescence assays that demonstrated a remarkable alteration in the cell cytoskeleton and formation of binuclear cells. Annexin-V-FITC incorporation demonstrated that DHCB did not induce apoptosis. About 10 μg/mL DHCB was found to decrease cyclin-A, and especially in cyclin-B1. The in vivo experiments showed that DHCB treatment (once a day up to 12 days; p.o.) was able to reduce the tumor growth and lung metastasis up to 83.5 and 50.3%, respectively. Conclusions  Dihydrocucurbitacin-B reduces cell proliferation due to a decrease in the expression of cyclins, mainly cyclin-B1 and disruption of the actin cytoskeleton, arresting B16F10 cells in G2/M phase. Taken together, the in vitro and in vivo experiments suggest that DHCB was effective against cancer, however, it remains to be proved if DHCB will be a good candidate for drug development.     

中国乳腺癌患者生活质量研究进展

生活质量（qualityoflife,QOL）又译作生命质量、生存质量,它是在世界卫生组织提倡的健康新概念“人们在躯体上、精神上及社会生活中处于一种完好的状态,而不仅仅是没有患病和衰弱”的基础上构建的,是医学模式由生物医学模式向生物一心理一社会医学模式转变的体现。西方发达国家已将此概念广泛应用于临床试验、卫生政策制定和卫生资源效益评价等众多领域。生存质量已作为评价肿瘤患者术后状况的首选指标。     

Survey of changes in dietary preferences in cancer patients in China

Objective The aim of this study was to investigate the changes in dietary preferences in cancer patients in China and to determine the need for encouraging the adherence to a sensible diet among such patients.Methods A total of 468 cancer patients were interviewed using a self-designed questionnaire focusing on changes in the intake of specific foods. Data were analyzed using SPSS 16.0. Results Most patients completely avoided roosters and carp(73.1%), condiments(51.9%), and meat of aquatic species(40.4%). All other types of the specific foods were completely avoided by different subpopulations of the patients.Conclusion In addition to focusing on disease treatment, medical professionals need to help cancer patients overcome barriers associated with the customs of avoiding specific foods encompassed by the term ”fawu” and provide them with dietary guidance in order to prevent negative nutritional effects.     

新疆维吾尔族妇女宫颈病变中DAPK表达的研究

[目的]探讨DAPK基因与新疆维吾尔族妇女宫颈病变的相关关系。[方法]选取维吾尔族妇女正常或炎症的宫颈组织30例、CINⅠ30例、CINⅡ/Ⅲ30例、宫颈鳞癌组织30例采用免疫组化SP法检测DAPK蛋白表达;为了进一步验证DAPK蛋白表达水平,采用逆转录聚合酶链反应（RT-PCR）法检测正常或炎症的宫颈组织10例、CINⅠ10例、CINⅡ/Ⅲ15例、宫颈鳞癌组织20例中mRNA的表达。[结果]DAPK的蛋白表达率在正常或炎症的宫颈组织、CINⅠ、CINⅡ/Ⅲ、宫颈鳞癌组织中分别为93.3%、83.3%、60.0%、33.3%,SCC组阳性表达率明显减少（P〈0.05）;四组mRNA的表达率分别为90.0%、90.0%、46.7%、10.0%,SCC组阳性表达率明显减少（P〈0.05）。宫颈组织中DAPK在蛋白水平和mRNA水平的表达均和宫颈病变程度成负关（P〈0.05）。[结论]新疆维吾尔族妇女宫颈病变组织中DAPK蛋白和mRNA水平均随病变程度加深而减少;DAPK蛋白检测可能为宫颈癌的早期诊断提供依据。