双调蛋白诱导乳腺癌细胞表达尿激酶型纤溶酶原活化物

目的:在人乳腺癌模型上研究双调蛋白与尿激酶型纤溶酶原活化物表达之间的关系.方法:乳腺癌NS2T2A1细胞经双调蛋白反义cDNA质粒转染后经潮霉素B筛选获得表达双调蛋白反义RNA的AR-AS1及AR-AS3两个细胞克隆,转染空载体获得NS2T2A1 V对照细胞,接种至裸鼠皮下形成肿瘤.测定细胞及肿瘤uPA表达水平,并研究uPA与细胞侵袭性之间的关系.结果:AR-AS1及AR-AS3细胞体外及体内uPA表达均被抑制.外源性双调蛋白可刺激对照细胞uPA的表达,并部分恢复AR-AS1及AR-AS3细胞uPA的表达水平.双调蛋白反义cDNA质粒转染及抗uPA抗体均导致乳腺癌细胞体外侵袭性的降低.结论:在乳腺癌模型上,uPA表达与肿瘤细胞的侵袭密切相关.双调蛋白反义RNA表达可有效地抑制uPA的表达,进而抑制肿瘤细胞的侵袭性.     

双调蛋白反义重组腺病毒治疗乳腺癌的实验研究

目的:在人乳腺癌模型上探讨双调蛋白(AR)反义重组腺病毒的治疗作用.方法:人AR的cDNA被反向亚克隆入E1/E3缺失的5型腺病毒载体中而得到AdA4,AR反义mRNA的表达由CMV启动子控制.进而研究其对恶性转化人乳腺上皮细胞株NS2T2A1体外、体内增殖的作用.结果:乳腺癌NS2T2A1细胞被AR反义重组腺病毒感染后,AR蛋白质的表达被强烈地抑制.以MOI为200和400pfu/细胞的AdA4感染4天后,细胞体外增殖分别被显著地抑制至空病毒对照组的69.3%和49.8%(P＜0.02,P＜0.005).3次肿瘤内注射109pfu AdA4病毒,至第35天肿瘤体积只为对照组的40.6%(P＜0.005).结论:在此乳腺癌模型上,AR反义重组腺病毒可有效地用于针对AR的反义治疗策略,抑制肿瘤细胞的体外增殖及体内肿瘤生长.     

血管内皮生长因子的表达对人胃癌细胞生物学表型的影响

 目的　探讨血管内皮生长因子对人胃癌细胞生物学表型的影响。方法　将 VEGF16 5正、反义 RNA表达载体导入人胃癌细胞 ,并观察其细胞周期、增殖、裸鼠致瘤生长等生物学指标。结果　与 VEGF正义转染细胞相比 ,在反义转染细胞的细胞周期中 G1期细胞数增加了 1 7.3% ,而S期细胞减少了 43.6 % ;正义转染细胞的克隆形成率明显高于反义转染细胞 ;正义转染细胞组的肿瘤生长速度及瘤体积明显高于其他组。结论　 VEGF可以加强肿瘤组织血管生成 ;VEGF反义RNA可以防治肿瘤生长 ;VEGF可能与肿瘤细胞增殖能力有关.     

VEGF反义RNA 抑制裸鼠体内食管癌细胞生长的实验研究

 目的 探讨VEGF反义RNA对食管癌细胞在裸鼠体内生长的影响。方法 观察转染VEGF反义RNA的食管癌细胞TE-1在裸鼠体内成瘤性；应用免疫组化法、RT—PCR法检测移植瘤组织中VEGF蛋白及mRNA表达和MVD；用流式细胞仪和透射电镜检测细胞凋亡情况。结果 转染VEGF反义RNA的TE-1细胞在裸鼠体内肿瘤形成的潜伏期明显延长，所形成肿瘤的重量和体积小于对照组及空载体组。肿瘤组织中VEGF蛋白和mRNA的表达降低，MVD降低；肿瘤细胞发生明显的凋亡形态学改变；G0／G1期细胞明显增多，S期细胞明显减少，细胞增殖能力降低。结论 VEGF反义RNA能抑制裸鼠体内TE-1细胞的生长，减少肿瘤内血管的生成，增加细胞凋亡；为食管癌的基因治疗提供了一定的实验依据。     

血管内皮生长因子反义RNA对裸鼠食管癌细胞增殖和凋亡的影响意义

目的：研究血管内皮生长因子（VEGF）反义RNA对裸鼠食管癌移植瘤细胞增殖和凋亡的影响。方法：将转染VEGF反义eDNA和空载体peDNA3．1的食管癌细胞株TE-1分别接种在裸鼠体内；应用免疫组化法、RT-PCR法检测移植瘤组织中VEGF蛋白和mRNA表达情况；流式细胞仪和透射电镜检测肿瘤细胞增殖及凋亡情况。结果：反义组肿瘤组织中VEGF蛋白和mRNA的表达降低，肿瘤细胞的细胞器发生扩张和肿胀、核染色质边集、凝集成块等凋亡形态学改变；Go／G，期细胞明显增多，S期细胞明显减少，细胞增殖指数降低；对照组和空载体组细胞凋亡较少。结论：VEGF反义RNA能抑制裸鼠食管癌细胞的增殖，诱导细胞凋亡，为食管癌基因治疗基础研究提供依据。     

VEGF反义RNA对人食管癌细胞生长转移的抑制作用

目的:探讨研究血管内皮生长因子(vascularendothelialgrowthfactor,VEGF)反义RNA在抑制恶性肿瘤生长和转移及抗肿瘤血管生成治疗中的意义。方法:采用脂质体法将反义VEGFcDNA质粒转染入食管癌细胞TE1;MTT法检测细胞增殖情况;原位杂交和RTPCR技术检测VEGF的表达水平,FCM分析细胞周期,并对转染前后细胞进行裸鼠体内生长转移等生物学行为实验。结果:转染反义VEGFcDNA质粒的TE1细胞中VEGF表达水平降低,与对照组比较,裸鼠体内成瘤时间延长,肿瘤生长速度减慢,质量和体积差异有显著性意义(P<0.05)。结论:VEGF反义RNA能抑制食管癌TE1细胞VEGF表达,对裸鼠体内TE1细胞的生长有抑制作用,有望成为食管癌基因治疗的优选基因之一。     

VEGF反义RNA对人食管癌细胞抑制作用的研究

目的: 研究血管内皮生长因子(VEGF)反义RNA对人食管癌细胞的抑制作用,探讨以VEGF反义RNA进行食管癌基因治疗的可行性.方法: 采用脂质体法将反义VEGFcDNA质粒转染入食管癌细胞TE-1;用MTT法检测细胞增殖情况;用免疫组化法检测VEGF蛋白表达;原位杂交和RT-PCR技术检测VEGFmRNA的表达.流式细胞术检测细胞的凋亡率和周期分布.结果: 被反义VEGFcDNA质粒转染的食管癌细胞有外源性VEGF反义基因的整合及表达,该细胞的VEGFmRNA及蛋白表达水平降低,但细胞生长速率无明显改变,未发生明显凋亡现象;接种裸鼠后,形成肿瘤的时间明显延长,肿瘤的体积和重量明显减小.结论: VEGF反义RNA可抑制食管癌细胞VEGF表达和裸鼠体内的肿瘤生长.该表达体系为食管癌基因治疗的进一步研究奠定了基础.     

血管内皮生长因子的表达和血管生成与人胃癌移植瘤生长的关系

探讨血管内皮生长因子的表达与肿瘤血管生成的关系。方法 :将VEGF165正、反义RNA表达载体导入人胃癌细胞 ,观察接种VEGF高表达和低表达胃癌细胞裸鼠移植瘤的生长情况 ,并对移植瘤进行组织学检查 ,检测其血管密度、组织增生及坏死程度等变化。结果 :VEGF正义转染细胞所致移植瘤的生长速度明显快于反义转染细胞所致的移植瘤 ;组织学检查发现 ,正义转染细胞移植瘤的血管密度显著高于反义转染细胞所致的肿瘤。结论 :血管内皮生长因子通过启动血管生成而促进肿瘤的生长 ,阻断血管内皮生长因子的产生可以抑制肿瘤的生长。     

可溶性VEGF受体基因sflt-1与反义VEGF核苷酸对新生血管形成的影响

背景与目的:肿瘤组织中新生血管提供的大量营养物质和生长因子是肿瘤快速生长的关键,因此如何抑制肿瘤组织中新生血管的形成、促使肿瘤组织坏死也是肿瘤治疗中的一条值得探讨的途径。本文拟研究和观察可溶性血管内皮细胞生长因子(vascularendothelialgrowthfactor,VEGF)受体基因sflt-1与反义VEGF对新生血管形成的影响。方法:用Ad-反义VEGF感染肝癌细胞株MM45T.Li后,观察反义VEGF对MM45T.Li分泌VEGF的影响;将人工重组的3'ΔFlt-1蛋白(C末端缺失的Flt-1蛋白)加入条件培养液中,观察3'ΔFlt-1对VEGF刺激的脐静脉血管内皮细胞(humanumbilicalvascularendotheliumcell,HUVEC)增殖的影响;并将Ad-反义VEGF、Ad-sflt-1注射于鸡胚尿囊绒毛膜中,观察sflt-1、反义VEGF对鸡胚新生血管形成的影响。结果:反义VEGF重组腺病毒感染MM45T.Li细胞后,细胞培养上清中VEGF浓度仅为对照组中VEGF浓度的15%(P<0.01);在含有3'ΔFlt-1蛋白的调价培养液中,HUVEC的增殖明显减慢,在一定的范围内与剂量呈负相关;两者都能有效地抑制鸡胚新生血管的形成。结论:sflt-1与反义VEGF均能有效抑制新生血管的形成,两者联合能增强抑制效果,但其作用机制不同。     

CH50多肽真核表达载体pCH510的构建、表达及体内趋化和抑瘤作用

目的：探讨血管内皮生长因子的表达与肿瘤血管生成的关系。方法：将VEGF165正、反义RNA表达载体导入人胃癌细胞,观察接种VEGF高表达和低表达胃癌细胞裸鼠移植瘤的生长情况,并对移植瘤进行组织学检查,检测其血管密度、组织增生及环死程度等变化。结果：VEGF正义转染细胞所致移植瘤的生长速度明显快于反义转染细胞所致的移植瘤;组织学检查发现,正义转染细胞移植瘤的血管密度显著高于的转染细胞所致的肿瘤。结论：血管皮生长因子通过启动血管生成而促进肿瘤的生长,阻断血管内皮生长因子的产生可以抑制肿瘤的生长。     

Antisense expression for amphiregulin suppresses tumorigenicity of a transformed human breast epithelial cell line

The epidermal growth factor (EFG) family of receptors and their respective ligands play a major role in breast cancer progression and are the targets of new therapeutic approaches. Following immortalization with SV40 T antigen of normal human breast epithelial cells, a transformed variant cell line (NS2T2A1) was selected for its increased tumorigenicity in nude mice. This cell line was shown to have a higher expression of EGF receptors (EGFR) and amphiregulin (AR) when compared to their normal counterparts or less aggressive transformed cells. Dual staining of EGFR and AR was observed in 50-60% of NS2T2A1 cells, while 30-40% cells expressed AR only. To explore the potential tumorigenic role of AR, a 1.1 kb AR cDNA in an antisense orientation was transfected in NS2T2A1 cells. Three clones, selected by hygromycin B, expressed AR antisense RNA (AR AS1, AR AS2 and AR AS3 cell lines) in which AR protein expression was reduced (ranging from about 50 to < 5%). The anchorage-independent growth of AR AS cell lines was reduced to levels ranging from 32.4-6.8% relative to the control cell line transfected with the vector alone. The clones expressing AR antisense RNA showed a reversion of the malignant phenotype when injected in nude mice, since a significant reduction of tumor intake was observed coincident with a significant tumor mass reduction (> 96%). Moreover, intra-tumoral vascularization decreased significantly in tumors derived from AR AS cells (26.7, 70.7 and 50.4% of control). These in vitro and in vivo data reveal the oncogenic nature of AR in transformed breast epithelial cells and imply a role for AR in tumor angiogenesis.     

Amphiregulin Antisense RNA Delivered by Adnovirus Suppresses Growth of Breast Cancer Cells In Vitro and In Vivo

OBJECTIVE To investigate the therapeutic potential of amphiregulin antisense RNA delivered by adenoviral vector in a human breast cancer model.METHODS Human amphiregulin cDNA was subcloned in the opposite orientation to the cytomegaloviral promoter and inserted into an E1/E3-deleted type 5 adenoviral vector to obtain an AdA4 construct which expresses amphiregulin antisense mRNA. Both in vitro and in vivo antiproliferative effects of the antisense RNA were studied by infecting transformed human breast epithelial NS2T2A1 cells and tumors.RESULTS Amphiregulin protein expression was inhibited dramatically in the NS2T2A1 cells after infection with AdA4. The in vitro cell growth was inhibited significantly at day 4 post-AdA4 infection compared with control empty virus AdC1 at a MOl of 200 and 400 pfu/cell to 69.3% and 49.8%, respectively (P<0.02, P<0.005). After 3 intra-tumoral injections of 109 pfu AdA4, tumor volumes were reduced to 40.6% of that of the control group at day 35 (P<0.005).CONCLUSION The transfer of amphiregulin RNA antisense by adenoviral vector is effective for amphiregulin targeting strategy, leading to an inhibition of in vitro cell proliferation and in vivo tumor growth in this breast cancer model.     

Regulation of extracellular matrix metalloproteinase inducer and matrix metalloproteinase expression by amphiregulin in transformed human breast epithelial cells

Amphiregulin (AR) and epidermal growth factor effects on expression and activity of the extracellular matrix metalloproteinase inducer (EMMPRIN) were examined in NS2T2A1 breast tumor cells. Both growth factors induced mRNA and protein expression of EMMPRIN, and matrix metalloproteinase (MMP) -2 and -9 enzymatic activity. The induction of EMMPRIN by AR was mediated by epidermal growth factor receptor (EGFR) tyrosine kinase activation and inhibited by ZD1839. AR and EGFR antisense (AS) cDNAs inhibited EMMPRIN expression and MMP activity. Coculture of NS2T2A1V expressing AR- or EGFR-AS with fibroblasts and endothelial cells showed a decreased MMP activity. In parallel, nude mice tumors derived from AR and EGFR-AS cells revealed reduced level of EMMPRIN and MMP activity. AR and epidermal growth factor, therefore, regulate EMMPRIN and its MMP-mediated expression, identifying EGFR signaling as critical to this regulation.     

Inhibition of breast cancer growth in vivo by antiangiogenesis gene therapy with adenovirus-mediated antisense-VEGF

Increased expression of VEGF in several types of tumours has been shown to correlate with poor prognosis. We used a replication-deficient adenoviral vector containing antisense VEGF cDNA (Ad5CMV-alphaVEGF) to down-regulate VEGF expression and increase the efficiency of delivery of the antisense sequence in the human breast cancer cell line MDA231-MB. Transfection of these cells with Ad5CMV-alphaVEGF in vitro reduced secreted levels of VEGF protein without affecting cell growth. Moreover, injection of the Ad5CMV-alphaVEGF vector into intramammary xenografts of these cells established in nude mice inhibited tumour growth and reduced the amount of VEGF protein and the density of microvessels in those tumours relative to tumours treated with the control vector Ad5(dl312). Our results showed that antisense VEGF(165)cDNA was efficiently delivered in vivo via an adenoviral vector and that this treatment significantly inhibited the growth of established experimental breast tumours. The Ad5CMV-alphaVEGF vector may be useful in targeting the tumour vasculature in the treatment of breast cancer.     

p53反义RNA对肠癌细胞恶性表型的抑制作用

研究ｐ５３反义ＲＮＡ对大肠癌细胞中突变型ｐ５３致癌性的抑制效应,为肿瘤基因治疗提供新思路。方法２．１ｋｂ的人ｐ５３全长ｃＤＮＡ反向插入哺乳动物表达载体ｐＲＥＰ９,得到ｐ５３反义ＲＮＡ表达载体ｐＲＥＰ９－ｐ５３（ＡＳ）,并将其导入人肠癌细胞株ＳＷ１１１６（内源性突变型ｐ５３）,采用ＭＴＴ和ＦＣＭ方法测定ｐＲＥＰ９－ｐ５３（ＡＳ）表达的ｐ５３反义ＲＮＡ对ＳＷ１１１６细胞生长的影响。结果带有ｐＲＥＰ９－ｐ５３（ＡＳ）的ＳＷ１１１６细胞,与对照组ＳＷ１１１６细胞和带ｐＲＥＰ９空载体的ＳＷ１１１６细胞相比,由于ｐ５３反义ＲＮＡ的表达,其增殖速度显著下降,ＦＣＭ的结果也证明带ｐＲＥＰ９－ｐ５３（ＡＳ）的细胞部分受阻于Ｇ０／１期,而带ｐＲＥＰ９空载体的细胞则无明显变化。结论ｐ５３反义ＲＮＡ可以有效地抑制大肠癌细胞中突变型ｐ５３的致癌性,可用于实验性肿瘤基因治疗研究     

Suppression of ganglioside GD3 expression in a rat F-11 tumor cell line reduces tumor growth, angiogenesis, and vascular endothelial growth factor production

Ganglioside GD3 is overexpressed in many types of tumors and may be associated with tumor progression and the development of metastatic potential. In our previous study (G. Zeng et al., Biochemistry, 38: 8762-8769, 1999), we established a subclone of the rat dorsal root ganglion-derived F-11 cells in which the expression of ganglioside GD3 was inhibited by stable transfection of the antisense vector against CMP-NeuAc: GM3 alpha2-8 sialyltransferase (GD3-synthase) gene. This cell line exhibits markedly reduced rate of tumor growth in vivo. Here, we further characterized the antisense-transfected cell line, and the results showed that these cells formed small, minimally vascularized tumors exhibiting extensive necrosis. In vivo Matrigel assay revealed reduced vascularization and low hemoglobin content in the antisense xenografts. Significantly fewer new vessels were found on the antisense xenografts and the skin around them than those on/around the xenografts formed by the sense-transfected and untransfected F-11 cells. The hemoglobin content of the antisense xenografts was much lower than that of the xenografts formed by the control cells. The reduced angiogenesis in the antisense xenografts was correlated with a decrease in vascular endothelial growth factor (VEGF) production. The expression of VEGF was suppressed in the antisense xenografts and the conditioned culture media of the antisense-transfected F-11 cells as determined by Western blotting analysis. This was further confirmed by immunohistochemistry of the tumors using antibodies against VEGF and platelet/endothelial cell adhesion molecule (PECAM-1). Therefore, our results demonstrate that reduced tumor growth in nude mice by suppression of GD3-synthase expression in F-11 cells results from minimal angiogenesis of the tumors through down-regulation of the VEGF expression, which indicates an important role for GD3 in tumor angiogenesis.     

Overexpression of insulin-like growth factor binding protein 4 (IGFBP-4) in MCF-7 breast cancer cells is associated with reduced responsiveness to insulin-like growth factors in vitro and reduced tumour growth in vivo

Insulin-like growth factors (IGF-I and IGF-II) are potent mitogens for breast cancer cells. IGF bioactivity is influenced by IGF binding proteins (IGFBPs). In vitro, most breast cancer cell lines express and secrete IGFBP-4. Sense and antisense complementary DMA of human IGFBP-4 were ligated into a mammalian expression vector and transfected into MCF-7 cells in order to investigate the role of IGFBP-4 on breast cancer cell proliferation in vitro and in vivo. IGFBP-4 concentrations were 4-8-fold higher in conditioned media (CM) of sense IGFBP-4 transfected cells compared to control cells, while IGFBP-4 concentrations in the CM of antisense IGFBP-4 transfected cells were lower than those present in the CM of control cells. Basal growth of sense IGFBP-4 transfected cells (S11) in media supplemented with 0.5% fetal bovine serum was significantly lower (P<0.01) than that of a vector-transfected control (C13) and antisense IGFBP-4 transfected cells (AS4). Loss of IGF but not EGF responsiveness in S11 cells was observed 48 h after exposure to these mitogens. Equal response to Des (1-3) IGF-I (an IGF-I analogue with reduced affinity for IGF binding proteins) was observed for C13, S11 and AS4 cells, suggesting that loss of responsiveness to IGFs by S11 cells is a consequence of IGFBP-4 expression. The in viva proliferation of S11 was significantly (P<0.01) less than that of control C13 and AS4 cells in both lit/lit (IGF-I deficient) or lit/+ (IGF-I replete) hosts. These data demonstrate that IGFBP-4 expression influences breast cancer behaviour.