TnI-fast基因表达抑制卵巢癌移植瘤生长

为探讨利用TnI-fast 基因进行卵巢癌基因治疗的有效性及其机制, 将TnI-fast基因 cDNA转染人卵巢癌细胞系SKOV3. 采用MTT法和流式细胞技术分别检测TnI-fast基因转染、空载体转染和未转染的SKOV3细胞体外生长状态. 收集3种细胞培养上清液, 检测3种培养上清液对人脐静脉内皮细胞增殖抑制效应. 3种细胞分别接种到裸鼠, 观察肿瘤生长、细胞凋亡、肿瘤血管生成和TnI-fast基因局部表达. 体外试验发现, 与空载体转染和未转染的SKOV3细胞比较, TnI-fast基因表达对肿瘤细胞自身的生长无抑制作用, 但可抑制人脐静脉内皮细胞增殖. 动物实验中, TnI-fast基因表达可显著抑制肿瘤生长, 生长抑制率达73%. 其肿瘤细胞增殖率与对照组相当, 但微血管密度显著降低, 细胞凋亡显著增加. 提示, 肿瘤自身血管生成抑制可显著延缓卵巢癌生长. 利用血管生成特异性抑制基因TnI-fast进行抗肿瘤血管生成基因治疗可作为肿瘤治疗的新策略之一.     

Ang2、Tie2基因的RNA干扰及其在体外抑制血管生成的作用

目的：探讨应用RNA干扰（RNA interference,RNAi）技术沉默Ang2、Tie2基因及其在体外抑制血管生成的研究,为将来进一步进行抑制肿瘤血管生成的动物实验研究奠定基础,为肿瘤的基因治疗提供实验依据。方法：用pSilencer 1.0-U6-Ang2/Tie2-siRNA重组质粒转染人脐静脉内皮细胞(HUVECs),采用RT PCR检测各组HUVECs Ang2、Tie2的mRNA表达状况。应用体外血管生成的三维培养模型研究转染后的HUVECs在体外形成血管样结构的情况。结果：pSilencer 1.0-U6-Ang2/Tie2-siRNA重组质粒转染HUVECs后,RT-PCR检测结果显示: Ang2、Tie2基因mRNA的表达水平均受到明显抑制（P<0.05）,并且siRNA的2条重组质粒之间均无明显差别（P>0.05）。转染后的HUVECs在体外三维培养模型中血管样结构形成的数量和长度均明显减少（P<0.05）,表明血管生成受到明显抑制。结论：Ang2-siRNA、Tie2-siRNA能够抑制HUVECs中Ang2和Tie2的mRNA表达,从而在体外抑制血管生成。     

FOXQ1在肝癌中的临床意义及其对SMMC-7721细胞体外血管形成的影响

探讨叉头框蛋白Q1(forkhead box Q1, FOXQ1)基因在肝癌中的临床意义及对肝癌细胞体外血管生成作用.利用 qRT-PCR法及Western印迹法,检测24例肝癌、癌旁组织、正常肝细胞L02及肝癌细胞SMMC-7721中FOXQ1的mRNA和蛋白质的表达;利用免疫组织化学法检测68例肝癌及癌旁组织中FOXQ1的蛋白质表达.合成shRNA-FOXQ1及shRNA-NC慢病毒,转染到SMMC-7721细胞.用体外血管生成实验检测转染shRNA-FOXQ1的肝癌细胞血管生成能力. 用qRT-PCR和Western印迹法检测细胞间FOXQ1、VEGF基因和蛋白质的表达.结果显示,癌组织和SMMC-7721细胞中FOXQ1 mRNA和蛋白质的表达均高于癌旁组织和正常肝细胞(P<0.05),FOXQ1蛋白的表达与TNM分期、肿瘤分化程度、肿瘤数目、肿瘤大小等参数差异显著(P<0.05).shRNA-FOXQ1组血管生成能力明显低于shRNA-NC组和空白组(P<0.05),FOXQ1、VEGF基因和蛋白质的表达也明显低于shRNA-NC组和空白组(P<0.05).研究结果证实,FOXQ1在肝癌中高表达,如果沉默FOXQ1的表达可抑制肝癌细胞血管生成,与肝癌的临床病理特征密切相关.     

人EGFR显性负性突变体抑制胃癌细胞促血管形成能力

目的探讨人表皮生长因子显性负性突变体(dominant negative epidermal growth factor receptor,DNEGFR))对胃癌细胞促血管形成能力的影响及其分子机制,并检测其对裸鼠皮下移植瘤生长的影响。方法选用2株人胃癌细胞,分为如下6组:SGC-7901及NCI-N87细胞未转染组(US组,UN组),SGC-7901及NCI-N87细胞pEGFP-N1质粒转染组(ES组,EN组),SGC-7901及NCI-N87细胞pEGFPN1-DNEGFR质粒转染组(DS组,DN组)。采用人脐静脉内皮细胞(humanumbilical vein endothelial cell,HUVEC)管腔结构形成实验检测体外促血管形成能力,采用酶联免疫吸附测定法(enzyme-linked immunosorbent assay,ELISA)测定细胞培养液中血管内皮生长因子(vascular endothelial growth factor,VEGF)的水平,建立人胃癌细胞裸鼠移植瘤模型,标本微血管密度(microvessel density,MVD)检测体内促血管形成能力,标本体积检测其对裸鼠皮下移植瘤生长的影响。结果转染pEGFPN1-DNEGFR质粒的人胃癌细胞株出现HUVEC管腔结构形成抑制,培养液中VEGF水平降低,MVD计数降低,裸鼠皮下移植瘤体积变小。结论 DNEGFR可能通过下调VEGF分泌抑制胃癌细胞体外及裸鼠体内促血管形成能力,最终抑制裸鼠皮下移植瘤生长。     

VEGF-α诱导对卵巢癌血管生成拟态形成及侵袭、迁移能力的影响

目的探讨细胞因子VEGF-α诱导对卵巢癌SKOV-3和OVCAR-3细胞系血管生成拟态形成及侵袭、迁移能力的影响。方法采用不同细胞因子诱导卵巢癌SKOV-3和OVCAR-3细胞系,通过三维培养来观察卵巢癌细胞形成血管生成拟态的能力;以划痕实验和侵袭实验来判断细胞因子诱导对卵巢癌细胞侵袭、迁移能力的影响。结果三维培养结果表明在VEGF-α组SKOV-3和OVCAR-3细胞可观察到大量、明显的血管样网状结构;细胞划痕试验结果表明卵巢癌细胞系经细胞因子诱导后,其迁移能力明显增强;体外侵袭实验表明VEGF-α能够明显增强卵巢癌SKOV-3和OVCAR-3细胞的体外侵袭能力。结论 VEGF-α能促进卵巢癌细胞系血管生成拟态的形成,并明显增强卵巢癌细胞侵袭和迁移的能力。     

RNA干扰VEGF对体外JAR细胞生长的影响

利用pSUPER质粒作为载体,在人绒癌JAR细胞内成功的沉默了VEGF基因的表达,建立了稳定转染pSUPER—shVEGF1,pSUPER—shVEGF2干扰质粒的JAR细胞株．随后利用RT—PCR证实了在JAR细胞株中,VEGF基因的表达被抑制．显微观察及流式细胞学检测转染后细胞株克隆生长情况显示体外培养条件下VEGF基因受抑后JAR细胞生长周期无发生变化,提示VEGF在体外可能对JAR细胞增殖无直接作用．     

膜联蛋白A7表达抑制对HepG-2细胞中galectin-3及PKC表达的影响

目的探讨抑制膜联蛋白A7(ANXA7)表达对人肝癌HepG-2细胞半乳糖凝集素3(galectin-3)的影响以及联合佛波酯(PMA)激活PKC后对ANXA7表达的影响。方法将细胞分为siRNA干扰组、阴性对照组和空白对照组。采用RNA干扰技术将靶向ANXA7的siRNA和阴性对照siRNA脂质体转染法分别转染肝癌HepG-2细胞,空白对照组不予任何处理。转染48h后,采用Western blot和RT-qPCR法进行抑制效果的鉴定。Western blot和RT-qPCR法分别检测ANXA7表达抑制的HepG-2细胞中galectin-3的表达。转染48h后用100ng/ml PMA处理24h,Western blot法检测ANXA7及PKC的表达。结果靶向ANXA7的siRNA可显著抑制ANXA7的表达;ANXA7表达受抑后的HepG-2细胞中galectin-3的表达下降,与阴性对照组和空白对照组相比,差异有显著性(P0.05)。PMA处理24h后,ANXA7及PKC表达变化不显著。结论 ANXA7表达抑制的HepG-2细胞中galectin-3的表达显著下调,这可能是ANXA7表达受抑的细胞行为学发生改变的机制之一。     

Maspin在卵巢癌中作用机制的体外研究

目的:检测卵巢癌细胞中Maspin对细胞增殖能力、VEGF和乙酰肝素酶Heparanase(HPA)表达的影响。方法:构建Maspin真核表达质粒,体外转染卵巢癌SKOV3细胞,磺基罗丹明B法((sulforhodamine B,SRB)检测转染后细胞增殖能力变化,细胞免疫化学及半定量逆转录聚合酶链反应(RT-PCR)方法检测VEGF和HPA的表达。结果:成功构建Maspin真核表达质粒并转染于卵巢癌细胞SKOV3后,证实转染目的基因的SKOV3-Maspin细胞中Maspin表达明显增强;转染Maspin cDNA的SKOV3细胞的体外增殖能力明显弱于转染空载体组和未转染组,而后两者之间差异无显著性;转染Maspin cDNA的SKOV3细胞中VEGF的表达明显弱于转染空载体组和未转染组,而后两者之间差异无显著性;但是HPA的表达无明显改变。结论:Maspin可能通过下调VEGF的表达抑制卵巢癌血管生成。HPA表达与卵巢癌的恶性生物学行为密切相关,但与Maspin无明显相关性。     

人IL-17F对裸鼠人肝癌移植瘤生长的影响

利用RT-PCR方法从PHA活化的人外周血单个核细胞(PBMCs)中克隆hIL-17F基因,亚克隆至逆转录病毒载体pSIV-1,与辅助病毒载体pHIT456和pHIT60脂质体法共转染293T包装细胞,获得的成熟重组逆转录病毒(RV-hIL-17F)再感染SMMC-7721人肝癌细胞,并经G418筛选建立hIL-17F转基因肝癌细胞。PCR、RT-PCR和Westernblot结果表明hIL-17F基因在肝癌细胞中能成功整合、转录和表达。MTT和FCM结果表明hIL-17F不能改变SMMC-7721肝癌细胞的增殖活力和细胞周期,但ELISA结果表明其能明显下调肝癌细胞IL-6、IL-8和VEGF的表达。转基因肝癌细胞rhIL-17F表达上清具有抑制ECV304人脐静脉内皮细胞生长的作用。裸鼠皮下成瘤试验结果表明hIL-17F转基因肝癌细胞裸鼠致瘤能力明显减弱,VEGF和CD34表达降低,血管形成显著减少。hIL-17F可通过减少肿瘤血管形成显著抑制裸鼠人肝癌移植瘤的生长,为其进一步开展肿瘤血管靶向基因治疗和开发抗血管新药提供了一定的实验依据。     

shRNA靶向干扰COX-2抑制人肝癌裸鼠皮下移植瘤及其血管生成

目的:探讨重组干扰质粒pshRNA-COX-2对人肝癌细胞Hep3B裸鼠皮下移植瘤生长和肿瘤血管生成的抑制作用。方法:重组干扰质粒pshRNA-COX-2转染Hep3B细胞并筛选后,RT-PCR和Western blot检测COX-2mRNA和蛋白表达,RT-PCR检测VEGFmRNA表达。将被成功转染的Hep3B细胞种植于裸鼠皮下,测量肿瘤大小,4周后处死裸鼠,免疫组织化学法检测肿瘤组织中COX-2蛋白表达和肿瘤微血管密度(MVD)。结果:与未转染细胞相比,干扰组COX-2mRNA和蛋白表达抑制率分别为65.3%和52.8%(P<0.05),干扰组VEGFmRNA表达抑制率为56.5%(P<0.05)。干扰组瘤体大小明显小于阴性组和空白组(P<0.01)。干扰组COX-2得分和MVD均明显低于阴性组和空白组(P<0.01)。结论:pshRNA-COX-2通过抑制COX-2表达明显抑制人肝癌细胞Hep3B裸鼠皮下移植瘤生长和肿瘤血管生成。     

The role of TG2 in ECV304-related vasculogenic mimicry

Tumour vasculogenesis can occur by a process referred to as vasculogenic mimicry, whereby the vascular structures are derived from the tumour itself. These tumours are highly aggressive and do not respond well to anti-angiogenic therapy. Here, we use the well characterised ECV304 cell line, now known as the bladder cancer epithelial cell line T24/83 which shows both epithelial and endothelial characteristics, as a model of in vitro vasculogenic mimicry. Using optimised ratios of co-cultures of ECV304 and C378 human fibroblasts, tubular structures were identifiable after 8 days. The tubular structures showed high levels of TG2 antigen and TG in situ activity. Tubular structures and in situ activity could be blocked either by site-directed irreversible inhibitors of TG2 or by silencing the ECV304 TG2 by antisense transfection. In situ activity for TG2 showed co-localisation with both fibronectin and collagen IV. Deposition of these proteins into the extracellular matrix could be reduced by inclusion of non-cell penetrating TG inhibitors when analysed by Western blotting suggesting that the contribution of TG2 to tube formation is extracellular. Incubation of ECV304 cells with these same irreversible inhibitors reduced cell migration which paralleled a loss in focal adhesion assembly, actin cytoskeleton formation and fibronectin deposition. TG2 appears essential for ECV304 tube formation, thus representing a potential novel therapeutic target in the inhibition of vasculogenic mimicry.     

Lycorine hydrochloride inhibits metastatic melanoma cell-dominant vasculogenic mimicry

Melanoma cells actively participate in tumor angiogenesis and vasculogenic mimicry. However, anti-angiogenic therapy in patients with melanoma has not shown a significant survival gain. Thus, new anti-melanoma angiogenic and vasculogenic drugs are highly desired. Using the metastatic melanoma cell line C8161 as a model, we explored melanoma vasculogenic inhibitors and found that lycorine hydrochloride (LH) effectively suppressed C8161 cell-dominant formation of capillary-like tubes in vitro and generation of tumor blood vessels in vivo with low toxicity. Mechanistic studies revealed that LH markedly hindered expression of VE-cadherin in C8161 cells, but did not affect expression of six other important angiogenic and vasculogenic genes. Luciferase assays showed that LH significantly impeded promoter activity of the VE-cadherin gene in a dose-dependent manner. Together, these data suggest that LH inhibits melanoma C8161 cell-dominant vasculogenic mimicry by reducing VE-cadherin gene expression and diminishing cell surface exposure of the protein.     

TEL Induces Aggregation in Transformed Cells and Induces Tube Formation in NIH3T3-UCLA Cells

TEL/ETV6 is the frequent target of translocations associated with lymphoid and myeloid leukemias and solid tumors. We show that TEL induces aggregation of immortalized and transformed fibroblasts, endothelial cells and astrocytes. These aggregates form cellular cords in NIH3T3-UCLA by a cell autonomous process, which occurs when the monolayer is made up of over 75% of cells expressing exogenous TEL. Cords with a diameter of 15-25 microm contain a lumen and occur as tube structures. The possible relevance for vasculogenic mimicry is discussed. By contrast TEL did not induce aggregation of regular NIH3T3 cells, an effect that could only be induced by co-expression of oncogenic RAS/Lys12. Also transduction of TEL and RAS retroviral vectors into the endothelial MS1 cell line and TEL alone in the highly transformed glioblastoma cell lines EH-A and EH-B resulted in extensive aggregation. Thus, the induction of cellular aggregation by TEL correlates with transformation.     

Transdifferentiation of cancer stem cells into endothelial cells

Vasculogenic mimicry was first described as the unique ability of aggressive melanoma cells to express an endothelial phenotype and to form vessel-like networks in three dimensional cultures, “mimicking” the pattern of embryonic vascular networks and recapitulating the patterned networks seen in patients with aggressive tumors correlated with poor prognosis. Recent work shows the occurrence of alternative vasculogenic patterns is due to the presence of stem cell population (cancer stem cells, CSC) at least in melanoma and glioblastoma. In the present review the new perspectives to target vasculogenic mimicry for an anti-vascular treatment strategy and the possible use of AQP1 as target, are discussed. Interest in AQP1 as a target arises from the pivotal role it plays in the organisation of vascular network affecting the cytoskeleton.     

食管鳞癌血管生成拟态的组织学和细胞学研究

目的:探讨血管生成拟态(vasculogenic mimicry,VM)与食管鳞癌临床病理特征的关系及其对患者预后的影响,并分析食管癌血管生成拟态的形成机制。方法:收集57例食管鳞癌石蜡包埋样本,进行过碘酸雪夫氏(PAS)及CD34免疫组织化学双重染色,结合HE染色,观察食管鳞癌血管生成拟态的发生情况。对患者临床病理和预后信息进行单因素分析,Kaplan-Meier生存比较和Cox风险模型分析。通过食管鳞癌细胞株Eca-109三维培养建立,观察RNAi沉默VE-cadherin对食管鳞癌Eca109血管生成拟态形成的影响。结果:食管鳞癌中VM表达的阳性率为54.3%,显著高于正常食管黏膜组织;VM在病理分型为低分化食管鳞癌的阳性表达率为78.9%,显著高于中高分化组(P0.05);III-Ⅳ期食管鳞癌患者VM阳性率显著高于Ⅰ-Ⅱ期食管鳞癌患者(P0.05);有淋巴结转移的食管鳞癌者VM阳性率明显高于无淋巴结转移者(P0.05)。单因素分析结果显示食管鳞癌VM的发生率与肿瘤的分化程度、TNM分期和淋巴转移显著相关。Kaplan-Meier生存分析显示有VM组食管鳞癌患者的生存期明显短于无VM组(P0.05);Cox分析显示VM是影响食管鳞癌患者预后的独立危险因素(RF=0.67)。三维培养结果显示Eca-109细胞在基质胶上形成典型的血管网状样结构,VE-cadherin-siRNA可有效抑制VE-cadherin在Eca109的表达,抑制体外培养的Eca109细胞VM的形成。结论:血管生成拟态是食管鳞癌一种独特的血液供应模式,与食管鳞癌的分化程度、TNM分期、淋巴转移密切相关,是食管鳞癌患者术后生存期的独立危险因素。     

Detection of lecithin: cholesterol acyltransferase (LCAT) in a human hepatoma cell line

A human hepatoma cell line (HepG-2) was probed for the presence of lecithin: cholesterol acyltransferase (LCAT) using an antiserum to human plasma LCAT. Double immunodiffusion analysis using antiserum to human plasma LCAT revealed a single precipitin line in the sonicated cell homogenate. This precipitin line showed a reaction of identity with highly purified plasma LCAT. The presence of LCAT within the hepatoma cells was also confirmed by an immunofluorescence test. In contrast, the cell culture supernate showed a weak and inconsistent precipitin line. These data suggest that HepG-2 cells synthesize LCAT but secretion of the enzyme by these cells into the culture medium may be partially or totally impaired.     

Pro-angiogenic activity and vasculogenic mimicry in the tumor microenvironment by leptin in cancer

The acquired ability to induce the formation of a functional vasculature is a hallmark of cancer. Blood vessels in tumors are formed through various mechanisms, among the most important in cancer biology, angiogenesis, and vasculogenic mimicry have been described. Leptin is one of the main adipokines secreted by adipocytes in normal breast tissue and the tumor microenvironment. Here, we provide information on the relationship between leptin and the development of angiogenesis and vasculogenic mimicry in different types of cancer. Here, we report that leptin activates different pathways such as JAK-STAT3, MAPK/ERK, PKC, JNK, p38, and PI3K-Akt to induce the expression of various angiogenic factors and vasculogenic mimicry. In vivo models, leptin induces blood vessel formation through the PI3K-Akt-mTOR pathway. Interestingly, the relationship between leptin and vasculogenic mimicry was more significant in breast cancer. The information obtained suggests that leptin could be playing an essential role in tumor survival and metastasis through the induction of vascular mechanisms such as angiogenesis and vasculogenic mimicry; thus, leptin-induced pathways could be suggested as a promising therapeutic target.     

The epigenetic reprogramming of poorly aggressive melanoma cells by a metastatic microenvironment

A dynamic, complex relationship exists between tumor cells and their microenvironment, which plays a pivotal role in cancer progression, yet remains poorly understood. Particularly perplexing is the finding that aggressive melanoma cells express genes associated with multiple cellular phenotypes, in addition to their ability to form vasculogenic-like networks in three-dimensional matrix--called vasculogenic mimicry, which is illustrative of tumor cell plasticity. This study addressed the unique epigenetic effect of the microenvironment of aggressive melanoma cells on the behavior of poorly aggressive melanoma cells exposed to it. The data show significant changes in the global gene expression of the cells exposed to 3-D matrices preconditioned by aggressive melanoma cells, including the acquisition of a vasculogenic cell phenotype, upregulation of ECM remodeling genes, and increased invasive ability--indicative of an epigenetic, microenvironment-induced reprogramming of poorly aggressive melanoma cells. However, this epigenetic effect was completely abrogated when a highly cross-linked collagen matrix was used, which could not be remodeled by the aggressive melanoma cells. These findings offer an unique perspective of the inductive properties associated with an aggressive melanoma microenvironment that might provide new insights into the epigenetic regulation of tumor cell plasticity and differentiation, as well as mechanisms that could be targeted for novel therapeutic strategies.     

An upstream open reading frame regulates vasculogenic mimicry of glioma via ZNRD1-AS1/miR-499a-5p/ELF1/EMI1 pathway

Increasing evidence has suggested that gliomas can supply blood through vasculogenic mimicry. In this study, the expression and function of ZNRD1-AS1-144aa-uORF (144aa-uORF) and some non-coding RNAs in gliomas were assessed. Real-time quantitative PCR or Western blot was used to discover the expression of 144aa-uORF, ZNRD1-AS1, miR-499a-5p, ELF1 and EMI1 in gliomas. In addition, RIP and RNA pull-down assays were applied to explore the interrelationship between 144aa-uORF and ZNRD1-AS1. The role of the 144aa-uORF\ZNRD1-AS1\miR-499a-5p\ELF1\EMI1 axis in vasculogenic mimicry formation of gliomas was analysed. This study illustrates the reduced expression of the 144aa-uORF in glioma tissues and cells. Up-regulation of 144aa-uORF inhibits proliferation, migration, invasion and vasculogenic mimicry formation within glioma cells. The up-regulated 144aa-uORF can increase the degradation of ZNRD1-AS1 through the nonsense-mediated RNA decay (NMD) pathway. Knockdown of ZNRD1-AS1 inhibits vasculogenic mimicry in glioma cells by modulating miR-499a-5p. At the same time, miR-499a-5p is down-regulated and has a tumour-suppressive effect in gliomas. In addition, ZNRD1-AS1 serves as a competitive endogenous RNA (ceRNA) and regulates the expression of ELF1 by binding to miR-499a-5p. Notably, ELF1 binds to the promoter region of EMI1 and up-regulates EMI1 expression, while simultaneously promoting vasculogenic mimicry in glioma cells. This study suggests that the 144aa-uORF\ZNRD1-AS1\miR-499a-5p\ELF1\EMI1 axis takes key part in regulating the formation of vasculogenic mimicry in gliomas and may provide a potential target for glioma treatment.