Vascular Endothelial Growth Factor165-regulated Nasopharyngeal Carcinoma Cell Lines Invasion and Migration Involve Expression and Activation of Matrix Metalloproteinase-2

The effect of vascular endothelial growth factor （VEGF） overexpression on matrix metalloproteinase-2 （MMP-2） in nasopharyngeal carcinoma （NPC） cells in vitro and the possible mechanism involved were investigated, and the correlation between the expression of VEGF and MMP-2 in NPC evaluated. The NPC cells were transfected with PAd-trackVEGF165 plasmid. The expression levels of VEGF and MMP-2 mRNA and protein in NPC cells were detected by semi-quantitative RT-PCR and Western blot respectively. It was found that the expression of VEGF and MMP-2 mRNA and protein was significantly increased in NPC cells after transfection of VEGF 165. It was concluded that the expression of VEGF was correlated to the in vitro invasion of NPC cells, and the induction of MMP-2 by VEGF was a key process of NPC cell invasion.     

Antitumor Effect of Interferon-α on U937 Human Acute Leukemia Cells in vitro and Its Molecular Mechanism

In order to investigate the antitumor effect and molecular mechanism of interferon-α(IFN-α) on human acute myeloid leukemia cell line U937 cells in vitro,the proliferation of U937 cells was determined by MTT assay,the apoptosis rate was analyzed by flow cytometry(FCM),and the mRNA expression of cell cycle regulatory protein cyclin E was detected by RT-PCR.The results showed that IFN-α could inhibit the proliferation of U937 cells significantly in a dose-and time-dependent way(P<0.01),and induce the apoptosis of U937 cells also in a dose-and time-dependent manner at the concentration of 1000-4000 U/L(P<0.01).The apoptosis rate of U937 cells was even over 50% when cultured with IFN-α for 36-48 h at the concentration of 2000-4000 U/L.Moreover,the expression of cyclin E mRNA was markedly inhibited by the addition of IFN-α,and the inhibition was time-dependent(P<0.01).It was concluded that the anti-leukemia mechanism of IFN-α might be correlated with its antiproliferative and apoptotic inducing effects,and the down-regulation of the cyclin E expression might be one of its molecular mechanisms.     

Effect of N-tosyl-L-phenylalanylchloromethyl Ketone on Tumor Necrosis Factor-alpha -induced NF-κB Activation and Apoptosis in U937 Cell Line

Summary: To investigate the effect of N-tosyl-L-phenylalanylchloromethyl ketone (TPCK) on tumor necrosis factor-alpha-induced NF-κB activation and apoptosis in U937 cell line, changes and subcellular localization of NF-κB/p65 and IκB-α were observed by fluorescencemicroscopy and expression and degradation of IκB-α by flow cytometry. The apoptosis of U937 cells was measured by flow cytometry and electrophoresis of DNA. Immunolfluorescence assay showed that NF-κB/p65,IκB-α only localized in cytoplasm. After TNF-α stimulation, p65 was localized only in nuclei, and IκB-α was only localized in cytoplasm and decreased. The changes of TNF-α stimulation were specifically inhibited by TPCK. Flow cytometry also revealed the downregulation of IκB-α protein during TNF-α-induced apoptosis and the down-regulation was specifically inhibited by TPCK. Flow cytometry also showed the apoptosis of U937 cells after TNF-α induction. DNA ladder can be detected in cells treated by TNF-α. It is concluded that degradation of IκB-α protein and NF-κB/p65 translocation occur during TNF-α-induced apoptosis of U937 cells, suggesting the activation of NF-κB.TPCK-sensitive protease plays an important role in the degradation of IκB-α protein induced by TNF-α in U937 cells. TPCK sensitive protease also plays an important role in the apoptosis of U937 cells induced by TNF-α.     

Resveratrol Inhibits the Secretion of Vascular Endothelial Growth Factor and Subsequent Proliferation in Human Leukemia U937 Cells

This study examined the effect of resveratrol on the secretion of vascular endothelial growth factor(VEGF) and subsequent proliferation of human leukemia U937 cells,and explored the mechanisms involved.Human leukemia U937 cells were treated with resveratrol of different concentrations(12.5-200 μmol/L) for different time lengths(12-48 h).The proliferation of the U937 leukemic cells was determined by MTT assay.Apoptosis was observed by Annexin-Ⅴ-FIFC/PI double staining and flow cytometry(FCM).Cells cycle was analyzed by PI staining and FCM.The content of VEGF was determined by ELISA.Human umbibical vein endothelial cells were examined for vasoformation in vitro after exposures to resveratrol of various concetrations.The results showed that resveratrol inhibited the proliferation of U937 leukemia cells in a dose-and time-dependent manner.Resveratrol induced apoptosis and S-phase cell cycle arrest in human leukemic U937 cells.Resveratrol inhibited the secretion of VEGF in U937 cells.Resveratrol inhibited the vasoformation of human vein endothelial cells in a dose-dependent manner.It was concluded that resveratrol could down-regulate the secretion of VEGF,induce apoptosis and suppress the proliferation of U937 cells.     

Over-expression of hypoxia-inducible factor 1 alpha increases angiogenesis of LNCaP cells

Objective:To evaluate the effect of HIF-1 α over-expression on angiogenesis in human prostate cancer cells. Methods:LNCaP cells(a human prostate cancer cell line) were transfected with the recombinant plasmid pcDNA3.1(-)-HIF-1α with Lipofectamine 2000 system. The positive clones were selected by G418 being further confirmed by Western blot and immunofluorescence. The expression levels of VEGF, iNOS and Ang- Ⅱ were determined. Results:The expression of HIF-1α in the LNCaP/HIF1α cells was significantly increased in transfected cells, which induced the up-regulation of VEGF, iNOS, whereas Ang- Ⅱ expression remained un- changed. Conclusion :Over-expression of HIF-1α can induce angiogenesis proteins and may improve the angiogenesis potency of prostate cancer.     

Effects of Gambogic Acid on the Regulation of Nucleoporin Nup88 in U937 Cells

In order to investigate the anti-leukemia effects of gambogic acid （GA） and its relation to the regulation of nucleoporin Nup88 in U937 cells in vitro, the inhibitory effect of GA on the growth of U937 cells was examined by using MTT assay. Apoptosis was detected by Annexin-V FITC/PI double-labeled cytometry. Cell cycle regulation was studied by propidium iodide method. Both flow cytometry （FCM） and RT-PCR were employed to assess the expression of Nup88, and the localization of Nup88 was determined by confocal microscopy. The results indicated that GA had strong inhibitory effect on cell proliferation and apoptosis induction activity in U937 cells in vitro in a time-and dose-dependent manner. The 24-h IC50 value was （1.019±0.134） mg/L. Moreover, GA induced arrest of U937 cells in G0/G1 phase. Over-expression of Nup88 was found in U937 cells, whereas GA could significantly down-regulate both the protein and mRNA levels of Nup88. Nup88 was diffusely distributed between nucleus and cytoplasm and was located at the cytoplasmic side of nuclear rim, and occasionally in cytoplasm. It is suggested that GA exerts its anti-leukemia effects by regulating the expression and distribution of nucleoporin Nup88. It promises to be new agent for the treatment of acute leukemia.     

Vascular Endothelial Growth Factorl65-regulated Nasopharyngeal Carcinoma Cell Lines Invasion and Migration Involve Expression and Activation of Matrix Metalloproteinase-2

The effect of vascular endothelial growth factor (VEGF) overexpression on matrix met-alloproteinase-2 (MMP-2) in nasopharyngeal carcinoma (NPC) cells in vitro and the possible mechanism involved were investigated, and the correlation between the expression of VEGF and MMP-2 in NPC evaluated. The NPC cells were transfected with PAd-trackVEGF165 plasmid. The expression levels of VEGF and MMP-2 mRNA and protein in NPC cells were detected by semi-quantitative RT-PCR and Western blot respectively. It was found that the expression of VEGF and MMP-2 mRNA and protein was significantly increased in NPC cells after transfection of VEGF165. It was concluded that the expression of VEGF was correlated to the in vitro invasion of NPC cells, and the induction of MMP-2 by VEGF was a key process of NPC cell invasion.     

Ginsenoside Rgl-induced alterations in gene expression in TNF-α stimulated endothelial cells

Background In China the ginseng root began to be used in medicine over 2000 years ago.Ginsenosides are the most important component isolated from ginseng. The authors investigated the effect of ginsenoside Rgl on the spectrum of gene expression in the endothelial cells stimulated by TNF-α and further explored the potential molecular mechanism of endothelial protection by ginsenoside Rgl.Methods Nitric oxide (NO) production in(HUVECs) was measured by using an NOthe cultured human umbilical vein endothelial cells assay kit. A home-made oligonucleotide microarray containing approximately 400 cardiovascular disease-related genes was constructed. The alteration of the spectrum of gene expression induced by ginsenoside Rgl in HUVECs which were activated by TNF-α were detected by oligonucleotide microarray analysis.Results NO production in HUVECs was decreased significantly after TNF-α treatment, while pretreatment with ginsenoside Rgl enhanced NO production in TNF-αstimulated HUVECs.Ginsenoside Rg1 affected the expression levels of genes involved in vascular constriction, cell adherence, coagulation, cell growth and signal transduction in TNF-αstimulated HUVECs.Conclusions Ginsenoside Rgl could enhance NO production and the expression of eNOS mRNA in TNF-α stimulated HUVECs. Ginsenoside Rgl regulated sets of genes in endothelial cells and protected endothelial cells from TNF-αectivation. Microarray analysis provided us with valuable insights into the atheroprotective mechanism by gingsenoside Rg1.     

Comparison of hyaluronidase expression,invasiveness and tubule formation promotion in ER （-） and ER （＋） breast cancer cell lines in vitro

Background Hyaluronidase （Hyase） is an enzyme which hydrolyses hyaluronan （HA）, a large nonsulfated glycosaminoglycan. Several genes have been identified to code for hyaluronidases in humans. Its role has only recently been underlined in the invasion of prostate cancer, colonic cancer, and breast cancer. Moreover, the findings were in agreement with some experimental results which showed that HA-derived oligosaccharides had angiogenesis-promoting activity. All these findings prompted us to investigate factors that had been characterized as putative invasive factors in different human breast cancer-derived cell lines. Methods We selected two series of human breast cancer-derived cell lines whose expression of estrogen receptors （ER） was previously published. Hyaluronidase secretion in culture medium and expression of matrix metallo-proteinase （MMP）-9, cathepsin-D （cath-D） and vascular endothelial growth factor （VEGF） by cells were determined. We also investigated cell invasiveness in the Matrigel invasion assay, and studied the capability of cancer cells to promote in vitro formation of tubules by endothelial cells. Results ER（-） cells secreted significantly more hyaluronidase （P 〈0.001） and expressed significantly more VEGF （P 〈0.01）, MMP-9 （P 〈0.05） and cath-D （P 〈0.0001） than ER（＋） cells. Invasion through Matrigel by ER（-） Hyase（＋） cells was significantly higher than that by ER（＋） Hyase（-） cells （P 〈0.05）. In both cases, invasion was decreased by heparin （P 〈0.05）. When ECV-304 endothelial cells were co-cultivated in millicell chambers with cancer cells, ECV-304 cells were induced to form tubules. Tubule formation was demonstrated to be more prominent with ER（-） Hyase（＋） cells than with ER（＋） Hyase（-） cells （P 〈0.05）. Conclusion Invasive features of ER（-） breast cancer cells can be characterized in vitro by an invasive Matrigel assay, as the induction of tubule formation by ECV-304 endothelial cells, higher secretion of hyaluronidase, and higher expression of proteinases MMP-9, cath-D, and the angiogenesis promoting factor VEGF.     

巨噬细胞对血管内皮细胞增殖、Hoxb2、血管内皮生长因子受体和整合素αvβ3表达的影响

OBJECTIVE: To explore the mechanism by which macrophages regulate angiogenesis by co-culturing human umbilical vein endothelial cells (ECV-304) with human macrophage cells (U937) stimulated by concanavalin A (ConA). METHODS: Monolayer ECV-304 cells growing to 60% confluence were co-cultured with 1 x 10(5)/ml U937 cells in the presence or absence of ConA (ConA+U937+ECV-304 and U937+ECV-304 groups, respectively), with non-treated and ConA-treated ECV-304 cells serving as the control groups (ECV-304 and ConA+ECV-304 groups, respectively). Forty-eight h later, U937 cells were removed from the cell co-culture for examining changes in DNA synthesis of ECV-304 cells with (3)H-TdR incorporation assay and for cell cycle analysis with flow cytometry. RT-PCR was employed to assess the influence of macrophages stimulated by ConA on the expression of the target genes. With immunofluorescent method, the changes in the expression of integrin receptor alphavbeta3 of ECV-304 were determined. RESULTS: A significant increase in S-phase ECV-304 cells with enhanced DNA synthesis was observed after co-culture of the cells with ConA-stimulated U937 cells (P<0.01), which also resulted in significant up-regulation of the expressions of KDR mRNA (0.879+/-0.003), Hoxb2 mRNA (0.947+/-0.003) and integrin receptor alphavbeta3 (10.26+/-1.73). CONCLUSION: Macrophages can accelerate the proliferation, migration and adhesion of the vascular endothelial cells to the basilar membrane matrix by affecting their cell cycle, DNA synthesis, expression of KDR mRNA, Hoxb2 mRNA and integrin alphavbeta3, so as to modulate the angiogenetic process of the latter cells.     

骨髓间充质干细胞移植对脑动脉栓塞大鼠VEGF165、Notch1表达的影响

为探究骨髓间充质干细胞(BMSCs)移植对脑损伤大鼠的改善作用机制,本实验通过建立脑损伤大鼠模型,观察BMSCs移植对脑动脉栓塞大鼠血管内皮生长因子(VEGF) 165、Notch1表达的影响。将45只SD大鼠随机分为假手术对照组、动脉栓塞(MCAO)组、BMSCs移植组。检测脑组织栓塞区微血管数量,及各组大鼠VEGF165、Notch1蛋白和mRNA的表达。结果发现MACO组、BMSCs移植组大鼠的脑组织中微血管数量明显多于假手术对照组;MACO组和BMSCs移植组的VEGF165与Notch1的蛋白表达、VEGF165与Notch1的mRNA表达均高于假手术对照组;BMSCs移植组较MACO组更高。根据结果推测BMSCs移植可能通过激活Notch信号通路促进VEGF165的表达,而促进脑动脉栓塞区的血管新生。     

血管内皮生长因子对血管内皮细胞增殖及DNA合成的影响

目的　探讨血管内皮生长因子 (VEGF)诱导血管增生性疾病中血管生成的作用机制。方法　取体外培养的人脐静脉内皮细胞系ECV 30 4细胞 ,用MTT法和3H -TdR掺入法观察VEGF对ECV 30 4细胞增殖及DNA合成的影响。结果　VEGF对ECV 30 4细胞增殖及DNA合成均有明显刺激作用 ,且均呈剂量依赖性关系。结论　VEGF可能通过刺激血管内皮细胞增殖及DNA合成 ,促进血管生成。在血管增生性疾病中可能起重要促进作用。     

苏拉明对肺癌血管生成的抑制作用

目的　研究苏拉明对肺癌血管生成的抑制作用及其机制。方法　采用细胞培养和免疫组织化学的方法离体研究肺癌A5 49细胞、人血管内皮ECV 30 4细胞VEGF及其受体 (Flt、KDR)的表达及苏拉明的影响。结果　苏拉明对肺癌细胞产生和分泌VEGF无影响 ;ECV 30 4细胞KDR、Flt的蛋白表达在苏拉明浓度为 0 .2 5ng/ml和 2 .5ng/ml时 ,受到显著抑制 ;而苏拉明浓度为 0 .2 5ng/ml和 2 5ng/ml时Flt的表达 ,以及苏拉明浓度为 2 .5ng/ml和 2 5ng/ml时KDR的表达则无明显变化 (与对照组比较 ,P >0 .0 5 ) ;苏拉明对A5 49、ECV 30 4细胞增生无影响。结论　苏拉明抑制肺癌血管生成的作用机制可能是通过抑制血管内皮细胞上的VEGF受体表达 ,减少VEGF与其受体结合所致。     

羟基红花黄色素A抑制异常增殖血管内皮细胞的机制研究

目的研究羟基红花黄色素A(HSYA)抑制异常增殖血管内皮细胞的作用机理。方法建立人结肠腺癌细胞LS180上清液和人脐静脉内皮细胞ECV304体外共培养模型,通过实时荧光定量PCR检测ECV304细胞中血管内皮生长因子(VEGF)及其受体(KDR)、碱性成纤维细胞生长因子(b FGF)及其受体(b FGFR)、HSPG2、p53、c-myc mRNA水平的表达;ELISA法检测细胞培养上清VEGF、VEGFR(KDR)、b FGF、b FGFR蛋白的表达。结果在共培养细胞模型中,0.66、0.33 mg/L浓度的HSYA对血管生成促进因子VEGF及其受体KDR、b FGF及其受体b FGFR和癌基因c-myc及与细胞增殖相关蛋白多糖HSPG2的mRNA表达具有抑制作用;对抑癌基因p53 mRNA的表达具有促进作用。0.66、0.33 mg/L浓度的HSYA对血管生成促进因子VEGF及其受体KDR、b FGF及其受体b FGFR的蛋白表达具有抑制作用。结论 HSYA抑制新生血管的生成、抑制共培养模型中血管内皮细胞的异常增殖,其可能的作用机理是通过调控VEGF及其受体、b FGF及其受体、HSPG2、c-myc和野生型p53的表达发挥抗肿瘤作用,揭示HSYA可能是潜在的肿瘤血管生成抑制剂。     

氧化低密度脂蛋白功能性调节人内皮细胞的生长调节致癌基因α

目的　探讨oxLDL对人内皮细胞的CXC亚家族趋化因子GROα的调节作用及生理意义。方法　超高速离心得LDL ,氧化后得oxLDL。逆转录PCR分析人内皮细胞系ECV30 4细胞GROαmRNA。GAPDH被用作PCR中正常改变的对照物。酶联免疫检测仪测定ECV30 4细胞表面连接及分泌到溶液中的GROα蛋白。静态细胞粘附试验测定ECV30 4细胞表面连接的GROα蛋白的生理意义。结果　正常ECV30 4细胞不表达GROαmRNA ;OxLDL显著调节其表达 ,诱导效应首先出现在处理后 1h ,最大在 2h ,在 4h时下降。相比较 ,LDL对其mRNA表达没有影响。正常ECV30 4细胞低水平表达细胞表面的GROα蛋白。OxLDL呈浓度依赖性、时间依赖性地上调其表面的GROα蛋白。相比较 ,LDL对其表面表达的GROα蛋白无调节作用。OxLDL对ECV30 4细胞分泌到细胞溶液中GROα蛋白很少有影响。 4 0 μg/mloxLDL处理ECV30 4细胞 2 4h ,造成显著的人单核细胞系U937细胞粘附到ECV30 4细胞数目的增加。用GROα抗体预处理oxLDL刺激的ECV30 4细胞 ,可显著减低U937细胞粘附到ECV30 4细胞的U937细胞数目 (大约 2 / 3)。结论　oxLDL可能功能性上调内皮细胞GROα的表达。     

三羟异黄酮对脐静脉内皮细胞ECV304增殖影响与VEGFR的关系

目的探讨三羟异黄酮(genistein)抗肿瘤血管生成的机制.方法通过绘制生长曲线和流式细胞仪检测三羟异黄酮和血管内皮生长因子(vaScular endothelial growth factor,VEGF)对脐静脉内皮细胞ECV304增殖的影响,应用免疫沉淀和激酶活性分析方法检测ECV304细胞血管内皮生长因子受体(vascular endothelial growthfactor receptor,VEGFR)磷酸化水平和蛋白酪氨酸激酶(protein tyrosine kinase,PTK)活性.结果VEGF单独处理能使ECV304细胞增殖,VEGFR磷酸化水平和PTK活性升高,而三羟异黄酮单独处理能抑制ECV304细胞生长,细胞周期主要被阻止在G2/M期,并出现细胞凋亡现象,VEGFR磷酸化水平和PTK活性降低(P＜0.01),三羟异黄酮和VEGF同时处理时,细胞周期主要仍被阻止在G2/M期,但凋亡率下降,VEGFR磷酸化水平和PTK活性与VEGF单独处理组相比降低.结论三羟异黄酮能下调ECV304细胞VEGFR的磷酸化水平及PTK活性,从而阻断胞外生长刺激信号向胞内转导的级联反应,阻遏血管内皮细胞生长,抑制肿瘤血管生成.     

阿魏酸钠对小鼠H22肝癌生长的抑制作用及其机制研究

目的 观察注射用阿魏酸钠对小鼠H22肝癌生长及血管生成抑制作用及其对血管内皮生长因子(VEGF)Mrna转录的影响.方法 昆明小鼠前腋下皮下接种H22小鼠肝癌细胞,腹腔注射阿魏酸钠,每3 d测量1次肿瘤体积.用免疫组化法测定VEGF及增殖细胞核抗原(PCNA)的表达.MTT法检测阿魏酸钠对H22肿瘤细胞及血管内皮细胞(ECV304)增殖的影响,RT-PCR法测定肿瘤组织的VEGF Mrna的转录.结果 阿魏酸钠组小鼠H22肿瘤体积、重量增长明显较对照组缓慢(P＜0.05),同时阿魏酸钠组的肿瘤微血管密度及VEGF、PCNA阳性细胞较对照组显著减少(P＜0.05).阿魏酸钠组VEGF Mrna转录比对照组显著减少(P＜0.05).体外实验,阿魏酸钠对ECV304及H22细胞的增殖均无显著抑制作用.结论 阿魏酸钠可以显著抑制小鼠H22肿瘤的生长及血管生成,且能抑制VEGF的表达,但不能抑制ECV304及H22细胞的增殖.阿魏酸钠对肿瘤组织VEGF表达的抑制作用可能是其抗H22肿瘤及抗血管生成的一个重要机制.     

血管内皮生长因子重组DNA的构建及体外表达

目的:以质粒PCNDA3.0为载体,研究血管内皮生长因子(VEGF)目的基因在体外真核细胞中的表达.方法:将编码人可溶性VEGF165的目的基因克隆于带有CMV启动子/增强子的PCNDA3.0载体上,重组为PCNDA3.0-VEGF165质粒载体.直接以质粒DNA形式应用脂质体介导的方法转染人脐静脉内皮细胞ECV304,收取细胞上清,用ELISA和Western blot方法检测上清中VEGF165可溶性表达产物.结果:VEGF165基因在CMV启动子/增强子的调控下,可在ECV304细胞高效表达,且在转染后72 h表达量明显高于转染后48 h的表达.结论:以质粒PCNDA3.0为载体,VEGF165基因可以在体外真核细胞中表达,为治疗缺血性疾病提供一个新的基因治疗途径.