Circulating angiogenesis inhibitor endostatin and positive endothelial growth regulators in patients with systemic lupus erythematosus

Serum concentrations of three angiogenic cytokines: vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), interleukin-18 (IL-18) and antiangiogenic factor endostatin in the serum of 52 patients with systemic lupus erythematosus (SLE) and 20 healthy subjects were investigated. The possible association between serum levels of these proteins and SLE activity as well as correlation between the concentrations of angiogenic cytokines and the level of endostatin was also analyzed. VEGF and IL-18 were detectable in all SLE patients and healthy control group. bFGF was measurable in 71.2% of patients with SLE and 65% of healthy persons. Endostatin was detectable in 94.2% of SLE patients and 95% of normal subjects. The serum levels of endostatin and bFGF were not significantly different in SLE and healthy control (P > 0.05). The median concentration of VEGF was higher in active SLE (238.4 pg/ml) than in inactive disease (118.1 pg/ml, P < 0.05) or in control group (133.5 pg/ml, P < 0.04). The median serum level of IL-18 was higher in the SLE patients (595.2 pg/ml) than in the control group (252.7 pg/ml) (P < 0.001). The correlations between the levels of angiogenic cytokines and endostatin with clinical features, laboratory abnormalities and also with the type of treatment were analysed. We found a positive correlation between VEGF serum concentration and SLE activity according to SLAM score (p = 0.275, P < 0.05). The significant positive correlation was also found between IL-18 and endostatin (p = 0.289, P < 0.04). In contrast, the correlation between bFGF and endostatin was significantly negative (p = - 0.299, P < 0.04). In conclusion, serum levels of the angiogenic and antiangiogenic factors may play an important role in SLE pathogenesis.     

Regulation of lactate production and glucose transport as well as of glucose transporter 1 and lactate dehydrogenase A mRNA levels by basic fibroblast growth factor in rat Sertoli cells

By using cultured rat Sertoli cells as a model, both the action of basic fibroblast growth factor (bFGF) on lactate production and the site of this action were studied. bFGF stimulated Sertoli cell lactate production in a dose-dependent manner (basal: 7.3+/-0.5; 0.1 ng/ml bFGF: 7.5+/-0.5; 1 ng/ml bFGF: 7.5+/-0.6; 10 ng/ml bFGF: 10.3+/-1.0; 30 ng/ml bFGF: 15.2+/-1.5; 50 ng/ml bFGF: 15.4+/-1.6 microg/microg DNA). Two major sites for the action of this growth factor were identified. First, bFGF was shown to exert short- and long-term stimulatory effects on glucose transport (basal: 1170+/-102; 30 ng/ml bFGF for 120 min: 1718+/-152 and basal: 718+/-64; 30 ng/ml bFGF for 48 h: 1069+/-69 d.p.m./microg DNA respectively). Short-term bFGF stimulation of glucose transport was not inhibited by the protein synthesis inhibitor cycloheximide. These results indicate that short-term bFGF stimulation of glucose uptake does not involve an increase in the number of glucose transporters. On the other hand, stimulation with bFGF for periods of time longer than 12 h increased glucose transporter 1 (GLUT1) mRNA levels. These increased mRNA levels were probably ultimately responsible for the increments in glucose uptake that are observed in long-term treated cultures. Secondly, bFGF increased lactate dehydrogenase (LDH) activity (basal: 31.0+/-1.4; 30 ng/ml bFGF: 45.7+/- 2.4 mIU/microg DNA). The principal subunit component of those LDH isozymes that favors the transformation of pyruvate to lactate is subunit A. bFGF increased LDH A mRNA levels in a dose- and time-dependent manner. In summary, the results presented herein show that glucose transport, LDH activity and GLUT1 and LDH A mRNA levels are regulated by bFGF to achieve an increase in lactate production. These observed regulatory actions provide unequivocal evidence of the participation of bFGF in Sertoli cell lactate production which may be related to normal germ cell development.     

Matrix metalloproteinases, tissue inhibitors of matrix metalloproteinases and angiogenic cytokines in peripheral blood of patients with thyroid cancer.

Stimulation of growth of endothelial cells from preexisting blood vessels, i.e., angiogenesis, is one of the essential elements necessary to create a permissive environment in which a tumor can grow. During angiogenesis, the matrix metalloproteinase (MMP) family of tissue enzymes contributes to normal (embriogenesis or wound repair) and pathologic tissue remodeling (chronic inflammation and tumor genesis). The proposed pathogenic roles of MMPs in cancer are tissue breakdown and remodeling during invasive tumor growth and tumor angiogenesis. Tissue inhibitors of metalloproteinases (TIMPs) form a complex with MMPs, which in turn inhibits active MMPs. Vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) are unique among mediators of angiogenesis with synergistic effect, and both can also be secreted by thyroid cancer cells. The goal of the study was to evaluate the plasma blood concentration of VEGF, bFGF, MMP-1, MMP-2, MMP-3, MMP-8, MMP-9, TIMP-1, and TIMP-2 in patients with cancer and in normal subjects. Twenty-two patients with thyroid cancers (papillary cancer, 11; partly papillary and partly follicular cancer, 3; anaplastic cancer, 5; medullary cancer, 3) and 16 healthy subjects (controls) were included in the study. VEGF, bFGF MMPs, and TIMPs were evaluated by enzyme-linked immunosorbent assay (ELISA). In patients with thyroid cancer, normal VEGF concentrations (74.29 +/- 13.38 vs. 84.85 +/- 21.71 pg/mL; p > 0.05) and increased bFGF (29.52 +/- 4.99 vs. 6.05 +/- 1.43 pg/mL; p < 0.001), MMP-2 (605.95 +/- 81.83 vs. 148.75 +/- 43.53 ng/mL; p < 0.001), TIMP-2 (114.19 +/- 6.62 vs. 60.75 +/- 9.18 ng/mL; p < 0.001), as well as lower MMP-1 (0.70 +/- 0.42 vs. 3.87 +/- 0.53; p < 0.001) levels have been noted. Increased plasma levels of MMP-3 and MMP-9 were also found in patients with medullary carcinoma. In conclusion, predominance of MMP-2 over TIMP-2 and TIMP-1 over MMP-1 as well as increased concentration of bFGF in peripheral blood are common features in patients with thyroid cancer.     

Angiogenic synergistic effect of basic fibroblast growth factor and vascular endothelial growth factor in an in vitro quantitative microcarrier-based three-dimensional fibrin angiogenesis system

AIM: To develop an in vitro three-dimensional (3-D) angiogenesis system to analyse the capillary sprouts induced in response to the concentration ranges of basic fibroblast growth factor (bFGF) and vascular endothelial growth factor (VEGF) and to quantify their synergistic activity.METHODS: Microcarriers (MCs) coated with human microvascular endothelial cells (HMVECs) were embedded in fibrin gel and cultured in 24-well plates with assay media. The growth factors bFGF, or VEGF, or both were added to the system. The wells (n = 8/group) were digitally photographed and the average length of capillary-like sprouts (ALS) from each microcarrier was quantitated.RESULTS: In aprotinin-stabilized fibrin matrix, human microvascular endothelial cells on the MCs invaded fibrin,forming sprouts and capillary networks with lumina. The angiogenic effects of bFGF or VEGF were dose-clependent in bhe range from 10 to 40 ng/mL. At d 1, 10 ng/mL of bFGF and VEGF induced angiogenesis with an ALS of 32.13&#177;16.6 μm and 43.75&#177;27.92 μm, respectively, which were significantly higher than that of the control (5.88&#177;4.45 μm, P&lt;0.01),and the differences became more significant as the time increased. In addition, the combination of 10 ng/mL of bFGF and VEGF each induced a more significant effect than the summed effects of bFGF (10 ng/mL) alone and VEGF (10 ng/mL) alone when analyzed using SPSS system for general linear model (GLM) (P= 0.011), and bhat also exceeded the effects by 20 ng/mL of either bFGF or VEGF.CONCLUSION: A microcarrier-based in vitro threedimensional angiogenesis model can be developed in fibrin.It offers a unique system for quantitative analysis of angiogenesis. Both bFGF and VEGF exert their angiogenic effects on HMVECs synergistically and in a dose-dependent manner.     

Jagged1基因沉默对人胰腺癌细胞SW1990和PANC1血管相关因子分泌及迁移能力的影响

目的 以RNA干扰技术靶向沉默人胰腺癌细胞株Jagged1基因,观察细胞VEGF、Angiopoietin2、bFGF、MMP9的分泌及细胞迁移能力的变化.方法 应用靶向Jagged1的siRNA、对照siRNA(c-siRNA)转染人胰腺癌细胞株SW1990和PANC1,实时PCR法和蛋白质印迹法检测细胞Jagged1 mRNA和蛋白的表达,ELISA法检测细胞培养上清中VEGF、angiopoietin2、bFGF、MMP9的分泌量,Transwell小室观察细胞的迁移能力.结果 SW1990和PANC1细胞均高表达Jagged1基因.15 nmol/L Jagged1 siRNA转染胰腺癌细胞72 h后,SW1990、PANC1细胞的Jagged1 mRNA表达被抑制,分别为c-siRNA组的(59.62 ±2.75)％和(76.96 ±6.16)％,Jagged1蛋白表达几乎完全被抑制.SW1990、PANC1细胞的VEGF分泌量均较c-siRNA组显著减少[(867.93±58.69) pg/ml比(1516.24±37.58)pg/ml,(951.13±120.49) pg/ml比(1413.68±33.56) pg/ml,P＜0.05],但angiopoietin2、bFGF、MMP9蛋白分泌无明显变化.另外,Jagged1 siRNA转染后,SW1990细胞VEGF mRNA表达水平为c-siRNA组的(52.26 ±4.85)％ (P＜ 0.05);PANCI细胞为c-siRNA组的(59.75±4.91)％(P＜0.05).转染后的SW1990和PANC1细胞的穿膜细胞数分别为(65.25±5.56)、(57.50±8.58)个,较c-siRNA组的( 122.25±11.09)、(112.00±12.52)个显著减少(P＜0.05).结论 人胰腺癌细胞高表达Jagged1,沉默Jagged1基因可明显抑制人胰腺癌细胞VEGF的产生和分泌,并且可降低癌细胞的体外迁移能力.     

The role of the matrix metalloproteinases during in vitro vessel formation

Matrix metalloproteinases (MMPs) constitute a large family of extracellular matrix degrading proteases implicated in a number of physiological and pathological processes, including angiogenesis. However, the relative importance of the individual MMPs in vessel formation is poorly understood. Using the three-dimensional rat aortic model, the role of the MMPs in angiogenesis in vitro was investigated both by the use of synthetic MMP inhibitors, and by a study of the expression of nine MMPs and three of their endogenous inhibitors (the TIMPs) during vessel formation. Inhibition of microvessel growth in this model by the MMP inhibitor Marimastat demonstrated the requirement of the MMPs for angiogenesis in both collagen and fibrin matrices (half-maximal inhibition at 5 and 80 nM, respectively). The profile of MMP expression was seen to be modified by both matrix composition and exogenous growth factors. For example, whilst the gelatinase MMP-2 and stromelysin MMP-3 were present at high levels in fibrin culture, the stromelysin MMP-11 and membrane-type-1-MMP were more highly expressed during vessel formation in collagen. The angiogenic basic fibroblast growth factor (bFGF) upregulated the expression of the gelatinases (MMP-2 and MMP-9), the stromelysins (MMP-3, MMP-10 and MMP-11) and the interstitial collagenase MMP-13, whereas vascular endothelial growth factor (VEGF) led to a marked increase in expression of MMP-2 only. Together, the environment-dependent upregulation in expression of a number of MMPs during angiogenesis, and the total inhibition of vessel growth observed at nanomolar concentrations of synthetic MMP inhibitors, suggests a major collective role of these enzymes in angiogenesis, and provides a basis for further development of MMP inhibitors for anti-angiogenic therapy.     

Reductions of circulating matrix metalloproteinase 2 and vascular endothelial growth factor levels after treatment with pegvisomant in subjects with acromegaly

BACKGROUND: Vascular endothelial growth factor (VEGF) is involved in activation of the matrix metalloproteinase (MMP) system; the latter is implicated in atherosclerosis and cardiovascular disease. Patients with acromegaly have reduced life expectancy primarily due to cardiac disease. AIM: This study assessed plasma MMPs and VEGF levels in patients with active acromegaly (IGF-I > 130% upper limit of normal), and on treatment with pegvisomant. SUBJECTS AND METHODS: Twenty patients [nine female, mean age 56.1 +/- 13.8 yr (mean +/- sd)] were studied at baseline and on pegvisomant therapy and compared with data from 25 healthy volunteers (12 female; 56.6 +/- 14.2 yr). Plasma MMP-2, MMP-9, and VEGF levels were measured. RESULTS: Serum IGF-I fell from a baseline (mean +/- sd) level of 620.1 +/- 209.3 ng/ml to 237.5 +/- 118.5 ng/ml on pegvisomant (doses 10-60 mg; P < 0.001). MMP-2 levels at baseline were significantly higher in patients compared with healthy controls (380.7 +/- 204.8 vs. 207.4 +/- 62.6 ng/ml; P < 0.001), but with treatment a significant reduction in MMP-2 [380.7 +/- 204.8 vs. 203.0 +/- 77.4 ng/ml; P < 0.001] and VEGF (283.4 +/- 233.6 vs. 229.1 +/- 157.4 pg/ml; P = 0.008) was noted. There was no significant difference in MMP-9 levels between patients and controls at baseline (797.5 +/- 142.1 vs. 788.3 +/- 218.0 ng/ml; P = 0.87) or between baseline and posttreatment levels (797.5 +/- 142.1 vs. 780.0 +/- 214 ng/ml; P = 0.76). CONCLUSIONS: Our novel data demonstrate that treatment of acromegaly with pegvisomant leads to reductions in MMP-2 and VEGF concentrations. Further studies are required to determine the significance of these findings with relation to cardiac disease.     

Angiogenic synergy of bFGF and VEGF is antagonized by Angiopoietin-2 in a modified in vivo Matrigel assay

A murine modification of the Matrigel chamber assay originally developed for use on rats is presented. This modified assay permits improved quantification due to subcutaneous Matrigel implants of constant shape and volume. We have quantitatively assessed the angiogenic potential of the growth factors basic fibroblast growth factor (bFGF), VEGF, and Angiopoietin-2 (Ang-2) with special emphasis on their mutual interactions. A reproducible dose-response relationship for bFGF was established for doses between 150 and 1000 ng per chamber, whereas VEGF did not display angiogenic activity on its own in the tested dose of up to 200 ng per chamber. Conversely, we found a strong synergistic action of bFGF and VEGF when combined in a 3:1 ratio. Two other combinations (ratios) with greater VEGF doses were also tested, but the synergistic effect was only observed when 50 ng of VEGF was added to 150 ng per chamber of bFGF. This synergistic effect of bFGF and VEGF was significantly reduced by further addition of 100 ng Angiopoietin-2. Inhibition of the response to bFGF and VEGF was confirmed by in vitro EC migration experiments, which, together with our in vivo results, indicates that Ang-2 may target chemotactic responses to bFGF and VEGF in vivo.     

S179D prolactin primarily uses the extrinsic pathway and mitogen-activated protein kinase signaling to induce apoptosis in human endothelial cells

We have demonstrated that S179D prolactin (PRL) is potently antiangiogenic in vivo. Here, we examined apoptosis in human endothelial cells, using procaspase-8 and cytochrome c release as markers of the extrinsic and intrinsic pathways, respectively. Both pathways converge at caspase-3, which is responsible for cleavage of DNA fragmentation factor (DFF45). A 3-d incubation in 50 ng/ml S179D PRL quadrupled the number of early apoptotic cells; this effect was doubled at 100 ng/ml and became maximal at 500 ng/ml. DFF45 and procaspase 8 cleavage were detectable at 100 ng/ml. Cytochrome c, however, was unaffected until 500 ng/ml. The p21 increased at 24 h, whereas a change in p53 required both triple the time and higher doses. The p21 promoter activity was maximal at 50 ng/ml, whereas 500 ng/ml were required to see a significant change in the Bax promoter (a measure of p53 activity). Because S179D PRL and basic fibroblast growth factor (bFGF) have both been shown to activate ERK, the effect of S179D PRL on bFGF-induced ERK signaling was examined. S179D PRL blocked ERK phosphorylation in response to bFGF, whereas continued coincubation caused a delayed and prolonged activation of ERK. PD98059 inhibited this delayed activation of ERK and effects of S179D PRL on all measures except p53 levels or activity of the Bax promoter. We conclude that S179D PRL blocks bFGF-induced ERK signaling and yet uses ERK in a different time frame to elevate p21 and activate the extrinsic pathway. Prolonged incubations and high concentrations additionally activate the intrinsic pathway using an alternate intracellular signal.     

Role of Serum Vascular Endothelial Growth Factor in the Prediction of Angiogenesis and Prognosis for Non-small Cell Lung Cancer

Although vascular endothelial growth factor (VEGF) and matrix metalloproteinase (MMP)-9 are involved in angiogenesis of various cancers, clinical utility of preoperative serum concentration of these molecules in non-small cell lung cancer (NSCLC) has not yet been elucidated. In this study, we determined the concentration of VEGF, MMP-9 and various other tumor markers in serum prior to surgery and evaluated the results compared with intratumoral vasculature to isolate a valuable marker in determining the prediction of angiogenesis in NSCLC. Among these molecules and serum tumor markers, circulating serum VEGF was identified to markedly correlate with microvessel density (MVD) of the resected tumor specimens. Moreover, overall survival of patients with low VEGF levels (326 ng/ml) was significantly greater than that of patients with high VEGF levels (>326 ng/ml), while patients with low MMP-9 levels (189 ng/ml) and those with high MMP-9 levels (>189 ng/ml) revealed similar overall survival. Conclusively, preoperative concentration of serum VEGF may be the most valuable marker in the prediction of intratumoral angiogenesis and prognosis of patients with NSCLC.     

Epidermal growth factor and basic fibroblast growth factor increase the production of matrix metalloproteinases during in vitro decidualization of rat endometrial stromal cells

Numerous growth factors are involved in mediating proliferation and differentiation of endometrial stromal cells during decidualization. During this period, the extracellular matrix of the endometrium undergoes extensive remodeling. We tested the hypothesis that epidermal growth factor (EGF), basic fibroblast growth factor (bFGF), and transforming growth factor-beta regulate expression of matrix metalloproteinases (MMPs) and their inhibitors, tissue inhibitors of metalloproteinases (TIMPs), during decidualization. Stromal cells were isolated from uteri hormonally sensitized to undergo decidualization and were cultured in the absence or presence of a growth factor. Using substrate-gel electrophoresis with gelatin as the substrate, we detected activity for gelatinase A and B, and collagenase-3, and using casein as a substrate, we detected activity for stromelysin-1. Increasing concentrations of EGF and bFGF resulted in increased activity of gelatinase B, collagenase-3, and stromelysin-1. Northern blot analyses revealed that EGF and bFGF also increased messenger RNA levels for these MMPs. There was no effect of these growth factors on gelatinase or TIMP-1, -2, and -3, nor was there an effect of transforming growth factor-beta on any MMP or TIMP examined. These data demonstrate that EGF and bFGF increase levels of proteolytic enzymes produced by endometrial stromal cells undergoing decidualization in vitro while having no effect on their inhibitors.     

TLR9 agonist acts by different mechanisms synergizing with bevacizumab in sensitive and cetuximab-resistant colon cancer xenografts

Synthetic agonists of Toll-like receptor 9 (TLR9), a class of agents that induce specific immune response, exhibit antitumor activity and are currently being investigated in cancer patients. Intriguingly, their mechanisms of action on tumor growth and angiogenesis are still incompletely understood. We recently discovered that a synthetic agonist of TLR9, immune modulatory oligonucleotide (IMO), acts by impairing epidermal growth factor receptor (EGFR) signaling and potently synergizes with anti-EGFR antibody cetuximab in GEO human colon cancer xenografts, whereas it is ineffective in VEGF-overexpressing cetuximab-resistant GEO cetuximab-resistant (GEO-CR) tumors. VEGF is activated by EGFR, and its overexpression causes resistance to EGFR inhibitors. Therefore, we used IMO and the anti-VEGF antibody bevacizumab as tools to study IMO's role on EGFR and angiogenesis and to explore its therapeutic potential in GEO, LS174T, and GEO-CR cancer xenografts. We found that IMO enhances the antibody-dependent cell-mediated cytotoxicity (ADCC) activity of cetuximab, that bevacizumab has no ADCC, and IMO is unable to enhance it. Nevertheless, the IMO-plus-bevacizumab combination synergistically inhibits the growth of GEO and LS174T as well as of GEO-CR tumors, preceded by inhibition of signaling protein expression, microvessel formation, and human, but not murine, VEGF secretion. Moreover, IMO inhibited the growth, adhesion, migration, and capillary formation of VEGF-stimulated endothelial cells. The antitumor activity was irrespective of the TLR9 expression on tumor cells. These studies demonstrate that synthetic agonists of TLR9 interfere with growth and angiogenesis also by EGFR- and ADCC-independent mechanisms affecting endothelial cell functions and provide a strong rationale to combine IMO with bevacizumab and EGFR inhibitory drugs in colon cancer patients.     

Basic fibroblast growth factor inhibits the anabolic activity of insulin-like growth factor 1 and osteogenic protein 1 in adult human articular chondrocytes

OBJECTIVE: To determine the effects of basic fibroblast growth factor (bFGF) on the chondrocyte anabolic activity promoted by insulin-like growth factor 1 (IGF-1) and osteogenic protein 1 (OP-1). METHODS: Human articular chondrocytes were cultured in alginate beads or as cartilage explants in serum-free medium with or without IGF-1 (100 ng/ml), OP-1 (100 ng/ml), or bFGF (0-100 ng/ml). Cell survival, proliferation, proteoglycan synthesis, and total proteoglycan accumulation were measured after 21 days of culture in alginate beads, and proteoglycan synthesis was measured in explants. RESULTS: Cell survival was not altered by bFGF at any dose, and chondrocyte proliferation was stimulated only at doses above 1 ng/ml. When combined with IGF-1, 1 ng/ml of bFGF stimulated proliferation to 170% of control, but when combined with IGF-1 and OP-1, proliferation increased to 373% of control. Doses of bFGF of 100 ng/ml decreased total proteoglycan levels accumulated per cell by 60% compared with control and also inhibited the ability of IGF-1 or OP-1 to increase proteoglycan production. Likewise, sulfate incorporation in response to IGF-1 and OP-1 alone or together was completely inhibited by 50 ng/ml bFGF in both alginate and explant cultures. CONCLUSION: The anabolic activity of IGF-1 and OP-1, alone and in combination, is significantly inhibited by bFGF. The results suggest that excessive release of bFGF from the cartilage matrix during injury, with loading, or in arthritis could contribute to increased proliferation and reduced anabolic activity in articular cartilage.     

Effects of adenoviral-mediated gene transduction of NK4 on proliferation, movement, and invasion of human colonic LS174T cancer cells in vitro

AIM: To investigate the inhibitory effects of a recombinant adenovirus vector that expresses NK4, a truncated form of human hepatocyte growth factor (HGF), on human colonic adenocarcinoma cells in vitro to establish a basis for future NK4 gene cancer therapy. METHODS: Cells from the LS174T human colonic adenocarcinoma cell line were infected with recombinant adenovirus rvAdCMV/NK4 and the effects of the manipulation on tumor cell proliferation, scatter, migration, and basement membrane invasion were assessed. Cells infected with a recombinant adenovirus vector (Ad-LacZ) expressingβ-galactosidase served as the controls. RESULTS: We found that rvAdCMV/NK4 expression attenuated HGF-induced tumor cell scatter, migration, and basement membrane invasion (P<0.05), but did not inhibit tumor cell proliferation. CONCLUSION: HGF-induced LS174T tumor cell scatter, migration, and invasion can be antagonized by the recombinant NK4-expressing adenovirus.     

A novel, quantitative model for study of endothelial cell migration and sprout formation within three-dimensional collagen matrices

Interactions between migratory endothelial cells (ECs) and surrounding extracellular matrix (ECM) are of central importance to vascular growth. Here, we present a new model of EC migration and morphogenesis within three-dimensional ECM termed "radial invasion of matrix by aggregated cells" (RIMAC). In the RIMAC model, single aggregates of defined numbers of bovine aortic ECs were embedded within small, lenticular gels of type I collagen supported by annuli of nylon mesh. Culture of the gels in nutrient media resulted in quantifiable, reproducible, radial migration of ECs into the collagen. The angiogenic proteins basic fibroblast growth factor (bFGF) and vascular endothelial growth factor (VEGF) each stimulated migration of ECs in a concentration-dependent manner. In combination, bFGF and VEGF stimulated migration synergistically. In contrast, transforming growth factor-beta1 inhibited migration of ECs. Low concentrations (0.1-0.5 ng/ml) of VEGF induced ECs to form multicellular sprouts, some of which possessed lumen-like spaces. Mitomycin C, an inhibitor of cell proliferation, did not affect the migration of ECs into collagen induced by 0.5 ng/ml VEGF but moderately inhibited migration induced by 5 ng/ml VEGF. Increasing the density (concentration) of the collagen gel inhibited the migration of single ECs and increased the branching and anastomosis of multicellular sprouts. We conclude that the RIMAC model is a highly efficacious assay for the screening of potentially angiogenic and angiostatic compounds and, moreover, is advantageous for mechanistic studies of vascular morphogenesis.     

Hemoglobin induces the production and release of matrix metalloproteinase-9 from human malignant cells.

Matrix metalloproteinase-9 (MMP-9) plays a crucial role in both angiogenesis and tumor invasion. Vascular endothelial growth factor (VEGF) has been shown to up-regulate the expression of MMP-9 in vascular smooth muscle cells. We recently reported that hemoglobin (Hb) enhances the expression of tissue factor (TF) and VEGF on TF-positive human malignant cells. Therefore, to explore the relationship between tumor cell angiogenic protein VEGF and MMP-9, we studied the effect of Hb on MMP-9 production in human A375 malignant melanoma and J82 bladder carcinoma (TF+) cells and in KG1 myeloid leukemia (TF-) cells. Malignant cells were incubated with varying concentrations (0-1.0 mg/ml) of Hb and analyzed for released MMP-9 by gelatin zymography, dot immunoblotting, enzyme-linked immunosorbent assay, and Western blotting. Hb (0.50 mg/ml) induced an almost two-fold increase of MMP-9 in both A375 malignant melanoma (398 +/- 62 versus 233 +/- 61.0 ng/ml, P = 0.027) and J82 bladder carcinoma cells (1.55 +/- 0.12 versus 0.80 +/- 0.004 ng/ml, P = 0.004), compared with cells incubated without Hb. This release of MMP-9 was significantly inhibited by cycloheximide (95%) and by the specific inhibitors of protein tyrosine kinase, genistein (70 +/- 3.0%, P = 0.00027 and 67 +/- 1.0%, P = 0.00005) and mitogen-activated protein (MAP)-kinase, PD98059 (56 +/- 2.0%, P = 0.0001 and 62 +/- 1.0%, P = 0.00003) in A375 and J82 cells, respectively. In contrast, Hb (2.0 mg/ml) did not increase MMP-9 in KG1 cells. We conclude that Hb-induced synthesis of active MMP-9 in TF-bearing malignant cells is due to de novo synthesis of newly formed protein and is mediated by protein tyrosine kinase and by mitogen-activated protein kinase pathways.     

Marked elevation of vascular endothelial growth factor and basic fibroblast growth factor in pericardial fluid of patients with angina pectoris

Although we reported that basic fibroblast growth factor (bFGF) levels in pericardial fluid of patients with unstable angina are apparently increased, it was unclear whether vascular endothelial growth factor (VEGF) is also increased in patients with myocardial ischemia. Using an enzyme-linked immunosorbent assay, we measured the concentrations of VEGF and bFGF in pericardial fluid of 51 patients with open heart surgery. Patients were divided into group A (n=10) with class III unstable angina (Braunwald's classification), group B (n=24) with class I or II unstable angina or stable angina and group C (n=17) with non-ischemic heart disease. The VEGF level in pericardial fluid in group A was 83±7 pg/ml, being significantly (p<0.001) higher than the 27±3 pg/ml in group B and the 28±5 pg/ml in group C. The concentrations of bFGF in pericardial fluid in groups A and B were 1461±579 and 1224±161 pg/ml, respectively, significantly (p<0.05) higher than the 292±97 pg/ml in group C. The level of VEGF in pericardial fluid was increased only in patients with severe rest angina within 2 days before emergency coronary artery bypass graft surgery (CABG), while bFGF was increased in all patients undergoing CABG for coronary artery disease. Thus VEGF and bFGF may play important roles in mediating collateral growth in humans.     

CoCl2缺氧处理对脐带间充质干细胞促血管生长因子表达的影响

目的: 探讨氯化钴(CoCl2)模拟缺氧预处理对人脐带间充质干细胞(UC-MSCs)中碱性成纤维生长因子(bFGF)和血管内皮生长因子(VEGF)基因表达及蛋白分泌的影响。方法: 分离、培养UC-MSCs。取第3代的UC-MSCs,运用含150 μmol/L的CoCl2培养液培养细胞72 h,用流式细胞仪检测缺氧对UC-MSCs表面标志物(CD34、CD45、CD90、CD105、CD29及CD49)的影响。依据CoCl2的浓度(0、50、100 μmol/L及150 μmol/L)将UC-MSCs分为4个组,即对照组、低、中、高CoCl2组,每个组处理24 h、48 h和72 h。用SYBRGREN荧光定量RT-PCR检测bFGF、VEGF mRNA的表达,用ELISA法检测bFGF和VEGF蛋白的表达。结果: 经含150 μmol/L CoCl2的培养液缺氧处理,没有改变细胞的形态和表面标记物。在缺氧培养时间相同的情况下,bFGF、VEGF基因的表达均随着CoCl2浓度的增加而增加,CoCl2为150μmol/L时达到峰值（P<0.05）。当CoCl2浓度为150μmol/L培养不同时间(24h、48 h及72 h)时,随着缺氧预处理时间的延长,bFGF、VEGF基因的表达随之增加,于48 h时达到峰值（P<0.05）,bFGF、VEGF基因的表达分别为8.15±0.10和16.67±0.17,延长缺氧培养的时间基因的表达减小（P<0.05）;蛋白与基因表达的变化基本一致。在含150 μmol/L CoCl2的培养液培养48 h,bFGF和VEGF的表达达到顶峰（P<0.05）,分别为(69.63±7.90) ng/L和(89.55±5.45) ng/L。结论: 适当浓度的CoCl2(<150 μmol/L)对UC-MSCs的生物学功能影响轻微。CoCl2可用于细胞的模拟缺氧,缺氧对UC-MSCs bFGF、VEGF的分泌具有时间和剂量依赖性,以含150 μmol/L CoCl2的培养液培养48 h,为促进bFGF、VEGF基因和其蛋白表达的最适条件。     

Serum levels of vascular endothelial growth factor and basic fibroblast growth factor in patients with soft-tissue sarcoma

Purpose: Vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) have been suggested to be important mediators for tumor-induced angiogenesis. We measured serum VEGF and bFGF levels from patients with soft-tissue sarcomas and correlated serum VEGF and bFGF levels with tumor status at surgery and histological grading. Materials and methods: A group of 18 healthy controls and 85 patients with soft-tissue sarcoma were enrolled in this study. The patients were classified according to tumor status at surgery. Serum levels of VEGF and bFGF were also correlated with histological grading. VEGF and bFGF levels were determined by enzyme-linked immunosorbent assay (Quantikine R&D Systems). Results: Serum VEGF and bFGF levels were significantly elevated in the patient group (VEGF: 580pg/ml, bFbF: 21pg/ml, P = 0.0001). The highest concentrations of serum VEGF and bFGF were found in patients with macroscopic tumor lesions or G3 histology. Serum VEGF levels showed a statistically significant correlation with tumor status and grading (P = 0.006 for tumor status, P = 0.0001 for grading). Conclusions: This study reveals that elevated preoperative serum VEGF and bFGF levels can be detected in the majority of patients with soft-tissue sarcoma. The significant correlation with tumor mass and histological grading suggests that a consecutive monitoring of VEGF and bFGF in the serum of patients with soft-tissue sarcoma might be a valuable marker for tumor follow-up. Received: 26 April 1999 / Accepted: 17 May 1999