Interleukin-17 enhances bFGF-, HGF- and VEGF-induced growth of vascular endothelial cells

Interleukin-17 (IL-17) is a CD4 T cell-derived proinflammatry and proangiogenic cytokine. In this study, we investigated the effects of this cytokine on vascular endothelial cell growth induced by a well-known direct angiogenic factor bFGF, HGF, VEGF, CXCL5/ENA-78 or CXCL8/IL-8. While a wide range of doses of IL-17 alone did not show the ability to stimulate the growth of human dermal microvascular endothelial cells (HMVECs), bFGF, HGF, VEGF, CXCL5 or CXCL8 significantly induced the growth of HMVECs in vitro. When bFGF and IL-17 were used in combination, 10 or 100 ng/ml IL-17 enhanced 10 ng/ml bFGF-induced growth of HMVECs. Similarly, when HGF and IL-17 were combined together, 10 or 100 ng/ml IL-17 potentiated 10 ng/ml HGF-induced growth of HMVECs. When VEGF and IL-17 were used together, 10 ng/ml IL-17 did not significantly enhance 10 ng/ml VEGF-induced growth, whereas 100 ng/ml IL-17 clearly promoted 10ng/ml VEGF-mediated proliferation of HMVECs. On the contrary, IL-17 did not augment CXCL5- and CXCL8-mediated growth. These results indicate that IL-17 itself does not have the capability to stimulate the growth of vascular endothelial cells, whereas IL-17 is able to selectively enhance the mitogenic activity of bFGF, HGF, and VEGF for vascular endothelial cells. Our findings also suggest that IL-17 may promote bFGF-, HGF- and VEGF-mediated angiogenesis through enhancing bFGF-, HGF- and VEGF-induced growth of vascular endothelial cells.     

血管内皮生长因子和碱性成纤维细胞生长因子在急性白血病患儿血清中的表达及意义

目的:探讨血管内皮生长因子(VEGF)和碱性成纤维细胞生长因子( bFGF)急性白血病(AL)患儿血清中的表达及其与临床意义.方法:采用ELISA方法检测40例初治AL患儿化疗前及治疗1疗程后37例患儿和40例健康儿童血清中VEGF和bFGF的水平.结果:治疗前,AL组以及ALL组、ANLL组血清VEGF和bFGF水平均显著高于对照组(P＜0.05),而血清VEGF和bFGF水平在AL不同类型之间差异无统计学意义(P＞0.05).治疗前,AL缓解(CR)和未缓解(NR)患儿血清VEGF和bFGF水平差异无统计学意义;治疗后,CR患儿血清VEGF和bFGF水平显著下降,与治疗前和NR患儿比较均有显著性差异(P＜0.05);而NR患儿治疗前后血清VEGF和bFGF水平差异无统计学意义.结论:VEGF和bFGF在AL患儿血清中呈高表达,血清VEGF和bFGF水平可作为AL患儿疗效观察指标,并且与患儿的预后有关.     

Effect of EGF and bFGF on Fibroblast Proliferation and Angiogenic Cytokine Production from Cultured Dermal Substitutes

Abstract

Growth factors accelerate wound healing but the underlying mechanisms remain poorly understood. The aim of this study was to investigate the effect of epidermal growth factor (EGF) and basic fibroblast growth factor (bFGF) on fibroblast proliferation and production of angiogenic factors from cultured dermal substitutes (CDS). In the first experiment, fibroblasts were seeded into a flask at a density of 1 × 10⁴ cells/cm².Cell proliferation was assessed after culturing in media containing EGF or bFGF at concentrations ranging from 2 to 50 μg. The number of fibroblasts increased significantly in the presence of EGF or bFGF, but fibroblasts detached from the flasks in the presence of 50 μg bFGF. In the second experiment, CDS were prepared by incorporating fibroblasts into collagen gels. To make a wound surface model, the CDS was elevated to the air–liquid interface, on which a spongy sheet of hyaluronic acid (HA) containing EGF or bFGF was placed. The amount of vascular endothelial growth factor (VEGF) and hepatocyte growth factor (HGF) released from the CDS after 1 week of cultivation was measured by ELISA. When the CDS was covered with a HA sponge containing EGF (Group 1), fibroblasts released 3.5-times more VEGF compared with a HA-alone sponge (control group). When covered with a HA sponge containing bFGF (Group 2), 8.7-times more VEGF was released compared with the control group. Fibroblasts in Groups 1 and 2 released 9.6- and 9.3-times more HGF, respectively, compared with the control group. Thus, EGF stimulates fibroblasts to produce VEGF and HGF, in addition to its ability to enhance epidermal cell proliferation.     

Plasma concentrations of vascular endothelial growth factor and basic fibroblast growth factor in lymphoproliferative disorders

Angiogenesis plays a major role in the development and progression of haematological malignancies. In our study we measured plasma concentrations of key angiogenic activators vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) using comercially available sandwich enzyme-linked immunosorbent assay (ELISA) in 37 patients with lymphoid malignancies and 20 healthy donors. We found a statistically significant increase in bFGF concentrations in patients with B-cell chronic lymphocytic leukemia (B-CLL, n=18) compared to the control group (median 118.8 vs. 9.3 pg/ml, p<0.001). However, we didn't find any significant difference in VEGF concentrations between B-CLL patients and the control group. There was also no significant increase in bFGF or VEGF in patients with multiple myeloma (n=7) and non-Hodgkin's lymphoma (n=12). Our pilot study shows that measurement of angiogenic activators in plasma is a feasible and reproducible method of angiogenesis assessment. Larger studies are needed for correlation between serum and plasma concentrations and detailed statistical evaluation including the impact on patients' survival.     

Collagenous matrices as release carriers of exogenous growth factors

We have investigated the use of natural and synthetic collagenous matrices as carriers of exogenous growth factors. A bladder acellular matrix (BAM) was processed from rat bladder and compared with sponge matrix of porcine type 1 collagen. The lyophilized matrices were rehydrated by the aqueous solutions of basic fibroblast growth factor (bFGF), hepatocyte growth factor (HGF), platelet derived growth factor-BB (PDGF-BB), vascular endothelial growth factor (VEGF), insulin like growth factor-1 (IGF-1) and heparin binding epidermal growth factor-like growth factor (HB-EGF), to obtain the matrix incorporating each growth factor. The rehydration method enabled the growth factor protein to distribute into the matrix homogeneously. In vivo release test in the mouse subcutis revealed that, the property of BAM for growth factor release was similar to that of collagen sponge. Among the growth factors examined, bFGF release was the most sustained, followed by HGF and PDGF-BB. bFGF released from the two matrices showed similar in vivo angiogenic activity at the mouse subcutis in a dose-dependent manner. These findings demonstrate that the collagenous matrices function as release carriers of growth factors. This feature is promising to create a scaffold, which has a nature to control the tissue regeneration actively.     

Increased plasma concentration of vascular endothelial growth factor in patients with atopic dermatitis and its relation to disease severity and platelet activation

Background

Overproduction of vascular endothelial growth factor (VEGF) in atopic dermatitis (AD) lesions has previously been observed. It is also known that platelet is an important source of VEGF and platelet factor 4 (PF-4), a potential marker of AD severity.

Aim

To evaluate concentrations of VEGF and its soluble receptors (sVEGF-R1 and sVEGF-R2) in the plasma of AD patients and to examine its possible correlation with disease severity and plasma concentrations of PF-4, a platelet activation marker.

Methods

Plasma concentrations of VEGF and its receptors and levels of PF-4 were measured by an immunoenzymatic assay in 51 AD patients and in 35 healthy non-atopic controls. The severity of the disease was evaluated using the eczema area and severity index.

Results

AD patients showed significantly increased VEGF and PF-4 plasma concentrations as compared with the controls. Plasma concentrations of sVEGF-R1 and sVEGF-R2 did not differ between the groups. There were no remarkable correlations between plasma VEGF concentration and disease severity or between VEGF and PF-4 concentration.

Conclusions

This study shows that plasma concentration of VEGF may be increased in patients suffering from AD. It seems that plasma VEGF concentration is not a useful marker of disease severity and, apart from platelets, other cells might also release the cytokine.     

Enhanced angiogenesis by multiple release of platelet-rich plasma contents and basic fibroblast growth factor from gelatin hydrogels

The objective of this study is to evaluate the angiogenic effects induced by biodegradable gelatin hydrogel granules incorporating mixed platelet-rich plasma (PRP) growth factor mixture (PGFM) and bioactive basic fibroblast growth factor (bFGF). The PRP was prepared by a double-spinning technique for isolating animal bloods, followed by treatment with different concentrations of calcium chloride (CaCl(2)) solution. The CaCl(2) solution treatment activated the platelets of PRP, allowing the release of various growth factors, such as platelet-derived growth factor (PDGF)-BB, vascular endothelial growth factor (VEGF), transforming growth factor (TGF)-β(1), and epithelial growth factor (EGF). In the PRP treated with different CaCl(2) solutions, high amounts of representative platelet growth factor, PDGF-BB, VEGF, EGF, and TGF-β(1) were detected in the CaCl(2) concentrations of 1, 2, and 4 wt.% compared with higher or lower ones. The PRP treated was impregnated into gelatin hydrogel granules freeze-dried at 37°C for 1h, and then the percentage of PGFM desorbed from the gelatin hydrogel granules was evaluated. The percentages of PDGF-BB, VEGF, EGF, and TGF-β(1) desorbed tended to decrease with decreasing CaCl(2) concentration. Taken together, the CaCl(2) concentration to activate PRP for PGFM release was fixed at 2 wt.%. In vitro release tests demonstrated that the PGFM was released from the gelatin hydrogel granules with time. For the gelatin hydrogels incorporating PGFM and bFGF, the time profile of PDGF-BB or bFGF release was in good correspondence with that of gelatin hydrogel degradation. The gelatin hydrogel granules incorporating mixed PGFM and bFGF were prepared and intramuscularly injected to a mouse leg ischemia model to evaluate the angiogenic effects in terms of histological and laser Doppler perfusion imaging examinations. As controls, hydrogel granules incorporating bFGF, PGFM, and platelet-poor plasma were used for the angiogenic evaluation. The number of blood vessels newly formed and the percentage of anti-α-smooth muscle actin antibody-positive cells increased around ischemic sites injected with the gelatin hydrogel granules incorporating mixed PGFM and bFGF, in marked contrast to other control groups. The blood reperfusion level of ischemic tissues was enhanced by the hydrogel granules incorporating mixed PGFM and bFGF, whereas no enhancement was observed for other groups. It is concluded that the dual-release system of PGFM and bFGF from gelatin hydrogel granules shows promise as a method to enhance angiogenic effects.     

The growth promoting effects of bFGF, PD-ECGF and VEGF on cultured postimplantation rat embryos deprived of serum fractions

Serum components in which embryos are cultured in vitro are very important for normal embryonic development. In this study, rat serum was fractionated using Macrosep filters to study the effect of a single growth factor. The fractionated serum, both that containing only material greater than 30 kDa molecular weight (> 30 kDa) and that from which material between 30 kDa and 50 kDa had been removed (< 30 kDa + > 50 kDa), caused significant embryonic growth retardation. Addition of different concentrations of basic fibroblast growth factor (bFGF, 18 kDa), vascular endothelial growth factor (VEGF, 45 kDa) and platelet-derived endothelial growth factor (PD-ECGF, 45 kDa), to fractionated serum (bFGF to > 30 kDa serum and VEGF or PD-ECGF to < 30 kDa + > 50 kDa serum) partially restored embryonic growth and development according to a morphological scoring system and protein assay. This restoration was clear by all criteria, as well as in yolk sac vascularisation and heart development. The growth promoting effects of all 3 factors were significant but did not reach the level seen in embryos grown in whole rat serum. The effect of these growth factors was also investigated on anembryonic yolk sac development using a concentration for which maximum whole embryonic growth was seen (128 ng/ml bFGF, 1.6 ng/ml VEGF and 4 ng/ml PD-ECGF), and significant anembryonic yolk sac development was found. These findings suggest that the angiogenic factors may have a growth promoting effect on total embryonic development and vascularisation.     

Growth factor regulation of neutrophil-endothelial cell interactions

The effects of the angiogenic factors basic fibroblast growth factor (bFGF) and vascular endothelial growth factor (VEGF) on human polymorphonuclear leukocyte (PMNL)-endothelial cell adhesion and transendothelial migration (TEM) were investigated. Stimulation of human umbilical vein endothelial cells by VEGF or bFGF for 18 h up-regulated intercellular adhesion molecule 1 and vascular cell adhesion molecule 1 expression and significantly increased PMNL adhesion and TEM in response to complement fragment 5a (C5a) or interleukin (IL)-8. In contrast, continued exposure to bFGF (24 h-6 days) down-regulated basal and IL-1- or tumor necrosis factor (TNF)-induced intercellular adhesion molecule 1, vascular cell adhesion molecule 1, and E-selectin expression as well as PMNL adhesion and TEM. These effects could be reversed by introduction of high concentrations of TNF-alpha, C5a, or IL-8. None of these inhibitory effects was observed with VEGF. The acute effects of bFGF and VEGF may facilitate PMNL emigration during acute inflammation, but continued bFGF production may have anti-inflammatory actions during chronic inflammation, angiogenesis, and tumor defense by inhibition of endothelial activation for leukocyte recruitment.     

Growth factors expression in patients with erosive esophagitis

Although the pathogenesis and treatment of erosive esophagitis (EE) is well recognized, little is known about the cellular and molecular mechanisms of mucosal healing in EE patients. In this pilot study, we enrolled typical EE patients to evaluate what kinds of growth factors and their receptors were activated in their injured esophageal mucosa. Forty endoscopically proved EE patients were consecutively enrolled. Messenger RNA expressions, which includes keratinocyte growth factor (KGF) and its receptor (KGFR), epidermal growth factor (EGF) and its receptor (EGFR), hepatocyte growth factor (HGF) and its receptor (HGFR), basic fibroblast growth factor (bFGF), vascular endothelial growth factor (VEGF), and cyclooxygenase (COX)-1 and COX-2, were measured using real-time polymerase chain reaction (PCR). Data were compared between the injured EE mucosa and their normal esophageal mucosa above EE. The mRNA expressions of HGF, HGFR, EGF, VEGF, and COX-2, but not EGFR, KGF, KGFR, bFGF, and COX-1, were significantly increased in the injured mucosa of EE patients compared with those of normal mucosa (P < 0.05). The study found that HGF, HGFR, EGF, VEGF, and, COX-2 are activated in the injured mucosa of EE patients; their activation might be involved in mucosal repair and ulcer healing of EE.     

Expression of angiogenesis-related genes in ovarian carcinoma--a clinicopathologic study

Angiogenic factors play a role in tumor growth and spread. The object of this study was to analyze the correlation between mRNA expression of angiogenesis-related genes and disease outcome in advanced-stage ovarian carcinomas. Sections from 66 primary ovarian carcinomas and metastatic lesions from 41 patients diagnosed with advanced stage ovarian carcinoma (FIGO stages III-IV) were evaluated for expression of basic fibroblast factor (bFGF), interleukin-8 (IL-8), and vascular endothelial growth factor (VEGF) using mRNA In Situ Hybridization (ISH). Patients were divided in two groups based on disease outcome. Long-term survivors (17 patients) and short-term survivors (24 patients) were defined using a double cut-off of 36 months for disease-free survival (DFS) and 60 months for overall survival (OS). Mean follow-up period was 70 months. The mean values for DFS and OS were 116 and 133 months for long-term survivors, as compared to 3 and 21 months for short-term survivors, respectively. Expression of bFGF mRNA, most often intense, was detected in tumor and stromal cells in the majority of cases. Weak expression of IL-8 mRNA was detected in both cell compartments, while VEGF mRNA expression was limited to few cases. Primary tumors displayed higher bFGF and IL-8 mRNA expression. However, these differences did not reach statistical significance (P > 0.05). bFGF, IL-8 and VEGF mRNA expression in both tumor and stromal cells was comparable in tumors of long-term and short-term survivors, and showed no correlation with disease outcome in survival analysis (P > 0.05). bFGF is the major angiogenic factor expressed in ovarian carcinoma at the mRNA level. mRNA expression of VEGF, bFGF, and IL-8 does not appear to be a predictor of disease outcome in advanced-stage ovarian carcinoma.     

Vascular endothelial growth factor overproduced by tumour cells acts predominantly as a potent angiogenic factor contributing to malignant progression

To elucidate the role of vascular endothelial growth factor (VEGF), an endothelial cell-specific mitogen, in tumour angiogenesis and malignant progression, an expression vector harboring human VEGF cDNA was stably transfected into three human cancer cell lines with poor VEGF productivity. Though their in vitro growth rate and intrinsic productivity of another angiogenic factor, basic fibroblast growth factor (bFGF), were not changed by transfection, those clones with higher VEGF production were endowed with tumorigenic and angiogenic potentials as follows: firstly, nontumorigenic, lung carcinoma QG90 cells having lower bFGF productivity acquired tumorigenicity as well as significant in vivo angiogenesis-inducing ability, secondly, tumorigenic colorectal carcinoma RPMI4788 cells having higher potency for bFGF production could form more vascularized solid tumour with faster growth rate and thirdly, oestrogen-dependent breast carcinoma MCF-7 cells, which did not produce detectable bFGF, acquired tumorigenicity even in the absence of oestrogen and the solid tumour growth rate was remarkably enhanced, accompanied with increased vascularization, in the presence of oestrogen. These results suggest that tumour progression closely depends on angiogenesis, and VEGF significantly contributes to malignant progression of a variety of tumour cells through its potent angiogenic activity, independent on the bFGF productivity of tumour cells.     

Vascular endothelial growth factor and basic fibroblast growth factor present in Kaposi's sarcoma (KS) are induced by inflammatory cytokines and synergize to promote vascular permeability and KS lesion development.

All forms of Kaposi''s sarcoma (KS) are characterized by spindle cell proliferation, angiogenesis, inflammatory cell infiltration, and edema. We have previously reported that spindle cells of primary KS lesions and KS-derived spindle cell cultures express high levels of basic fibroblast growth factor (bFGF), which is promoted by the inflammatory cytokines identified in these lesions. These cytokines, namely, tumor necrosis factor, interleukin-1, and interferon-gamma, induce production and release of bFGF, which stimulates angiogenesis and spindle cell growth in an autocrine fashion. Here we show that both AIDS-KS and classical KS lesions co-express vascular endothelial growth factor (VEGF) and bFGF. VEGF production by KS cells is promoted synergistically by inflammatory cytokines present in conditioned media from activated T cells and in KS lesions. KS cells show synthesis of VEGF isoforms that are mitogenic to endothelial cells but not to KS spindle cells, suggesting a prevailing paracrine effect of this cytokine. This may be due to the level of expression of the flt-1-VEGF receptor that is down-regulated in KS cells as compared with endothelial cells. KS-derived bFGF and VEGF synergize in inducing endothelial cell growth as shown by studies using both neutralizing antibodies and antisense oligodeoxynucleotides directed against these cytokines. In addition, VEGF and bFGF synergize to induce angiogenic KS-like lesions in nude mice and vascular permeability and edema in guinea pigs. These results indicate that inflammatory cytokines present in KS lesions stimulate the production of bFGF and VEGF, which, in turn, cooperate to induce angiogenesis, edema, and KS lesion formation.     

Pro-Angiogenic Cytokines as Cardiovascular Therapeutics

Coronary artery and peripheral vascular disease are global health concerns with limited therapies. Currently available medical and surgical therapies for these disease processes are highly effective for only a fraction of patients. Extensive effort has been devoted to finding molecular therapies to enhance perfusion and function of ischemic myocardial and peripheral skeletal muscle. Angiogenic cytokines (fibroblast growth factor [FGF], vascular endothelial growth factor [VEGF], hepatocyte growth factor [HGF], placental growth factor, stromal cell-derived factor-1alpha) have shown theoretical and experimental promise in upregulating endogenous endothelial progenitor cell-mediated angiogenesis. Preliminary clinical trials have suggested improvements in myocardial and peripheral perfusion following therapy with FGF, VEGF, and HGF. Further studies on the efficacy of cytokine-mediated angiogenesis are required before widespread clinical application is possible. Investigation into adjunctive cytokine therapies for myocardial and peripheral muscle ischemia is warranted. Based on experimental evidence, appropriate angiogenic cytokine therapy should provide benefits in both perfusion and hemodynamic function.     

Quantitation and physiological characterization of angiogenic vessels in mice: effect of basic fibroblast growth factor, vascular endothelial growth factor/vascular permeability factor, and host microenvironment.

A prerequisite for the development of novel angiogenic and anti-angiogenic agents is the availability of routine in vivo assays that permit 1) repeated, long-term quantitation of angiogenesis and 2) physiological characterization of angiogenic vessels. We report here the development of such an assay in mice. Using this assay, we tested the hypothesis that the physiological properties of angiogenic vessels governed by the microenvironment and vessel origin rather than the initial angiogenic stimulus. Gels containing basic fibroblast growth factor (bFGF) or vascular endothelial growth (VEGF) were implanted in transparent windows in the dorsal skin or cranium of mice. Vessels could be continuously and non-invasively monitored and easily quantified for more than 5 weeks after gel implantation. Newly formed vessels were first visible on day 4 in the cranial window and day 10 in the dorsal skinfold chamber, respectively. The number of vessels was dependent on the dose of bFGF and VEGF. At 3000 ng/ml, bFGF- and VEGF-induced blood vessels had similar diameters, red blood cell velocities, and microvascular permeability to albumin. However, red blood cell velocities and microvascular permeability to albumin were higher in the cranial window than in the dorsal skinfold chamber. Leukocyte-endothelial interaction was nearly zero in both sites. Thus, newly grown microvessels resembled vessels of granulation and neoplastic tissue in many aspects. Their physiological properties were mainly determined by the microenvironment, whereas the initial angiogenic response was stimulated by growth factors.     

Expression of angiogenesis-related genes in ovarian carcinoma – A clinicopathologic study

Angiogenic factors play a role in tumor growth and spread. The object of this study was to analyze the correlation between mRNA expression of angiogenesis-related genes and disease outcome in advanced-stage ovarian carcinomas. Sections from 66 primary ovarian carcinomas and metastatic lesions from 41 patients diagnosed with advanced stage ovarian carcinoma (FIGO stages III-IV) were evaluated for expression of basic fibroblast factor (bFGF), interleukin-8 (IL-8), and vascular endothelial growth factor (VEGF) using mRNA In Situ Hybridization (ISH). Patients were divided in two groups based on disease outcome. Long-term survivors (17 patients) and short-term survivors (24 patients) were defined using a double cut-off of 36 months for disease-free survival (DFS) and 60 months for overall survival (OS). Mean follow-up period was 70 months. The mean values for DFS and OS were 116 and 133 months for long-term survivors, as compared to 3 and 21 months for short-term survivors, respectively. Expression of bFGF mRNA, most often intense, was detected in tumor and stromal cells in the majority of cases. Weak expression of IL-8 mRNA was detected in both cell compartments, while VEGF mRNA expression was limited to few cases. Primary tumors displayed higher bFGF and IL-8 mRNA expression. However, these differences did not reach statistical significance (P>0.05). bFGF, IL-8 and VEGF mRNA expression in both tumor and stromal cells was comparable in tumors of long-term and short-term survivors, and showed no correlation with disease outcome in survival analysis (P>0.05). bFGF is the major angiogenic factor expressed in ovarian carcinoma at the mRNA level. mRNA expression of VEGF, bFGF, and IL-8 does not appear to be a predictor of disease outcome in advanced-stage ovarian carcinoma. This revised version was published online in July 2006 with corrections to the Cover Date.     

Vascular endothelial growth factor, platelet-derived growth factor, and insulin-like growth factor-1 promote rat aortic angiogenesis in vitro.

The purpose of this study was to evaluate the vasoformative response of isolated vascular explants to a variety of growth factors that have been shown to stimulate angiogenesis. Rings of rat aorta were cultured in collagen gels under serum-free conditions in the presence or absence of vascular endothelial growth factor (VEGF), natural platelet-derived growth factor (PDGF), PDGF-AA, PDGF-BB, insulin-like growth factor-1 (IGF-1), transforming growth factor-alpha (TGF-alpha), transforming growth factor-beta 1 (TGF-beta 1), epidermal growth factor (EGF), interleukin-1 alpha (IL-1 alpha), or hepatocyte growth factor (HGF). The angiogenic response of the rat aorta was stimulated by VEGF, PDGF, PDGF-AA, PDGF-BB, and IGF-1. Maximum stimulatory effects were obtained with VEGF and PDGF-BB. By contrast, TGF-beta 1 and IL-1 alpha had inhibitory activity. No significant effects were observed with TGF-alpha, EGF, or HGF. The vascular outgrowth of VEGF-stimulated cultures was primarily composed of microvessels, whereas that of PDGF- and IGF-1-stimulated cultures contained an increased number of fibroblast-like cells. The inability of TGF-alpha, TGF-beta 1, IL-1 alpha, EGF, and HGF to stimulate rat aortic angiogenesis in serum-free culture suggests that either these factors require the mediatory activity of accessory cells that are not present in the rat aorta model or that blood vessels are heterogeneous in their capacity to respond to different angiogenic factors.     

Serum levels of angiogenic cytokines decrease after radiotherapy in non-Hodgkin lymphomas

PURPOSE: Serum levels of angiogenic cytokines decrease after radiotherapy in patients with cancer, and this may be relevant for treatment response and progression-free survival. Herein, we set out to determine whether circulating fibroblast growth factor-2 (FGF-2), vascular endothelial growth factor (VEGF), hepatocyte growth factor (HGF) and platelet-derived growth factor-beta (PDGF-beta) decrease after radiotherapy in patients with non-Hodgkin lymphomas (NHLs) and if so, whether their decrease correlates with age, tumour histotype and stage, and radiation dose. MATERIAL AND METHODS: The serum levels of FGF-2, VEGF, HGF and PDGF-beta were evaluated before and after radiotherapy by an enzyme-linked immunosorbent assay (ELISA). These levels were correlated both reciprocally and with age, histotype, stage and radiation dose. RESULTS: After radiotherapy, FGF-2, VEGF and PDGF-beta, but not HGF, significantly decreased in relation to the radiation dose and response. No correlation was established between cytokine levels, except for VEGF and PDGF-beta, which decreased in parallel. Haemoglobin levels did not decrease after radiotherapy, while FGF-2, VEGF, HGF and PDGF-beta levels did not correlate with age, NHL stage and histotype. CONCLUSIONS: Soluble FGF-2, VEGF and PDGF-beta levels decline after radiotherapy in NHLs, and may have predictive significance for response to treatment and recurrence.     

Immunohistochemical expression of angiogenic cytokines and their receptors in reactive benign lymph nodes and non-Hodgkin lymphoma

Angiogenic cytokines regulate B-cell lymphopoiesis and are related to prognosis in B-cell lymphoproliferative disorders. Transforming growth factor-beta (TGF-beta) inhibits mature B-cell proliferation and immunoglobulin production. Increased levels of serum vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) are associated with poor prognosis in non-Hodgkin lymphoma (NHL). To understand the expression of angiogenic cytokines at different stages of B-cell differentiation in lymph nodes, we examined the immunohistochemical expression of TGF-beta, VEGF, bFGF, and their receptors in five patients with reactive benign lymphadenopathy and 12 patients with B-cell NHL (mantle cell lymphoma, 4; small cleaved cell follicular lymphoma, 5; lymphoplasmacytic lymphoma, 3). In benign lymph nodes, TGF-beta1, TGF-beta2, and TGFbetaRII were positive in prefollicular mantle cells, follicular center cells, and postfollicular plasma cells. Basic FGF, FGF-R1, and FGF-R4 were positive in large follicular center cells and postfollicular plasma cells. Vascular endothelial growth factor was positive in large follicular center cells and postfollicular plasma cells. In NHL, TGF-beta and its receptors were weakly positive in small cleaved cell follicular lymphoma; VEGF was strongly positive in lymphoplasmacytic lymphoma and weakly positive in mantle cell lymphoma. Basic FGF and its receptors were negative in NHL; however, FGF-R4 was positive in some cases of small cleaved cell follicular lymphoma. Our findings suggest that TGF-beta, bFGF, and their receptors have opposite roles in B-cell differentiation and maturation in benign lymph nodes. Transforming growth factor-beta and its receptors have an important role in germinal center development; loss of their activity could be associated with abnormal clonal proliferation of NHL.