Angiogenesis in a human neuroblastoma xenograft model: mechanisms and inhibition by tumour-derived interferon-gamma

Tumour progression in neuroblastoma (NB) patients correlates with high vascular index. We have previously shown that the ACN NB cell line is tumorigenic and angiogenic in immunodeficient mice, and that interferon-γ (IFN-γ) gene transfer dampens ACN tumorigenicity. As IFN-γ represses lymphocyte-induced tumour angiogenesis in various murine models and inhibits proliferation and migration of human endothelial cells, we have investigated the antiangiogenic activity of tumour-derived IFN-γ and the underlying mechanism(s). In addition, we characterised the tumour vasculature of the ACN xenografts, using the chick embryo chorioallantoic membrane assay. We show that the ACN/IFN-γ xenografts had a lower microvessel density and less in vivo angiogenic potential than the vector-transfected ACN/neo. The vascular channels of both xenografts were formed by a mixed endothelial cell population of murine and human origin, as assessed by the FICTION (fluorescence immunophenotyping and interphase cytogenetics) technique. With respect to ACN/neo, the ACN/IFN-γ xenografts showed more terminal deoxynucleotidyl transferase-mediated dUTP nick end labelling-positive human and murine endothelial cells, suggesting that inhibition of angiogenesis by IFN-γ was dependent on the induction of apoptosis, likely mediated by nitric oxide. Once the dual origin of tumour vasculature is confirmed in NB patients, the xenograft model described here will prove useful in testing the efficacy of different antiangiogenic compounds.

Angiogenesis in rheumatoid arthritis

There is much evidence that rheumatoid arthritis is closely linked to angiogenesis. Important angiogenic mediators have been demonstrated in synovium and tenosynovium of rheumatoid joints. VEGF (Vascular Endothelial Growth Factor), expressed in response to soluble mediators such as cytokines and growth factors and its receptors are the best characterized system in the angiogenesis regulation of rheumatoid joints. Moreover, other angiogenic mediators such as platelet-derived growth factor (PDGF), fibroblast growth factor-2 (FGF-2), epidermal growth factor (EGF), insulin-like growth factor (IGF), hepatocyte growth factor (HGF), transforming growth factor beta (TGF-beta), tumor necrosis factor alpha (TNF-alpha), interleukin-1 (IL-1), IL-6, IL-8, IL-13, IL-15, IL-18, angiogenin, platelet activating factor (PAF), angiopoietin, soluble adhesion molecules, endothelial mediator (endoglin) play an important role in angiogenesis in rheumatoid arthritis. On the other hand, endostatin, thrombospondin-1 and -2 are angiogenic inhibitors in rheumatoid arthritis. The persistence of inflammation in rheumatoid joints is a consequence of an imbalance between these inducers and inhibitors of angiogenesis.

Bone marrow angiogenesis in multiple myeloma

Angiogenesis is a constant hallmark of multiple myeloma (MM) progression and has prognostic potential. It is induced by plasma cells via angiogenic factors with the transition from monoclonal gammopathy of undetermined significance (MGUS) to MM, and probably with loss of angiostatic activity on the part of MGUS. The pathophysiology of MM-induced angiogenesis is complex and involves both direct production of angiogenic cytokines by plasma cells and their induction within the microenvironment. The latter are secreted by stromal cells, endothelial cells (EC) and osteoclasts, and promote plasma cell growth, survival and migration, as well as paracrine cytokine secretion and angiogenesis in the bone marrow milieu. Angiogenesis is also supported by inflammatory cells following their recruitment and activation by plasma cells. Finally, circulating EC and endothelial precursor cells (EPC) contribute to the neovascularization, and the presence of EPC suggests that vasculogenesis (new vessel formation from EPC) may also contribute to the full MM vascular tree.

Importance of the bone marrow microenvironment in inducing the angiogenic response in multiple myeloma

Tumor microenvironment is essential for tumor cell proliferation, angiogenesis, invasion and metastasis through its provision of survival signals, secretion of growth and pro-angiogenic factors, and direct adhesion molecule interactions. This review examines its importance in the induction of an angiogenic response in multiple myeloma (MM). The encouraging results of preclinical and clinical trials in which MM has been treated by targeting the tumor microenvironment are also discussed.

Endothelial progenitor cells in health and disease

There is currently great excitement and expectation in the stem cell community following the discovery that multipotent stem cells can be cultured from human fetal tissue and retain their ability to give rise to a variety of differentiated cell types found in all three embryonic germ layers. Although the earliest sites of hematopoietic cell and endothelial cell differentiation in the yolk sac blood islands were identified about 100 years ago, cells with hemangioblast properties have not yet been identified in vivo. Endothelial cells differentiate from angioblasts in the embryo and from endothelial progenitor cells, mesoangioblasts and multipotent adult progenitor cells in the adult bone marrow. Circulating endothelial progenitor cells (EPC) have been detected in the circulation after vascular injury and during tumor growth. The molecular and cellular mechanisms underlying EPC recruitment and differentiation are not yet understood, and remain as one of the central issues in stem cell biology. For many years, the prevailing dogma stated that the vessels in the embryo develop from endothelial progenitors, whereas sprouting of vessels in the adult results only from division of differentiated endothelial cells. Recent evidence, however, indicates that EPC contribute to vessel growth in the embryo and in ischemic, malignant or inflammed tissues in the adult, and can even be therapeutically used to stimulate vessel growth in ischemic tissues.

Increased matrix-metalloproteinase-2 and matrix-metalloproteinase-9 expression in the brain of dystrophic mdx mouse

Brain edema and severe alterations of the glial and endothelial cells have recently been demonstrated in the dystrophin-deficient mdx mouse, an experimental model of Duchenne muscular dystrophy, and an increase in microvessel density in patients affected by Duchenne muscular dystrophy has also been shown. In order to further elucidate the mechanisms underlying the angiogenetic processes occurring in Duchenne muscular dystrophy, in this study we analyzed matrix-metalloproteinase-2 and -9 expression in the brain of 20-month-old mdx and control mice by means of immunohistochemistry, in situ hybridization, immunoblotting and gelatin zymography. Moreover, we studied vascular endothelial growth factor expression by means of Western blot and immunohistochemistry, and by dual immunofluorescence using anti-vascular endothelial growth factor and anti matrix-metalloproteinase-2 and-9 antibodies. Ultrastructural features of the brain choroidal plexuses were evaluated by electron microscopy. Spatial relationships between endothelium and astrocyte processes were studied by confocal laser microscopy, using an anti-CD31 antibody as a marker of endothelial cells, and anti-glial fibrillary acidic protein (GFAP) as a marker of glial cells. The results demonstrate that high expression of matrix-metalloproteinase-2 and matrix-metalloproteinase-9 protein content occurs in mdx brain and in choroidal plexuses where, by in situ hybridization, matrix-metalloproteinase-2 and matrix-metalloproteinase-9 mRNA was localized in the epithelial cells. Moreover, matrix-metalloproteinase-2 mRNA was found in both mdx perivascular astrocytes and blood vessels, while matrix-metalloproteinase-9 mRNA was localized in mdx vessels. Through zymography, increased expression of matrix-metalloproteinase-2 and matrix-metalloproteinase-9 was found in mdx brain compared with the controls. These enhanced matrix-metalloproteinase levels in mdx mice were found to be associated with increased vascular endothelial growth factor expression, as determined by immunoblotting and immunocytochemistry and with ultrastructural alterations of the mdx choroidal epithelial cells and brain vessels, as previously reported [Nico B, Frigeri A, Nicchia GP, Corsi P, Ribatti D, Quondamatteo F, Herken R, Girolamo F, Marzullo A, Svelto M, Roncali L (2003) Severe alterations of endothelial and glial cells in the blood-brain barrier of dystrophic mdx mice. Glia 42:235-251]. Indeed, in the mdx epithelial cells of the plexuses, the apical microvilli were located on the lateral membranes, whereas in the controls they were uniformly distributed over the free ventricular surface. Moreover, by dual immunofluorescence, a colocalization of vascular endothelial growth factor and matrix-metalloproteinase-2 and matrix-metalloproteinase-9 was found in the ependymal and epithelial cells of plexuses in mdx mice and, under confocal laser microscopy, mdx CD-31 positive vessels were enveloped by less GFAP-positive astrocyte processes than the controls. Overall, these data point to a specific pathogenetic role of matrix-metalloproteinase-2 and matrix-metalloproteinase-9 in neurological dysfunctions associated with Duchenne muscular dystrophy.

Levocetirizine in the treatment of chronic idiopathic urticaria: a randomized, double-blind, placebo-controlled study

BACKGROUND

Chronic urticaria is a common skin condition. It is frequently a disabling disease because of the persistence of clinical symptoms, the unpredictable course and its negative influence on the quality of life.

OBJECTIVES

To determine whether levocetirizine is efficacious in the treatment of chronic idiopathic urticaria.

METHODS

A randomized, double-blind, placebo-controlled study was conducted in 106 patients with a diagnosis of chronic idiopathic urticaria. A 1-week single blind placebo run-in period (baseline) was followed by a 6-week double blind active treatment period. The patients were randomized to receive one of the following treatments once daily: (a) oral levocetirizine 5 mg, or (b) oral placebo. The study ended after another 1-week single blind placebo washout period.

RESULTS

The evaluable population consisted of 100 patients. Levocetirizine administered once daily is effective and well tolerated in the treatment of the symptoms of chronic idiopathic urticaria and in improving the patient's quality of life. Levocetirizine was superior to placebo in reducing the mean total symptoms score as well as individual symptoms, the number of daily episodes and the number of weals, the overall severity of symptoms and the quality of life. The significant beneficial effects of levocetirizine lasted only during the active trial, while at follow-up there was a significant worsening of all the variables evaluated in this study, after the end of the active trial (week 7).

CONCLUSIONS

A global assessment indicates that levocetirizine 5 mg once daily is an effective agent in patients with chronic idiopathic urticaria, as its action provides a rapid and satisfactory control of the symptoms and measures of subjective disease, although this is limited to the duration of treatment.

Acquired C1-inhibitor deficiency in a patient with systemic lupus erythematosus: a case report and review of the literature

The C1-inhibitor (C1-INH) is an important member of the serpin family which inhibits the first component of the human complement system and controls contact activation of the coagulation and kinin system. An acquired form of C1-INH deficiency was recognized and classified as type I, which is characterized by accelerated catabolism of C1-INH, whereas type II is defined by the presence of an autoantibody directed against the C1 inhibitor molecule. This study reports the case of a 32-year-old woman with systemic lupus erythematosus (SLE) who experienced recurrent angioedema because of an acquired C1-INH deficiency. The relevant literature is reviewed.

Decision-making in adult thalassemia patients undergoing unrelated bone marrow transplantation: quality of life, communication and ethical issues

Bone marrow transplantation (BMT) represents a potentially curative treatment of thalassemia. For patients without an HLA-identical sibling donor, recourse to an unrelated donor is a practicable option but the candidates and their families are faced with a difficult decision. They can either choose to continue the supportive therapy, with no chance of definitive cure, or they accept the mortality risk of BMT in the hope of obtaining a definitive resolution of the disease. We investigated the communication strategies and the post transplantation quality of life (QoL) in 19 adult thalassemia patients surviving after an unrelated donor BMT. The patients were given two questionnaires: a questionnaire to evaluate pre-transplantation communication factors and the EORTC QLQ-C30 questionnaire to assess global QoL. All patients were satisfied with the communication modalities employed by the physicians. The global post transplantation QoL in our patient cohort was found to be good. The approach used in this study may offer a contribution to understanding the decision-making process leading to the choice of a treatment with a high mortality risk for a chronic, non-malignant disease. Finally, some ethical issues of this therapeutic approach are briefly addressed.

Therapeutic renaissance of thalidomide in the treatment of haematological malignancies

Very few drugs had a history similar to that of thalidomide (alpha-N-[phthalimido] gluramide). First introduced in the late 1950s in Germany, in 1961 thalidomide was withdrawn due to its teratogenic effects. More than three decades after, it is attracting growing interest because of its reported immunomodulatory and anti-inflammatory properties. The discovery that thalidomide inhibits angiogenesis led to preclinical and clinical trials as an anticancer agent in the treatment of solid tumours and haematological malignancies, as summarized in this review article. More recently, structural analogues of thalidomide have been synthesized in order to explore potential molecular targets of thalidomide, as well as to identify new agents with improved therapeutic efficacy.

Unrelated donor stem cell transplantation in adult patients with thalassemia

Allogeneic SCT remains the only potential cure for patients with thalassemia. However, most BMT candidates lack a suitable family donor and require an unrelated donor (UD). We evaluated whether BMT using UDs in high-risk adult thalassemia patients can offer a probability of cure comparable to that reported employing an HLA-compatible sibling as donor. A total of 27 adult thalassemia patients (15 males and 12 females, median age 22 years) underwent BMT from a UD selected by high-resolution HLA molecular typing. The conditioning regimen consisted of Busulphan (BU, 14 mg/kg) plus Cyclophosphamide (CY, 120 or 160 mg/kg) in 12 cases and BU (14 mg/kg), Thiotepa (10 mg/kg) and CY (120-160 mg/kg) in the remaining 15 cases. Cyclosporine-A and short-term Methotrexate were used for graft-versus-host disease (GVHD) prophylaxis. In all, 19 patients (70%) are alive and transfusion-independent after a median follow-up of 43 months (range 16-137). A total of 10 patients (37%) developed grade II-IV acute GVHD and six (27%) chronic GVHD. Eight patients (30%) died from transplant-related causes. UD-BMT can cure more than two-thirds of adult thalassemia patients, and is a particularly attractive option for patients who are not compliant with conventional treatment.

Mast cell contribution to angiogenesis related to tumour progression

The current wisdom is that tumours are endowed with an angiogenic capability and that their growth, invasion and metastasis are angiogenesis dependent. It is now well documented that neoplastic cells are influenced by their microenvironment and vice versa. The specific organ microenvironment determines the extent of cancer cell proliferation, angiogenesis, invasion and survival. Tumour cells are surrounded by an infiltrate of inflammatory cells, namely lymphocytes, neutrophils, macrophages and mast cells (MCs), which communicate via a complex network of intercellular signalling pathways, mediated by surface adhesion molecules, cytokines and their receptors. This review article summarizes: (i) the MC mediators involved in angiogenesis; (ii) the experimental evidence concerning the role played by MCs in angiogenesis; (iii) the list of solid and haematological tumours in which a close relationship between angiogenesis, tumour progression and MCs has been demonstrated; (iv) the circumstances in which MCs are a critical source of angiogenic factors in vivo, and in such cases, the signals that regulate their production and secretion that need to be determined as a prelude to the elaboration of new therapeutic strategies associated with MC presence and activation.

Allogeneic gene-modified tumour cells in metastatic kidney cancer. Preliminary report

An allogeneic irradiated RCC cell line, engineered to produce IL-2 (ACHN-IL-2), admixed with autologous metastatic formalin-treated tumour cells, was used to vaccinate ten MRCC patients in progression of disease in spite of IL-2 immunotherapy. The cells were administered subcutaneously and/or intra-tumourally. Sixty-four MRCC patients in progressive disease, not treated by vaccination but receiving similar IL-2 immunotherapy, were considered as the control group. Patients received 4-16 injections (mean 9 +/- 4), containing an average of 10.6 x 10(7) +/- 7.7 x 10(7) ACHN-IL-2-transfected cells (a minimum of 4 x 10(7), and a maximum of 31 x 10(7)). Four patients also received intra-tumour injections. Vaccination was administered during 30-418 days, and the follow-up continued for 649 +/- 353 days (190-1342). Throughout this period, the patients continued receiving the previously set immunotherapy treatment. No adverse side effects related to the treatment were observed. One complete and one partial tumour response were observed, as well as two stable and one no-relapse disease. All but one patient died. Responding patients resumed progression in 4-11 months and died 18 and 36 months after beginning the vaccine therapy. In spite of the small number of treated patients, Wilcoxon's test showed a significant (P < 0.05) improvement of the survival in the vaccinated group compared to that of the control. The described vaccination protocol seems safe, devoid of adverse side effects and promising. It warrants further investigation.

Crosstalk between angiogenesis and lymphangiogenesis in tumor progression

Extensive studies have identified reliable markers of lymphatic endothelial cells, and mechanisms and molecules that regulate development and growth of the lymphatic vessels. Vascular endothelial growth factors (VEGF)-C and VEGF-D, and their cognate receptor tyrosine kinase, VEGF receptor-3 (VEGFR-3), are critical regulators of lymphangiogenesis. By binding to its endothelial cell surface receptors VEGFR-1 and VEGFR-2, VEGF-A mediates vascular leakage, endothelial proliferation and migration. Angiopoietin-2 (Ang-2) is expressed at sites of blood vessel remodeling and invasion, and factors that induce angiogenesis in vivo, such as VEGF-A, upregulate Ang-2 in endothelial cells. In this review, we summarize the literature concerning the crosstalk between angiogenesis and lymphangiogenesis in tumor progression, that is, involvement of VEGF-C, VEGF-D and VEGFR-3 in angiogenesis, and the role played by VEGF-A and Ang-2 in lymphangiogenesis, respectively.

A possible role of tryptase in angiogenesis in the brain of mdx mouse, a model of Duchenne muscular dystrophy

Duchenne muscular dystrophy (DMD) is characterized by muscle degeneration and affects the CNS. Dystrophin is absent in muscle and CNS of both DMD patients and mdx mouse, a model of DMD. While the involvement of vascular compartment in DMD was poorly investigated, some studies suggested a role for mast cells (MC). Tryptase, contained in the MC granules, stimulates angiogenesis in vitro and in vivo. We demonstrated for the first time a correlation between the extent of angiogenesis and the number of tryptase-positive neurons and microvessels and suggest that the tryptase contained in the neurons and in the endothelial cells of the mdx mouse brain may be involved in the regulation of angiogenesis taking place in mdx mouse.

Allogeneic gene-modified tumour cells in metastatic kidney cancer. Report II

In a limited study, comprising only ten patients, we have previously reported that allogeneic irradiated RCC-cell-line cells, engineered to produce IL-2 (ACHN-IL-2), admixed with autologous metastatic formalin-treated tumour cells were used to vaccinate MRCC patients in progression of disease and also receiving IL-2 immunotherapy. The cells, admixed to autologous TC, were administered subcutaneously. We now report an extended study on thirty patients and one hundred thirty-one controls. Patients received 4-20 injections (mean 10 +/- 4), containing an average of 92 x 10(6) +/- 45 x 10(6) ACHN-IL-2 transfected cells (a minimum of 25 x 10(6), and a maximum of 200 x 10(6)). Autologous TC, admixed to allogeneic, were also administered by 4-16 s.c. injections (mean 7 +/- 3), i.e. a total of 12 x 10(6)-160 x 10(6) cells. Vaccination was administered during 73-1451 (307 +/- 316) days, and the follow-up continued for 1122 +/- 1240 days (106-5137). Throughout this period, the patients continued receiving the previously set immunotherapy treatment. No adverse side effects related to the treatment were noticed. One complete and four partial tumour responses were observed, as well as nine cases of stable disease. Thirteen patients died in the treated group (43%) and 63 (44%) in the control group. Responding patients resumed progression in 4-11 months and died 18 and 36 months after beginning the vaccine therapy. The Gehan Wilcoxon's test showed a significantly (P < 0.01) better survival in the vaccinated patients compared to that of the controls. Thus, we confirm, in an increased number of patients and an extensive follow-up, that our vaccination protocol is safe, devoid of adverse side effects, and promising.

Recombinant human erythropoietin induces intussusceptive microvascular growth in vivo

The role of erythropoietin (Epo) in angiogenesis has not been completely clarified. Epo induces endothelial cell proliferation and migration and stimulates angiogenesis on rat aortic rings in vitro and in vivo in the chick embryo chorioallantoic membrane (CAM) assay. The aim of the present study was to evaluate the ultrastructural aspects of angiogenesis in the CAM vasculature after recombinant human Epo (rHuEpo) exposure. The results demonstrated that after rHuEpo stimulation, the generation of new blood vessels occurred more frequently following an intussusceptive microvascular growth (IMG) mechanism. We have performed our experiments between days 8 and 12 of incubation, that is, when in the normal condition the capillary network expands mainly by IMG, and because it is generally accepted that implants made from days 8 to 10 are strongly angiogenic. This response is peculiar of rHuEpo, because it is abolished when an Epo-blocking antibody was coadministered with Epo.

Endogenous and exogenous fibroblast growth factor-2 modulate wound healing in the chick embryo chorioallantoic membrane

Re-epithelization and the formation of a granulation tissue consisting of inflammatory cells, newly formed blood vessels, and fibroblasts embedded in a loose collagenous extracellular matrix, are critical events occurring during wound healing. In this study, utilizing the chick embryo chorioallantoic membrane (CAM) as an in vivo model of wound healing, we investigated the role of endogenous and exogenous fibroblast growth factor-2 (FGF-2) in the wound healing reparative processes. The results showed that: (1) neutralizing anti-FGF-2 antibodies (400 ng/embryo) decreased significantly the rate of wound healing (occurring only in 25% of specimens) when applied close to the edge of the wound, causing a significant decrease of microvessel and fibroblast density, and of an inflammatory macrophage infiltrate in the wounded area; (2) conversely, the application of exogenous recombinant FGF-2 (1.0 microg/embryo) greatly accelerated the wound repair occurring approximately 24h earlier than in untreated CAMs, stimulating angiogenesis, fibroblast proliferation, and macrophage infiltration. These findings demonstrate the role of FGF-2 in wound healing of the CAM and suggest that CAM, usually employed as an in vivo assay to study angiogenesis, can also be utilized as an in vivo model for the easy, rapid, and economic screening of molecules potentially able to affect the wound healing process.

Erythropoietin as an angiogenic factor

Erythropoietin (Epo) is produced by the fetal liver and adult kidney and is an essential stimulator of erythropoiesis. It has, however, been shown to modulate host cellular signal transduction pathway to perform many other functions. New sites of Epo production have been found, such as the female reproductive organs and central nervous system. This review summarizes the involvement of Epo in the regulation of angiogenesis in both normal and pathological conditions.