Current status of antiangiogenic factors

Multiple pulmonary cavernous haemangiomas with concurrent primary pulmonary adenocarcinoma: a case report and literature review

Background

Cavernous haemangiomas (CHs) commonly occurred in the skin, subcutaneous tissue, muscles, and liver. Pulmonary cavernous haemangiomas (PCHs) are quite rare and usually present with nonspecific clinical symptoms. When lung cancer patients are complicated with pulmonary cavernous haemangiomas, radiologically, these haemangioma lesions can be easily misinterpreted as intrapulmonary metastases, potentially resulting in misdiagnosis, or missed diagnosis.

Case presentation

The present study reported the case of a 53-year-old female patient with pulmonary adenocarcinoma coexisting with multiple PCHs. 18F-FDG-Positron emission tomography-computed tomography (PET-CT) showed an elevated glucose metabolism in the apicoposterior segment of the left upper lobe; however, the other nodules were not hypermetabolic. Percutaneous lung biopsy was performed on the nodule in the apicoposterior segment of the left upper lobe, which were diagnosed as primary adenocarcinoma. Some nodules in the upper left lobe underwent wedge resection by video-assisted thoracic surgery (VATS) and intraoperative frozen section identified as PCHs. Finally, the patient underwent lobectomy of the left upper lobe via VATS, cancerous nodule in the apicoposterior segment of the left upper lobe underwent genetic molecular testing of PCR-Sanger sequencing, suggested EGFR mutation, and patient received treatment with Osimertinib. During the 4-months follow-up, contrast-enhanced CT showed no recurrence of either disease. PCHs are rare benign tumours of the lung, which can lead to misdiagnosis due to their non-specific clinical symptoms and radiological features, especially when they coexist with lung cancer. PCHs is easily misunderstood as metastatic lung cancer, in this case, PET-CT can assist in differentiating benign from malignant. For the cases of early lung cancer complicated with PCHs, lung cancer can be surgically resected, and whether PCHs should be removed or not should be determined according to the size and distribution of the lesions.

Advanced Technologies of Drug Delivery to the Posterior Eye Segment Targeting Angiogenesis and Ocular Cancer

Retinoblastoma (RB), a childhood retinal cancer is caused due to RB1 gene mutation which affects the child below 5 years of age. Angiogenesis has been proven its role in RB metastasis due to the presence of vascular endothelial growth factor (VEGF) in RB cells. Therefore, exploring angiogenic pathway by inhibiting VEGF in treating RB would pave the way for future treatment. In preclinical studies, anti-VEGF molecule have shown their efficacy in treating RB. However, treatment requires recurrent intra-vitreal injections causing various side effects along with patient nonadherence. As a result, delivery of anti-VEGF agent to retina requires an ocular delivery system that can transport it in a non-invasive manner to achieve patient compliance. Moreover, development of these type of systems are challenging due to the complicated physiological barriers of eye. Adopting a non-invasive or minimally invasive approach for delivery of anti-VEGF agents would not only address the bioavailability issues but also improve patient adherence to therapy overcoming the side effects associated with invasive approach. The present review focuses on the eye cancer, angiogenesis and various novel ocular drug delivery systems that can facilitate inhibition of VEGF in the posterior eye segment by overcoming the eye barriers.

Infantile hemangioma models: is the needle in a haystack?

Infantile hemangioma (IH) is the most prevalent benign vascular tumor in infants, with distinct disease stages and durations. Despite the fact that the majority of IHs can regress spontaneously, a small percentage can cause disfigurement or even be fatal. The mechanisms underlying the development of IH have not been fully elucidated. Establishing stable and reliable IH models provides a standardized experimental platform for elucidating its pathogenesis, thereby facilitating the development of new drugs and the identification of effective treatments. Common IH models include the cell suspension implantation model, the viral gene transfer model, the tissue block transplantation model, and the most recent three-dimensional (3D) microtumor model. This article summarizes the research progress and clinical utility of various IH models, as well as the benefits and drawbacks of each. Researchers should select distinct IH models based on their individual research objectives to achieve their anticipated experimental objectives, thereby increasing the clinical relevance of their findings.

Targeted therapy of chronic liver diseases with the inhibitors of angiogenesis

Angiogenesis appears to be intrinsically associated with the progression of chronic liver diseases, which eventually leads to the development of cirrhosis and related complications, including hepatocellular carcinoma. Several studies have suggested that this association is relevant for chronic liver disease (CLD) progression, with angiogenesis. The fact that angiogenesis plays a pivotal role in CLDs gives rise to new opportunities for treating CLDs. Inhibitor of angiogenesis has proved effective for the treatment of patients suffering from CLD. However, it is limited in diagnosis. The last decade has witnessed a plethora of publications which elucidate the potential of angiogenesis inhibitors for the therapy of CLD. The close relationship between the progression of CLDs and angiogenesis emphasizes the need for anti-angiogenic therapy to block/slow down CLD progression. The present review summarizes all these discussions, the results of the related studies carried out to date and the future prospects in this field. We discuss liver angiogenesis in normal and pathophysiologic conditions with a focus on the role and future use of angiogenic factors as second-line treatment of CLD. This review compiles relevant findings and offers opinions that have emerged in last few years relating liver angiogenesis and its treatment using anti-angiogenic factors.

δ-Tocotrienol oxazine derivative antagonizes mammary tumor cell compensatory response to CoCl2-induced hypoxia

In response to low oxygen supply, cancer cells elevate production of HIF-1α, a hypoxia-inducible transcription factor that subsequently acts to stimulate blood vessel formation and promote survival. Studies were conducted to determine the role of δ-tocotrienol and a semisynthetic δ-tocotrienol oxazine derivative, compound 44, on +SA mammary tumor cell hypoxic response. Treatment with 150 µM CoCl₂ induced a hypoxic response in +SA mammary tumor cells as evidenced by a large increase in HIF-1α levels, and combined treatment with compound 44 attenuated this response. CoCl₂-induced hypoxia was also associated with a large increase in Akt/mTOR signaling, activation of downstream targets p70S6K and eIF-4E1, and a significant increase in VEGF production, and combined treatment with compound 44 blocked this response. Additional in vivo studies showed that intralesional treatment with compound 44 in BALB/c mice bearing +SA mammary tumors significantly decreased the levels of HIF-1α, and this effect was associated with a corresponding decrease in Akt/mTOR signaling and activation of downstream targets p70S6kinase and eIF-4E1. These findings demonstrate that treatment with the δ-tocotrienol oxazine derivative, compound 44, significantly attenuates +SA mammary tumor cell compensatory responses to hypoxia and suggests that this compound may provide benefit in the treatment of rapidly growing solid breast tumors.

Plasminogen activators are involved in angiostatin generation in vivo in benign and malignant ovarian tumor cyst fluids

In many tumor types, angiogenesis is the net result of pro- and anti-angiogenic mediators and correlated with metabolic activity, growth, and degree of malignancy. One of the first discovered anti-angiogenic compounds is angiostatin, a proteolytic fragment of plasminogen. The requirements for in vivo angiostatin generation have not yet been determined. We investigated the levels of plasminogen and angiostatin by western blotting and of components of the plasminogen activator complex by ELISA in cyst fluid derived from benign and malignant ovarian tumors. Fluid samples from functional ovarian follicles, dermoid cysts and endometriotic lesions were evaluated separately. When no or minimal amounts of plasminogen were present in the cyst fluids, angiostatin was generally absent as well, irrespective of plasminogen activator concentrations. When plasminogen was present, the degree of conversion of plasminogen to angiostatin was significantly correlated with the level of uPA, and, to a lesser extent, to the tPA level. However, angiostatin was also found in a number of cyst fluid samples with minimal or no plasminogen activators, suggesting the involvement of other angiostatin generating proteases in these samples. Conversely, no angiostatin was observed in a number of cyst fluid samples containing both plasminogen and plasminogen activators. The presence of an inhibitor of the enzymatic activity of uPA and/or tPA, like PAI-1, may explain this finding. Our data show that plasminogen activators are clearly involved in in vivo angiostatin formation in ovarian cysts. Most likely, however, other proteases, as well as inhibitors of plasminogen activators, are involved as well.

The pathophysiology of retinopathy of prematurity: an update of previous and recent knowledge

Retinopathy of prematurity (ROP) is a disease that can cause blindness in very low birthweight infants. The incidence of ROP is closely correlated with the weight and the gestational age at birth. Despite current therapies, ROP continues to be a highly debilitating disease. Our advancing knowledge of the pathogenesis of ROP has encouraged investigations into new antivasculogenic therapies. The purpose of this article is to review the findings on the pathophysiological mechanisms that contribute to the transition between the first and second phases of ROP and to investigate new potential therapies. Oxygen has been well characterized for the key role that it plays in retinal neoangiogenesis. Low or high levels of pO2 regulate the normal or abnormal production of hypoxia-inducible factor 1 and vascular endothelial growth factors (VEGF), which are the predominant regulators of retinal angiogenesis. Although low oxygen saturation appears to reduce the risk of severe ROP when carefully controlled within the first few weeks of life, the optimal level of saturation still remains uncertain. IGF-1 and Epo are fundamentally required during both phases of ROP, as alterations in their protein levels can modulate disease progression. Therefore, rhIGF-1 and rhEpo were tested for their abilities to prevent the loss of vasculature during the first phase of ROP, whereas anti-VEGF drugs were tested during the second phase. At present, previous hypotheses concerning ROP should be amended with new pathogenetic theories. Studies on the role of genetic components, nitric oxide, adenosine, apelin and β-adrenergic receptor have revealed new possibilities for the treatment of ROP. The genetic hypothesis that single-nucleotide polymorphisms within the β-ARs play an active role in the pathogenesis of ROP suggests the concept of disease prevention using β-blockers. In conclusion, all factors that can mediate the progression from the avascular to the proliferative phase might have significant implications for the further understanding and treatment of ROP.

Expression of b-FGF and endostatin and their clinical significance in human osteosarcoma

OBJECTIVE

To investigate the expression and the clinical significance of basic fibroblast growth factor (b-FGF) and endostatin in osteosarcoma.

METHODS

From January 2003 to December 2005, expression of b-FGF, endostatin and CD34 were detected in 30 osteosarcoma and 30 osteochondroma tissue specimens by the immunohistochemical Elivision method. All data were post-processed with SPSS 13.0 software and prepared for investigation and analysis of these expressions and the relationships between the parameters.

RESULTS

(i) The rates of expression of b-FGF, endostatin and CD34 protein in osteosarcoma were 76.7%, 93.3%, and 96.7%, respectively, and in osteochondroma 43.3%, 40.0% and 16.7%, respectively. Each of the three expressions showed obvious differences between the osteosarcoma and the osteochondroma group. (ii) In the osteosarcoma group, expression of endostatin was positively correlated with that of CD34 (P < 0.05, γs = 0.528), and expression of endostatin in poorly differentiated osteosarcoma was much greater than that in highly differentiated osteosarcoma (P= 0.004). Expression of endostatin correlated with osteosarcoma metastasis (P= 0.036). (iii) There was no correlation between b-FGF and endostatin expression rates (P= 0.182) in the osteosarcoma group.

CONCLUSION

Angiogenesis is the basis of tumor metastasis, as well as being an important factor in tumor growth. Expression of endostatin could be adopted as a parameter for the diagnosis of postoperative metastases and for assessing prognosis, and could act as an adjuvant indicator in the grading of osteosarcoma.

Role of endothelial cell-selective adhesion molecule in hematogeneous metastasis

The spread of malignant cells from a localized tumor is thought to be directly related to the number of microvessels in the tumor. The endothelial cell-selective adhesion molecule (ESAM) is a member of the immunoglobulin superfamily that mediates homophilic interactions between endothelial cells. Previous studies have indicated that ESAM regulates angiogenesis in the primary tumor growth and endothelial permeability. In this study, we aimed to further elucidate the role of ESAM in tumor metastasis through angiogenic processes. ESAM expression was higher in hypervascular metastatic tumor tissues than in normal tissues in human lungs. Cell culture studies found that conditioned medium from B16F10 melanoma cells increased ESAM expression in endothelial cells and promoted endothelial migration and tube formation. The B16F10 medium-induced endothelial migration and tube formation were significantly attenuated when ESAM was downregulated by siRNA transfection. Intravenous injection of B16F10 cells into ESAM+/+ and ESAM-/- mice for comparison of metastatic potential resulted in the number of metastatic lung nodules in ESAM-/- mice being 83% lower than of those in ESAM+/+ mice. The microvascular density in the tumor was also lower in ESAM-/- than in ESAM+/+ mice. These findings indicate that ESAM regulates tumor metastasis through endothelial cell migration and tube formation in metastatic nodules. Inhibition of ESAM may therefore inhibit tumor metastasis by inhibiting the angiogenic processes.

Micro-vessel density and the expression of vascular endothelial growth factor (VEGF) and platelet-derived endothelial cell growth factor (PdEGF) in classical Hodgkin lymphoma (HL)

There is little information to date regarding the role of angiogenesis in Hodgkin lymphoma (HL). The present study examines micro-vessel density and the expression of vascular endothelial growth factor (VEGF) and platelet-derived endothelial growth factor (PdEGF) in lymph node biopsies of patients with HL at presentation and relapse. Using immunohistochemistry, the degree of new blood vessel formation and the expression of VEGF and PdEGF was assessed in Hodgkin-rich tissue. The micro-vessel density (MVD) increased with disease progression in seven out of 11 cases. Expression of VEGF was observed in endothelial cells (EC) of some micro-vessels and also in follicular dendritic cells. The Hodgkin/Reed-Sternberg (H-RS) cells as well as the inflammatory lymphocytes were negative for VEGF. Cytoplasmic or cytoplasmic and nuclear expression of PdEGF by the H-RS cells was observed in five of the 11 presentation cases. The expression of PdEGF increased with disease progression in seven cases. In conclusion, Hodgkin tissue shows prominent vascularization. The increased MVD and PdEGF expression with disease progression merits further investigation.

Reduction of endogenous angiogenesis inhibitors in Bruch's membrane of the submacular region in eyes with age-related macular degeneration

OBJECTIVES

To determine the relative levels of 3 potent inhibitors of angiogenesis (endostatin, pigment epithelium-derived factor, and thrombospondin 1) in the retinal pigment epithelium-Bruch's membrane-choriocapillaris complex in the submacular region in aged control eyes and eyes with age-related macular degeneration (AMD).

METHODS

Immunohistochemical analysis with antibodies against endostatin, pigment epithelium-derived factor, and thrombospondin 1 was performed on the macular region of aged control donor eyes (n = 8; mean age, 79.8 years) and eyes with AMD (n = 12; mean age, 83.9 years). Three independent masked observers scored the reaction product (scored from 0-7). Mean scores from the control eyes and the eyes with AMD were analyzed using 1-way analysis of variance and unpaired t test.

RESULTS

In control eyes, strong immunoreactivity of all 3 inhibitors was observed in the retinal pigment epithelium-Bruch's membrane-choriocapillaris complex. Immunoreactivity for endostatin, pigment epithelium-derived factor, and thrombospondin 1 in Bruch's membrane was significantly lower in eyes with AMD compared with aged control eyes (analysis of variance, P = .003, P = .009, and P < .001, respectively). In the choriocapillaris, a significant reduction was observed in endostatin (analysis of variance, P = .02) and thrombospondin 1 (analysis of variance, P = .005) in eyes with AMD.

CONCLUSIONS

These findings suggest that endogenous angiogenesis inhibitors in the retinal pigment epithelium-Bruch's membrane-choriocapillaris complex may provide a biochemical barrier for choroidal neovascular invasion.

CLINICAL RELEVANCE

Decreased levels of angiogenic inhibitors at the retinal pigment epithelium-Bruch's membrane-choriocapillaris complex in eyes with AMD make Bruch's membrane vulnerable to choroidal neovascularization.

Serum levels of vascular endothelial growth factor in children and adolescents with systemic lupus erythematosus

The angiogenic cytokine vascular endothelial growth factor (VEGF) may have a role in the pathogenesis of collagen diseases. We aimed to assess its serum levels in children and adolescents with systemic lupus erythematosus (SLE) and to elucidate its correlation with clinical features, laboratory parameters, and the overall disease activity. This study comprised 25 children and adolescents with SLE and 30 healthy controls. Disease activity was evaluated by SLE disease activity index (SLEDAI) score. Laboratory investigations included complete blood count, erythrocyte sedimentation rate (ESR), urine analysis, 24-h total urinary protein, assay of serum creatinine, ANA, anti-DNA, complement component C3, lupus anticoagulant, and VEGF. Serum levels of VEGF were significantly increased in SLE patients (579.5 +/- 184.7 pg/ml) when compared with controls (113.2 +/- 30.8 pg/ml) (p < 0.0001). VEGF serum levels were significantly increased in patients having renal involvement and neurologic symptoms than those who did not have them (p < 0.0001, p < 0.005, respectively). Serum levels of VEGF were higher in patients with antiphospholipid syndrome, vasculitis, and skin symptoms than those without, but the difference did not reach statistical significance. Meanwhile, they were similar in patients with and without arthritis (p > 0.05). VEGF serum levels were not correlated to age; inversely correlated to platelet count, serum C3 level; and positively correlated to ESR. SLEDAI score was positively correlated to VEGF serum level (r = 0.86, p < 0.0001). VEGF may be relevant to SLE pathogenesis. Its concentration seems to be a marker of SLE activity, which could help in disease monitoring and planning of treatment.

Proangiogenic role of ephrinB1/EphB1 in basic fibroblast growth factor-induced corneal angiogenesis

Corneal neovascularization is a vision-threatening condition caused by various ocular pathological conditions. The aim of this study was to evaluate the function of the ephrin ligands and Eph receptors in vitro and in vivo in corneal angiogenesis in a mouse model. The Eph tyrosine kinase receptors and their ligands, ephrins, are expressed on the cell surface. The functions of Eph and ephrins have been shown to regulate axonal guidance, segmentation, cell migration, and angiogenesis. Understanding the roles of Eph and ephrin in corneal angiogenesis may provide a therapeutic intervention for the treatment of angiogenesis-related disorders. Immunohistochemical studies demonstrated that ephrinB1 and EphB1 were expressed in basic fibroblast growth factor (bFGF)-induced vascularized corneas. EphB1 was specifically colocalized with vascular endothelial marker CD31 surrounded by type IV collagen. EphrinB1 was expressed in corneal-resident keratocytes and neutrophils. Recombinant ephrinB1-Fc, which induces EphB receptor activation, enhanced bFGF-induced tube formation in an in vitro aortic ring assay and promoted bFGF-induced corneal angiogenesis in vivo in a corneal pocket assay. Synergistically enhanced and sustained activation of extracellular signal-regulated kinase was noted in vascular endothelial cell lines after stimulation with ephrin B1 and bFGF combinations. These results suggest that ephrinB1 plays a synergistic role in corneal neovascularization.

Circulating total and active metalloproteinase-9 and tissue inhibitor of metalloproteinases-1 in patients with systemic lupus erythomatosus

We investigated the serum concentration of total metalloproteinase-9 (tMPP-9), active MMP-9 (aMMP-9), and tissue inhibitor of metalloproteinase-1 (TIMP-1) in a group of 41 patients with SLE and 20 healthy controls. Serum levels of tMMP-9 and TIMP-1 were assessed by an enzyme-linked immunosorbent assay (ELISA) and aMMP-9 by fluorometric assay. The tMMP-9 level was lower in SLE patients (mean 262 ng/mL) than in healthy volunteers (mean 325 ng/mL) (P = .048). Similarly, aMMP-9 level was lower in SLE patients (mean 121 ng/mL) than in control group (mean 169 ng/mL) (P = .0355) and lower in active SLE (mean 54 ng/mL) than in inactive disease (mean 99 ng/mL) (P = .033). TIMP-1 level was also lower in SLE patients (mean 181 ng/mL) than in control group (mean 233 ng/mL) (P = .004). In SLE patients, a positive correlation was found between tMMP-9 and aMMP-9 (rho = 0.568; P = .001). We also found a positive correlation of tMMP-9 and TIMP-1 with VEGF concentrations (rho = 0.450, P = .005 and rho = 0.387; P = .018, resp). tMMP-9, aMMP-9, and TIMP-1 serum levels are lower in SLE patients than in healthy control group.

Synthetic Osteopontin-derived Peptide SVVYGLR can Induce Neovascularization in Artificial Bone Marrow Scaffold Biomaterials

We have previously reported that an osteopontin-derived SVVYGLR peptide exhibited potent angiogenic activity in vitro and in vivo. In the present study, the focus points were on the in vitro effect of SVVYGLR on bone marrow stromal cell proliferation, as well as its in vivo effect on bone tissue formation when grafts made of CO3Ap-collagen sponge- as a scaffold biomaterial containing the SVVYGLR motif - were implanted. SVVYGLR peptide promoted bone marrow stromal cell proliferation. When a CO3Ap-collagen sponge containing SVVYGLR peptide was implanted as a graft into a tissue defect created in rat tibia, the migration of numerous vascular endothelial cells - as well as prominent angiogenesis - inside the graft could be detected after one week. These results thus suggested that our scaffold biomaterials including the peptide could be useful for bone tissue regeneration.

Angiogenesis and antiangiogenic therapy in hematologic malignancies

Angiogenesis, the generation of new blood capillaries from preexisting blood vessels, is tightly regulated in the adult organism. Although many of the initial studies were performed on solid tumors, increasing evidence indicates that angiogenesis also plays an important role in hematologic malignancies. Overexpression of angiogenic factors in particular VEGF and bFGF in most hematologic malignancies may explain the increased angiogenesis found in these malignancies and correlate with poor prognosis as well as decreased overall survival. In this review, we focus on the current literature of angiogenesis and antiangiogenic therapy in hematologic malignancies, and finally describe advances and potential challenges in antiangiogenic treatment in hematologic malignancies.

Vaccines targeting tumour angiogenesis--a novel strategy for cancer immunotherapy

AIMS

To review the concept of tumour angiogenesis and anti-angiogenic therapy, limitations of recently used anti-angiogenic therapeutics; provide an up-to-date overview of the growing number of reports on vaccines targeting tumour angiogenesis; and finally discuss potential complications and future directions in the development of more potent and specific vaccines.

METHODS

A literature search was carried out from PubMed for indexed articles. The most important articles were analysed and discussed.

FINDINGS

The search yielded a large number of important indexed published articles that were reviewed, screened and tracked for other relevant publications. The most relevant articles, including those previously published by authors, were analysed and discussed.

CONCLUSIONS

Recently, different vaccine strategies have been reported to inhibit tumour growth and metastasis by induction of specific cellular and/or humoral immunity against angiogenesis-associated antigens in pre-clinical models, suggesting effective combination of anti-angiogenesis and cancer immunotherapy. Evaluation of tumour endothelial cells and clinical phase I study of the vaccines are recently ongoing, and should give us better insight into the possibilities of this novel strategy for cancer immunotherapy.

131I-chTNT Radioimmunotherapy of 43 Patients with Advanced Lung Cancer

The treatment of advanced lung cancer remains a major challenge in clinical medicine, justifying an urgent need for new therapeutic approaches. In a rather unique international collaboration, 43 patients with advanced lung cancer were treated using iodine-131-labeled tumor necrosis therapy chimeric antibody (131I-chTNT).

METHODS

Patients were treated either with intravenous (i.v.) infusion (n = 22), intratumoral injection using a computer tomography (CT)-guided catheter (n = 16), or combination i.v. and intratumoral infusion (n = 5). All patients, regardless of route of administration, received 2 doses of 131I-chTNT on days 1 and 14.

RESULTS

The results showed that of those patients receiving i.v. injection alone, 2 achieved partial response (PR) (9%), 16 had stable disease (73%), and 4 progressed (18%). Of those patients receiving intratumoral injection only, 1 had a complete response (CR) (6%), 8 achieved PR (50%), 7 had stable disease (44%), and none (0%) progressed. Finally, of those patients receiving both i.v. and intratumoral administration, 1 had a CR (20%), 1 achieved PR (20%), 2 had stable disease (40%), and 1 (20%) showed progression.

CONCLUSIONS

These promising results demonstrate that sufficient doses of radiolabeled antibody can be safely delivered to tumors to cause significant therapeutic effects in advanced lung cancer.

Myelodysplastic syndromes: clinicopathologic features, pathobiology, and molecular pathogenesis

CONTEXT

Myelodysplastic syndromes (MDSs) are clonal stem cell diseases characterized by ineffective hematopoiesis, multilineage dysplasia, and peripheral cytopenias with normocellular or hypercellular marrow. They represent a heterogeneous group of disorders with a varied spectrum of clinical, morphologic, biologic, and genetic characteristics. This heterogeneity in disease characterization has led to evolving classification systems, developing prognostic models, and continuing research efforts to elucidate its pathobiology and pathogenesis.

OBJECTIVE

To summarize updated information and provide a general overview of the clinicopathologic features, pathobiology, and cytogenetic and molecular pathogenesis of MDSs.

DATA SOURCES

Relevant articles indexed in PubMed (National Library of Medicine) between 1982 and 2005 and reference medical texts.

CONCLUSIONS

Although MDSs remain a relatively poorly defined disease entity, recent advancements in cytogenetic and molecular studies have significantly contributed to our present knowledge of MDSs. Novel strategies for studying the pathogenesis and evolution of MDSs continue to shape our understanding of this disease and guide our approaches to diagnosis and treatment.

Selective inhibition of the human tie-1 promoter with triplex-forming oligonucleotides targeted to Ets binding sites

The Tie receptors (Tie-1 and Tie-2/Tek) are essential for angiogenesis and vascular remodeling/integrity. Tie receptors are up-regulated in tumor-associated endothelium, and their inhibition disrupts angiogenesis and can prevent tumor growth as a consequence. To investigate the potential of anti-gene approaches to inhibit tie gene expression for anti-angiogenic therapy, we have examined triple-helical (triplex) DNA formation at 2 tandem Ets transcription factor binding motifs (designated E-1 and E-2) in the human tie-1 promoter. Various tie-1 promoter deletion/mutation luciferase reporter constructs were generated and transfected into endothelial cells to examine the relative activities of E-1 and E-2. The binding of antiparallel and parallel (control) purine motif oligonucleotides (21-22 bp) targeted to E-1 and E-2 was assessed by plasmid DNA fragment binding and electrophoretic mobility shift assays. Triplex-forming oligonucleotides were incubated with tie-1 reporter constructs and transfected into endothelial cells to determine their activity. The Ets binding motifs in the E-1 sequence were essential for human tie-1 promoter activity in endothelial cells, whereas the deletion of E-2 had no effect. Antiparallel purine motif oligonucleotides targeted at E-1 or E-2 selectively formed strong triplex DNA (K(d) approximately 10(-7) M) at 37 degrees C. Transfection of tie-1 reporter constructs with triplex DNA at E-1, but not E-2, specifically inhibited tie-1 promoter activity by up to 75% compared with control oligonucleotides in endothelial cells. As similar multiple Ets binding sites are important for the regulation of several endothelial-restricted genes, this approach may have broad therapeutic potential for cancer and other pathologies involving endothelial proliferation/dysfunction.

A novel mechanism of action of the fumagillin analog, TNP-470, in the B16F10 murine melanoma cell line

TNP-470, a semisynthetic derivative of fumagillin, is an acknowledged angiogenesis inhibitor, presently undergoing clinical trials. It exerts an anti-proliferative effect directed against endothelial cells. This effect is known to be based on cell cycle inhibition effected by the p53/p21 pathway. We observed short-term toxicity of TNP-470 in the B16F10 murine melanoma cell line in vitro and investigated the mechanism of action. Cell death occurred as soon as 2 h after the addition of TNP-470, without typical apoptotic features. The toxic effect could be modulated and it depended on the type of culture medium or supplementation with anti-oxidants. Addition of N-acetylcysteine protected B16F10 cells from TNP-470-induced death and inhibited an increase in the generation of reactive oxygen species (ROS), which are detected by the 2',7'-dichlorodihydrofluorescein diacetate probe. We conclude that TNP-470 can induce intracellular generation of ROS, which act toxically inside B16F10 cells. One may suggest that this novel activity of TNP-470 might be beneficial in some cases, but it could also be responsible for some undesirable side-effects. The possibility of its modulation gives a prospect for controlling the action of this potential drug and probably its derivatives.

Vascular endothelial growth factor: a therapeutic target for tumors of the Ewing's sarcoma family

PURPOSE

We have reported previously that intratumoral microvessel density (MVD) is a significant prognostic indicator of event-free survival in the Ewing's sarcoma family of tumors (ESFT). Here, the angiogenic growth factor expression profile and its relationship with MVD has been investigated in ESFT.

EXPERIMENTAL DESIGN AND RESULTS

Using ESFT model systems, the potential of these factors as therapeutic targets has been evaluated. A significant correlation (P = 0.02) was observed between vascular endothelial growth factor (VEGF) expression and MVD, consistent with the hypothesis that VEGF regulates the development of microvessels in ESFT. There was no correlation between MVD and any of the other growth factors studied. All six ESFT cell lines studied produced and secreted VEGF; five of six cell lines also secreted placental growth factor, one cell line (A673) at high levels. Tumor conditioned medium induced proliferation of human umbilical vein endothelial cells. Expression of VEGF receptors Flt-1 and Flk-1/KDR was heterogeneous across the cell lines. Both receptor tyrosine kinase inhibitors SU6668 (targets Flk-1/KDR, platelet-derived growth factor receptor-beta, and fibroblast growth factor receptor 1) and SU5416 (targets Flk-1/KDR) as well as anti-VEGF agents rhuMAb-VEGF (bevacizumab) and VEGF Trap delayed s.c. growth of ESFT in mice compared with untreated groups: SU6668 (100 mg/kg/d), SU5416 (25 mg/kg/d), rhuMAb-VEGF (10 mg/kg twice weekly), and VEGF Trap (2.5 or 25 mg/kg twice weekly).

CONCLUSIONS

These data suggest that VEGF is the single most important regulator of angiogenesis in ESFT and may be exploited for therapeutic advantage.

Vascular endothelial growth factor levels in vitreous and serum of patients with either proliferative diabetic retinopathy or proliferative vitreoretinopathy

PURPOSES

To confirm the role of vascular endothelial growth factor (VEGF) in the pathogenesis of proliferative diabetic retinopathy (PDR) and proliferative vitreoretinopathy (PVR) and to investigate the relationship between the level of VEGF in serum and its vitreal level in patients with either disease.

METHODS

Venous blood and vitreous of 18 patients with PDR, 15 patients with PVR and 20 patients forming a control group were collected during vitrectomy. The VEGF level was quantified by using ELISA methods in either serum or vitreous.

RESULTS

The VEGF level in serum and vitreous was similarly high in the case of PDR, but its level was only high in serum in the case of PVR.

DISCUSSION

PDR is closely linked with systemic diabetes mellitus whereas PVR is more localized. More selective systemic anti-VEGF medications with reduced side effects are required to treat PDR successfully.

Hematopoietic Cancer and Angiogenesis

The growth of solid tumors is certainly angiogenesis dependent. However, the role of angiogenesis in the growth and survival of leukemias and other hematological malignancies has only been rendered evident since 1994 in a series of demonstrations showing that the progression of several forms is clearly related to their degree of angiogenesis. Here, we present an overview of the literature concerning the relationship between angiogenesis and disease progression in several hematological malignancies and the recent advances in antiangiogenesis in these diseases and we describe the most important active substances, preclinical and clinical data, and future perspectives.

Somatostatin analogues: multiple roles in cellular proliferation, neoplasia, and angiogenesis

Angiogenesis, the development of new blood vessels is a crucial process both for tumor growth and metastatic dissemination. Additionally, dysregulation in angiogenesis has been implicated in the pathogenesis of cardiovascular disease, proliferative retinopathy, diabetic nephropathy, and rheumatoid arthritis (RA). The neuropeptide somatostatin has been shown to be a powerful inhibitor of neovascularization in several experimental models. Furthermore, somatostatin receptors (sst) are expressed on endothelial cells; particularly, sst2 has been found to be uniquely up-regulated during the angiogenic switch, from quiescent to proliferative endothelium. The present manuscript reviews the anti-angiogenic activity of somatostatin and its analogues in neoplastic and nonneoplastic disease. The role of sst subtypes particularly sst2 in mediating its angioinhibitory activity is described. Somatostatin agonists may also exert their anti-angiogenic activity indirectly by inhibition of growth factors like vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), and the growth hormone (GH)/insulin-like growth factor-I (IGF-I) axis or through its immunomodulatory effects. However, the therapeutic utility of somatostatin agonists as anti-angiogenic drugs in these diseases remains confusing because of conflicting results from different studies. More basic research, as well as patient-oriented studies, is required to firmly establish the clinical potential of somatostatin agonists in therapeutic angiogenesis. The currently available somatostatin agonists have high affinity of sst2 with lower affinities for sst3 and sst5. The emergence of novel somatostatin agonists especially bispecific analogues (agonists targeting multiple cellular receptors) and conjugates (synthesized by chemically linking somatostatin analogues with other antineoplastic agents) with improved receptor specificity signify a new generation of anti-angiogenics, which may represent novel strategies in the treatment of neovascularization-related diseases.

Angiogenesis in developing follicle and corpus luteum

Angiogenesis is a process of vascular growth that is mainly limited to the reproductive system in healthy adult animals. The development of new blood vessels in the ovary is essential to guarantee the necessary supply of nutrients and hormones to promote follicular growth and corpus luteum formation. In developing follicles, the pre-existing endothelial cells that form the vascular network in the theca layer markedly develop in response to the stimulus of several growth factors, mainly produced by granulosa cells, such as vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF). The angiogenic factors also promote vessel permeability, thus favouring the antrum formation and the events inducing follicle rupture. After ovulation, newly formed blood vessels cross the basement membrane between theca and granulosa layers and continue a rapid growth to sustain corpus luteum development and function. The length of luteal vascular growth varies in cycling and pregnant animals and among species; both angiogenesis and subsequent angioregression are finely regulated by systemic and local factors. The control of angiogenic development in the ovary could be a useful tool to improve animal reproductive performances.

High serum level of endostatin in multiple myeloma at diagnosis but not in the plateau phase after treatment

We investigated the serum concentration of endostatin in 84 patients with multiple myeloma (MM) and in 13 healthy controls. The level of measured anti-angiogenic agent was correlated with the phase and stage of the disease, and most importantly with clinical and laboratory parameters depicting the disease activity (haemoglobin, creatinine, albumins, calcium, M-component, C-reactive protein, beta2-microglobulin, lactate dehydrogenase, stage of bone disease) as well as serum levels of pro-angiogenic cytokines such as vascular endothelial growth factor, hepatocyte growth factor, fibroblast growth factor and transforming growth factor-beta. The median serum level of endostatin in MM patients was 58 ng/ml and was statistically significantly higher than in the control group (median, 40 ng/ml; p=0.015). MM patients in phase I (at diagnosis) had higher levels of endostatin (median, 69 ng/ml) than those in phase II (plateau phase after treatment) (median, 49 pg/ml; p=0.044). We did not find any statistical correlation between the level of endostatin and stage of MM according to the Durie and Salmon system. The serum concentration of endostatin in MM patients with a normal level of albumins was significantly higher than in others with hypoalbuminaemia (median, 62 ng/ml versus 39 ng/ml; p=0.033). Also, patients with a normal value of lactate dehydrogenase had a higher concentration of endostatin than those with values >425 U/l (median, 70 ng/ml versus 39 ng/ml; p=0.019). We did not show any statistical correlation between the concentration of endostatin and level of haemoglobin, creatinine, calcium, C-reactive protein, beta2-microglobulin and stage of bone disease. We failed to find positive or negative correlations between the level of endostatin and vascular endothelial growth factor, hepatocyte growth factor, fibroblast growth factor and transforming growth factor-beta. The concentration of endostatin did not influence the probability of survival in MM patients in our study. In conclusion, our data indicate that endostatin has a higher level in MM patients than in healthy controls. Highest values were stated in active phases of the disease (at presentation and in progression). Different clinical and laboratory parameters generally do not influence the concentration of endostatin (except albumins and lactate dehydrogenase).

Short-term human prostate primary xenografts: an in vivo model of human prostate cancer vasculature and angiogenesis

Transgenic spontaneously occurring and transplantable xenograft models of adenocarcinoma of the prostate (CaP) are established tools for the study of CaP progression and metastasis. However, no animal model of CaP has been characterized that recapitulates the response of the human prostate vascular compartment to the evolving tumor microenvironment during CaP progression. We report that primary xenografts of human CaP and of noninvolved areas of the human prostate peripheral zone transplanted to athymic nude mice provide a unique model of human angiogenesis occurring in an intact human prostate tissue microenvironment. Angiogenesis in human kidney primary xenografts established from human renal cell carcinoma and noninvolved kidney tissue, a highly vascular organ and cancer, was compared with angiogenesis in xenografts from the relatively less vascularized prostate. Immunohistochemical identification of the human versus mouse host origin of the endothelial cells and of human endothelial cell proliferation in the human prostate and human kidney xenografts demonstrated that: (a) the majority of the vessels in primary xenografts of benign and malignant tissue of both organs were lined with human endothelial cells through the 30-day study period; (b) the mean vessel density was increased in both the CaP and benign prostate xenografts relative to the initial tissue, whereas there was no significant difference in mean vessel density in the renal cell carcinoma and benign kidney xenografts compared with the initial tissue; and (c) the number of vessels with proliferating endothelial cells in primary xenografts of CaP and benign prostate increased compared with their respective initial tissue specimens, whereas the number of vessels with proliferating endothelial cells decreased in the benign kidney xenografts. Short-term primary human prostate xenografts, therefore, represent a valuable in vivo model for the study of human angiogenesis within a human tissue microenvironment and for comparison of angiogenesis in CaP versus benign prostate.

Increased microvascular network in bone marrow of HIV-positive haemophilic patients

OBJECTIVES

Angiogenesis has been associated with the pathogenesis of myelodysplastic syndromes (MDSs). However, less is known about the significance of this process in the bone marrow of HIV-positive patients with myelodysplastic features (MDF).

METHODS

Trephines from 22 HIV-positive haemophilic patients were immunostained for CD34 antigen, and the microvessel density (MVD) was quantitatively evaluated and compared with that of 21 biopsies from patients with primary MDS and with that of 12 control bone marrows with no evidence of marrow disease.

RESULTS

Bone marrow MVD in HIV-positive haemophilic patients was similar to that in patients with MDS; however, both groups revealed significantly higher MVD counts than those of control bone marrows (P=0.002). Mean MVD counts of HIV-positive haemophilic patients were significantly associated with HIV RNA levels (P=0.008). In contrast, no correlation was found between MVD and clinical HIV stage or CD4 counts at the time of biopsy.

CONCLUSIONS

These results suggest a direct involvement of HIV in the pathogenesis of MDF in HIV infection. Elucidation of the mechanisms underlying bone marrow angiogenesis in HIV-positive patients may provide further insights into the pathobiology of AIDS.

Perlecan and tumor angiogenesis

Perlecan is a major heparan sulfate proteoglycan (HSPG) of basement membranes (BMs) and connective tissues. The core protein of perlecan is divided into five domains based on sequence homology to other known proteins. Commonly, the N-terminal domain I of mammalian perlecan is substituted with three HS chains that can bind a number of matrix molecules, cytokines, and growth factors. Perlecan is essential for metazoan life, as shown by genetic manipulations of nematodes, insects, and mice. There are also known human mutations that can be lethal. In vertebrates, new functions of perlecan emerged with the acquisition of a closed vascular system and skeletal connective tissues. Many of perlecan's functions may be related to the binding and presentation of growth factors to high-affinity tyrosine kinase (TK) receptors. Data are accumulating, as discussed here, that similar growth factor-mediated processes may have unwanted promoting effects on tumor cell proliferation and tumor angiogenesis. Understanding of these attributes at the molecular level may offer opportunities for therapeutic intervention.

Angiogenic activity of osteopontin-derived peptide SVVYGLR

Angiogenesis plays an important role in various pathological conditions as well as some physiological processes. Although a number of soluble angiogenic factors have been reported, extracellular matrix also has crucial effect on angiogenesis through interaction with endothelial cells. Since recent reports showed osteopontin had some angiogenic activity, the effect of the SVVYGLR peptide, novel binding motif in osteopontin molecule, on angiogenesis was examined in this study. Synthetic peptide SVVYGLR did not have proliferative effect on endothelial cells but adhesion and migration activity to endothelial cells. Furthermore, SVVYGLR had as potent activity for tube formation in three-dimensional collagen gel as vascular endothelial growth factor which is known to be the strongest angiogenic factor. Electron microscopical analysis showed a number of microvilli on the endothelial luminar surface and tight junction formation in the luminar intercellular border between endothelial cells, indicating SVVYGLR induced cell porarity and differentiation of endothelial cells. This small peptide might be expected to stimulate angiogenesis to improve some ischemic conditions in the future because of some advantages due to smaller molecular weight.

The Role of Growth Factors for Disease and Therapy in Diseases of the Head and Neck

Growth factors are a large family of polypeptide molecules that regulate cell division in many tissues by autocrine or paracrine mechanisms. Depending on what receptors are activated, growth factors can initiate mitogenic, antiproliferative, or trophic effects, that is, growth factors act as positive or negative modulators of cell proliferation. Therefore, growth factors do not only play an important role in embryonic development and adult tissue homeostasis, but also in pathological situations like infection, wound healing, and tumorigenesis. Consequently, the application of growth factors, or vice versa the application of substances which are directed against growth factors like antigrowth factor antibodies, may have therapeutic applications. This review provides a brief account of what we know regarding growth factors in otorhinolaryngology, particularly in the field of otology, wound healing, oncology, peripheral nerve regeneration, and rhinology.

A morphometric study of bone marrow angiogenesis in hairy cell leukaemia with clinicopathological correlations

Bone marrow angiogenesis has recently been implicated in the pathophysiology and course of various haematological malignancies. Little is known, however, about the significance of this phenomenon in hairy cell leukaemia (HCL). We evaluated various morphometric characteristics of microvessels, highlighted by means of anti-CD34 immunohistochemistry, in the bone marrow of 44 patients with typical HCL, before and after treatment with interferon-alpha (IFN-alpha). Overall, bone marrow from 103 HCL patients and 20 controls was examined. Microvessel density (MVD) and several size- and shape-related parameters were quantified in the region of most intense vascularization using image analysis. MVD, size-related parameters and the percentage of branching microvessels were higher in HCL than in controls. Likewise, perimeter counts were higher in partial/non-responders than in complete responders. Achievement of complete response was accompanied by smaller calibre microvessels. IFN-alpha induced a decrease in MVD and branching values in cases with diffuse marrow involvement. In univariate analysis, progression-free survival was adversely affected by MVD, branching and major axis length. Multivariate analysis indicated that MVD/branching independently affected progression-free survival and the likelihood of complete response. Our data suggest that the generation of bone marrow microvessels indicated an increased risk of progression and IFN-alpha treatment failure in HCL. Furthermore, the prognostic significance of angiogenesis requires the concomitant assessment of MVD and the complexity of the microvascular network.

Curative treatment of gastric cancer: towards a multidisciplinary approach?

Despite marked decreases in incidence over the last century, particularly in developed countries, gastric cancer is still the second-most common tumor worldwide. Surgery remains the gold standard for the cure of locoregional disease. However, in most countries, the diagnosis is made at an advanced stage, and the 5-year survival for surgically resectable disease stays far below 50%. The efficacy of chemotherapy and/or radiation therapy in addition to surgery has been actively studied over the last 30 years. Unfortunately, with few exceptions, most studies of adjuvant therapy in gastric cancer have given deceiving results. The purpose of this review is to address the reasons for our failure to objectivate an improvement in the cure of gastric cancer with adjuvant treatment in most trials, and to consider potential solutions. The low efficacy of chemotherapy regimens available up to now may have hampered our progress. In addition, many previous studies suffered limitations of design or methodology (e.g. low accrual, inadequate disease stage selection, inadequate surgical treatment) that may have obscured a treatment effect. Furthermore, the reduced treatment tolerance of post-gastrectomy patients, perhaps due to their poor nutritional status, results in decreased or delayed adjuvant systemic therapy, with potential adverse consequences in its efficacy. Among potential solutions, the arrival of new drugs, taxanes and topoisomerase I inhibitors in particular, which have shown encouraging results in metastatic disease, may increase the impact of chemotherapy in a multidisciplinary treatment approach. Pre-treatment with chemotherapy and/or radiation therapy prior to surgery may also be advantageous, averting the problems associated with post-surgical treatment. Such an approach has been shown to be feasible in phase II studies, and is relatively well tolerated by patients. Several carefully designed randomized phase III trials are underway to answer this question.

Angiogenesis in hematologic malignancies

Angiogenesis is defined as the formation of new capillaries from preexisting blood vessels and plays an important role in the progression of solid tumors. Recently a similar relationship has been described in several hematologic malignancies. Expression of the angiogenic peptides vascular endothelial growth factor (VEGF) and basic fibroblast growth factor correlates with clinical characteristics in leukemia and non-Hodgkin's-lymphoma and the serum/plasma concentrations serve as predictors of poor prognosis. Increased bone marrow microvessels in multiple myeloma (MM) are correlated with decreased overall survival. Thalidomide which has antiangiogenic effects and direct cytotoxic effects was found to be effective in MM, myelodysplastic syndrome and acute myeloid leukemia (AML). Preliminary data indicate activity of VEGF-tyrosine kinase inhibitors in AML. Clinical research is now aimed at testing antiangiogenic treatment strategies in several hematologic neoplasms as well as identifying the best candidate patients for specific approaches.

Angiogenesis and anti-angiogenesis in hematological malignancies

Although it is well established that the growth of solid tumors requires vigorous neovascularization, it has been assumed that leukemias and other hematological malignancies do not depend on angiogenesis. However, the role of angiogenesis in growth and survival of neoplastic cells of the hematopoietic system has recently been recognized, and provides a rationale for novel therapeutic approaches to hematological malignancy. This review summarizes the literature concerning the relationship between angiogenesis and disease progression of several hematological malignancies. It is becoming increasingly evident that agents that interfere with blood vessel formation also block tumor progression, and, accordingly, antiangiogenic therapy has gained much interest as a potential adjunct to conventional therapy of many hematological malignancies. Recent successful applications of antiangiogenic agents that interfere or block the progression of hematological malignancies are evaluated in light of recent demonstrations of potent angiogenic activity of several hematopoietic growth factors. A novel finding regarding the role of angiogenesis in hematological malignancies, which accounts for many clinical observations as well as the apparent independence of these tumors on marrow vascularity, is presented. The information presented in this review will facilitate the design of future clinical trials using antiangiogenic agents for the treatment of hematological malignancies and will provide a basis for the design of experiments undertaken to define the mechanisms involved, mechanisms that may shed new light on the pathology of hematological malignancies.

Angiogenesis relates to estrogen receptor negativity, c-erbB-2 overexpression and early relapse in node-negative ductal carcinoma of the breast

Tumor angiogenic activity is an important process linked to tumor growth, metastasis, and invasion. In the present study we investigated whether intratumoral microvessel density (MVD), as assessed with immunohistochemistry, is of prognostic relevance in a series of 77 breast cancer patients with node-negative disease. The mean MVD in the hot spots ranged from 9 to 106 (median 31) vessels per x200 optical field. Patients were grouped into 3 categories of low (27 pts), medium (26 pts), and high (24 pts) MVD. Angiogenesis was not related to the primary tumor dimensions (T-stage) or the histology differentiation. An inverse association of MVD with estrogen receptor (ER) expression was noted (p=0.0007), while high MVD was directly related to c-erbB-2 overexpression (p=0.04) and high MIB1 proliferation index (p=0.02). In univariate and multivariate analysis of relapse-free survival, MVD was the only variable significantly and independently linked to relapse. It is concluded that high intratumoral angiogenic activity is linked with early relapse in node-negative breast cancer.

Armed therapeutic viruses: strategies and challenges to arming oncolytic viruses with therapeutic genes

Oncolytic viruses are attractive therapeutics for cancer because they selectively amplify, through replication and spread, the input dose of virus in the target tumor. To date, clinical trials have demonstrated marked safety but have not realized their theoretical efficacy potential. In this review, we consider the potential of armed therapeutic viruses, whose lytic potential is enhanced by genetically engineered therapeutic transgene expression from the virus, as potential vehicles to increase the potency of these agents. Several classes of therapeutic genes are outlined, and potential synergies and hurdles to their delivery from replicating viruses are discussed.

Molecular Biology and Immunology for Clinicians 20

If we accept the perfectly reasonable premise that the mass of inflammatory tissue in rheumatoid arthritis (and psoriatic arthritis or any other inflammatory joint disease) requires oxygen and nutrition to survive and grow, we are confronted with a novel concept for therapy: if we can block the nutritional supply of the pannus, we can suppress or prevent its growth and the subsequent destruction of the joint. Thus, an understanding of how new blood vessels nourish the inflammatory mass could be pivotal in successfully treating our patients. Angiogenesis is the process whereby new blood vessels enter the site of inflammation or growing malignancy to supply the invading tissue. Many growth factors and local tissue conditions help to determine blood vessel growth, there being pro- and anti-angiogenetic influences. Thus, this is fertile ground for therapeutic molecular manipulations.

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.

Thromboembolic disease and cancer: possible new treatments

Hypoxia-induced endothelin (ET) and vascular endothelial growth or permeability factor (VEGF) play an important role in tumor biology by promoting angiogenesis. Angiogenesis alters hemostasis and promotes thromboembolic disease (TED). Therapeutic angiogenesis directed against ET and VEGF may reduce the incidence of TED in cancer patients.

Age-related macular degeneration: epidemiology and optimal treatment

Age-related macular degeneration (AMD) is a common macular disease affecting elderly people in the Western world. It is characterised by the appearance of drusen in the macula, accompanied by choroidal neovascularisation (CNV) or geographic atrophy. The disease is more common in Caucasian individuals than in pigmented races. In predominantly Caucasian populations, the age-standardised prevalence of AMD in at least one eye is 7760 cases per million. The age-standardised cumulated 1-year incidence of AMD in at least one eye is 1051 cases per million individuals. AMD is the most important single cause of blindness among Caucasian individuals in developed countries. Blindness resulting from AMD rarely occurs before age 70, and most cases occur after age 80. The age-standardised 1-year incidence of legal blindness resulting from AMD is 212 cases per million. Two-thirds of AMD cases have CNV (exudative cases); the remainder has only geographic atrophy. In cross-sectional population-based studies about 45% of eyes with AMD have visual acuity reduced to 20/200 or worse. This is true both for exudative AMD and pure geographic atrophy. Age and genetic predisposition are known risk factors for AMD. Smoking is probably also a risk factor. Preventive strategies using macular laser photocoagulation are under investigation, but their efficacy in preventing visual loss is as yet unproven. There is no treatment with proven efficacy for geographic atrophy. Optimal treatment for exudative AMD requires a fluorescein angiographic study and a physician capable of interpreting it. For CNV not involving the foveal centre, the only evidence-based treatment is laser photocoagulation. For AMD cases with subfoveal CNV, good visual acuity, and predominantly classic fluorescence pattern on fluorescein angiography, photodynamic therapy with verteporfin is the treatment of choice. Photodynamic therapy is also effective in eyes with pure occult CNV and evidence of recent disease progression. For new subfoveal CNV with poor vision and recurrent CNV, laser photocoagulation can be considered.

Murine 5T multiple myeloma cells induce angiogenesis in vitro and in vivo

Multiple myeloma is a B cell malignancy. Recently, it has been demonstrated that bone marrow samples of patients with multiple myeloma display an enhanced angiogenesis. The mechanisms involved seem to be multiple and complex. We here demonstrate that the murine 5T multiple myeloma models are able to induce angiogenesis in vitro by using a rat aortic ring assay and in vivo by determining the microvessel density. The rat aortic rings cultured in 5T multiple myeloma conditioned medium exhibit a higher number of longer and more branched microvessels than the rings cultured in control medium. In bone marrow samples from 5T multiple myeloma diseased mice, a statistically significant increase of the microvessel density was observed when compared to bone marrow samples from age-matched controls. The angiogenic phenotype of both 5T multiple myeloma cells could be related, at least in part, to their capacity to produce vascular endothelial growth factor. These data clearly demonstrate that the 5T multiple myeloma models are good models to study angiogenesis in multiple myeloma and will allow to unravel the mechanisms of neovascularisation, as well as to test new putative inhibitors of angiogenesis.

Regulation and action of angiogenic factors in the primate ovary

The ephemerality of the maturing follicle and subsequent corpus luteum as they perform their gametogenic and/or endocrine functions during the ovarian cycle is associated with remarkable changes in local vasculature. Studies on the angiogenic and angiolytic process in the ovary, rare in healthy adult tissues, complement recent efforts to understand vasculogenesis in embryonic tissues and to control angiogenesis in pathologic states such as cancer. Several reports indicate that the newly discovered vascular-specific angiogenic factors are expressed in the ovary, notably members of the vascular endothelial growth factor (VEGF) and angiopoietin (Ang) families plus their receptors (VEGF-Rs, neuropilins, Tie). Unlike in many other tissues, gonadotropic hormones (particularly luteinizing hormone, [LH]) are major stimulators of angiogenesis and VEGF/Ang expression in the ovary. However, local factors such as insulin-like growth factors or oxygen tension likely modulate the angiogenic processes. Recent studies employing systemic or local administration of anti-angiogenic drugs (TNP-470 or fumagillin) or specific VEGF antagonists (VEGF antibody or soluble VEGFR-1) demonstrate a vital role for normal angiogenesis and VEGF action in follicle development, ovulation, or corpus luteum function. Further studies discerning the various angiogenic factors and their roles in controlling the growth, maturation, function, and regression of the vasculature in ovarian compartments during the menstrual cycle could yield novel strategies for manipulating fertility or for alleviating infertility.