Propranolol treatment was recently reported to be successful for the management of severe infantile hemangioma. Known adverse effects of propranolol treatment include transient bradycardia, hypotension, hypoglycemia, and bronchospasm (in patients with underlying spastic respiratory illnesses), which led to a general recommendation to gradually increase propranolol dosage and closely monitor patients' hemodynamics at the onset of therapy. To date, no serious or unexpected adverse effects that required specific intervention have been reported. In this report, we describe the case of a 17-week-old female preterm infant who presented with a large, ulcerated, cutaneous-subcutaneous hemangioma of the right lateral thoracic wall, which we treated successfully with propranolol. A few days into therapy, a potentially life-threatening adverse effect, severe hyperkalemia, was observed and required treatment with loop diuretics, fluids, and nebulized salbutamol to normalize her serum potassium levels. This therapy could be gradually tapered and finally discontinued only after several weeks of propranolol treatment. Our case report indicates that, at least during the initial phase of the propranolol treatment of infantile hemangioma, close monitoring of serum electrolytes, besides the monitoring of hemodynamics and blood glucose, is necessary.

Purpose: Tumor progression correlates with the induction of a dense supply of blood vessels and the formation of peritumoral lymphatics. Hemangiogenesis and lymphangiogenesis are potently regulated by members of the vascular endothelial growth factor (VEGF) family. Previous studies have indicated the upregulation of VEGF-A and -C in progressed neuroblastoma, however, quantification was performed using semiquantitative methods, or patients who had received radiotherapy or chemotherapy were studied. Experimental Design: We have analyzed primary neuroblastoma from 49 patients using real-time reverse transcription-PCR and quantified VEGF-A, -C, and -D and VEGF receptors (VEGFR)-1, 2, 3, as well as the soluble form of VEGFR2 (sVEGFR-2), which has recently been characterized as an endogenous inhibitor of lymphangiogenesis. None of the patients had received radiotherapy or chemotherapy before tumor resection. Results: We did not observe upregulation of VEGF-A, -C, and -D in metastatic neuroblastoma, but found significant downregulation of the lymphangiogenesis inhibitor sVEGFR-2 in metastatic stages III, IV, and IVs. In stage IV neuroblastoma, there were tendencies for the upregulation of VEGF-A and -D and the downregulation of the hemangiogenesis/lymphangiogenesis inhibitors VEGFR-1 and sVEGFR-2 in MYCN-amplified tumors. Similarly, MYCN transfection of the neuroblastoma cell line SH-EP induced the upregulation of VEGF-A and -D and the switching-off of sVEGFR-2. Conclusion: We provide evidence for the downregulation of the lymphangiogenesis inhibitor sVEGFR-2 in metastatic neuroblastoma stages, which may promote lymphogenic metastases. Downregulation of hemangiogenesis and lymphangiogenesis inhibitors VEGFR-1 and sVEGFR-2, and upregulation of angiogenic activators VEGF-A and VEGF-D in MYCN-amplified stage IV neuroblastoma supports the crucial effect of this oncogene on neuroblastoma progression. Clin Cancer Res; 16(5); 1431–41

Humoral angiogenesis stimulators including vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) have been implicated in the pathogenesis of solid malignancies. However, it has remained unclear whether both stimulators contribute to the development and progression of solid malignancies of children. The aim of the present study was to determine whether VEGF and bFGF are elevated in body fluids of children with solid malignancies and, if so, whether these elevated levels correlate with clinical parameters. Using enzyme‐linked immunosorbent assays (ELISAs), we quantified VEGF and bFGF in serum (n = 107) and urine (n = 57) of healthy children and of children with solid malignancies (serum: nVEGF = 69, nbFGF = 60; urine: nVEGF or nbFGF = 13). Finally, we compared patients' pre‐therapeutic and post‐therapeutic levels. Serum VEGF was elevated in children with several solid tumors (Ewing's sarcoma, primitive neuroectodermal tumours, malignant lymphoma, Langerhans cell histiocytosis and medulloblastoma). In contrast, serum bFGF, urinary bFGF or urinary VEGF were not significantly elevated. Upon successful therapy, elevated pre‐therapeutic serum VEGF levels declined to levels present in healthy children. VEGF could contribute to the progression of pediatric solid malignancies, and serum VEGF could be used to monitor therapeutic response. Furthermore, the determination of angiogenesis stimulators could identify patients eligible for anti‐angiogenic therapy. © 2001 Wiley‐Liss, Inc.

The Vascular Endothelial Growth Factor (VEGF) family of secreted proteins and their receptors are major regulators of blood vessel development (hemangiogenesis) and lymphatic vessel development (lymphangiogenesis). VEGF acts through a complex system of receptor tyrosine kinases, which can be membrane-bound or soluble. New data concerning the receptor system are still emerging, thus contributing to the complexity of the system. Very recently a soluble form of VEGFR-2, termed sVEGFR-2, that is a result of alternative splicing has been discovered. It has been shown earlier that a secreted/soluble form of VEGFR-1, termed sVEGFR-1, is produced by alternative splicing and exerts an anti-hemangiogenic effect by binding VEGF-A. The newly discovered spliced variant of sVEGFR-2 binds the lymphangiogenic growth factor VEGF-C and thus inhibits VEGF-C-induced activation of VEGFR-3, consequently inhibiting lymphatic endothelial cell proliferation. Its inactivation in murine embryos permits hyperplasia of dermal lymphatics and invasion of lymphatics into the cornea. Tumor lymphangiogenesis seems to influence the metastatic behavior of malignant cells. A correlation has been found between the downregulation of sVEGFR-2 and the malignant progression of neuroblastoma, which is characterized e.g. by lymphogenic metastases in progressed stages. Data show that lymphangiogenesis is regulated by both activators and inhibitors, and its balance is crucial in health and disease.

In this study, the importance of angiogenesis (the growth of new blood vessels from existing ones) for the growth of retinoblastoma was investigated by a retrospective immunohistochemical analysis. An individual vessel index for each tumor was determined using the endothelial-specific antibody CD 31 for vessel staining. The obtained data were correlated with clinical features, pathohistological characteristics, and the presence of metastasis. In 107 retinoblastomas collected between 1980 and 1990, we found no difference in the vessel densities between uni- and bilateral retinoblastomas (P = 0.41). However, tumors that had invaded the chorioid and/or the optic nerve statistically showed higher vessel densities than tumors without local invasive growth (P = 0.05 and P = 0.024). A tendency of higher vessel densities in retinoblastomas presenting with metastasis at the time of diagnosis was observed (P = 0.11). Based on this observation, we proceeded to examine all retinoblastomas presenting with metastasis at the time of diagnosis. These included patients that were treated between 1968 and 1993. The 18 investigated retinoblastomas had significantly higher vessel densities than all other retinoblastomas presenting without metastasis (P = 0.025). Our data indicate that in retinoblastoma, blood vessels are essential for local and systemic invasive growth. Therefore, an anti-angiogenic therapy could be considered in the multimodal therapy concept for retinoblastomas with invasive growth, both locally and systemically.

Anti-angiogenesis is likely to develop into a novel therapeutic approach for patients with solid malignancies. Most current clinical trials evaluate anti-angiogenic drugs aimed primarily against single angiogenesis stimulators. Here, we show that a single solid malignancy, i.e., a human embryonal rhabdomyosarcoma, produces in vivo at least three biologically active angiogenesis stimulators (vascular endothelial growth factor, basic fibroblast growth factor and interleukin-8). This suggests that tumour angiogenesis results from the activity of multiple, rather than a single angiogenesis stimulator(s). We, furthermore, show that a combination of anti-angiogenic drugs is more effective in inhibiting tumour-induced endothelial cell growth than a single agent. Our results imply that clinical anti-angiogenic strategies for the treatment of solid malignancies may be most effective when multiple rather than single antiangiogenic drugs are used.

Hemangiomas are the most common vascular tumors in children. They occur in 8-12% of all infants and in 22% of premature infants (female: male = 3: 1). Hemangiomas are usually sporadic; their etiology is unknown. A premature female infant, born at 28 weeks of gestation, presented with a large hemangioma of the right thoracic wall. Within the first few weeks, the hemangioma showed rapid horizontal and vertical growth as well as ulceration, which led us to initiate systemic therapy. The effectiveness of propranolol (non-selective ss-blocker) in the management of severe cases of hemangioma has been shown in a recent series of cases. We began oral propranolol treatment, in close interdisciplinary cooperation. After a few days of therapy, the tumor had stopped expanding. After 18 weeks, there has been marked regression but the therapy is still being continued. We propose that propranolol may be an effective and relatively well tolerable alternative in the management of selected cases of severe hemangiomas in infancy, providing interdisciplinary cooperation between dermatologists and pediatricians is available.

Previously, we observed expression of the homeobox transcription factor Prox1 in neuroectodermal embryonic tissues. Besides essential functions during embryonic development, Prox1 has been implicated in both progression and suppression of malignancies. Here, we show that Prox1 is expressed in embryonic sympathetic trunk ganglia of avian and murine embryos. Prox1 protein is localized in the nucleus of neurofilament-positive sympathetic neurons. Sympathetic progenitors represent the cell of origin of neuroblastoma (NB), the most frequent solid extracranial malignancy of children. NB may progress to life-threatening stage 4, or regress spontaneously in the special stage 4s. By qRT-PCR, we show that Prox1 is expressed at low levels in 24 human NB cell lines compared with human lymphatic endothelial cells (LECs), whereas equal immunostaining of nuclei can be seen in embryonic LECs and sympathetic neurons. In NB stages 1, 2, 3, and 4, we observed almost equal expression levels, but significantly higher amounts in stage 4s NB. By immunohistochemistry, we found variable amounts of Prox1 protein in nuclei of NB cells, showing intra and interindividual differences. Because stage 4s NB are susceptible to postnatal apoptosis, we assume that high Prox1 levels are critical for their behavior. (Pediatr Res 68: 112-117, 2010)