Neonatal-onset multisystem inflammatory disease (NOMID) due to a novel S331R mutation of the CIAS1 gene and response to interleukin-1 receptor antagonist treatment.

Neonatal-onset multisystem inflammatory disease (NOMID) is due to mutations in the CIAS1 gene. We describe the case of a 5-year-old boy with neonatal onset of urticaria-like rash, chronic fever, laboratory findings of systemic inflammation, hepatosplenomegaly, and chronic CNS inflammation associated with sensorineural deafness. Sequence analysis of exon 3 of the CIAS1 gene revealed a novel C1754A/S331R mutation. Since experimental evidence suggests that patients with cryopyrin-associated periodic syndromes (CAPS) could respond to inhibition of binding of interleukin IL-1alpha and IL-1beta to the IL-1 receptor type 1, we treated the child with the IL-1 receptor antagonist anakinra. A remarkable clinical and serological response to therapy was observed, suggesting that pharmacological inhibition of the IL-1 signaling pathway offers an important new treatment option for patients with NOMID.

The homeobox transcription factor Prox1 is highly conserved in embryonic hepatoblasts and in adult and transformed hepatocytes, but is absent from bile duct epithelium.

Prox1 is a transcription factor with two highly conserved domains, a homeobox and a prospero domain. It has been shown that Prox1 knock-out mice die during early embryonic stages and display a rudimentary liver. We have studied the expression of Prox1 at RNA and protein levels in chick, rat, mouse and human liver and in transformed and non-transformed hepatic cell lines. Prox1 is expressed in early embryonic hepatoblasts and is still expressed in adult hepatocytes. Prox1 protein is located in the nuclei of hepatoblasts, which grow into the neighboring embryonic mesenchyme. The expression pattern in chick, mouse, rat and human embryos is highly conserved. Besides albumin and alpha-fetal protein, Prox1 belongs to the earliest markers of the developing liver. In adult liver, Prox1 is expressed in hepatocytes but is absent from bile duct epithelial and non-parenchymal cells (Kupffer cells, hepatic stellate cells, sinusoidal endothelial cells and myofibroblasts). Isolated primary hepatocytes and hepatoma cell lines (HepG2, Hep3B) are Prox1 positive, whereas the immortalized murine liver cell-line MMH, which constitutively expresses the receptor c-met, is Prox1 negative. Transfection of MMH with Prox1 cDNA increases the expression level significantly as compared to control transfectants. In HepG2 and Hep3B, the Prox1 levels are even up to 100 times higher. Our studies show that Prox1 is a highly conserved transcription factor, expressed in hepatocytes from the earliest stages of development into adulthood and over-expressed in hepatoma cell lines. Its absence from bile duct epithelial cells suggests a function for the specification of hepatoblasts into hepatocytes. The genes controlled by Prox1 need to be studied in the future.

Quantification of angiogenesis stimulators in children with solid malignancies.

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: n(VEGF) = 69, n(bFGF) = 60; urine: n(VEGF) or n(bFGF) = 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.

Hypoxia promotes apoptosis of human neuroblastoma cell lines with enhanced N-myc expression.

We have examined the effect of hypoxia and nutrient depletion on the growth of human neuroblastoma cells with normal or enhanced expression of the N-myc oncogene. The combination of both conditions reduced the growth of neuroblastoma cells with normal N-myc expression. However, this effect was much more pronounced in neuroblastoma cells with enhanced N-myc expression and eventually resulted in apoptosis, presumably by the up-regulation of CD95. Our data suggest that therapeutic induction of tumor hypoxia and nutrient depletion (for example, by anti-angiogenesis) could help to improve the outcome of patients with neuroblastomas carrying the prognostically unfavourable N-myc amplification.

Multiple angiogenesis stimulators in a single malignancy: implications for anti-angiogenic tumour therapy.

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.

The N-myc oncogene in human neuroblastoma cells: down-regulation of an angiogenesis inhibitor identified as activin A.

Angiogenesis, the formation of new blood vessels, is seen during embryonic development and tumor progression, but the mechanisms have remained unclear. Recent data indicate that developmental and tumor angiogenesis can be induced by cellular oncogenes, leading to the enhanced activity of molecules stimulating angiogenesis. However, activated oncogenes might also facilitate angiogenesis by down-regulating endogenous inhibitors of angiogenesis. We report here that enhanced expression of the N-myc oncogene in human neuroblastoma cells down-regulates an inhibitor of endothelial cell proliferation, identified by amino acid sequencing as being identical with activin A, a developmentally regulated protein. Down-regulation appears to involve interaction of the N-Myc protein with the activin A promoter. In addition, activin A inhibits both endothelial cell proliferation in vitro and angiogenesis in vivo, and it induces hemorrhage in vivo. We suggest that the N-myc-induced down-regulation of activin A could contribute to developmental and tumor angiogenesis.

MYCN oncogene and angiogenesis: down-regulation of endothelial growth inhibitors in human neuroblastoma cells. Purification, structural, and functional characterization.

Angiogenesis, the formation of new blood vessels, is seen during embryonic development and tumor progression, but the mechanisms have remained unclear. Recent data indicate that tumor angiogenesis can be induced by cellular oncogenes, leading to the enhanced activity of molecules stimulating angiogenesis. However, activated oncogenes might also facilitate angiogenesis by down-regulating endogenous inhibitors of angiogenesis. We report here that enhanced expression of the N-myc oncogene in human neuroblastoma cells down-regulates three inhibitors of endothelial cell proliferation. One of them was identified by amino acid sequencing as being identical with activin A, a developmentally-regulated protein. Down-regulation involves interaction of the N-myc protein with the activin A promoter. Work is ongoing to characterize the other two endothelial cell inhibitors. We suggest that the N-myc induced down-regulation of angiogenesis inhibitors could contribute to tumor angiogenesis.

N-myc down-regulates activin A.

N-myc oncogene amplification is frequent in human neuroblastoma and predicts poor prognosis, but the molecular consequences have remained obscure. We report here that enhanced N-myc expression correlates with low or undetectable expression of activin A, but not other closely related members of the transforming growth factor-beta superfamily. N-myc interacts with the activin A promoter, eventually inducing down-regulation of activin A mRNA and protein. This study demonstrates for the first time N-myc-induced down-regulation of a gene implicated in signal transduction. Down-regulation of activin A could deprive neuroblastomas from a signal with growth-inhibitory activities toward the tumor and its stroma and thereby permit neuroblastoma progression.

Arginine deiminase inhibits proliferation of human leukemia cells more potently than asparaginase by inducing cell cycle arrest and apoptosis.

L-Asparaginase is used for the treatment of acute leukemias, but is sometimes ineffective or associated with severe side-effects. We report here that the enzyme arginine deiminase is approximately 100-fold more potent than L-asparaginase in inhibiting the proliferation of cultured human lymphatic leukemia cell lines while it appears to be less effective in leukemia cells of myeloid origin. The inhibition of cell proliferation involves cell growth arrest in the G1- and/or S-phase and eventually apoptotic cell death. Our results suggest the possibility of a future use of arginine deiminase for the therapy of leukemia.

Down-regulation of endothelial cell growth inhibitors by enhanced MYCN oncogene expression in human neuroblastoma cells.

Recent evidence indicates that the genetic alterations of the multistage process of malignant transformation appear to activate tumor neovascularization by altering the balance between stimulators and inhibitors of angiogenesis. In the present study, we have attempted to define the effect of enhanced MYCN oncogene expression on the profile of endothelial cell growth modulators in neuroblastoma cells. We report here that conditioned medium of human neuroblastoma cells with normal MYCN expression contains three inhibitors of endothelial cell proliferation, which appear to be novel proteins as judged by their physicochemical, immunological and biological properties. All three inhibitors are diminished or become undetectable upon experimental increase of MYCN expression. Our results suggest that enhanced MYCN expression in human neuroblastoma cells alters the angiogenic balance by down-regulating endothelial cell growth inhibitors but leaving the expression of the stimulators unaffected. These data shed light on the molecular mechanisms linking the genetic changes of malignant transformation with initiation of tumor angiogenesis. Moreover, our observations might explain the poor prognosis of human neuroblastomas following MYCN oncogene amplification through initiation of angiogenesis and subsequent tumor growth and spread.

Arginine deiminase inhibits cell proliferation by arresting cell cycle and inducing apoptosis.

We have previously demonstrated that arginine deiminase inhibits the proliferation of vascular endothelial cells, but the mechanisms leading to growth inhibition have remained unclear. We report here that low concentrations of arginine deiminase purified from Mycoplasma arginini inhibit proliferation of various cultured cells by arresting the cell cycle in G(1) and/or S phase with higher arginine deiminase concentrations leading to subsequent apoptosis. Our results demonstrate that arginine deiminase inhibits cell proliferation not only by depletion of arginine, but also by mechanisms involving the cell cycle and death signals.

Vascular endothelial growth factor expression in human neuroblastoma: up-regulation by hypoxia.

Enhanced angiogenesis apparently contributes to the poor clinical outcome of human neuroblastoma, but the mechanisms have remained unclear. We report here that cultured human neuroblastoma cells express a bioactive endothelial cell growth factor indistinguishable from the angiogenesis stimulator vascular endothelial growth factor (VEGF). VEGF is present in neuroblastoma but not vascular endothelial cells, whereas the corresponding VEGF receptors (Flt-1 and Flk-1/KDR) are expressed in endothelial but not neuroblastoma cells. Exposure of neuroblastoma cells to hypoxia induces a marked increase in bioactive VEGF. VEGF is also present in human neuroblastoma specimens, with substantial amounts in apparently hypoxic neuroblastoma cells, eventually accumulating in tumor microvessels. Our results indicate that VEGF (i) is present in human neuroblastomas, (ii) is up-regulated by tumor hypoxia and (iii) may stimulate neuroblastoma angiogenesis by paracrine mechanisms, thereby contributing to the progression of human neuroblastomas. We suggest that inhibition of VEGF activity may represent a novel approach for the therapy of human neuroblastoma.

Phytoestrogens and inhibition of angiogenesis.

The consumption of a plant-based diet can prevent the development and progression of chronic diseases associated with extensive neovascularization, including the progression and growth of solid malignant tumours. We have previously shown that the plant-derived isoflavonoid genistein is a potent inhibitor of cell proliferation and in vitro angiogenesis. Moreover, the concentration of genistein in the urine of subjects consuming a plant-based diet is 30-fold higher than that in subjects consuming a traditional Western diet. We have also reported that certain structurally related flavonoids are more potent inhibitors than genistein. Indeed, 3-hydroxyflavone, 3',4'-dihydroxyflavone, 2',3'-dihydroxyflavone, fisetin, apigenin and luteolin inhibit the proliferation of normal and tumour cells as well as in vitro angiogenesis at half-maximal concentrations in the lower micromolar range. The wide distribution of isoflavonoids and flavonoids in the plant kingdom, together with their anti-angiogenic and anti-mitotic properties, suggest that these phytoestrogens may contribute to the preventive effect of a plant-based diet on chronic diseases, including solid tumours.

Modulation of the proteolytic balance plasminogen activator/plasminogen activator inhibitor by enhanced N-myc oncogene expression or application of genistein.

The aim of this study was to determine whether enhanced expression of N-myc in a neuroblastoma cell line affects the balance of plasminogen activator/plasminogen activator inhibitor (PA/PAI), a shift towards proteolysis having been observed in other malignant tissues. Two transfected neuroblastoma cell lines with (WAC2 cells) or without (SH-EP007 cells) enhanced expression of the N-myc oncogene were examined by zymography and RNA extraction to determine UPA and PAI enzyme activity and uPA RNA and PAI RNA expression, respectively. The effect of genistein, an inhibitor of tyrosine protein kinase, on uPA/PAI was also investigated. Both the uPA/PAI-1 ratio at mRNA level and the PA/PAI ratio at protein activity level were higher in the more malignant, WAC2 cell line. Genistein attenuated uPA activity and stimulated PAI activity in both cell lines, leading to a decrease in the PA/PAI ratio. This effect was more pronounced in the more malignant, WAC2 cell line.

Flavonoids, dietary-derived inhibitors of cell proliferation and in vitro angiogenesis.

Consumption of a plant-based diet can prevent the development and progression of chronic diseases associated with extensive neovascularization, including solid malignant tumors. In previous studies, we have shown that the plant-derived isoflavonoid genistein is a potent inhibitor of cell proliferation and in vitro angiogenesis. In the present study, we report that certain structurally related flavonoids are more potent inhibitors than genistein. Indeed, 3-hydroxyflavone, 3',4'-dihydroxyflavone, 2',3'-dihydroxyflavone, fisetin, apigenin, and luteolin inhibited the proliferation of normal and tumor cells, as well as in vitro angiogenesis, at half-maximal concentrations in the low micromolar range. We have previously demonstrated that genistein concentrations in the urine of subjects consuming a plant-based diet is 30-fold higher than in subjects consuming a traditional Western diet. The wider distribution and the more abundant presence of flavonoids in the plant kingdom, together with the present results, suggest that flavonoids may contribute to the preventive effect of a plant-based diet on chronic diseases, including solid tumors.

Clinical perspectives of tumor angiogenesis in pediatric oncology.

Angiogenesis, the formation of new capillaries from existing blood vessels, is necessary for embryonic growth and development. It is also seen later during the female cycle and wound healing, but is virtually absent otherwise in the healthy adult organism. Angiogenesis is again observed under pathological conditions, like for example in solid pediatric malignancies. Once grown to a diameter of several millimeters, the latter depend on angiogenesis in order to further grow and to metastasize. Recent experimental and clinical evidence suggests 1) that the extent of tumor angiogenesis could serve to predict clinical outcome and 2) that the inhibition of angiogenesis could be a means to improve the conventional therapy of solid pediatric malignancies.

[Inhibition of neovascularization of the eye by dietary factors exemplified by isoflavonoids]. / Hemmung der Neubildung von Gefässen am Auge durch Nahrungsfaktoren am Beispiel der Isoflavonoide.

UNLABELLED: Chronic malignant diseases with neovascularization sometimes seem to improve when an exclusively plant-based diet is followed. In order to identify antiangiogenic substances in such diets, inhibitory factors such as genistein were isolated. We investigated the antiangiogenic substance genistein with regard to the possibility of an inhibitory effect on corneal angiogenesis in vivo. METHODS: Corneal neovascularization was experimentally induced in NZW rabbits by the use of methylcellulose discs loaded with 250 ng basic fibroblast growth factor (bFGF). Blood vessels grew from the limbus towards the pellet and were quantified under the microscope. Genistein was injected subconjunctivally (0.04 mg genistein/day). RESULTS: All eyes which received genistein subconjunctivally showed a statistically significant reduction of blood vessels at the limbus (from 63 +/- 40 vessels to 36 +/- 11 vessels; P = 0.001). Vascularized areas in the eyes treated with genistein also decreased, from 21.4 +/- 6.7 mm2 to 10.4 +/- 5.0 mm2 (P < 0.0001). CONCLUSION: Our results show that components of a plant-based diet, such as genistein, inhibit ocular neovascularization in vivo. The genistein level rises significantly in human urine following ingestion of soy products, for example. Therefore, certain vegetarian diets could have a positive effect on ocular diseases characterized by progressive neovascularization.

[Type 1 neurofibromatosis. Molecular and clinical aspects]. / Neurofibromatose Typ 1. Molekulare und klinische Aspekte.

The pathogenesis of neurofibromatosis type 1 (NF1) is poorly understood. However, molecular studies have identified the NF1 gene and specific mutations that contribute to the development of NF1 have been found in afflicted patients. These mutations probably result in a loss of function of the NF1 gene product, a protein named neurofibromin which is thought to attenuate exaggerated growth of neuroectodermal tissues. The results of basic research could shed new light on our understanding of the clinical symptoms of NF1 and result in new approaches to diagnosis and therapy.

Femtomole sequencing of proteins from polyacrylamide gels by nano-electrospray mass spectrometry.

Molecular analysis of complex biological structures and processes increasingly requires sensitive methods for protein sequencing. Electrospray mass spectrometry has been applied to the high-sensitivity sequencing of short peptides, but technical difficulties have prevented similar success with gel-isolated proteins. Here we report a simple and robust technique for the sequencing of proteins isolated by polyacrylamide gel electrophoresis, using nano-electrospray tandem mass spectrometry. As little as 5 ng protein starting material on Coomassie- or silver-stained gels can be sequenced. Multiple-sequence stretches of up to 16 amino acids are obtained, which identify the protein unambiguously if already present in databases or provide information to clone the corresponding gene. We have applied this method to the sequencing and cloning of a protein which inhibits the proliferation of capillary endothelial cells in vitro and thus may have potential antiangiogenic effects on solid tumours.