The correlation of angiogenesis with metastasis in primary cutaneous melanoma: a comparative analysis of microvessel density, expression of vascular endothelial growth factor and basic fibroblastic growth factor

AIM: To establish whether there is a correlation between angiogenesis and metastasis in primary cutaneous melanoma (PCMM). METHODS: We studied the microvessel density and the expression of vascular endothelial growth factor (VEGF) and basic fibroblastic growth factor (bFGF) in 22 cases of PCMM with metastasis at presentation (metastatic group) and 28 cases of PCMM without metastasis for 24 months or more (non-metastatic group). Microvessels were stained with CD31/PECAM-1 antibody and counted. We assessed the proportion of VEGF expression in tumour cells, lymphocytes infiltrating the tumour (TIL) and lymphocytes at the periphery of the tumour, as well as the proportion of bFGF expression in tumour cell cytoplasms, nuclei and intra- and peritumoral vessels. RESULTS: An increased microvessel density was detected in the metastatic group (15-33 [24.09 +/- 5.55] versus 2-24 [12.96 +/- 6.02]). Moreover, enhanced expression of VEGF in tumour cells and peritumoral lymphocytes (Chi-square p = 0.038 and p = 0.018) and bFGF in peritumoral vessels (chi(2) p = 0.013) correlated with the simultaneous presence of melanoma metastasis in PCMM. Furthermore, microvessel density was correlated with the expression of bFGF in peritumoral vessels (rs = 0.53, p = 0.049) and VEGF in tumour cells (rs = 0.37, p = 0.019). CONCLUSION: Microvessel density as well as the expression of both VEGF and bFGF might be informative concerning the progression of melanoma.     

The p75 neurotrophin receptor influences NT-3 responsiveness of sympathetic neurons in vivo.

To determine the role of the p75 neurotrophin receptor (p75NTR) in sympathetic neuron development, we crossed transgenic mice with mutations in p75NTR, nerve growth factor (NGF) and neurotrophin-3 (NT-3). Neuron number is normal in sympathetic ganglia of adult p75NTR-/- mice. Mice heterozygous for a NGF deletion (NGF+/-) have 50% fewer sympathetic neurons. In the absence of p75NTR (p75NTR-/- NGF+/-), however, neuron number is restored to wild-type levels. When NT-3 levels are reduced (p75NTR-/- NGF+/- NT3 +/-), neuron number decreases compared to p75NTR-/- NGF+/- NT3+/+. Thus, without p75NTR, NT3 substitutes for NGF, suggesting that p75 alters the neurotrophin specificity of TrkA in vivo.     

Peripheral axon crush elevates transport of p75NTR in the central projection of sensory neurones of rats

The effect of peripheral axon crush on the axonal transport of the neurotrophin receptors, p75(NTR) and trkA, was studied in dorsal roots of adult rats. Lumbar dorsal roots were crushed for 3-6 h to cause accumulation of p75(NTR) and trkA. Immunohistochemistry showed the presence of the NGF receptors in axons, indicating retrograde and anterograde axonal transport in the dorsal root. Western blots confirmed that the time course of accumulation of p75(NTR) was consistent with fast axonal transport. However, trkA accumulation was too low to indicate significant levels of axonal transport. Sciatic nerve crush induced a 2-fold increase (P<0.05) in the bidirectional axonal transport of p75(NTR) in the dorsal root while trkA transport remained below detectable levels.     

高亲和性神经生长因子受体对神经生长因子诱导神经母细胞瘤 …

观察人神经母细胞瘤细胞系ＩＭＲ－３２细胞在恢复高亲和性神经生长因子受体基因ｔｒｋＡ表达后对神经生长因子（ＮＧＦ）诱导分化的反应。方法应用基因重组技术构建含外源ｔｒｋＡ ｃＤＮＡ的逆转录病毒载体,经ＰＡ３１７细胞包装后感染靶细胞系ＩＭＲ－３２细胞,经Ｓｏｕｔｈｅｒｎ ｂｌｏｔ杂交,逆转录－聚合酶链反应（ＲＴ－ＰＣＲ）证实转化细胞系中含有外源基因的整合及稳定表达后,进行神经生长因子诱导分化实验。结果转     

Lack of association of two lipoprotein lipase polymorphisms with Alzheimer's disease

Recent studies suggest that nerve growth factor (NGF), a neurotrophic factor known to play a crucial role in neurite growth and differentiation, may also modulate vascular cell functions. In the present study, it was investigated whether NGF exhibits an angiogenic effect in a mouse model of hindlimb ischemia induced by femoral artery occlusion. Enzyme-linked immunosorbent assay determination revealed an enhanced endogenous NGF production (378 +/- 100 and 54 +/- 26 pg/g tissue in 7 day ischemic and normoperfused adductor muscles, respectively; P<0.05). Furthermore, exogenous NGF, administered subcutaneously for 7 days in ischemic hindlimb, induced a marked increase of arteriole length density (NGF =41 +/- 5 vs. Saline=22 +/- 4 mm/mm(3); P<0.05). However, capillaries were not significantly increased (NGF =1035 +/- 182 vs. Saline= 829 +/- 60 mm/mm(3); P>0.05). In conclusion, the present study provides first evidence that NGF exerts angiogenic properties in vivo.     

Nerve growth factor-induced substance P in capsaicin-insensitive vagal neurons innervating the lower mouse airway

BACKGROUND: Nerve growth factor (NGF) is elevated in allergic diseases such as bronchial asthma and can lead to an induction of substance P (SP) and related neuropeptides in guinea-pigs large-diameter, neurofilament-positive airway neurons. OBJECTIVE: In the present study, the effect of NGF on tyrosine kinase receptor trkA and the capsaicin receptor TRPV1 expression in airway-specific vagal sensory neurons located in the jugular-nodose ganglia complex (JNC) of mice was investigated. METHODS: Using retrograde neuronal tracing in combination with double-labelling immunohistochemistry, SP, trkA- and TRPV1-receptor expression was examined in airway-specific sensory neurons of BALB/c mice before and after NGF treatment. RESULTS: NGF injected into the lower airway was able to induce SP (13.0+/-2.03% vs. 5.9+/-0.33%) and trkA expression (78+/-2.66% vs. 60+/-2.11%) in larger diameter (>25 microm), capsaicin-insensitive and trkA-positive vagal sensory neurons that were retrograde-labelled with Fast Blue dye from the main stem bronchi. CONCLUSION: Based on the extent of SP and trkA co-expression in airway-specific neurons by NGF treatment, the present study suggests that, following a peripheral activation of trkA receptor on SP afferent by NGF which is elevated in allergic inflammation, there may be trkA-mediated SP induction to mediate neurogenic airway inflammation.     

Up-Regulation of Insulin-Like Growth Factor-II Expression Is a Feature of TrkA but Not TrkB Activation in SH-SY5Y Neuroblastoma Cells

The types of neurotrophin receptors that are expressed in neuroblastomas have different prognostic implications; trkA is a marker of good prognosis, whereas trkB expression is associated with poor prognosis. This suggests that either the signaling that is mediated via these receptors modulates the biological features of neuroblastoma cells differently, or that distinct lineages of sympathoadrenal precursors have been transformed. In this report, we evaluate the biological effects after activation of trkA or trkB by their major ligands in SH-SY5Y human neuroblastoma cells. Both trkA and trkB induce differentiation, inhibit growth, and promote the survival of cells under conditions of nutrient deprivation. However, the up-regulation of insulin-like growth factor-II (IGF-II) expression is a predominant feature of trkA activation by nerve growth factor (NGF). The growth inhibition induced by blocking the insulin-like growth factor-I receptor suggests that IGF-II is a component of the effector mechanism of trkA activation by NGF in trkA-transfected cells. Although trkA and trkB expression is associated with different prognoses in neuroblastoma, our study indicates that the effects mediated by these receptors in vivo may be quite similar for certain subsets of neuroblastomas.     

Nerve growth factor activates aorta endothelial cells causing PI3K/Akt- and ERK-dependent migration

Nerve growth factor (NGF) is a well-known neurotrophin. We determined whether NGF can activate endothelial cell migration and signalling that underlie angiogenic processes. We showed that aorta endothelial cells express mRNA for both the receptor tyrosine kinase TrkA and the p75 neurotrophin receptor (p75NTR) that associates with TrkA when signalling occurs. Pig aortic endothelial cells migrated when exposed to an NGF gradient, due to the simultaneous activation of the phosphatidylinositol 3-kinase and extracellular signal-regulated kinase signalling pathways. Furthermore, morphological changes were found in migrating cells: they appear with elongated structures with a smaller cell volume than control cells. Our data show that NGF is an activator of endothelial cells and suggest that NGF plays a role in mediating angiogenesis.     

Activation of trkA induces differentiation and inhibits the growth of JK-GMS Askin tumor cells

Peripheral primitive neuroectodermal tumor (PNET) and Ewing's sarcoma (ES) constitute a unique group of small round cell tumors in childhood and young adults that are characterized by the same chromosomal translocation t(11;22)(q24;q12). Recently, the expression of neurotrophin receptors has been found in various human tumors including PNET/ES, but the functional significance of these receptor expressions has not been documented in PNET/ES. In the present study, we investigated the biologic effects of trkA neurotrophin receptor activation by nerve growth factor (NGF) in a newly established Askin tumor cell line, JK-GMS, which constitutively expresses a high level of trkA. The activation of trkA induced differentiation and inhibited the growth of JK-GMS cells, which was characteristically associated with down-regulation of c-myc and N-myc mRNA expression. NGF did not exert significant changes in two different PNET/ES cell lines, CADO-ES1 and RD-ES, which did not express detectable levels of trkA. The biologic effects mediated by NGF were abrogated by treatment of the cells with K-252a, and the treatment with brain-derived neurotrophic factor did not affect the biologic behavior of JK-GMS cells, indicating that the effects are trkA specific. The results observed were quite similar to those of neuroblastoma cells, another childhood tumor of neural crest origin. Overall findings strongly suggest that the trkA-mediated signaling pathway plays a crucial role in controlling the basic biologic properties of JK-GMS cells.     

Early postnatal corticosterone administration regulates neurotrophins and their receptors in septum and hippocampus of the rat

The principal glucocorticoid in rats, corticosterone, interacts with neurons in the limbic system and leads to morphological and behavioral changes. Putative corticosterone-triggered mediators are neurotrophins. In the present study we investigated the effects of early postnatal corticosterone treatment in rats on neurotrophic factors of the nerve growth factor (NGF) family and their receptors. Newborn rats were treated with corticosterone-containing polymers until postnatal day 12. The mRNA and protein levels of the neurotrophins of the NGF family (NGF, BDNF, NT-3 and NT-4/5) and their receptors (trkA, trkB, trkC and p75) were quantified in septum and hippocampus using RT-PCR. In the septal region, we found an unchanged mRNA expression after corticosterone treatment, whereas in the hippocampus there was a general increase in mRNA. Particularly, the gene expression of NGF, NT-3, and the high affinity receptors trkA, trkB and trkC increased significantly. Quantification of the neurotrophin protein levels using an ELISA revealed significant treatment effects for NGF and NT-4/5 in the hippocampus. The present study of corticosterone treatment in young rats demonstrates interactions of steroid hormones with neurotrophic factors and their receptors in the septo-hippocampal system during the first two postnatal weeks.     

Angiogenesis, vascular endothelial growth factor and the endometrium

Angiogenesis is an essential component of endometrial renewal. The formation of new vessels depends on interactions between various hormones and growth factors, and this review focuses on the expression of angiogenic growth factors in the human endometrium. Peptide and non-peptide angiogenic factors interact during endometrial renewal, including epidermal growth factor (EGF), transforming growth factors (e.g. TGF-beta), platelet-derived endothelial growth factor/thymidine phosphorylase (PD-ECGF/TP), tumour necrosis growth factors and vascular endothelial growth factor (VEGF). Their role in the proliferation and migration of endothelial cells from pre-existing vessels is described, concentrating on VGEF and its receptors (VEG-R1 and -R2), and the fibroblast growth factor (FGF) family. The actions of the products of the VEGF gene are outlined, and the hormonal and non-hormonal control of their localization in the human endometrium and biological actions on vasculature and coagulation are described. Finally, the role of VEGF in menorrhagia is assessed.     

Vascularization of embryonic adrenal gland grafted onto chorioallantoic membrane

 Vascularization and endothelial phenotype expression were analysed in embryonic adrenal tissue grafted onto chorioallantoic membrane (CAM), by means of routine light microscopy and immunocytochemical staining, and of electron microscopy. Adrenal gland tissue from chick or quail embryos (donors) was grafted onto CAMs of chick or quail embryos (host). Vessels of chick origin were discriminated from those of quail origin by monoclonal antibodies, anti-MB1, specific for quail endothelial and haemopoietic cells, and QCPN, which labels quail cell nuclei. Vessels of adrenal type were distinguished from those of CAM-type by their ultrastructural endothelial phenotype – porous in the former and continuous in the latter. The observations carried out 6 days after implantation indicate that the adrenal gland develops and differentiates according to a virtually normal histological pattern. As regards the adrenal and CAM vascularization, the grafting procedure elicits angiogenic events consisting in the formation of peripheral anastomoses between the graft and the CAM original microvasculature and in new-growth of vessels from the CAM into the grafted tissue and vice versa. As to the endothelial phenotype, the ultrastructural results demonstrate that besides its own native vasculature, the adrenal tissue contains vessels with continuous endothelium and the CAM mesenchyme is supplied by adrenal-type, fenestrated vessels. Accepted: 27 April 1998     

Alterations of blood vessel development by endothelial cells overexpressing fibroblast growth factor-2

A close relationship exists between angiogenesis and the formation of vascular lesions. The development of the vascular system in the chick embryo chorioallantoic membrane (CAM) may thus represent a model to study the effects of the deregulation of endothelial cell behaviour. Alterations of the developing vascular tree of the CAM were observed after exposure to murine aortic endothelial (MAE) cells overexpressing human fibroblast growth factor-2 (FGF2) cDNA (pZipFGF2 MAE cells), or to their conditioned medium (CM). pZipFGF2 MAE cells injected into the allantoic sac or applied on to the CAM of day 8-9 chick embryos induce neovascularization and the appearance of haemangioma-like lesions. This activity was not prevented by anti-FGF2 antibodies. The CM from pZipFGF2 MAE cells was also active when adsorbed into a gelatin sponge and applied on to the CAM, both in the absence and in the presence of anti-FGF2 antibodies. No effects on vessel development were exerted by parental MAE cells, FGF2-transfected NIH 3T3 fibroblasts, or their conditioned media. In vitro, pZipFGF2 MAE cell CM caused parental MAE cells to invade fibrin gels and to undergo morphogenesis on Matrigel. This activity was not mimicked by recombinant FGF2 nor affected by anti-FGF2 antibodies, and depended on a M (r) approximately 45 000 heat-labile heparin-binding factor. Size exclusion chromatography of pZipFGF2 MAE cell CM demonstrated that the in vitro activity co-purified with an in vivo angiogenic capacity. Thus, FGF2 overexpression in mouse endothelial cells induces the production of an angiogenic activity distinct from FGF2, which may contribute to the genesis of angioproliferative lesions.     

Cutaneous malignant melanoma: correlation between neovascularization and peritumor accumulation of mast cells overexpressing vascular endothelial growth factor

To investigate the possible role of mast cells (MC) in the angiogenic process in cutaneous melanoma, we examined tissue samples from 35 adult patients with primary malignant melanoma and compared with 20 intradermal benign nevi. MC were identified by anti-tryptase, microvessels by anti-CD34, and vascular endothelial growth factor (VEGF) expression by standard immunohistochemical methods. Tryptase-positive MC expressing VEGF were identified by double immunostaining. The numbers of MC and microvessels around the tumor were determined by the point counting method. MC density was significantly greater in melanoma compared with benign nevi (197.6 +/- 19.4 v 95.7 +/- 5.0/mm2, P < .001). Vascular density was also significantly higher in melanoma than in benign lesions (3.6-fold, P < .001). Double immunostaining showed the presence of VEGF in the cytoplasm of tryptase-positive peritumoral MC. The percentage of this MC-subtype was significantly higher in melanoma than in nevus tissues (71.9 +/- 2.4% v 30.6 +/- 2.5%, P < .001). A strong significant correlation was shown between the number of VEGF+ MC and microvessel density (r = .811, P < .001). MC count and VEGF+ MC count, as well as microvessel density were significantly higher in aggressive (metastasizing) melanomas (P < .001). Our results suggest that peritumoral accumulation of MC and the subsequent release of potent angiogenic factor such as VEGF may thus represent a tumor-host interaction that may favor progression of this tumor.     

Angiogenesis in lipoma: An experimental study in the chick embryo chorioallantoic membrane

Lipoma is one of the most common benign mesenchymal tumors. Its ability to trigger an angiogenic response is a critical step for its growth. Because adipose tissue serves as an important conduit for the vasculature, it is conceivable that the angiogenic properties of this tissue may modulate the growth of the vasculature in a paracrine manner. We investigated in vivo the angiogenic potential of bioptic fragments of human lipoma by using the chick embryo chorioallantoic membrane (CAM), a useful model for such an investigation. The angiogenic response in pathological and control implants was assessed on histologic sections by a morphometric method, 96 h after grafting. Results showed that pathological samples were surrounded by numerous allantoic vessels with a radially arranged pattern around the implant. The vascular counts in the CAMs treated with lipoma implants were comparable to that of FGF-2. The role played in vasoproliferative response by angiogenic cytokines (FGF-2, VEGF) released by adipocytes, by endogenous cytokines, such as FGF-2, stored in the CAM extracellular matrix and by angiogenic growth factors released by perivascular mononuclear cells around the newly-formed blood vessels, were supported by this study.     

Overexpression of VEGF and angiopoietin 2: a key to high vascularity of hepatocellular carcinoma?

Hepatocellular carcinoma (HCC) is becoming one of the most common malignant tumors worldwide and is characterized by a high vascularity. Angiogenesis, formation of new microvessels, is critical for the growth and progression of various human solid tumors. Vascular endothelial growth factor (VEGF) and angiopoietins (Ang1 and Ang2) are endothelial cell-specific vasculogenic and angiogenic growth factors, but their expression and roles in HCC have not been extensively explored. The aim of this study was to determine the expression and cellular localization of VEGF, Ang1, and Ang2 in specimens of resected human HCC using in situ hybridization and immunohistochemical staining and to examine their relationship to microvessel density (MVD) and tumor size. We also investigated whether mutation of p53 protein might affect the expression of the above angiogenic growth factors. VEGF and Ang2 were strongly expressed and localized predominantly to cancer cells, whereas Ang1 was detected in supportive cells of large blood vessels, stromal cells, endothelial cells, and tumor cells. Expression of the VEGF protein and the Ang2 (but not Ang1) mRNA were strongly correlated with MVD (P <.05, P =.001) and tumor size (P <.05). There was also a strong correlation between VEGF protein and Ang2 mRNA expression (P <.001). However, no significant correlation was found between overexpression of p53 and the expression of VEGF, angiopoietins, or MVD. These findings suggest that overproduction of the angiogenic growth factors VEGF and Ang2 by HCC cells may increase vascularity and tumor growth in a paracrine manner. Our findings also suggest that interaction between VEGF and Ang2 may play a critical role in tumor angiogenesis in HCC.     

人脑胶质母细胞瘤细胞质SHG—44中血管生成因子和细胞周期调 …

OBJECTIVE: To investigate the biological features and immunophenotypes of human glioblastoma cell line SHG-44 after long term passage. METHODS: Immunohistochemistry and in situ hybridization were used to study the proliferative activity, intermediate filament protein coexistence, expressions of oncoprotein, angiogenic factors and cell cycle regulation factors. RESULTS: After 130 to 150 passages, SHG-44 cells were weakly positive for glial fibrillary acidic protein (GFAP), but strongly positive for vimentin. The labeling index of Ki-67 and PCNA were 83.5% +/- 10.2% and 70.0% +/- 18.7% respectively. Overexpression of p21 ras, c-erbB-2, epidermal growth factor (EGF) and EGF receptor were obtained. Basic fibroblast growth factor (bFGF), FGF receptor, vascular endothelial growth factor (VEGF) and inducible nitric oxide synthase (iNOS) were also up-regulated in this cell line. p16, p53, cdk4 and cyclin D1 could be detected in the cells and their indices were 43.1% +/- 11.2%, 20.7% +/- 6.6%, 33.1% +/- 11.4% and 29.2% +/- 4.7% respectively. CONCLUSION: Expressive abnormalities of these growth factors, their receptors and the above oncoproteins as well as disorders of cell cycle regulation contribute to the rapid growth and high degree of malignancy of this cell line.     

Adenovirus-mediated lung vascular endothelial growth factor overexpression protects against hypoxic pulmonary hypertension in rats

Chronic hypoxic pulmonary hypertension (PH) is associated with vasoconstriction and structural remodeling of pulmonary vessels including narrowing of the arterial lumen and loss of distal functional arteries. To test whether lung overexpression of the angiogenic factor vascular endothelial growth factor (VEGF) is beneficial in hypoxic PH, recombinant adenovirus encoding the human VEGF 165 gene under the control of a cytomegalovirus promoter (Ad. VEGF) or control vector containing no gene in the expression cassette (Ad.Null) was administered intratracheally to rats. With Ad. VEGF (10(8) plaque-forming units [pfu]), VEGF protein was present in bronchoalveolar lavage fluid as early as 2 d and until 17 d after gene transfer, but was not detected in serum. Only small patchy areas of mononuclear cells without cell damage, edema, or hemorrhage were observed on lung histology with no significant change in lung permeability. In rats pretreated with Ad.VEGF (10(8) pfu) 2 d before a 2-wk exposure to hypoxia (10% O(2)), lower values versus Ad. Null-pretreated controls were found for pulmonary artery pressure (25 +/- 1 versus 30 +/- 2 mm Hg, P < 0.05), right ventricular over left ventricular-plus-septum weight (0.37 +/- 0.01 versus 0.47 +/- 0. 02, P < 0.001), normalized wall thickness of 50- to 200-microm vessels (P < 0.001), and muscularization of distal vessels (P < 0. 001). Pretreatment with Ad.VEGF (10(8) pfu) increased endothelial nitric oxide synthase activity in lung tissue and partially restored endothelium-dependent vasodilation in isolated lungs from chronically hypoxic rats, as assessed by improvement of ionophore A23187-induced vasodilation and attenuation of endothelin-1 (300 pmol)-induced vasoconstriction, an effect abolished in the presence of nitro-L-arginine methylester. We conclude that adenoviral-mediated VEGF overexpression in the lungs attenuates development of hypoxic PH, in part by protecting endothelium-dependent function.