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At least 19 recordsLinked to original sources
PubMed2006

Neuropilin-1 and neuropilin-2 enhance VEGF121 stimulated signal transduction by the VEGFR-2 receptor.

The neuropilin-1 (np1) receptor binds the 165 amino-acid form of vascular endothelial growth factor165 (VEGF165) and functions as an enhancer that potentiates VEGF165 signaling via the VEGFR-2 tyrosine-kinase receptor. To study the mechanism by which neuropilins potentiate VEGF activity we produced a VEGF165 mutant (VEGF165KF) that binds to neuropilins but displays a much lower affinity toward VEGFR-1 and VEGFR-2. VEGF165KF failed to induce VEGFR-2 phosphorylation in cells lacking neuropilins. However, in the presence of np1, VEGF165KF bound weakly to VEGFR-2, induced VEGFR-2 phosphorylation, and activated ERK1/2. Interestingly, VEGF165KF did not promote formation of VEGFR-2/np1 complexes nor did high concentrations of VEGF165KF inhibit VEGF165 induced formation of such complexes, suggesting that VEGF165 does not stabilize VEGFR-2/np1 complexes by forming bridges spanning VEGFR-2 and np1. VEGF121 is a VEGF form that does not bind to neuropilins. Surprisingly, both np1 and neuropilin-2 (np2) enhanced VEGF121-induced phosphorylation of VEGFR-2 and VEGF121-induced proliferation of endothelial cells. The enhancement of VEGF121 activity by np1 was accompanied by a 10-fold increase in binding affinity to VEGFR-2 and was not associated with the formation of new VEGFR-2/np1 complexes. These observations suggest that neuropilins enhance the activity of VEGF forms that do not bind to neuropilins, indicate that np2 is a functional VEGF receptor, and imply that spontaneously formed VEGFR-2/np1 complexes suffice for efficient neuropilin mediated enhancement of VEGF activity.

Amino Acid Substitution↗
PubMed2002

The interaction of Neuropilin-1 and Neuropilin-2 with tyrosine-kinase receptors for VEGF.

The Neuropilin-1 (NRP1) and Neuropilin-2 (NRP2) receptors were initially described as receptors for axon guidance factors belonging to the class-3 Semaphorin sub-family. Subsequently, it was found the Neuropilins also function as receptors for some forms of vascular endothelial growth factor (VEGF). VEGF165 binds to both NRP1 and to NRP2 but VEGF121, does not bind to either of these receptors. VEGF145 on the other hand, binds to NRP2 but not to NRP1. Additional VEGF family members such as the heparin binding form of placenta growth factor (PlGF-2) and VEGF-B bind to NRP1, and it was also shown that both PlGF-2 and VEGF-C bind to NRP2. The intracellular domains of the Neuropilins are short, and do not suffice for independent transduction of biological signals subsequent to Semaphorin or VEGF binding. It was shown that both Neuropilins can form complexes with receptors belonging to the Plexin family, and that such Plexin/Neuropilin complexes are able to transduce signals following the binding of class-3 Semaphorins to Neuropilins. The VEGF165 induced proliferation and migration of cells that express the VEGF tyrosine-kinase receptor VEGFR2 is enhanced in the presence of NRP1, suggesting that Neuropilins may also form complexes with VEGF tyrosine-kinase receptors such as VEGFR2. However, it is not yet clear whether VEGFR2 and NRPI form complexes and contrasting results have been reported with regard to this issue. In contrast, it was recently reported by two laboratories that Neuropilins can form complexes with the second tyrosine-kinase receptor of VEGF, VEGFR1. However, the biological function of these complexes is still unclear.

Animals↗
PubMed1997

Neuropilin-2, a novel member of the neuropilin family, is a high affinity receptor for the semaphorins Sema E and Sema IV but not Sema III.

Semaphorins are a large family of secreted and transmembrane proteins, several of which are implicated in repulsive axon guidance. Neuropilin (neuropilin-1) was recently identified as a receptor for Collapsin-1/Semaphorin III/D (Sema III). We report the identification of a related protein, neuropilin-2, whose mRNA is expressed by developing neurons in a pattern largely, though not completely, nonoverlapping with that of neuropilin-1. Unlike neuropilin-1, which binds with high affinity to the three structurally related semaphorins Sema III, Sema E, and Sema IV, neuropilin-2 shows high affinity binding only to Sema E and Sema IV, not Sema III. These results identify neuropilins as a family of receptors (or components of receptors) for at least one semaphorin subfamily. They also suggest that the specificity of action of different members of this subfamily may be determined by the complement of neuropilins expressed by responsive cells.

Animals↗
PubMed2001

Differential expression of neuropilin-1 and neuropilin-2 in arteries and veins.

Neuropilin-1 (np1) and neuropilin-2 (np2) are receptors for class-3 semaphorins and for several isoforms of VEGF. We have cloned and characterized two chick isoforms of np2 cDNA. Expression patterns of np1, np2, and ephrin-B2 were compared in the developing vascular system of 24-72 h old chick embryos. We show for the first time that np2 is expressed in blood vessels in vivo from the earliest stages of their formation. In contrast to ephrin-B2, both np1 and np2 are expressed in blood islands of 24 h old chick embryos. At 48-72 h, np1 expression is localized preferentially in arteries with an expression pattern that resembles that of ephrin-B2. In contrast, np2 is expressed preferentially in veins. Thus, neuropilins may play a role in determining the arterial or venous identity of blood vessels.

Amino Acid Sequence↗
PubMed2001

Differential expression and regulation of the vascular endothelial growth factor receptors neuropilin-1 and neuropilin-2 in rat uterus.

Vascular endothelial growth factor (VEGF) is a potent modulator of vascular remodeling and angiogenesis in the uterus. Recently, neuropilins (Npn), semaphorin receptors associated with neuronal guidance, were demonstrated to bind VEGF isoforms with high affinity, facilitating VEGF(165) binding to the tyrosine kinase receptor VEGFR2. The current studies examined rat uterus neuropilin expression and regulation. Npn-1 and Npn-2 transcripts and 135-kDa proteins were observed in uterine extracts. Both uterine vascular endothelial cells and glandular epithelium expressed Npn-1 immunoreactivity, whereas Npn-2 was restricted to the glandular epithelium. In hormone-replaced ovariectomized animals, progesterone increased uterine 6.5-kb Npn-1 messenger RNA (mRNA) expression approximately 2-fold compared with that in tissues from ovariectomized controls. 17ss-Estradiol alone had no effect, but blunted the progesterone response; by contrast, Npn-2 mRNA expression was decreased by estrogen. VEGFR2 mRNA was coregulated with Npn-1. Consistent with these results, Npn-1 mRNA expression was augmented nearly 7- and 4-fold at metestrus and diestrus, respectively, during periods of high progesterone; Npn-2 mRNA expression was not significantly altered during the estrous cycle. The regulated expression and differential localization of neuropilins in the rat uterus suggest that these receptors may participate in hormonally regulated changes occurring throughout the female reproductive cycle.

Animals↗
PubMed2004

Expression and mapping of duplicate neuropilin-1 and neuropilin-2 genes in developing zebrafish.

Previously, we described the isolation and characterization of the first zebrafish neuropilin gene, which we now call nrp1a, and found its protein to be a mediator of vascular endothelial growth factor (VEGF)-dependent angiogenesis [Proc. Natl Acad. Sci. USA 99 (2002) 10470]. Subsequently, we have isolated three other full-length neuropilin genes (nrp1b, nrp2a, and nrp2b) and find that they map to independent zebrafish linkage groups. The nrp1s and nrp2s had differential spatio-temporal gene expression profiles with nrp1a being most prominent in the gut, brain, retina, hypochord, motorneurons, fin bud and mandibular cartilage, nrp1b in the brain, dorsal aorta, melanophores, ventral fin, and heart, nrp2a in the brain, retina, heart, and caudal vessels, and nrp2b in the brain, retina, gut, fin bud, melanophores, heart, and caudal vessels. In addition, we have identified an alternatively-spliced transcript of the nrp1b gene (denoted as nrp1b(s)) which is predicted to encode a soluble form of Nrp1b, containing only the a, b, and c extracellular domains. Transcript expression of nrp1b(s) was different from full-length nrp1b transcript, with prominence in the brain, developing mouth, heart, and fin bud. The NRP1s were tested for VEGF-binding ability. Both 125 kDa Nrp1a and 145 kDa Nrp1b bound 125I-labelled VEGFA165. In summary, two nrp1 and two nrp2 genes, with expression patterns similar to higher vertebrates, have been isolated from zebrafish.

Alternative Splicing↗
PubMed2000

Genomic organization of human neuropilin-1 and neuropilin-2 genes: identification and distribution of splice variants and soluble isoforms.

Neuropilin-1 (NRP1) and neuropilin-2 (NRP2) are both receptors for semaphorins, which regulate neuronal guidance, and vascular endothelial growth factor (VEGF), an angiogenic factor. The two human NRP1 and NRP2 genes were cloned, and the exon-intron boundaries were determined. The NRP1 and NRP2 genes span over 120 and 112 kb, respectively, and are composed of 17 exons. Five of the exons are identical in size in the two genes, suggesting that they arose by gene duplication. Both NRP genes are characterized by multiple alternatively spliced variants. Two NRP2 isoforms, NRP2a and NRP2b, were cloned. A striking feature of these two isoforms is that they have identical extracellular domains but have divergent transmembrane and cytoplasmic domains. In these domains, NRP2a is closer in sequence identity to NRP1 than to NRP2b. As determined by Northern blot analysis, both NRP2a and NRP2b are expressed in a variety of tissues, mostly in a nonoverlapping manner. Within NRP2a and NRP2b, there are several alternatively spliced species: NRP2a(17), NRP2a(22), NRP2b(0), and NRP2b(5). In addition to full-length NRPs, there are truncated NRPs as well, which contain only the extracellular a/CUB and b/coagulation factor domains. These genes encode proteins that are soluble (sNRP) and released by cells. In addition to s12NRP1, which was previously cloned, s11NRP1 and s9NRP2 have now been cloned. These sNRP molecules are characterized by having intron-derived sequences at their C-termini. Altogether, eight NRP isoforms are described in this report. It was concluded that there are multiple NRP1 and NRP2 isoforms including intact and soluble forms. Characterization of these isoforms should help to elucidate the function of NRPs in neuronal guidance and angiogenesis.

Amino Acid Sequence↗
PubMed1998

Semaphorins A and E act as antagonists of neuropilin-1 and agonists of neuropilin-2 receptors.

Neuropilin-1 (NP-1) has been identified as a necessary component of a semaphorin D (SemD) receptor that repulses dorsal root ganglion (DRG) axons during development. SemA and SemE are related to SemD and bind to NP-1, but do not repulse DRG axons. By expressing NP-1 in retinal neurons and NP-2 in DRG neurons, we demonstrate that neuropilins are sufficient to determine the functional specificity of semaphorin responsiveness. SemA and SemE block SemD binding to NP-1 and abolish SemD repulsion in axons expressing NP-1. SemA and SemE seem to have a newly discovered protein antagonist capacity at NP-1 receptors, whereas they act as agonists at receptors containing NP-2.

Animals↗
PubMed2005

A peptide corresponding to the neuropilin-1-binding site on VEGF(165) induces apoptosis of neuropilin-1-expressing breast tumour cells.

There is increasing evidence that vascular endothelial growth factor (VEGF) has autocrine as well as paracrine functions in tumour biology. Vascular endothelial growth factor-mediated cell survival signalling occurs via the classical tyrosine kinase receptors Flt-1, KDR/Flk-1 and the more novel neuropilin (NP) receptors, NP-1 and NP-2. A 24-mer peptide, which binds to neuropilin-1, induced apoptosis of murine and human breast carcinoma cells, whereas a peptide directed against KDR had no effect. Both anti-NP1 and anti-KDR peptides induced endothelial cell apoptosis. Confocal microscopy using 5-(6)-carboxyfluorescein-labelled peptides showed that anti-NP1 bound to both tumour and endothelial cells, whereas anti-KDR bound endothelial cells only. This study demonstrates that NP-1 plays an essential role in autocrine antiapoptotic signalling by VEGF in tumour cells and that NP1-blockade induces tumour cell and endothelial cell apoptosis. Specific peptides can therefore be used to target both autocrine (tumour cells) and paracrine (endothelial cells) signalling by VEGF.

Adenocarcinoma↗
PubMed2002

Neuropilin 1 and neuropilin 2 co-expression is significantly correlated with increased vascularity and poor prognosis in nonsmall cell lung carcinoma.

BACKGROUND: Cell-retained isoforms of vascular endothelial growth factor A (VEGF-A) have been reported to play an essential role in tumor progression through stromal neovascularization in malignant solid tumors. While more than 95% of nonsmall cell lung carcinoma (NSCLC) expresses cell-retained VEGF-A isoform, the clinicopathologic implications of neuropilin (NRP), considered the specific receptor for limited types of VEGF-A isoform, are not well understood. METHODS: The authors examined NRP1 and NRP2 mRNA expression in 68 NSCLCs and 15 extraneoplastic tissues by a densitometry-assisted, semi-quantitative reverse transcription-polymerase chain reaction. The authors determined the distinct expression of NRPs using the expression level of NRPs relative by optical density to beta2-microglobulin. The authors also investigated VEGF-A isoforms, their receptors, and the clinical implications. Vascularity of NSCLC was morphologically estimated on sections immunostained with anti-CD34 antibody. RESULTS: Eleven of 15 extraneoplastic specimens showed NRP1 expression (73.3%) and 8 showed NRP2 expression (53.3%). The expression level of NRP1 or NRP2 of neoplasmic tissue was higher than that of extraneoplastic tissues (P < 0.01, Mann-Whitney U test). Fifty-five and 44 NSCLCs expressed NRP1 and NRP2, respectively. Forty patients co-expressing NRP1 and NRP2 showed significantly poorer prognosis and increased vessel counts as compared to those 28 cases without co-expression (P < 0.05, log-rank test; P < 0.05, Mann-Whitney U test). CONCLUSIONS: The co-expression of NRP1 and NRP2 genes is significantly correlated with tumor progression through neovascularization in NSCLC. These results suggest that both NRP1 and NRP2 are key molecules for stromal vascularization by cell-retained VEGF in NSCLC.

Carcinoma, Non-Small-Cell Lung↗
PubMed2001

Expressions of neuropilin-1, neuropilin-2 and semaphorin 3A mRNA in the rat brain after middle cerebral artery occlusion.

This study investigated the spatial and temporal expressions of mRNA encoding neuropilin (Npn)-1, Npn-2 and semaphorin3A (Sema3A) in the rat brain after occlusion of the middle cerebral artery (MAC) distal to the striate branches. The expression of Npn-1 mRNA was transiently upregulated in layers V and VI of the parietal cortex not entering infarction on the lesion side from 3 to 6 h after MCA occlusion. The transient up-regulation of Npn-1 mRNA expression was presumably accompanied by an increase in Npn-1 protein as shown by immunohistochemistry in combination with in situ hybridization histochemistry. Intense Npn-2 mRNA expression was noted temporarily in layer II of the parietal cortex on the lesion side from 1 to 6 h after MCA occlusion. The expression of Sema3A mRNA was upregulated in layer VI of the non-infarcted parietal cortex on the lesion side at 6 h after MCA occlusion. The above increases in mRNA expression were no longer observed at 12 h after MCA occlusion. The expressions of Npn-1, -2 and Sema3A mRNA were not detected in the ventroposterior thalamic nucleus undergoing secondary degeneration after MCA occlusion. In the infarct lesion or ischemic core, neuronal expressions of Npn-1, -2 and Sema3A disappeared by 3 days after MCA occlusion as the neurons in situ entered apoptosis or necrosis. In contrast, ED-1-positive microglia/macrophages with Npn-1 and Npn-2 mRNA were observed in the infarct lesion at 1 week after MCA occlusion. These findings suggest that the temporal up-regulation of Npn-1 and Sema 3A mRNA expressions in the non-infarcted parietal cortex on the lesion side is insufficient to induce neuronal cell death possibly because the up-regulated mRNA molecules are not fully translated and that the overexpression of Npn-1 and/or Npn-2 in the ischemic core with degenerating neurons enables activated microglial cells to contact the damaged neurons in situ for phagocytosis.

Animals↗
PubMed2002

Targeting of both mouse neuropilin-1 and neuropilin-2 genes severely impairs developmental yolk sac and embryonic angiogenesis.

Neuropilins (NP1 and NP2) are vascular endothelial growth factor (VEGF) receptors that mediate developmental and tumor angiogenesis. Transgenic mice, in which both NP1 and NP2 were targeted (NP1(-/-)NP2(-/-)) died in utero at E8.5. Their yolk sacs were totally avascular. Mice deficient for NP2 but heterozygous for NP1 (NP1(+/-)NP2(-/-)) or deficient for NP1 but heterozygous for NP2 (NP1(-/-)NP2(+/-)) were also embryonic lethal and survived to E10-E10.5. The E10 yolk sacs and embryos were easier to analyze for vascular phenotype than the fragile poorly formed 8.5 embryos. The vascular phenotypes of these E10 mice were very abnormal. The yolk sacs, although of normal size, lacked the larger collecting vessels and had less dense capillary networks. PECAM staining of yolk sac endothelial cells showed the absence of branching arteries and veins, the absence of a capillary bed, and the presence of large avascular spaces between the blood vessels. The embryos displayed blood vessels heterogeneous in size, large avascular regions in the head and trunk, and blood vessel sprouts that were unconnected. The embryos were about 50% the length of wild-type mice and had multiple hemorrhages. These double NP1/NP2 knockout mice had a more severe abnormal vascular phenotype than either NP1 or NP2 single knockouts. Their abnormal vascular phenotype resembled those of VEGF and VEGFR-2 knockouts. These results suggest that NRPs are early genes in embryonic vessel development and that both NP1 and NP2 are required.

Animals↗
PubMed2005

Neuropilin-1 suppresses tumorigenic properties in a human pancreatic adenocarcinoma cell line lacking neuropilin-1 coreceptors.

Neuropilin-1 (NRP-1) was first described as a coreceptor implicated in neuronal guidance that bound members of the semaphorin/collapsin family. NRP-1 is also expressed in endothelial cells and is believed to promote angiogenesis by acting as a coreceptor with vascular endothelial growth factor (VEGF) receptor 2. Recent studies suggest that NRP-1 can function through both a VEGF-dependent and VEGF-independent fashion. Expression of NRP-1 has been shown in many human tumors, including pancreatic adenocarcinomas. The exact role of NRP-1 in tumor cells is unknown, particularly in cells that lack the NRP-1 coreceptors VEGF receptor 2 and Plexin-A1. To discern the regulatory role(s) of NRP-1 in pancreatic adenocarcinoma that lack these coreceptors, we overexpressed both full-length NRP-1 and a deletion form of NRP-1 that does not interact with semaphorin or VEGF. Overexpression of either isoform reduced several key tumorigenic properties, including anchorage-independent cell growth and migration in vitro, and resulted in reduced tumor incidence and tumor volume in vivo. Conversely, reduction of NRP-1 expression by small interfering RNA targeting led to enhanced tumor growth. Thus, NRP-1 may play distinct growth regulatory roles in different tumor types, and altering NRP-1 expression or function may be a means of influencing the growth of pancreatic cancers.

Adenocarcinoma↗
PubMed1999

Cloning and characterization of neuropilin-1-interacting protein: a PSD-95/Dlg/ZO-1 domain-containing protein that interacts with the cytoplasmic domain of neuropilin-1.

Neuropilin-1 (Npn-1), a receptor for semaphorin III, mediates the guidance of growth cones on extending neurites. The molecular mechanism of Npn-1 signaling remains unclear. We have used a yeast two-hybrid system to isolate a protein that interacts with the cytoplasmic domain of Npn-1. This Npn-1-interacting protein (NIP) contains a central PSD-95/Dlg/ZO-1 (PDZ) domain and a C-terminal acyl carrier protein domain. The physiological interaction of Npn-1 and NIP is supported by co-immunoprecipitation of these two proteins in extracts from a heterologous expression system and from a native tissue. The C-terminal three amino acids of Npn-1 (S-E-A-COOH), which is conserved from Xenopus to human, is responsible for interaction with the PDZ domain-containing C-terminal two-thirds of NIP. NIP as well as Npn-1 are broadly expressed in mice as assayed by Northern and Western analysis. Immunohistochemistry and in situ hybridization experiments revealed that NIP expression overlaps with that of Npn-1. NIP has been independently cloned as RGS-GAIP-interacting protein (GIPC), where it was identified by virtue of its interaction with the C terminus of RGS-GAIP and suggested to participate in clathrin-coated vesicular trafficking. We suggest that NIP and GIPC may participate in regulation of Npn-1-mediated signaling as a molecular adapter that couples Npn-1 to membrane trafficking machinery in the dynamic axon growth cone.

Adaptor Proteins, Signal Transducing↗
PubMed2002

Structural and functional relation of neuropilins.

Neuropilin is a type I transmembrane protein and the molecular mass is 120 kDa. Two homologues, Neuropilin-1 and -2, are identified. The primary structure of Neuropilin-1 and Neuropilin-2 is well conserved and is divided into four domains, CUB (a1/a2) domain, FV/FVIII (b1/b2) domain, MAM (c) domain, and (d) domain that contains a transmembrane and a short cytoplasmic region. Both Neuropilin-1 and Neuropilin-2 have truncated and secreted form of splice variants. Neuropilins act as a receptor for two different extracellular ligands, class 3 semaphorins and specific isoforms of vascular endothelial growth factor. In both cases, neuropilin requires an additional transmembrane molecule to exhibit biological activity. Plexin-A is essential for class 3 semaphorin signaling. Vascular endothelial cell growth factor (VEGF) receptor is the major receptor for VEGF and neuropilin acts as isoform specific co-receptor for VEGF. The CUB and FV/FVIII domains of Neuropilin are the binding sites of semaphorin and VEGF. The MAM domain mediates semaphorin signaling to Plexin-A. Cross talk between semaphorin and VEGF on neuropilin suggests that class 3 semaphorins and the secreted forms of neuropilin act as antagonists to VEGF and its related growth factors.

Animals↗
PubMed1995

Expression of a cell adhesion molecule, neuropilin, in the developing chick nervous system.

Neuropilin (previously known as the A5 protein) is a membrane protein identified in Xenopus and is presumed to be involved in the target recognition of the optic nerve fibers. We have isolated cDNAs encoding the chick homologue of neuropilin, using the Xenopus neuropilin cDNA as a hybridization probe. The predicted amino acid sequence of chick neuropilin is 75% identical to that of the Xenopus homologue. A cell aggregation assay showed that fibroblasts transfected with the chick neuropilin cDNA acquired cell adhesiveness. This adhesion is mediated by a heterophilic interaction between neuropilin and protease-sensitive molecules on fibroblasts. The expression of chick neuropilin is restricted to certain neuronal circuits and is dynamically regulated during development, as is the Xenopus homologue. However, their expression patterns differed significantly in the visual systems between the two species: In the chick optic tectum, the localization of neuropilin is confined to layers d and e of SGFS, two of the six layers receiving the retinal input; the chick optic nerve fibers do not express neuropilin; in the chick retina, amacrine cells transiently express neuropilin. Cultured neurons of the dorsal root ganglia express chick neuropilin on their neurites including growth cones. These results suggests that neuropilin functions as a cell adhesion molecule during the formation of certain neuronal circuits in vivo.

3T3 Cells↗
PubMedDate not supplied

Vascular endothelial growth factor (VEGF) receptor neuropilin-1's distribution in astrocytic tumors.

Neuropilin-1 is a VEGF165- and semaphorin receptor expressed by endothelial cells and tumor cells. The specific function of neuropilin-1 is not fully known, but in the developing nervous system neuropilin, as a semaphorin receptor, has been shown to influence neuronal guidance. The expression of neuropilin-1 was studied in low-grade and high-grade astrocytic tumors, the latter characterized by extensive angiogenesis. We examined 20 low-grade astrocytomas (WHO grade II) and 46 glioblastomas (WHO grade IV) immunohistochemically for neuropilin-1, p53 and EGFR. The glioblastomas were according to the p53 and EGFR expression classified as 35 primary--de novo--glioblastomas, 9 secondary glioblastomas, and 2 uncertain cases. Furthermore, the presence of mast cells was evaluated to search for any potential function in angiogenesis. The glioblastomas expressed neuropilin-1 in the endothelial cells of the proliferating vessels and the majority of the glioblastomas had immunoreactive neoplastic astrocytes, with no difference between the glioblastoma subgroups. Six out of twenty of the low-grade astrocytomas were negative in the endothelial cells and 8 out of 20 in the tumor cells for neuropilin-1. Mast cells were observed in the collagen matrix around larger vessels in the leptomeninges, but not adjacent to malignant tumor vessels or as part of the tumor process itself. Increased expression of neuropilin-1 is shown in endothelial cells and in neoplastic astrocytes of glioblastomas. Less neuropilin-1 expression is found in about half of the low-grade astrocytomas in both neoplastic astrocytes and endothelial cells. The results suggest a correlation between neuropilin-1 and vascularity in human astrocytic tumors and a possible role for neuropilin-1 as a receptor for VEGF-induced angiogenesis.

Astrocytoma↗