Vascular Endothelial Growth Factor Variants Research Articles

Genetic variations of VEGF gene were associated with tetralogy of fallot risk in a Chinese Han population.

Tetralogy of Fallot (TOF) is one of the most common forms of congenital heart disease. In this study, we aimed at investigating the associations between genetic variations of vascular endothelial growth factor (VEGF) gene and the risk of TOF in a Chinese Han population. Our findings may contribute to a deeper understanding of TOF pathogenesis and better diagnostic and therapeutic suggestions. A total of 165 TOF patients and 240 controls from a Chinese Han population in Shenyang and Harbin were recruited in the current study. Nine single-nucleotide polymorphisms (SNPs) (-2578C/A, -460T/C, -1154G/A, -634G/C, 534C/T, +398G/A, +963C/T, 752C/T, 913G/A) were genotyped by the MALDI-TOF MassARRAY system. Individual SNPs as well as their haplotypes were analyzed for their associations with TOF risk, using odds ratios and the 95% confidence interval under codominant and dominant models. In the single SNP analyses, the mutant homozygous genotypes of -2578C/A (rs699947) and +963C/T (rs3025039) were related with an increased risk of TOF. In addition, carriers with the mutant A allele of -1154G/A (rs1570360) were supposed to have a significantly elevated TOF risk. Similarly, compared with the wild homozygote GG carriers, the GC carrier of -634G/C (rs2010963) revealed a significant relationship with susceptibility of TOF, but not for the mutant homozygote CC carriers. However, no significant association was found for the other five SNPs. Meanwhile, haplotype analysis revealed that CCA and ATA in block 1 (-2578C/A, -460T/C, and -1154G/A) and TTG and TCA in block 3 (+963C/T, 752C/T, and 913G/A) were significantly related with an increased TOF risk compared with the most common haplotypes. In summary, our results suggested that VEGF variants (-2578C/A, -1154G/A, -634G/C, +963G/A) were involved in the susceptibility of TOF. However, validation of our study needs further study in various ethnics to reveal the functional relationship between VEGF polymorphisms and TOF risk, which may contribute to diagnosis and therapy of TOF.

Response to letter to the Editor from Dr. Carbillon on our article about first pregnancy characteristics, genetics, and breast density

My co-authors and I would like to thank Dr. Carbillon for his comments on our article about first pregnancy characteristics, genetics, and breast density. We found a modification in the association between pregnancy induced hypertension (PIH) and breast density (measured as percent fibroglandular volume, or %FGV) by specific vascular endothelial growth factor (VEGF) (rs3025039) and insulinlike growth factor receptor-1 (IGFR1) (rs2016347) gene variants. We appreciate the additional detail Dr. Carbillon added to the discussion of PIH, VEGF, and the risk of breast cancer. The various lines of evidence pointing to the potential role of VEGF and an elevated anti-angiogenic response in the pathophysiology of breast cancer merit additional focused research. Replication of our findings of an interaction between inherited IGFR and VEGF gene variants in other populations would bolster confidence in the overall association, and indeed such studies are being planned. In addition, molecular studies examining the distribution of VEGF and IGFR1 gene variants associated with protein expression levels in women with a known history of PIH, prior breast density measurements, and subsequent diagnosis of specific breast cancer subtypes would be most informative and would help further advance our understanding of the mechanistic interaction of these risk factors.

Unusual angiogenic factor plays a role in lizard pregnancy but is not unique to viviparity.

Angiogenesis (blood vessel growth), a key process of mammalian pregnancy, facilitates gas exchange and nutrient transport between the mother and the embryo and is regulated by a suite of growth factors. Vascular endothelial growth factor (VEGF) is crucial to this process in pregnant mammals and potentially pregnant squamates (lizards and snakes), as we investigate here. VEGF111 , an unusual and potent angiogenic splice variant of VEGF, increases its expression during pregnancy in the uterus of a viviparous lizard, in parallel with similar increases in uterine angiogenesis during gestation. However, we also find that VEGF111 is expressed in oviparous skinks, and is not ubiquitous among viviparous skinks. Thus, different mechanisms of uterine angiogenesis during pregnancy may evolve concurrent with viviparity in different lizard lineages.

VEGF Splicing and the Role of VEGF Splice Variants: From Physiological-Pathological Conditions to Specific Pre-mRNA Splicing.

During this past decade, the vascular endothelial growth factor (VEGF) pathway has been extensively studied. VEGF is a paradigm of molecular regulation since its expression is controlled at all possible steps including transcription, mRNA stability, translation, and pre-mRNA splicing. The latter form of molecular regulation is probably the least studied. This field has been neglected; yet different forms of VEGF with different sizes and different physiological properties issued from alternative splicing have been described a long time ago. Recently a new level of complexity was added to the field of splicing of VEGF pre-mRNA. Whereas thousands of publications have described VEGF as a pro-angiogenic factor, an alternative splicing event generates specific anti-angiogenic forms of VEGF that only differ from the others by a modification in the last six amino acids of the protein. According to the scientists who discovered these isoforms, which are indistinguishable from the pro-angiogenic ones with pan VEGF antibodies, some of the literature on VEGF is at least inexact if not completely false. Moreover, the presence of anti-angiogenic forms of VEGF may explain the disappointing efficacy of anti-VEGF therapies on the overall survival of patients with different forms of cancers and with wet age-related macular degeneration. This review focuses on the existence of the different alternative splice variants of VEGF and the molecular mechanisms associated with their expression and function.

Relationship of common vascular endothelial growth factor polymorphisms and haplotypes with the risk of cervical cancer in Tunisians

ObjectiveWe investigated the association between common vascular endothelial growth factor (VEGF) single nucleotide polymorphisms (SNPs) and the risk of cervical cancer (CC) in Tunisian patients and control women. MethodsStudy subjects comprised 86 CC cases and 124 control women. Genotyping of VEGF rs699947, rs833061, rs1570360, rs2010963, rs25648, rs833068, rs833070, rs3025039 SNPs was done by real-time PCR. ResultsHigher minor allele frequencies (MAF) of rs699947 (−2578C/A) [P=0.04; OR (95% CI)=1.52 (1.02–2.29)], and rs1570360 (−1154G/A) [P=0.04; OR (95% CI)=1.58 (1.01–2.47)] were seen in CC cases compared to control women. Marked differences in the distribution of rs699947 (P=9×10−4) and rs1570360 (P=0.03) genotypes were seen between CC cases and control groups; the distribution of the remaining SNPs was comparable between CC cases and control women. The association of rs699947 and rs1570360 with heightened CC risk with was seen in the heterozygous, and more so in the homozygous states. Haploview analysis revealed high LD between rs699947, rs833061, rs1570360, rs2010963, rs25648, rs833068 and rs833070 but weak or no LD between rs3025039 and the other SNPs. Seven-locus (rs699947/rs833061/rs1570360/rs2010963/rs25648/rs833068/ rs833070) haploview analysis identified only CTGCCAG haplotype to be positively associated with CC [P=0.022; OR(95% CI)=1.74 (1.08–2.79)]. ConclusionSpecific VEGF variants (rs699947, rs1570360) and haplotype (CTGCCAG) may contribute to the development of CC among Tunisian women.

Development of a highly-potent anti-angiogenic VEGF8-109 heterodimer by directed blocking of its VEGFR-2 binding site.

Angiogenesis is a hallmark of various pathological conditions and is controlled by a variety of angiogenic factors. Blockade of vascular endothelial growth factor (VEGF) as the most pivotal stimulator of angiogenesis offers a promising therapeutic approach for some diseases, typically cancer. In the present study, a heterodimeric antagonistic VEGF was precisely designed based on structural information of recently-crystallized VEGF/VEGF receptor-2 (VEGFR-2/fetal liver kinase 1/kinase domain region) complex. Directed blocking of kinase domain region occurs via substitution of a VEGF receptor binding site by two peptide segments in one pole, whereas the binding domain of the other pole of VEGF was intact. Candidate peptides for substitution were selected considering to some sequence and structural criteria. A reliable model of modified VEGF was built, refined using molecular dynamics simulation and docked with VEGFR-2. Docking analysis revealed that binding affinity of mutant VEGF was notably diminished, corroborating our design. Heterodimeric VEGF was expressed, refolded and highly purified by two-step affinity chromatography. Dimerization of this antagonist was confirmed using some analytical techniques. Spectroscopic studies assured us to obtain the heterodimeric form of VEGF. Some angiogenic in vitro assays such endothelial cell proliferation and tube formation indicated that this antagonist is not only strongly capable of inhibiting angiogenesis (half maximal inhibitory concentration of 33 and 24 ng · mL(-1) , respectively), but also showed the highest inhibitory effect compared to all other heterodimeric VEGF variants. The high anti-angiogenic potency of this VEGF antagonist may allow its future use as an anti-tumor agent.

Association of vascular endothelial growth factor – A gene polymorphisms and haplotypes with breast cancer metastases

Background. Vascular endothelial growth factor (VEGF-A) is a key regulator of tumor-induced angiogenesis and essential for tumor growth and distant tumor spread. The aim of the present study was to evaluate the role of VEGF-A polymorphisms and haplotypes for metastatic progression in breast cancer patients.Material and methods. We performed a prospective study including 801 breast cancer patients. Occurrence of metastases was examined in regular follow-up investigations. Seven VEGF-A polymorphisms were selected and determined by 5′-nuclease assays (TaqMan). The selection of VEGF-A variants was based upon their location (promoter or UTR) as well as a minor allele frequency of at least 0.10. Haplotypes and linkage disequilibrium were determined using the Haploview program.Results. Within a median follow-up time of 84 months, 165 (21%) patients developed distant metastases. In univariate analysis, carriers of the CCCCC haplotype formed by five polymorphisms upstream the coding region were at decreased risk of distant metastases [hazard ratio (HR) = 0.743; 95% CI 0.579–0.953; p = 0.019]. Univariate analysis also revealed a decreased risk of distant metastases for postmenopausal patients carrying the -634G> C polymorphism (HR 0.704; 95% CI 0.514–0.965; p = 0.029) and the CCCCC haplotype (HR = 0.645; 95% CI 0.464–0.898; p = 0.009). After adjustment for other co-variates, the HR for distant metastases was 0.651 (95% CI 0.447–0.948) for postmenopausal carriers of the -634G> C polymorphism (p = 0.025; corrected p-value = 0.262), and 0.586 (95% CI 0.393–0.873) for postmenopausal patients with the CCCCC haplotype (p = 0.009, corrected p-value = 0.189).Conclusion. The results from univariate and multivariate analyses suggest an influence of VEGF-A gene variants on the development of distant metastases in breast cancer patients. However, none of the observed associations reached statistical significance after correction for the effects of multiple testing. Additional prospective and sufficiently powered studies are essential before firm conclusions about the role of VEGF-A gene variants for distant progression in breast cancer can be drawn.

First pregnancy events and future breast density: modification by age at first pregnancy and specific VEGF and IGF1R gene variants.

Purpose Pregnancy characteristics have been associated with breast cancer risk, but information is limited on their relationship with breast density. Our objective was to examine the relationship between first pregnancy characteristics and later life breast density, and whether the association is modified by genotype.Methods The Marin Women’s Study was initiated to examine breast cancer in a high-incidence mammography population (Marin County, CA). Reproductive characteristics and pregnancy information including pregnancy-induced hypertension (PIH) were self-reported at the time of mammography. Forty-seven candidate single nucleotide polymorphisms were obtained from saliva samples; seven were assessed in relation to PIH and percent fibroglandular volume (%FGV). Breast density assessed as %FGV was measured on full-field digital mammograms by the San Francisco Mammography Registry.ResultsA multivariable regression model including 2,440 parous women showed that PIH during first pregnancy was associated with a statistically significant decrease in %FGV (b = −0.31, 95 % CI −0.52, −0.11), while each month of breast-feeding after first birth was associated with a statistically significant increase in %FGV (b = 0.01, 95 % CI 0.003, 0.02). PIH and breast-feeding associations with %FGV were modified by age at first birth. In a subsample of 1,240 women, there was evidence of modification in the association between PIH and %FGV by specific vascular endothelial growth factor (VEGF) (rs3025039) and insulin growth factor receptor-1 (IGFR1) (rs2016347) gene variants.ConclusionThese findings suggest that first pregnancy characteristics may exert an influence on extent of breast density later in life and that this influence may vary depending on inherited IGFR1 and VEGF genotypes.Electronic supplementary materialThe online version of this article (doi:10.1007/s10552-014-0386-2) contains supplementary material, which is available to authorized users.

Abstract 544: Nrp-1+Foxp3-CD4 T Cells Are a Novel Subset of T Lymphocytes that Are Induced in Aorta During Development of Atherosclerosis

Neuropilin 1 (Nrp-1) is a type I transmembrane protein that plays an important role in axonal guidance and neuronal development as well as vascular sprouting and angiogenesis through the interaction with Semaphorin-3A and vascular endothelial growth factor (VEGF), respectively. Recently, Nrp-1 was found on a subset of thymus-derived regulatory T cells (Treg) that migrated into VEGF producing tumors. Moreover, Nrp-1+ CD4 T cells were protective in a murine experimental model of autoimmune encephalomyelitis, suggesting that these cells may have a participating role in other inflammatory diseases. Since atherosclerosis is a chronic inflammatory disease where T cells, macrophages, and other immune cells orchestrate disease progression, we hypothesized that Nrp-1+ CD4 T cells are induced in the aorta during atherosclerosis development and play a role during disease progression. We fed ApoE-/- mice a western diet for 15 weeks and found a 2-fold increase in Nrp-1+Foxp3- CD4 T cells in the spleens, peri-aortic lymph nodes and aortas of western diet fed mice compared to chow-fed mice. In addition, these Nrp-1+Foxp3- CD4 T cells expressed higher levels of the memory marker CD44 and produced more IFNγ when compared to Nrp-1- CD4 T cells, suggesting that these cells are more activated. Treatment of CD4 T cells with oxidized LDL (OxLDL), but not minimally modified LDL (mmLDL), oxidized cholesterol ester (OxCE) or oxidized phospholipids (POVPC), caused upregulation of Nrp-1 on CD4 T cells. Using a transwell migration assay, we found that Nrp1+ CD4 T cells had a 2-fold higher migration index towards VEGF165, a splice variant of VEGF, than did Nrp1- CD4 T cells; thus this migration was dependent on Nrp-1 expression. Similarly, CD4 T cells from ApoE-/- mice fed a western diet, which expressed more Nrp-1, had a higher migration index towards VEGF165 compared to cells from chow controls. In conclusion, we have identified a novel subset of Nrp-1+CD4+ T lymphocytes that is increased during atherosclerosis development, and is induced by OxLDL. Our data suggest that Nrp-1 may play a role in the migration of CD4 T cells to the aorta during atherosclerosis development.

Positive association between vascular endothelial growth factor (VEGF) -2578 C/A variant and prostate cancer

Vascular endothelial growth factor (VEGF) gene is an important angiogenesis regulator related to cancer development and progression. We evaluated the association between -2578 C/A (rs699947) VEGF polymorphism and PCa in Mexican subjects, to contribute to knowledge of VEGF role in genetic epidemiology of prostate cancer (PCa). The aim of this study was to evaluate the association between -2578 C/A VEGF variant and PCa in Mexican population. A total of 249 men (77 PCa cases and 172 controls) from the Northwestern region of Mexico were screened for the -2578 C/A VEGF variant. The polymorphism was determined by polymerase chain reaction-based restriction analysis. Genotype frequencies for C/C, C/A, and A/A, were 0.48, 0.49, 0.03 for cases and 0.41, 0.45, 0.14 for controls respectively. Genotype A/A of -2578 VEGF variant reduces the risk of PCa in an 84% among studied population (Odds Ratio 0.16; 95% CI: 0.04-0.71, P=0.007). C/C carriers showed an increased PCa risk of 6.1 times among the study population. Inheritance of -2578 A/A genotype of VEGF gene may modify PCa susceptibility risk in Mexican population.

The role of genetic polymorphisms at the chromosomes 5p15, 6p12, 6p21 and 15q25 in non-small-cell lung cancer prognosis: a Portuguese prospective study

Genome Wide Association Study (GWAS) variants on chromosome 15q25 and 5p15 and genetic polymorphisms on the vascular endothelial growth factor (VEGF) gene showed that they may contribute to lung carcinogenesis. Therefore, this study was performed in order to assess the role of GWAS, and VEGF variants in non-small-cell lung cancer (NSCLC) prognosis.

Enhanced secretion of biologically active, non-glycosylated VEGF from Saccharomyces cerevisiae

Vascular endothelial growth factor (VEGF) mediates angiogenesis, which plays a critical role in the development and differentiation of the vascular system. VEGF is a homodimeric glycoprotein that contains one N-glycosylation site. In this study, we evaluated Saccharomyces cerevisiae expression systems producing glycosylated and non-glycosylated splice variants of human VEGF, VEGF121, and VEGF165. The pre region of the mating factor α1 (MFα1) signal sequence was found to perform better than the entire MFα1 prepro signal sequence in secreting glycosylated VEGF. Secretion of non-glycosylated VEGF165 was completely blocked, indicating the importance of glycosylation in VEGF165 secretion. Interestingly, non-glycosylated VEGF165 was secreted when guided by the MFα1 prepro signal sequence, albeit to a lesser degree, compared to glycosylated VEGF165. N-glycosylation in the pro region was required for the prepro sequence to promote VEGF secretion. Furthermore, substitution of asparagine at the VEGF glycosylation site with lysine or glutamic acid increased secretion of non-glycosylated VEGF, a finding not previously reported. Our findings suggest that S. cerevisiae could be a suitable host for secreting biologically active, non-glycosylated VEGF for clinical use.

The relation of vascular endothelial growth factor (VEGF) gene polymorphisms on VEGF levels and the risk of vasoocclusive crisis in sickle cell disease

The association of vascular endothelial growth factor (VEGFA) variants and VEGF secretion with sickle cell disease (SCD) vasoocclusive crisis (VOC) was investigated in 210 VOC patients and 114 pain-free control patients. VEGFA -2578C/A (rs699947), -460T/C (rs833061), -1154G/A (rs15703060), -634G/C (rs2010963), 398G/A (rs833068), 497G/A (rs833070), -583T/C (rs3025020), and 936C/T (rs3025039) were carried out by real-time PCR. Higher frequency of rs2010963 C-allele, rs833068 A-allele, and rs3025020 C-allele and significant differences in rs2010963, rs833068, and rs3025020 genotype distribution were seen in VOC than steady-state patients. Increased VOC risk was seen with rs2010963 as heterozygous and more as homozygous, and in rs833068 and rs3025020 homozygous carriers. While there were no differences in VEGF levels between VOC and steady-state controls, there was a progressive decline in serum VEGF in rs2010963 and rs833068 heterozygous and homozygous genotypes, but an opposite trend was seen in VOC patients. Haploview analysis revealed high LD between rs699947, rs833061, rs1570360, rs2010963, rs833068, and rs833070, but weak or no LD between rs3025020 and rs3025039 and other SNPs. Six-locus (rs699947/rs833061/rs1570360/rs2010963/rs833068/rs833070) VEGFA haplotype analysis identified haplotype 111111 to be negatively (OR = 0.68) and haplotype 111222 to be positively (OR = 1.89) associated with VOC. rs2010963, rs833068, and rs3025020 were correlated with VOC type, while rs3025020 was correlated with hospitalization, VOC treatment, and duration. Specific VEGFA variants contribute to the pathogenesis of SCD VOC.

VEGF Spliced Variants: Possible Role of Anti-Angiogenesis Therapy

Angiogenesis has been targeted in retinopathies, psoriasis, and a variety of cancers (colon, breast, lung, and kidney). Among these tumour types, clear cell renal cell carcinomas (RCCs) are the most vascularized tumours due to mutations of the von Hippel Lindau gene resulting in HIF-1 alpha stabilisation and overexpression of Vascular Endothelial Growth Factor (VEGF). Surgical nephrectomy remains the most efficient curative treatment for patients with noninvasive disease, while VEGF targeting has resulted in varying degrees of success for treating metastatic disease. VEGF pre-mRNA undergoes alternative splicing generating pro-angiogenic isoforms. However, the recent identification of novel splice variants of VEGF with anti-angiogenic properties has provided some insight for the lack of current treatment efficacy. Here we discuss an explanation for the relapse to anti-angiogenesis treatment as being due to either an initial or acquired resistance to the therapy. We also discuss targeting angiogenesis via SR (serine/arginine-rich) proteins implicated in VEGF splicing.

Dynamics of a Heparin-Binding Domain of VEGF165 Complexed with Its Inhibitor Triamterene

Vascular endothelial growth factor (VEGF), which has neurotrophic and neuroprotective effects in addition to its major role in angiogenesis, interacts with Aβ and accumulates in the senile plaques of Alzheimer's disease (AD) patients' brains. It is known that Aβ binds to the heparin-binding domain (HBD) of the 165-amino acid VEGF variant, VEGF(165). In this study, we showed that triamterene (Trm) inhibits VEGF--Aβ interaction without affecting other biological activities of VEGF or Aβ. We investigated the importance of structural and dynamic features of HBD for its molecular-recognition processes. The binding model of HBD and Trm was constructed based on measurements of chemical shift changes and docking study. The results showed that the loop region (S11-L17) and F18 at the beginning of the first β-sheet in the HBD constitute the inhibitor binding site. The N1 atom of pteridine ring of Trm forms hydrogen bonding with backbone amide proton of R13, and the phenyl ring took part in a hydrophobic interaction with the aromatic ring of F18. To investigate the functional importance of the inherent structural flexibility of the HBD in VEGF, the dynamic properties of free HBD and HBD--Trm complex were assessed by measuring spin relaxation rates, and the backbone dynamics were investigated by model-free analysis. The residues in the disordered loop region of the N-terminus exhibited conformational exchanges in free HBD, and flexibility of this loop region decreased dramatically upon binding to Trm, suggesting that Aβ as well as inhibitor may recognize these unique dynamic features of the HBD. Furthermore, C-terminal residues continued to exhibit slow conformational motions, even in the HBD--Trm complex, implying that these motions at the C-terminus of the HBD might be important for interactions with heparin molecules. The flexibility of HBD demonstrated here should be essential for VEGF function and interaction with other protein partners.

Vascular Endothelial Growth Factor Gene Polymorphisms and Risk of Cervical Intraepithelial Neoplasia

To evaluate the association between 3 vascular endothelial growth factor (VEGF) gene polymorphisms and susceptibility of cervical intraepithelial neoplasia (CIN). This prospectively collected case-control study investigates three common VEGF gene polymorphisms (ie, VEGF -460 [rs833061], VEGF +405 [rs2010963], and VEGF +936 [rs3025039]) in 203 women with CIN and 209 healthy women by DNA pyrosequencing. Associations between polymorphisms and CIN risk are evaluated with univariate and multivariable models and haplotype analysis. In a multivariable regression model, the variant VEGF +405C allele was associated (odds ratio [OR], 2.5; 95% confidence interval [CI], 1.2-5.1], P = 0.02) with increased susceptibility of CIN independent of number of sexual partners (OR, 2.2; 95% CI, 1.1-4.6; P = 0.03) and smoking (OR, 3.3; 95% CI, 1.6-6.6; P = 0.001). The haplotype VEGF -460C - +405C - +936C was associated with an OR of 5.2 (95% CI, 1.2-52.7) for the susceptibility of CIN. The presence of the variant VEGF +405C allele and the haplotype VEGF -460C - +405C - +936C are independently associated with higher susceptibility of CIN.

Association of Genetic Variants of VEGF gene with Gastric Carcinoma Risk

To date, few association analyses with regard to gene variants and expression of vascular endothelial growth factor (VEGF) in gastric carcinoma (GC) have been reported. We hypothesized the variants might also affect susceptibility to GC. To evaluate the correlation of VEGF variants with risk and clinicopathological characteristics of this disease in China, we detected fourteen single nucleotide polymorphisms (SNPs) of VEGF gene in 311 patients with gastric carcinoma and 425 age and gender-matched controls by using Sequenom iplex. We investigated expression of VEGF in combination with cyclooxygenase-2 (COX-2) in 238 tissues samples of the cases by tissue microarray (TMA) and immunohistochemistry (IHC). There were no significant differences in genotype, allele and haplotype distributions of the 14 VEGF SNPs between the cases and the controls. However, we found that there were significant clinicopathological correlations of the rs3024994C/T with gender, the rs3025021C/T with tumor size, the rs3025039C/T with tobacco smoking, the rs3025030G/C with tumor location, tobacco smoking and alcohol drinking (P<0.05, respectively). A/A genotype (P=0.050, OR=0.39, 95%CI=0.15-1.00) and A allele (P=0.024, OR=0.64, 95%CI=0.43-0.94) of the rs833052 significantly reduced the VEGF expression and T allele of the rs3025007 increased the VEGF expression (P=0.017, OR=1.70, 95%CI=1.10-2.61) when compared to the C allele of both the variants, respectively. The VEGF expression displayed a significant association with COX-2 (rs= 0.178, P=0.006). We concluded that none of the 14 SNPs of VEGF gene was significantly associated with the susceptibility to GC. Both VEGF and COX-2 showed close correlations with invasion and progression in advanced GC.

Isolation of a novel neutralizing antibody fragment against human vascular endothelial growth factor from a phage-displayed human antibody repertoire using an epitope disturbing strategy

Following the clinical success of Bevacizumab, a humanized monoclonal antibody that blocks the interaction between vascular endothelial growth factor (VEGF) and its receptors, the search for new neutralizing antibodies targeting this molecule has continued until now. We used a human VEGF variant containing three mutations in the region recognized by Bevacizumab to direct antibody selection towards recognition of other epitopes. A total of seven phage-displayed antibody fragments with diverse binding properties in terms of inter-species cross-reactivity and sensitivity to chemical modifications of the antigen were obtained from a human phage display library. All of them were able to recognize not only the selector mutated antigen, but also native VEGF. One of these phage-displayed antibody fragments, denominated 2H1, was shown to compete with the VEGF receptor 2 for VEGF binding. Purified soluble 2H1 inhibited in a dose dependent manner the ligand–receptor interaction and abolished VEGF-dependent proliferation of human umbilical vein endothelial cells. Our epitope disturbing strategy based on a triple mutant target antigen was successful to focus selection on epitopes different from a known one. Similar approaches could be used to direct phage isolation towards the desired specificity in other antigenic systems.

Safety and Efficacy of Ranibizumab in Diabetic Macular Edema (RESOLVE Study)

OBJECTIVEThe expression of vascular endothelial growth factor (VEGF) is elevated in diabetic macular edema (DME). Ranibizumab binds to and inhibits multiple VEGF variants. We investigated the safety and efficacy of ranibizumab in DME involving the foveal center.RESEARCH DESIGN AND METHODSThis was a 12-month, multicenter, sham-controlled, double-masked study with eyes (age >18 years, type 1 or 2 diabetes, central retinal thickness [CRT] ≥300 μm, and best corrected visual acuity [BCVA] of 73–39 ETDRS letters [Early Treatment Diabetic Retinopathy Study]) randomly assigned to intravitreal ranibizumab (0.3 or 0.5 mg; n = 51 each) or sham (n = 49). The treatment schedule comprised three monthly injections, after which treatment could be stopped/reinitiated with an opportunity for rescue laser photocoagulation (protocol-defined criteria). After month 1, dose-doubling was permitted (protocol-defined criteria, injection volume increased from 0.05 to 0.1 ml and remained at 0.1 ml thereafter). Efficacy (BCVA and CRT) and safety were compared between pooled ranibizumab and sham arms using the full analysis set (n = 151, patients receiving ≥1 injection).RESULTSAt month 12, mean ± SD BCVA improved from baseline by 10.3 ± 9.1 letters with ranibizumab and declined by 1.4 ± 14.2 letters with sham (P < 0.0001). Mean CRT reduction was 194.2 ± 135.1 μm with ranibizumab and 48.4 ± 153.4 μm with sham (P < 0.0001). Gain of ≥10 letters BCVA from baseline occurred in 60.8% of ranibizumab and 18.4% of sham eyes (P < 0.0001). Safety data were consistent with previous studies of intravitreal ranibizumab.CONCLUSIONSRanibizumab is effective in improving BCVA and is well tolerated in DME. Future clinical trials are required to confirm its long-term efficacy and safety.

Butyrate increases the formation of anti-angiogenic vascular endothelial growth factor variants in human lung microvascular endothelial cells

The primary transcript of vascular endothelial growth factor (VEGF) can be alternatively spliced and translated to pro-angiogenic and anti-angiogenic VEGF variants. We investigated the effect of sodium butyrate (NaB) on pro-angiogenic and anti-angiogenic VEGF variants production in immortalized human lung microvascular endothelial cells (HLMEC). These cells were cultured in the absence or in the presence of NaB, followed by total RNA and protein isolation. The transcript and protein levels of pro-angiogenic and anti-angiogenic VEGF variants were evaluated by reverse transcription, real-time quantitative PCR and western blot analysis. We found that NaB significantly increased the anti-angiogenic transcript and protein levels of the VEGF 121b, VEGF165b and VEGF189b variants in HLMEC cells. We did not find the pro-angiogenic VEGF189a transcript variant either in control or NaB treated cells. By contrast, the pro-angiogenic VEGF121a and VEGF165a transcript variants were present in HLMEC cells, but their levels were slightly modulated in the cells treated with NaB compared to controls. Since anti-angiogenic VEGF variants inhibit angiogenesis and tumour progression, and NaB is considered an anticancer drug, our findings may have clinical significance.