Impact of VEGF gene polymorphisms in elderly cancer patients: clinical outcome and toxicity

TGF-β/VEGF-A Genetic Variants Interplay in Genetic Susceptibility to Non-Melanocytic Skin Cancer

Differential genetically determined expression of transforming growth factor-β (TGF-β pathway and of vascular endothelial growth factor-A (VEGF-A) might modulate the molecular “milieu” involved in the etio-pathogenesis of non-melanoma skin cancer (NMSC). We have evaluated the frequency of some functionally relevant SNPs of TGF-β and VEGF-A genes in 70 NMSC patients and 161 healthy controls, typed for TGF-β1 rs1800471, TGF-β2 rs900, TGF-βR1 rs334348 and rs334349, TGF-βR2 rs4522809 and VEGF-A rs3025039 SNPs. TGF-βR2 rs1800629G allele and related genotypes were found to be associated with a possible protective role against NMSC, whereas VEGF-A rs3025039T was associated with an increased risk. To evaluate the effect of genotype combinations on NMSC susceptibility, we determined the frequencies of 31 pseudo-haplotypes due to non-random linkage among alleles of loci not lying on the same chromosome. Two pseudo-haplotypes that imply a minor allele of TGF-βR2 or minor allele of VEGF-A SNPs combined with major alleles of the other SNPs were, respectively, associated with a protective effect, and susceptibility to NMSC. In addition, a pseudo-haplotype involving minor alleles of TGF-β2 rs900, TGF-βR1 rs334348 and rs4522809 SNPs might be a susceptibility marker for NMSC. In conclusion, our data suggest that a complex interplay among the genetic polymorphisms of TGF-β, TGF-β receptors and VEGF-A genes might influence the net effect of genetic background of the patients on NMSC development. This might be relevant in the risk evaluation, diagnosis and treatment of NMSC.

A microRNA binding site polymorphism in the 3' UTR region of VEGF-A gene modifies colorectal cancer risk based on ethnicity: a meta-analysis

BACKGROUND

Vascular endothelial growth factor A (VEGF-A) plays an integral role in angiogenesis by contributing to growth, development, and metastasis of solid tumors. Recently, a single-nucleotide polymorphism +936C/T located in the VEGF-A 3' untranslated region (UTR) facilitated the susceptibility of colorectal cancer. The association between VEGF-A gene polymorphism +936C/T and colorectal cancer risk has been widely studied in the last decade, but presently, the results furnished remain enigmatic. Hence, the study aimed to investigate the association between VEGF-A +936C/T miRNA binding site polymorphism and the risk of developing colorectal cancer.

METHODS

This meta-analysis included 13 published case-control studies covering 3465 cases (colorectal cancer) and 3476 healthy controls. Publication bias was examined by means of Begg's funnel plots and Egger's regression tests. The quality of the studies included was evaluated using Newcastle-Ottawa scale. Subgroup analyses were performed in accordance to the various ethnicities of the study subjects and the study quality.

RESULTS

From the data obtained, it is implied that VEGF-A +936C/T polymorphism did not correlate with elevated colorectal cancer risk in all genetic models. But the results acquired from the subgroup analysis in over dominant model (CT vs. CC + TT: OR = 1.5047, 95% CI = 1.19-1.90) suggest that VEGF-A +936C/T polymorphism leads to the raise in the risk of developing CRC among the East Asian population. No association was observed in Caucasian and South Asian population.

CONCLUSIONS

Our results indicate that VEGF-A +936C/T polymorphism is not a risk factor for developing CRC in Caucasian and South Asian population. However, the East Asian population was related to an increased risk of developing colorectal cancer due to the presence of the minor allele.

Association between single nucleotide polymorphisms of VEGF gene and pelvic lymph node metastasis in patients with early-stage cervical cancer

Cervical cancer patients in early-stage cervical cancer (ECC) were divided into pelvic lymph node (PLN) metastasis and non-PLN metastasis group. Single nucleotide polymorphism (SNP) genotyping for the VEGF gene was conducted and plasma VEGF levels were measured. Multivariate analysis was performed to assess the correlation between SNPs of the VEGF gene and PLN metastasis. We found that SNP of the VEGF rs2010963 was independently associated with PLN metastasis. GG and CG genotype had increased susceptibility to PLN metastasis compared with CC genotype, and moreover, OR was higher in GG genotype than in CG genotype. Plasma VEGF levels were lowest in CC genotype, intermediate in GC genotype and highest in GG genotype. In summary, the SNP of the VEGF rs2010963 affected susceptibility to PLN metastasis in patients with ECC, and GG and CG genotype had increased susceptibility compared with CC genotype. The potential mechanism was associated with elevated plasma VEGF levels.Impact StatementWhat is already known on this subject? The positive expression of vascular endothelial growth factor (VEGF) is correlated with higher risk of lymph node metastasis among cervical cancer patients, and VEGF levels of patients with pelvic lymph node (PLN) metastasis are significantly higher than those without PLN metastasis. Additionally, single nucleotide polymorphisms (SNPs) of the VEGF gene have been indicated to be correlated with individual susceptibility to tumours and expression and protein production of VEGF.What do the results of this study add? The SNP of the VEGF rs2010963 was independently associated with PLN metastasis in patients with early-stage cervical cancer (ECC). The GG and CG genotype of the VEGF rs2010963 had increased susceptibility to PLN metastasis compared with CC genotype. Plasma VEGF levels were lowest in the CC genotype, intermediate in the GC genotype and highest in the GG genotype.What are the implications of these findings for clinical practice and/or further research? The SNP of the VEGF rs2010963 affected susceptibility to PLN metastasis in patients with ECC, and the potential mechanism was associated with elevated plasma VEGF levels.

Genetic effects of vascular endothelial growth factor and its receptor 2 on feather maturity in three chicken breeds

1. The goal of the current study was to evaluate the genetic effects of the vascular endothelial growth factor (VEGF) and its receptor (VEGFR-2) on feather maturity in the Qingyuan partridge chicken, Guangxi sanhuang chicken and Princess chicken. 2. Both SSCP-PCR and qPCR were employed to detect the polymorphism and gene expression of the VEGF and VEGFR-2 genes. 3. Four SNPs were identified in the VEGFR-2 gene. Exon10-A69G was associated with feather maturity (P < 0.01). Princess chickens with the genotype EF had higher feather maturity scores (P < 0.01). Higher expression levels of VEGF and VEGFR-2 were detected in the immature feather group of Qingyuan partridge chickens, especially in the skin. 4. The VEGF and VEGFR-2 genes play critical roles in feather maturity. In addition, exon10-A69G and genotype EF in the Princess chicken could potentially be utilised as genetic markers to improve efficiency in breeding.

Human Plasma Levels of VEGF-A, VEGF-C, VEGF-D, their Soluble Receptor - VEGFR-2 and Applicability of these Parameters as Tumor Markers in the Diagnostics of Breast Cancer

VEGF family members are important factors in promoting angio- and lymphangiogenesis. The aim of this study was to investigate concentrations, diagnostic utility and power of VEGF-A, VEGF-C, VEGF-D and VEGFR-2 in comparison to CA15-3 in breast cancer (BC) patients. The study included 120 BC patients and 60 control patients (28 with benign breast tumors and 32 healthy women). Plasma levels of tested parameters were determined by ELISA, CA15-3 by CMIA. Concentrations of all parameters showed statistical significance when compared BC patients to controls. VEGF-D showed the highest SE (82.50%) in total BC group. Highest SP and PPV in total BC group showed VEGF-A(76.67%;84.78%,respectively), but lower than CA15-3. Highest NPV showed VEGF-C(52.33%), but it was lower than CA15-3. VEGF-C was also the best parameter which had statistically significant AUC in total cancer group (0.7672), but also stages I(0.7684) and II(0.7772). In the total group of BC almost all tested parameters showed statistically significant AUC, but a maximum range was obtained for the combination of VEGF-C + CA15-3(0.8476). The combined analysis of tested parameters and CA15-3 resulted in increase in SE and AUC values, which provides hope for developing a new panel of biomarkers that may be used in the diagnosis of BC in the future.

MicroRNA-34a: A Key Regulator in the Hallmarks of Renal Cell Carcinoma

Renal cell carcinoma (RCC) incidence has increased over the past two decades. Recent studies reported microRNAs as promising biomarkers for early cancer detection, accurate prognosis, and molecular targets for future treatment. This study aimed to evaluate the expression levels of miR-34a and 11 of its bioinformatically selected target genes and proteins to test their potential dysregulation in RCC. Quantitative real-time PCR for miR-34a and its targets; MET oncogene; gene-regulating apoptosis (TP53INP2 and DFFA); cell proliferation (E2F3); and cell differentiation (SOX2 and TGFB3) as well as immunohistochemical assay for VEGFA, TP53, Bcl2, TGFB1, and Ki67 protein expression have been performed in 85 FFPE RCC tumor specimens. Clinicopathological parameter correlation and in silico network analysis have also implicated. We found RCC tissues displayed significantly higher miR-34a expression level than their corresponding noncancerous tissues, particularly in chromophobic subtype. MET and E2F3 were significantly upregulated, while TP53INP2 and SOX2 were downregulated. ROC analysis showed high diagnostic performance of miR-34a (AUC = 0.854), MET (AUC = 0.765), and E2F3 (AUC = 0.761). The advanced pathological grade was associated with strong TGFB1, VEGFA, and Ki67 protein expression and absent Tp53 staining. These findings indicate miR-34a along with its putative target genes could play a role in RCC tumorigenesis and progression.

KRAS and VEGF gene 3'-UTR single nucleotide polymorphisms predicted susceptibility in colorectal cancer

Single nucleotide polymorphisms (SNPs) in tumor-related genes have been reported to play important roles in cancer development. Recent studies have shown that 3’-untranslated regions (UTR) polymorphisms are associated with the occurrence and prognosis of cancers. The aim of this study is to analyze the association between KRAS and VEGF gene 3’-UTR SNPs and genetic susceptibility to colorectal cancer (CRC). In this case-control study of 371 CRC cases and 246 healthy controls, we analyzed the association between one SNP (rs1137188G > A) in the KRAS gene and four SNPs (rs3025039C > T, rs3025040C > T, rs3025053G > A and rs10434A > G) in the VEGF gene and CRC susceptibility by the improved multiplex ligase detection reaction (iMLDR) method. We checked the selected SNPs’ minor allele frequency and its distribution in the frequency of Chinese people by Hap-map database and Hardy-Weinberg equilibrium, and used multivariate logistic regression models to estimate adjusted odds ratios (AORs) and 95% confidence intervals (95% CIs). We found that the rs3025039C variant genotype in the VEGF gene was associated with a significant protection for CRC (AOR = 0.693, 95% CI = 0.485–0.989; P = 0.043 for CC and CT+TT). Nevertheless, the difference was no longer significant after Bonferroni correction (Bonferroni-adjusted P = 0.172). In genetic polymorphisms analysis, we found that the KRAS rs1137188 variant AA genotype had higher portion of tumor size (≥ 5 cm) (P = 0.01; Bonferroni-adjusted P = 0.04), which suggested that the rs1137188 variant AA genotype may significantly be associated with increased progression of CRC. In conclusion, our study suggested that these five SNPs in the KRAS gene and the VEGF gene were not associated with CRC susceptibility in Han Chinese in Sichuan province.

Marsdeniae tenacissimae extract (MTE) suppresses cell proliferation by attenuating VEGF/VEGFR2 interactions and promotes apoptosis through regulating PKC pathway in human umbilical vein endothelial cells

Marsdeniae tenacissimae extract (MTE), commonly known as Xiao-Ai-Ping in China, is a traditional Chinese herb medicine capable of inhibiting proliferation and metastasis and boosting apoptosis in various cancer cells. However, little is known about the contribution of MTE towards tumor angiogenesis and the underlying mechanism. The present study aimed to evaluate the effects of MTE on the proliferation and apoptosis of human umbilical vein endothelial cells (HUVECs) and the molecular mechanism. 3-(4,5-dimethylthiazol-2-yl)-5(3-carboxymethoxyphenyl)-2-(4-sulfopheny)-2H-tetrazolium, inner salt (MTS) and PI-stained flow cytometry assays revealed that MTE dose-dependently reduced the proliferation of HUVECs by arresting cell cycle at S phase (P < 0.05). Annexin V-FITC/PI-stained flow cytometry confirmed that MTE (160 μL·L^-1) enhanced the apoptosis of HUVECs significantly (P < 0.001). Real-time quantitative RT-PCR and Western blot analyses showed an increase in Bax expression and a sharply decline in Bcl-2 expression; caspase-3 was activated simultaneously in a dose-dependent manner (P < 0.05). Further study observed the dose-dependent down-regulation of vascular endothelial growth factor (VEGF) receptor-2 (VEGFR-2), P2Y6 receptor (P2Y6R), and chemokine (C-C motif) ligand 2 (CCL-2), along with the activation of PKC Δ and up-regulation of p53 in a dose-dependent manner in MTE-treated selected cells (P < 0.05). Collectively, the results from the present study suggested that MTE suppressed the proliferation by attenuating CCL-2-mediated VEGF/VEGFR2 interactions and promoted the apoptosis through PKCΔ-induced p53-dependent mitochondrial pathway in HUVECs, supporting that MTE may be developed as a potent anti-cancer medicine.

VEGF gene promoter polymorphisms and risk of VTE in chemotherapy-treated cancer patients

Among the possible genetic contributors to cancer-related venous thromboembolism (VTE), vascular endothelial growth factor (VEGFA) could play an important role, as an imbalance of the VEGFA system (either disease-related or drug-induced) may result in a disturbance of vascular homeostasis. Thus, this study was designed to investigate the predictive role of eight different VEGFA gene promoter single nucleotide polymorphisms (SNPs) for a first VTE episode in cancer out-patients undergoing chemotherapy. To this purpose, VEGFA gene promoter polymorphisms were analysed in 297 cancer patients using polymerase chain reaction amplification and direct DNA sequencing analysis. One hundred forty unrelated healthy subjects from the same geographical area were also analysed in order to evaluate and compare genotype/haplotype frequencies in our ethnicity. VTE occurred in 26 (9%) of cancer patients with a median time-to-event of 3.4 months. Association analyses showed that -1154G/A polymorphism was significantly associated with the risk of chemotherapy-triggered VTE, with the A allele exerting a protective role both in the overall population (hazard ratio [HR]: 0.21; 95% confidence interval [CI]: 0.07-0.58) or in bevacizumab-treated metastatic patients (HR: 0.09, 95%CI: 0.01-0.86) in whom VEGFA -1154AA genotype also conferred a reduced risk of early progression (HR: 0.58, 95%CI: 0.34-0.98). These results suggest that VEGFA may represent a candidate gene contributing to VTE development in chemotherapy treated cancer patients and that -1154G/A SNP might provide useful clinical information on the efficacy and toxicity of bevacizumab in metastatic patients. Validation studies are needed for translation into clinical practice.