Vascular endothelial growth factor/vascular permeability factor is detectable in the sera of tumor-bearing mice and cancer patients

OCTA-based research on changes of retinal microcirculation in digestive tract malignancy

PURPOSE

This cross-sectional study measured retinal vessel density (VD) in patients with digestive tract malignancy by optical coherence tomography angiography (OCTA), and compared them with healthy controls to explore the retinal microcirculation changes in patients with digestive tract malignancy.

METHODS

106 eligible participants were divided into three groups: gastric cancer (GC) group (36 individuals), colorectal cancer (CRC) group (34 individuals), and healthy control group (36 individuals). Angio 6*6 512*512 R4 and ONH Angio 6*6 512*512 R4 modes were performed to collect retinal vessel density data centered on fovea and papillary, respectively. The retina was automatically segmented into different layers (superficial vascular plexus (SVP), the inner retinal layer, radial peripapillary capillary plexus (RPCP), deep vascular plexus (DVP)) and areas to analyze.

RESULTS

At the optic nerve head (ONH) region, the VD of the inner retinal layer increased in both GC and CRC groups in all quadrants and areas. In the papillary area, VD in the inner retinal layer, SVP, and RPCP increased in the GC and CRC groups. In the parapapillary area, VD in the inner retinal layer increased in the GC and the CRC groups. Significant increase in the global VD were found in the GC group of the RPCP and SVP. Regarding the macular region, no statistical differences were observed in each layer.

CONCLUSIONS

The study suggested that retinal vessel density changed in patients with digestive tract malignancy, especially in the inner retinal layer of the ONH region, revealing the potential relevance of the relation between gastrointestinal cancer and retinal microcirculation.

Vascular endothelial growth factor and risk of malignant brain tumor: A genetic correlation and two-sample Mendelian randomization study

Objective

The relationship between vascular endothelial growth factor (VEGF) and the risk of malignant brain tumors has always been a concern in the medical field. However, the causal inferences from published observational studies on this issue may be affected by confounders, coinheritability and reverse causality. We aimed to investigate the causal relationship between VEGF and different types of malignant brain tumors.

Methods

Using publicly available summary data from genome-wide association studies (GWAS) of VEGF (n=16,112) and different types of malignant brain tumors (n=174,097-174,646), we adopted a standard two-sample bidirectional Mendelian randomization (MR) to estimate potential causal associations of circulating VEGF levels and the risk of malignant brain tumors. Inverse variance weighted (IVW) was used as the primary analysis method to estimate causality. MR-Egger regression, weighted median (WM), penalty weighted median (PWM), MR robust adjusted profile score (MR.RAPS) and causal analysis using summary effect estimates (CAUSE) methods were used in sensitivity analyses to verify the robustness of the findings. Meanwhile, we applied the MR pleiotropy residual sum and outlier (MR-PRESSO) test and PhenoScanner tool to identify and remove potential horizontal pleiotropic single nucleotide polymorphisms (SNPs). Additionally, linkage disequilibrium score regression (LDSC) analysis was conducted to assess the coinheritability of exposure and outcome.

Results

A total of 6 (VEGF), 12 (malignant brain tumor), 13 (brain glioblastoma) and 12 (malignant neoplasm of meninges) SNPs were identified as valid instrumental variables. No evidence supported a causal relationship between circulating VEGF levels and the risk of malignant brain tumors (forwards: odds ratio (OR) = 1.277, 95% confidence interval (CI), 0.812~2.009; reversed: β = 0.005, 95% CI, -0.029~0.038), brain glioblastoma (forwards: OR (95% CI) = 1.278(0.463~3.528); reversed: β = 0.010, 95% CI, -0.002~0.022) and malignant neoplasm of meninges (forwards: OR (95% CI) = 0.831(0.486~1.421); reversed: β = 0.010, 95% CI, -0.030~0.050) using the main IVW method. Outliers and pleiotropy bias were not detected by sensitivity analyses and pleiotropy-robust methods in any estimates. LDSC failed to identify genetic correlations between VEGF and different types of malignant brain tumors.

Conclusions

Our findings reported no coinheritability and failed to provide evidence for causal associations between VEGF and the risk of different types of malignant brain tumors. However, certain subtypes of VEGF for which genetic predictors have not been identified may play a role and need to be further investigated.

Serum vascular endothelial growth factor is associated with cardiovascular involvement and response to therapy in Erdheim-Chester disease

Erdheim-Chester disease (ECD) is a rare histiocytosis, considered to be an inflammatory myeloid neoplasm. Tropism for specific involvements of the disease remains unexplained. Vascular endothelial growth factor-A (VEGF) is implicated in cancer pathophysiology and mutations of the RAS oncogene have been shown to induce upregulation of VEGF gene expression. We therefore hypothesized that VEGF might play a particular role in ECD pathophysiology. We conducted a retrospective, single-center study to assess serum VEGF (sVEGF) concentrations and determine whether they were associated with the characteristics of ECD patients, and to determine whether VEGF was expressed by histiocytes. We evaluated 247 ECD patients, 53.4% of whom had sVEGF levels above the normal range (>500 pg/mL). Patients with high sVEGF levels more frequently had cardiac and vascular involvement (58.3% vs. 41.4%, P=0.008 and 70.5% vs. 48.3%, P=0.0004, respectively). In treatment-naïve patients (n=135), the association of C-reactive protein >5 mg/L and sVEGF >500 pg/mL was strongly associated with vascular involvement (odds ratio=5.54 [95% confidence interval: 2.39-13.62], P<0.001), and independently associated with cardiac involvement (odds ratio=3.18 [95% confidence interval: 1.34-7.83], P=0.010) after adjustment for the presence of the BRAF V600E mutation. Changes in sVEGF concentration on treatment were associated with a response of cardiac involvement on consecutive cardiac magnetic resonance images. All histological samples analyzed (n=24) displayed histiocytes with intracytoplasmic expression of VEGF, which was moderate to high in more than 90% of cases. Our study suggests a role for VEGF in cardiac and vascular involvement in ECD.

Combined detection of peripheral blood VEGF and inflammation biomarkers to evaluate the clinical response and prognostic prediction of non-operative ESCC

An association between angiogenesis/inflammation status and tumor has been reported in various types of cancer. This study sought to assess the role of peripheral blood VEGF and some inflammation biomarkers in evaluating clinical response and prognosis in patients with non-operative esophageal squamous cell carcinoma (ESCC). Peripheral blood of 143 patients with non-operative ESCC at our institute was dynamically collected at 5 time points including 1 day before radiotherapy, during radiotherapy (15f), at the end of radiotherapy, 1 month after radiotherapy, and 3 months after radiotherapy. VEGF expression in the peripheral blood was detected and related inflammation biomarkers such as GPS, CAR and CLR were counted. Logistic regression and Cox regression were implemented respectively to analyze the correlation of each predictor with clinical response and prognosis. The performance of combined testing was estimated using AUCs. Based on independent predictors, a nomogram prediction model was established to predict the probabilities of 1- and 2-year PFS of patients. The effectiveness of the nomogram model was characterized by C-index, AUC, calibration curves and DCA. VEGF and CLR levels at the end of radiotherapy were independent predictors of clinical response, while VEGF and GPS levels at 3 months after radiotherapy were independent prognostic predictors. The efficacy of combined detection of VEGF and CLR is superior to the single detection in evaluating clinical response and prognosis. The nomogram showed excellent accuracy in predicting PFS. The combined detection of VEGF and CLR at the end of radiotherapy can be used to evaluate the clinical response of patients with non-operative ESCC, and the combined detection of VEGF and GPS 3 months after radiotherapy can be used to predict the prognosis. Implemented by nomogram model, it is expected to provide practical and reliable method to evaluate the clinical response and prognosis of patients with non-operative ESCC tool.

Gene polymorphisms of VEGF and VEGFR2 are associated with the severity of Hashimoto's disease and the intractability of Graves' disease, respectively

Vascular endothelial growth factor (VEGF) is one of main regulators of angiogenesis that functions by binding to its receptors, including VEGF receptor (VEGFR) 2. There are few data available regarding the association between VEGF and VEGFR polymorphisms and the susceptibility to and prognosis of autoimmune thyroid diseases (AITDs). To elucidate this association, we genotyped four functional VEGF and two VEGFR2 polymorphisms and measured serum VEGF levels. In the four functional VEGF polymorphisms, the frequencies of the I carrier and I allele of VEGF -2549 I/D, which has lower activity, were higher in patients with severe HD than in those with mild HD. In the two functional VEGFR2 polymorphisms, the frequency of the rs2071559 CC genotype, which has higher activity, was higher in patients with intractable GD than in controls, and the proportion of GD patients with larger goiters was higher in those with the CC genotype. Moreover, the frequency of the rs1870377 TT genotype with higher activity was higher in patients with intractable GD than in those with GD in remission. Combinations of VEGF and VEGFR2 polymorphisms with stronger interactions were associated with the intractability of GD. Serum VEGF levels were higher in HD and AITD patients than those in controls. In conclusion, VEGF polymorphisms with lower activity were associated with the severity of HD, while VEGFR2 polymorphisms and the combinations of VEGF and VEGFR2 polymorphisms, which have stronger interactions, were associated with the intractability of GD. VEGF and VEGFR2 polymorphisms were associated with HD severity and GD intractability, respectively.

Association between vascular endothelial growth factor gene polymorphisms and the risk and prognosis of renal cell carcinoma: A systematic review and meta-analysis

The aim of the meta-analysis was to clarify the associations between vascular endothelial growth factor (VEGF) polymorphisms and the risk and prognosis of renal cell carcinoma (RCC). A meta-analysis was performed by searching the databases PubMed, EMBASE and Web of Science for the relevant available studies until August 1st, 2016, and fourteen studies met the inclusion criteria. The pooled odds ratios (ORs) with 95% confidence intervals (CIs) were calculated to evaluate the strength of such associations. Besides, the pooled hazard ratios (HRs) with 95% CIs were used to evaluate the overall survival (OS). Fixed- or random-effects models were conducted according to existence of heterogeneity. Publication bias was evaluated using Begg's funnel plots and Egger's regression test. Overall, this meta-analysis included a total of 8,275 patients, who had been accrued between November 2002 and September 2015. Meta-analysis indicated that -2578C/A, +936C/T and +405G/C polymorphisms in the VEGF gene correlated with elevated RCC risk, especially in Asian populations. Moreover, VEGF -1154G/A and -634C/G polymorphisms were found significantly associated with poor OS of RCC. Therefore, this meta-analysis revealed that VEGF -2578C/A, +936C/T, +405G/C polymorphisms were associated with an elevated susceptibility to RCC, indicating that these three polymorphisms might be risk factors for RCC, especially in Asian populations.

Circulating Angiogenesis Regulators in Cancer Patients

Background/Aims

To date, numerous studies have demonstrated that several angiogenesis regulators circulate in the blood and may function as endocrine factors in cancer patients. This review aims to give a comprehensive insight into the possible clinical value of circulating angiogenesis regulators, mainly basic fibroblast growth factor (bFGF), vascular endothelial growth factor (VEGF), and hepatocyte growth factor (HGF), angiogenin, pleiotrophin, thrombospondin (TSP) and endostatin (ES) in cancer patients.

Methods

A computerized (MEDLINE) and a manual search based on the reference lists of the publications were performed to identify articles published on this topic.

Results

In a detailed literature search, approximately 100 publications were found up to the end of 1999. Circulating angiogenic factors such as bFGF, VEGF, HGF and angiogenin have been evaluated not only as diagnostic and/or prognostic factors but also as predictive factors in cancer patients. On the other hand, little is known about the clinical significance of negative regulators. Neither the source nor the mechanism of protein externalization has been clarified in detail.

Conclusions

Although there are no known factors with established clinical utility, circulating angiogenesis regulators may be useful in several situations. They could be used to determine the risk of developing cancer, to screen for early detection, to distinguish benign from malignant disease, and to distinguish between different types of malignancies. In patients with established malignancies such factors might be used to determine prognosis, to predict the response to therapy, and to monitor the clinical course. Further investigations are warranted to assess the specific utility of each factor.

Surrogate Markers of Tumoral Angiogenesis

Background

Angiogenesis is a prerequisite for tumor growth and metastasis. Vascular cell adhesion molecule-1 (VCAM-1) is expressed on endothelial cells as a result of vascular endothelial growth factor (VEGF) stimulation.

Purpose

To determine if measurement in serum of VEGF or VCAM-1 provides an accurate measure of tumor angiogenesis.

Methods

VCAM-1 and VEGF were measured in the serum of women with early and advanced breast cancer by ELISA. Levels were compared to levels of VCAM-1 and VEGF in women with normal breasts and levels of the endothelial glycoprotein von Willebrand factor. Levels of VEGF and VCAM-1 in women with early breast cancer were correlated with established clinicopathological prognostic markers and intratumoral microvessel density (IMD).

Results

In early breast cancer serum VCAM-1 correlated closely with the microvessel density in tumors (r=0.61, p<0.001). Women with lymph node-positive and high-grade tumors had higher levels of serum VCAM-1 than women with lymph node-negative and low-grade tumors. Serum VEGF demonstrated no correlation with established prognostic features or IMD. Levels of VCAM-1 and VEGF were raised in women with advanced breast cancer.

Conclusion

Serum VCAM-1 is a surrogate marker of angiogenesis in breast cancer and its measurement may help in the assessment of antiangiogenic drugs currently in phase II trials.

Diagnostic Value of Plasma Vascular Endothelial Growth Factor as a Tumor Marker in Patients with Non-Small Cell Lung Cancer

We assessed the diagnostic value of circulating VEGF as a tumor marker in patients with lung cancer and compared its clinical utility with that of other markers such as carcinoembryonic antigen (CEA) and cytokeratin 19 (CYFRA). One hundred and sixty non-small cell lung cancer patients and 70 healthy volunteers were included in the study. Circulating VEGF was assessed by enzyme-linked immunosorbent assay (ELISA). The serum concentrations of both CEA and CYFRA were measured by means of immunoradiometric assays. The diagnostic value of plasma VEGF (VEGFp) was better than that of CYFRA and similar to that of CEA. When the diagnostic value of VEGFp and CEA for the diagnosis of adenocarcinoma was compared, the two markers proved to have nearly equal discriminatory power. In diagnosing squamous cell carcinoma, VEGFp showed less discrimination than CYFRA. When the diagnostic value of VEGFp was analyzed for stage I adenocarcinoma patients, VEGFp was slightly more discriminatory than CEA. The combination assay of VEGFp and CEA had a sensitivity of 75% and a specificity of 60% at a cutoff of 104.4 pg/mL for VEGFp and 5.2 ng/mL for CEA. The combination of VEGF and CEA was superior to CEA alone in the early diagnosis of adenocarcinoma of the lung.

Vascular Endothelial Growth Factor (Vegf) and Other Common Tissue Prognostic Indicators in Breast Cancer: A Case-Control Study

VEGF is a specific mitogen and survival factor for endothelial cells and a key promoter of angiogenesis in physiological and pathological conditions. Nevertheless, VEGF tissue evaluation in cancer patients as a prognostic factor compared to the conventional histological and biological parameters is still controversial. In this case-control study, tissue VEGF was retrospectively determined by immunohistochemistry and related to T, N, ER, PgR, c-erbB-2, p53, MIB-1 and cyclin D1 in 129 breast cancer patients. Seventy-four of these patients had developed distant metastases postoperatively. The remaining 55 patients had remained disease-free >10 years after surgery. In 17 (13%) of the 129 patients (six with distant metastases and eleven disease-free) tissue and plasma VEGF were concomitantly evaluated. In univariate analysis no significant differences in VEGF and tumor size were found between metastatic and disease-free patients, whereas there were significant differences in N, ER, PgR, c-erbB-2, p53, MIB-1 and cyclin D1 (p ranging from 0.001 to 0.0001). In multivariate analysis VEGF showed less significance than N, ER, c-erbB-2, MIB-1 and cyclin D1 (p=0.012, p=0.007, p=0.005, p=0.005, p=0.002 and p=0.001, respectively). VEGF was a significant unfavorable prognostic indicator only in the N+ subset (p=0.015), while ER (p=0.05 and p=0.021) and MIB-1 (p=0.031 and p=0.022) were significant in both the N+ and N– subgroups. In multivariate analysis in the 74 metastatic cases VEGF did not show any significance in relation to disease-free interval and overall survival from the time of mastectomy and from the time of relapse, whereas N and PgR did (p ranging from 0.018 to 0.001). In conclusion, tissue VEGF does not seem a suitable candidate to replace conventional histological and other common biological prognostic factors in breast cancer.

Upregulation of vascular endothelial growth factor (VEGF), its role in progression and prognosis of non-small cell lung carcinoma

Elevated VEGF mRNA (-ΔC_T) was significantly associated with adenocarcinoma histology (vs squamous) and advanced NSCLC clinical stages in a univariable analysis; however, this association did not remain significant in the multivariable analysis. Of interest, a Kaplan-Meier analysis showed that NSCLC patients with higher VEGF mRNA (-ΔC_T ≥10) had a significantly poorer overall survival and shorter postoperative relapse time in adenocarcinoma and in stage III/IV than those with VEGF mRNA of -ΔC_T <10 (P < 0.001). The multivariable analysis confirmed that patients with higher VEGF mRNA levels, as well as with adenocarcinoma and advanced stages, were independent predictors of a poorer survival. However, only the histology of adenocarcinoma remained a significant prognostic factor of a shorter postoperative relapse in the multivariable model. Quantity of VEGF mRNA can be used as a prognosis factor to predict shorter overall survival in patients with NSCLC.

Elevated serum levels of vascular endothelial growth factor predict a poor prognosis of platinum-based chemotherapy in non-small cell lung cancer

Aim

This study was designed to investigate the predictive and prognostic values of serum vascular endothelial growth factor (VEGF) level in non-small cell lung cancer (NSCLC) patients treated with platinum-based chemotherapy.

Methods

Patients’ peripheral blood samples were collected prior to chemotherapy and after 1 week of the third cycle of combination chemotherapy. Serum VEGF levels were evaluated through Luminex multiplex technique. Between September 2011 and August 2015, a total of 135 consecutive advanced or recurrent histologically verified NSCLC patients were enrolled in the study. Moreover, all the patients received platinum-based combination chemotherapy as a first-line treatment.

Results

No significant associations were found between pretreatment serum VEGF levels and clinical characteristics, such as sex (P=0.0975), age (P=0.2522), stage (P=0.1407), lymph node metastasis (P=0.6409), tumor location (P=0.3520), differentiated degree (P=0.5608), pathological (histological) type (P=0.4885), and response to treatment (P=0.9859). The VEGF load per platelet (VEGF^PLT) levels were not correlated with sex, age, primary tumor site, and pathological type in NSCLC patients (all P>0.05). The median survival time of progression-free survival (PFS) was 6.407 and 5.29 months in the low and high groups, respectively, when using 280 pg/mL VEGF level as the cutoff point (P=0.024).

Conclusion

In conclusion, the serum VEGF levels were found to be a poor prognostic biomarker for the efficacy of platinum-based chemotherapy in terms of PFS, but it was not shown to be a suitable predictive marker for clinical response to platinum-based chemotherapy.

Immunomodulatory Activity of VEGF in Cancer

The ability of tumor cells to escape tumor immunosurveillance contributes to cancer development. Factors produced in the tumor microenvironment create "tolerizing" conditions and thereby help the tumor to evade antitumoral immune responses. VEGF-A, already known for its major role in tumor vessel growth (neoangiogenesis), was recently identified as a key factor in tumor-induced immunosuppression. In particular, VEGF-A fosters the proliferation of immunosuppressive cells, limits T-cell recruitment into tumors, and promotes T-cell exhaustion. Antiangiogenic therapies have shown significant efficacy in patients with a variety of solid tumors, preventing tumor progression by limiting tumor-induced angiogenesis. VEGF-targeting therapies have also been shown to modulate the tumor-induced immunosuppressive microenvironment, enhancing Th1-type T-cell responses and increasing tumor infiltration by T cells. The immunomodulatory properties of VEGF-targeting therapies open up new perspectives for cancer treatment, especially through strategies combining antiangiogenic drugs with immunotherapy. Preclinical models and early clinical studies of these combined approaches have given promising results.

An analysis on the roles of angiogenesis-related factors including serum vitamin D, soluble endoglin (sEng), soluble fms-like tyrosine kinase 1 (sFlt1), and vascular endothelial growth factor (VEGF) in the diagnosis and severity of late-onset preeclampsia

AIM

The aim of this study was to evaluate the roles of proangiogenic factors including serum vitamin D and vascular endothelial growth factor (VEGF) and anti-angiogenic factors including soluble endoglin (sEng) and soluble fms-like tyrosine kinase 1 (sFlt1) in the diagnosis and severity of late-onset preeclampsia.

MATERIALS AND METHODS

The study was conducted at Yuzuncu Yil University Research and Education Hospital Department of Gynecology and Obstetrics. The study included a patient group of 40 women with late-onset preeclampsia who were pregnant at ≥32 weeks of gestation according to the last menstrual period (LMP) or ultrasonographic fetal biometric measurement and a control group of 40 healthy pregnant women who presented to our clinic for routine pregnancy examination and were at the same age and gestational period with those in the patient group. The two groups were compared in terms of maternal age, gravida, parity, week of gestation, systolic/diastolic blood pressure, total protein in spot urine sample, 24-h urine protein, white blood cell (WBC), hemoglobin (Hgb), platelet count, urea, creatinine, liver function tests (AST, ALT, LDH), vitamin D₃, 25(OH) vitamin D₃, 1,25(OH) vitamin D₃, sEng, sFlt1, and VEGF levels, mode of delivery, the infant APGAR score at 1 and 5 min after delivery, and infant weight at delivery.

RESULTS

The groups were similar in terms of age, gravida, parity, week of gestation, serum vitamin D₃, 25(OH) vitamin D₃, 1,25(OH)₂ vitamin D₃ and VEGF levels, and infant weight at delivery (p > 0.05). Systolic/diastolic blood pressure, total protein in spot urine sample, 24-h urine protein, WBC, Hgb, serum urea, creatine, AST, ALT, and LDH were significantly higher in the preeclamptic group compared to the healthy group (p < 0.05). However, thrombocyte level and the APGAR score at 1 and 5 min after delivery were significantly lower in the preeclamptic group compared to the healthy group (p < 0.05). No significant correlation was found between serum sEng, sFlt1, VEGF, vitamin D₃, 25(OH) vitamin D₃, and 1,25(OH)₂ vitamin D₃ levels. The sEng level was higher in the women with severe preeclampsia compared to the women with mild preeclampsia (p < 0.05) and no significant difference was observed in serum sFlt1, VEGF, vitamin D₃, 25(OH) vitamin D₃, and 1,25(OH)₂ vitamin D₃ levels between the subgroups of preeclampsia (p > 0.05).

CONCLUSION

Both sEng and sFlt1 levels are remarkably high in patients with late-onset preeclampsia; however, only sEng may be a useful tool in the determination of the severity of preeclampsia.

CD4+VEGFR1(HIGH) T cell as a novel Treg subset regulates inflammatory bowel disease in lymphopenic mice

Regulatory T cells (Tregs) are a specialized subpopulation of T cells that control the immune response and thereby maintain immune system homeostasis and tolerance to self-antigens. Many subsets of CD4(+) Tregs have been identified, including Foxp3(+), Tr1, Th3, and Foxp3neg iT(R)35 cells. In this study, we identified a new subset of CD4(+)VEGFR1(high) Tregs that have immunosuppressive capacity. CD4(+)VEGFR1high T cells, which constitute approximately 1.0% of CD4(+) T cells, are hyporesponsive to T-cell antigen receptor stimulation. Surface marker and FoxP3 expression analysis revealed that CD4(+)VEGFR1(high) T cells are distinct from known Tregs. CD4(+)VEGFR1(high) T cells suppressed the proliferation of CD4(+)CD25(-) T cell as efficiently as CD4(+)CD25(high) natural Tregs in a contact-independent manner. Furthermore, adoptive transfer of CD4(+)VEGFR1(+) T cells from wild type to RAG-2-deficient C57BL/6 mice inhibited effector T-cell-mediated inflammatory bowel disease. Thus, we report CD4(+) VEGFR1(high) T cells as a novel subset of Tregs that regulate the inflammatory response in the intestinal tract.

Brain-expressed X-linked 2 Is Pivotal for Hyperactive Mechanistic Target of Rapamycin (mTOR)-mediated Tumorigenesis

Frequent alteration of upstream proto-oncogenes and tumor suppressor genes activates mechanistic target of rapamycin (mTOR) and causes cancer. However, the downstream effectors of mTOR remain largely elusive. Here we report that brain-expressed X-linked 2 (BEX2) is a novel downstream effector of mTOR. Elevated BEX2 in Tsc2(-/-) mouse embryonic fibroblasts, Pten(-/-) mouse embryonic fibroblasts, Tsc2-deficient rat uterine leiomyoma cells, and brains of neuronal specific Tsc1 knock-out mice were abolished by mTOR inhibitor rapamycin. Furthermore, BEX2 was also increased in the liver of a hepatic specific Pten knock-out mouse and the kidneys of Tsc2 heterozygous deletion mice, and a patient with tuberous sclerosis complex (TSC). mTOR up-regulation of BEX2 was mediated in parallel by both STAT3 and NF-κB. BEX2 was involved in mTOR up-regulation of VEGF production and angiogenesis. Depletion of BEX2 blunted the tumorigenesis of cells with activated mTOR. Therefore, enhanced STAT3/NF-κB-BEX2-VEGF signaling pathway contributes to hyperactive mTOR-induced tumorigenesis. BEX2 may be targeted for the treatment of the cancers with aberrantly activated mTOR signaling pathway.

Circulating VEGF as a biomarker for diagnosis of ovarian cancer: a systematic review and a meta-analysis

VEGF is a frequently studied angiogenic factor in ovarian cancer (OC), and is considered to have an important role in the progression of OC. However, its diagnostic value has not been widely accepted because the conclusions are inconsistent and even conflicting. Therefore, we performed a meta-analysis to evaluate the diagnostic value of VEGF in OC. A systematic literature search was conducted using the PubMed, Cochrane Library, EMBASE, Chinese National Knowledge Infrastructure, and WANFANG databases for relevant published articles (the last search update was November 18, 2014). The diagnosis sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, diagnostic odds ratio, and the summary receiver operating characteristic curves were pooled by Meta DiSc 1.4 software. A total of ten studies with 1,131 subjects were finally included in this meta-analysis. The pooled sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, diagnostic odds ratio, and summary receiver operating characteristic curves were 0.67 (0.63–0.73), 0.78 (0.75–0.81), 3.08 (6.36–12.22), 0.39 (0.29–0.51), 9.10 (5.43–45.25), and 0.8175, respectively. Furthermore, to explore the sources of heterogeneity, we conducted subgroup analyses based on ethnicity and sample size. The diagnostic accuracy of VEGF was higher in an Asian population than in a Caucasian population. A similar finding was found in subgroups with the smaller sample size (<100 subjects). In conclusion, the present meta-analysis suggests that VEGF has moderate diagnostic accuracy for OC. Considering our limitations and the heterogeneity among our selected studies, larger, well-designed prospective and multicenter validation studies are needed to evaluate the diagnostic value of serum VEGF for OC.

Basic fibroblast growth factor shows prognostic impact on survival in operable non-small cell lung cancer patients

Background

The important role of angiogenesis displaying in tumor development and metastasis has been generally realized. Vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF) and endostatin (ES) are critical members of angiogenesis modulating the balance between pro-angiogenenic and anti-angiogenenic factors. The aim of this study was to evaluate the circulating level of these factors in serum and explore their prognostic significance in 96 operable non-small cell lung cancer (NSCLC) patients.

Methods

Pre-operational serum VEGF, bFGF, and ES were determined by commercially available enzyme-link immunosorbent assay for 96 NSCLC patients and compared to a cohort of healthy controls (n = 51). Values were correlated with clinicopathological features and overall survival (OS).

Results

The pretreatment serum levels of VEGF, bFGF and ES in NSCLC were significantly higher than in the healthy control (P < 0.001, P = 0.009 and P = 0.016, respectively). Univariate survival analysis showed that a high bFGF level correlated with shorter OS and remained an independent factor in multivariate analysis (hazard ratio [HR] = 1.918, 95% confidence interval [CI], 1.061–3.464). In the squamous subtype, a high bFGF indicated a particularly poor prognosis (HR = 2.609, 95% CI, 1.188–5.729).

Conclusions

bFGF is an independent predictor of poor survival in patients with NSCLC. For patients with high serum bFGF, aggressive antitumor treatments should be given after surgery. Approaches targeting the bFGF signaling pathway should be considered as potentially promising therapeutic strategies in NSCLC, especially for the squamous subtype.

[Changes in serum vascular endothelial growth factor and matrix metalloproteinase-9 after video-assisted thoracoscopic surgery and thoracotomic Lobectomy in the treatment of patients with non-small cell lung cancer]

BACKGROUND AND OBJECTIVE

Vascular endothelial growth factor (VEGF) and matrix metalloproteinase-9 (MMP-9) are important factors in angiogenesis. These factors function in the angiogenesis of lung cancers. The aim of this study is to determine the changes in serum VEGF and MMP-9 after patients with NSCLC were subjected to lobectomy. The aim of this study is also to compare the differences in the changes observed between video-assisted thoracoscopic surgery (VATS) and traditional open surgery (TOS).

METHODS

A total of 43 consecutive patients with NSCLC were recruited from October 2010 to August 2012. All of these patients underwent lobectomy and systematic mediastinal lymphadenectomy. Blood was drawn from these patients to measure the serum levels of VEGF and MMP-9 in the morning before surgery and on postoperative days 1, 2, 3, and 7 (POD1, POD2, POD3, and POD7, respectively). Perioperative variations in serum VEGF and MMP-9 were also observed. Using different surgical options, we divided the patients into two groups: VATS group (25 patients) and TOS group (18 patients). The differences in the changes in serum VEGF and MMP-9 were then compared between the two groups.

RESULTS

After surgery, the serum VEGF and MMP-9 of patients with NSCLC initially increased and subsequently decreased. The peak levels were observed on POD2 and POD3, and these levels were significantly higher than the preoperative levels (P=0.031, P=0.020). On POD7, the serum VEGF and MMP-9 remained higher than the preoperative levels. In VATS and TOS groups, the serum VEGF and MMP-9 levels also initially increased and subsequently decreased. The TOS group showed a more evident variation. However, no significant statistical differences in the changes of VEGF and MMP-9 were found between the two groups (F=2.022, P=0.163; F=1.703, P=0.199).

CONCLUSIONS

Serum VEGF and MMP-9 remarkably increase in TOS group and VATS group. Although the serum level of VEGF an MMP-9 in TOS group were higher than that in VATS group. But no significant difference was observed between VATS and TOS group.

High circulating VEGF level predicts poor overall survival in lung cancer

PURPOSE

Vascular endothelial growth factor (VEGF) is considered as the best-validated key regulator of angiogenesis, while the prognostic role of circulating VEGF in lung cancer remains controversial. We conducted a meta-analysis to evaluate the prognostic role of circulating VEGF.

METHODS

Nineteen studies with a total number of 2,890 patients were analyzed in our meta-analysis. Hazard ratios (HRs) and their 95 % confidence intervals (CIs) were used to quantify the predictive ability of circulating VEGF on survival.

RESULTS

The pooled HR of all 17 studies evaluating overall survival (OS) was 1.29 (95 % CI 1.19-1.40, p < 0.001), indicating high circulating VEGF predicted poor OS. When grouped by disease stages, the pooled HRs were 0.97 (95 % CI 0.47-1.47, p < 0.001) for operable stage and 1.34 (95 % CI 1.18-1.49, p < 0.001) for inoperable stage. The pooled HRs were 1.28 (95 % CI 1.15-1.42, p < 0.001) for serum and 1.31 (95 % CI 1.13-1.49, p < 0.001) for plasma, when categorized by blood sample. Meta-analysis of circulating VEGF related to progression-free survival (PFS) was performed in 7 studies, and the pooled HR was 1.03 (95 % CI 0.96-1.09).

CONCLUSIONS

Our results indicate that high level of circulating VEGF predicts poor OS in lung cancer, yet it does not predict poor PFS.

Biophysical characterization of VEGF-aHt DNA aptamer interactions

The binding of the well-studied DNA aptamer aHt (5'-ATACCAGTCTATTCAATTGGGCCCGTCCGTAT GGTGGGTGTGCTGGCCAG-3'), which has been demonstrated to recognize human vascular endothelial growth factor (VEGF₁₆₅) to recombinant VEGF was characterized using fluorescence anisotropy, isothermal titration calorimetry and analytical ultracentrifugation. The negatively-charged DNA aptamer is selective for VEGF and does not recognize positively-charged hen egg lysozyme, or bovine serum albumin. In contrast to the VEGF association of the previously-described aV DNA aptamer, where the binding is enthalpically driven and sequence-specific, the binding of the aHt aptamer to VEGF is entropically-driven and not abolished by scrambling of the sequence.

Affinity improvement of a VEGF aptamer by in silico maturation for a sensitive VEGF-detection system

Systematic evolution of ligands by exponential enrichment (SELEX) is an efficient method to identify aptamers; however, it sometimes fails to identify aptamers that bind to their target with high affinity. Thus, post-SELEX optimization of aptamers is required to improve aptamer binding affinity. We developed in silico maturation based on a genetic algorithm (1) as an efficient mutagenesis method to improve aptamer binding affinity. In silico maturation was performed to improve a VEGF-binding DNA aptamer (VEap121). The VEap121 aptamer is considered to fold into a G-quadruplex structure and this structure may be important for VEGF recognition. Using in silico maturation, VEap121 was mutated with the exception of the guanine tracts that are considered to form the G-quartet. As a result, four aptamers were obtained that showed higher affinity compared with VEap121. The dissociation constant (K(d)) of the most improved aptamer (3R02) was 300 pM. The affinity of 3R02 was 16-fold higher than that of VEap121. Moreover, a bivalent aptamer was constructed by connecting two identical 3R02s through a 10-mer thymine linker for further improvement of affinity. The bivalent aptamer (3R02 Bivalent) bound to VEGF with a K(d) value of 30 pM. Finally, by constructing a VEGF-detection system using a VEGF antibody as the capture molecule and monovalent 3R02 as the detection molecule, a more sensitive assay was developed compared with the system using VEap121. These results indicate that in silico maturation could be an efficient method to improve aptamer affinity for construction of sensitive detection systems.

Vascular endothelial growth factor serum levels in children with newly diagnosed rhabdomyosarcoma

BACKGROUND

The adverse prognostic impact of elevated levels of circulating Vascular Endothelial Growth Factor (VEGF) is described in several malignancies. However, no information is available in childhood rhabdomyosarcoma (RMS). In the present study, serum VEGF-A (sVEGF-A) was measured at diagnosis in a series of patients with RMS.

PROCEDURE

sVEGF-A was assessed retrospectively in 17 newly diagnosed RMS patients. sVEGF-A concentrations were determined by quantitative enzyme-linked immunoabsorbent ELISA kit and their possible associations with age at diagnosis, gender, histology, primary site, primary size, Intergroup Rhabdomyosarcoma Study (IRS) post-surgical group, and outcome were investigated.

RESULTS

sVEGF-A median value in patients with RMS was significantly higher than in controls: 499.0 pg/ml, range: 2,648.0 versus 301.5 pg/ml, range: 716.0 (P = 0.013). Although not statistically significant probably due to the limited number of patients, sVEGF-A median levels resulted higher in unfavorable primary sites (277.0 vs. 539.0 pg/ml; P = 0.31), and advanced groups (390.0 vs. 715.0; P = 0.29). Patients with shorter 5-year overall survival (OS) and 5-year progression-free survival (PFS) times also had higher sVEGF-A levels, although again the difference was not statistically significant (P = 0.18 and P = 0.22, respectively).

CONCLUSIONS

Circulating VEGF is significantly increased in pediatric patients with newly diagnosed RMS. Further studies in larger series of RMS patients are needed to understand whether measurements of circulating VEGF might have a role in assessing prognosis and modulating treatment.

Increased expression of Rab25 in breast cancer correlates with lymphatic metastasis

Breast cancer is the most common cancer in women worldwide. Studies have suggested that Ras-related protein 25 (Rab25), a member of Rab small GTPase family, is involved in the pathogenesis of breast cancer. In this study, we investigated whether the expression of Rab25 correlated with lymphatic metastasis in breast cancer and whether the expression of Rab25 was positively correlated with oestrogen receptor (ER) and progesterone receptor (PR) expression in breast cancer. Breast cancer tissues from 42 invasive ductal breast cancer patients with or without lymphatic metastasis were collected and the levels of Rab25 mRNA and protein measured by quantitative real-time PCR and immunohistochemistry, respectively. The mRNA level of Rab25 was significantly increased in invasive ductal breast cancer with lymphatic metastasis compared to that in invasive ductal breast cancer without lymphatic metastasis. Immunohistochemical analysis demonstrated that Rab25 and vascular endothelial growth factor (VEGF) were highly expressed in invasive ductal breast cancer with lymphatic metastasis regardless of whether the cancer is ER and PR positive or negative. Higher expression of Rab25 positively correlated with VEGF expression. However, the expressions of Rab25 in ER and PR-positive cancers were much higher than ER and PR-negative cancers regardless of whether lymphatic metastasis occurred. These data suggest that higher level of Rab25 was associated with lymphatic metastasis, specifically in ER and PR-positive breast cancer. The better understanding of the mechanism of Rab25 may provide a basis for the development of a novel therapeutic target in breast cancer.

Expression, prognostic and predictive impact of VEGF and bFGF in non-small cell lung cancer

Despite major advances in cancer therapeutics, the prognosis for lung cancer patients is still poor and the median survival for patients presenting with advanced non-small cell lung cancer (NSCLC) is only 8-10 months. Angiogenesis is an important biological process and a relatively early event during lung cancer pathogenesis. Anti-angiogenic agents are used in treating patients with NSCLC, and their molecular biomarkers are also being assessed to predict response. A better understanding of the biology of angiogenesis in NSCLC may reveal new targets for treating this malignancy. In this article, we review the expression and prognostic impact of the angiogenic growth factors, vascular endothelial growth factor and basic fibroblast growth factor, in NSCLC.

Ganoderma lucidum polysaccharides antagonize the suppression on lymphocytes induced by culture supernatants of B16F10 melanoma cells

Objectives

Tumour cells produce factors such as interleukin 10 (IL-10), transforming growth factor β1 (TGF-β1) and vascular endothelial growth factor (VEGF) that suppress the function of immune cells or induce apoptosis of immune cells. One of the most important goals of tumour immunotherapy is to antagonize this suppression on immune cells. Ganoderma lucidum polysaccharides (Gl-PS) may have this potential. The purpose of this study was to determine the antagonistic effects of Gl-PS on the suppression induced by B16F10 melanoma cell culture supernatant (B16F10-CS) on lymphocytes.

Methods

Gl-PS was used on lymphocytes incubated with B16F10-CS. Enzyme-linked immunosorbent assay was used to determine the levels of IL-10, TGF-β1 and VEGF in B16F10-CS. The MTT assay was used to determine the proliferation of lymphocytes. Immunocytochemistry and Western blot assay were used to determine perforin and granzyme B production in lymphocytes.

Key findings

There were elevated levels of IL-10, TGF-β1 and VEGF in B16F10-CS. The lymphocyte proliferation, and perforin and granzyme B production in lymphocytes after induction with phytohemagglutinin, as well as lymphocyte proliferation in the mixed lymphocyte reaction, were suppressed by B16F10-CS. This suppression was fully or partially antagonized by Gl-PS.

Conclusions

B16F10-CS suppressed lymphocyte proliferation and perforin and granzyme B production in lymphocytes after induction with phytohemagglutinin, as well as lymphocyte proliferation in the mixed lymphocyte reaction. This suppression may be associated with elevated levels of immunosuppressive IL-10, TGF-β1 and VEGF in B16F10-CS. Gl-PS had antagonistic effects on the immunosuppression induced by B16F10-CS, suggesting the potential for Gl-PS in cancer immunotherapy.

A serum-stable branched dimeric anti-VEGF peptide blocks tumor growth via anti-angiogenic activity

Angiogenesis is critical and indispensable for tumor progression. Since VEGF is known to play a central role in angiogenesis, the disruption of VEGF-VEGF receptor system is a promising target for anti-cancer therapy. Previously, we reported that a hexapeptide (RRKRRR, RK6) blocked the growth and metastasis of tumor by inhibiting VEGF binding to its receptors. In addition, dRK6, the D-form derivative of RK6, retained its biological activity with improved serum stability. In the present study, we developed a serum-stable branched dimeric peptide (MAP2-dRK6) with enhanced anti-VEGF and anti-tumor activity. MAP2-dRK6 is more effective than dRK6 in many respects: inhibition of VEGF binding to its receptors, VEGF- and tumor conditioned medium-induced proliferation and ERK signaling of endothelial cells, and VEGF-induced migration and tube formation of endothelial cells. Moreover, MAP2-dRK6 blocks in vivo growth of VEGF-secreting colorectal cancer cells by the suppression of angiogenesis and the subsequent induction of tumor cell apoptosis. Our observations suggest that MAP2-dRK6 can be a prospective therapeutic molecule or lead compound for the development of drugs for various VEGF-related angiogenic diseases.

Effect of pan-retinal laser photocoagulation on plasma VEGF, endothelin-1 and nitric oxide in PDR

AIM

To study plasma levels of vascular endothelial growth factor (VEGF), endothelin-1(ET-1) and nitric oxide (NO) in patients with proliferative diabetic retinopathy (PDR) before and after pan-retinal photocoagulation (PRP).

METHODS

Forty patients (23 females and 17 males, mean age 48.5±12.2 years) with PDR without previous PRP therapy were studied. Blood samples were obtained before and 3 months after the last PRP session. Baseline (prelaser) plasma levels of VEGF, ET-1 and NO were compared with their levels in 30 healthy age- and sex- matched controls and also with plasma levels 3 months post-PRP.

RESULTS

Patients with PDR had significantly raised plasma VEGF (375±89ng/L), ET-1(20±5ng/L) and NO (135±53µmol/L) when compared with healthy control group (P<0.01). After PRP, there was a significant reduction in plasma VEGF (179±66ng/L), ET-1 (11±5ng/L) and NO (91±49µmol/L) levels at 3 months' follow-up but still significantly higher than healthy controls.

CONCLUSION

Patients with PDR demonstrate elevated VEGF, ET-1 and NO, which decrease after successful laser treatment.

Serum Vascular Endothelial Growth Factor (VEGF) and Bcl-2 Levels in Advanced Stage Non-Small Cell Lung Cancer

The characteristic changes in cancer process are assumed to be genetic alterations about the imbalance of cell proliferation and apoptotic cell death. This study was conducted to determine the value of the circulating vascular endothelial growth factor (VEGF) and Bcl-2 in patients with advanced stage non-small cell lung cancer (NSCLC). These serum factors were measured of 52 NSCLC patients pathologically verified on before and after chemotherapy in comparison with 16 healthy controls by using ELISA method. Both of the serum levels of VEGF (p = 0.015) and Bcl-2 (p < 0.001) were increased significantly in NSCLC patients compared with the healthy controls. No statistically significant relationships between investigated elevated serum parameters and various characteristics of patients and disease such as stage and tumor burden were determined. Likewise, we also found no correlation between serum VEGF and Bcl-2. Cytotoxic therapy of patients was accompanied by unchanged serum levels of serum factors. The median survival of all patients was 27 weeks and one-year survival rate was 22.4 percent. With the median serum levels as the cut-off value, patients were divided into high- and low-serum parameter groups. While we found that patients' performance status (p < 0.0001), serum LDH level (p = 0.0002), response to chemotherapy (p = 0.0023), and stage of the disease (p = 0.0085) were prognostic factors for survival, serum VEGF (p = 0.48) and Bcl-2 (p = 0.91) levels were determined as ineffective on survival in patients with advanced NSCLC. In conclusion, our data suggest that these serum factors, VEGF and Bcl-2, are useful diagnostic factors, not predictive and prognostic markers for overall survival in advanced NSCLC patients.

The positive correlation between gene expression of the two angiogenic factors: VEGF and BMP-2 in lung cancer patients

Lung cancer is a particular challenge in oncology. More than 1 million new cases occur worldwide every year and despite many clinical trials and modern diagnostic techniques, long-term survival rate has only marginally improved. The aim of the current research is to explore new molecular prognostic factors and identify new targets for anticancer therapy. Current evidence shows that angiogenesis is controlled by several angiogenic factors including VEGF and BMP-2. It has been also demonstrated that VEGF plays a key role in this process that is essential in carcinogenesis. Our study has shown that the expressions of the VEGF, BMP-2 and BMP-4 mRNAs were significantly higher (7.1-fold, 25.6-fold and 2.3-fold, respectively) in lung cancer samples than in adjacent normal lung tissues (real-time RT-PCR). Analysis based on the Pearson's correlation coefficient indicated the positive correlation between VEGF and BMP-2 gene expression, whereas no significant correlation between VEGF and BMP-4 gene expression was found. The mean+/-standard deviation serum level of VEGF was 423+/-136 pg/ml. Significant differences in the serum levels of VEGF between patients with T1 tumors and patients with T2, T3 or T4 tumors were observed. Patients with T2, T3 and T4 tumors, respectively, had 1.6-fold, 1.8-fold and 2.3-fold greater serum levels of VEGF than their peers with T1 tumors. In current study patients homozygous for the 936T allele of the +936C/T VEGF gene polymorphism had 12-fold lower VEGF gene expression and 1.3-fold lower VEGF serum level than patients homozygous for the 936C allele. In conclusion, our findings underline the importance of the two angiogenic factors namely VEGF and BMP-2 as well as +936C/T VEGF gene polymorphism in the evaluation of lung cancer patients.

Prognostic and predictive value of vascular endothelial growth factor and its soluble receptors, VEGFR-1 and VEGFR-2 levels in the sera of small cell lung cancer patients

OBJECTIVES

Small cell lung cancer (SCLC) has a rapid growth rate and is characterized by early metastases. Tumor growth is dependent on angiogenesis. Vascular endothelial growth factor (VEGF) is an important regulator of angiogenesis. Whether surveillance of pre- and post-treatment serum VEGF and especially its receptors VEGF-1 and VEGF-2 levels in SCLC patients have impact on clinical outcome is unknown.

METHODS

From February 2001 to January 2003, 39 consecutive patients with histological proven SCLC were enrolled into the study. Pre-treatment (n: 39) and post-treatment (n: 25) samples of the same patients were collected at the time of their response evaluation. The levels of VEGF and its receptors VEGFR-1 and VEGFR-2 were measured in the serum by quantitative sandwich enzyme immunoassay technique.

RESULTS

The median pre-treatment serum VEGF, VEGFR-1, and VEGFR-2 levels which were significantly higher than the normal controls were 1,200 pg/ml (range, 1,414.3 +/- 956.2 pg/ml), 85 pg/ml (range, 97.8 +/- 70.7 pg/ml), and 11,550 pg/ml (range, 14,481 +/- 6,267 pg/ml), respectively. We detected a poor but positive correlation between VEGF and VEGFR-2 (r: 0.46, p: 0.003). Pre-treatment low serum VEGF (<728.5 pg/ml) value (p: 0.02) and good response to treatment (p: 0.008) were found as good prognostic factors by multivariate analysis.

CONCLUSIONS

Low serum VEGF concentration is a significant and independent prognostic factor in SCLC patients. Surveillance of VEGF and its receptors to predict chemotherapy response is not useful. Whether the levels of serum VEGF and its receptors VEGFR-1 and VEGFR-2 have value in detecting treatment modalities of SCLC need further studies.

Plasma level and tissue expression of vascular endothelial growth factor in renal cell carcinoma: a prospective study of 50 cases

Vascular endothelial growth factor (VEGF) is the major factor involved in angiogenesis. Although it is known that one of the functions of VEGF is to regulate neovascularization in renal cell carcinomas, the relationship between the production of VEGF in tumor tissue and its concentration in blood has not yet been studied. The aims of this study were to determine, in a series of conventional renal cell carcinoma (CRCC) cases, (1) VEGF expression and VEGF pattern in tumor cells, (2) the relationship between VEGF expression/pattern and VEGF levels in plasma (pVEGF), and (3) the association with usual clinical and pathologic prognostic factors. Fifty patients operated on for CRCC by radical nephrectomy were included. Clinical and histologic parameters were studied. VEGF expression and VEGF pattern in tumor cells was immunohistochemically recorded. pVEGF levels and platelet count were analyzed in relation to clinical and histologic parameters. Intratumoral VEGF expression associated with a cytoplasmic VEGF pattern was significantly higher in patients with high pVEGF levels (P = .01). Both VEGF expression and pVEGF levels were significantly correlated with Fuhrman grade (P = .002 and P = .01, respectively) and tumor stage (P = .006 and P = .008, respectively). In addition, VEGF expression was also correlated with tumor necrosis (P = .001) and progression (P = .001). We demonstrated that in CRCC with tumor necrosis, VEGF expression, pVEGF levels, and platelet count were significantly higher than in CRCC with no tumor necrosis (P = .001, P = .03, and P = .001, respectively). Our results revealed that cytoplasmic VEGF expression and pVEGF levels are associated with usual prognostic factors and progression in CRCC, which may allow VEGF to be used as a prognostic marker for CRCC, especially in patients with VEGF-targeted therapy.

Protective effects of vascular endothelial growth factor on intestinal epithelial apoptosis and bacterial translocation in experimental severe acute pancreatitis

OBJECTIVES

Bacterial translocation (BT) plays an important role in systemic complications in severe acute pancreatitis (SAP). We recently demonstrated that accelerated apoptosis of intestinal mucosa might have a role in BT. Effects of vascular endothelial growth factor (VEGF) on intestinal epithelial cell apoptosis and BT were investigated in SAP.

METHODS

Severe acute pancreatitis was induced by retrograde injection of sodium deoxycholate into the biliopancreatic duct in rats. Recombinant rat VEGF (2 microg) was injected, and SAP was immediately induced. Eight hours after the induction, serum amylase/lipase levels and apoptosis of ileal mucosa were evaluated. After 18 hours, the villous height of ileum was examined. After 22 hours, hematocrit, pancreatic water content, BT to the mesenteric lymph nodes, plasma plasminogen activator inhibitor 1 levels, and microvessel density in the small intestine were investigated.

RESULTS

Amylase/lipase levels were significantly elevated in SAP, but VEGF did not affect them. Apoptosis of ileal mucosa was accelerated in SAP, and VEGF significantly reduced the apoptosis. Villous height was significantly decreased in SAP, and VEGF significantly improved it. Vascular endothelial growth factor did not affect the hematocrit or pancreatic water content. Bacterial translocation occurred in the SAP group, and VEGF significantly prevented that. Plasminogen activator inhibitor 1 levels were significantly elevated in SAP, and VEGF significantly improved the elevation. Microvessel counts were significantly reduced in SAP, and VEGF significantly increased them.

CONCLUSION

These results suggest that VEGF inhibits intestinal epithelial cell apoptosis and subsequent BT in SAP.

Distinct roles of VEGFR-1 and VEGFR-2 in the aberrant hematopoiesis associated with elevated levels of VEGF

Vascular endothelial growth factor (VEGF), a major factor in tumor-host interactions, plays a critical role in the aberrant hematopoiesis observed in cancer-bearing hosts. To dissect the roles of VEGF receptor (VEGFR)-1 and VEGFR-2 in cancer-associated hematopoiesis in vivo, we selectively stimulated VEGFR-1 and VEGFR-2 by continuous infusion of receptor-specific ligands or selective blockade with VEGF receptor-specific antibodies in mice infused with recombinant VEGF at levels observed in tumor-bearing animals. We found that the effect of VEGF on the accumulation of Gr1(+)CD11b(+) cells is mediated by VEGFR-2, but that the 2 receptors have opposite effects on lymphocyte development. Pathophysiologic levels of VEGF strongly inhibit T-cell development via VEGFR-2, whereas VEGFR-1 signaling decreases this inhibition. VEGFR-1, and not VEGFR-2, signaling is responsible for the observed increase of splenic B cells. Both receptors are capable of inhibiting dendritic cell function. These data suggest that most of observed aberrant hematopoiesis caused by excess tumor-derived VEGF is mediated by VEGFR-2, and VEGFR-1 alone has very limited independent effects but clearly both positively and negatively modulates the effects of VEGFR-2. Our findings suggest that selective blockade of VEGFR-2 rather than of both receptors may optimally overcome the adverse hematologic consequences of elevated VEGF levels found in malignancy.

Serum VEGF as a significant marker of treatment response in hodgkin lymphoma

This pilot study aimed at determining serum VEGF levels (S-VEGF) at diagnosis and at restaging in children with Hodgkin lymphoma, and investigating whether this parameter provides prognostic information for remission after 2 courses of chemotherapy. PET-CT fusion was performed to assess response to treatment. Changes in S-VEGF levels were found to correlate with response to treatment for most of the children. This provides a rationale for exploring clinical interest in S-VEGF measurements in a larger group of children with Hodgkin lymphoma, and using the test for clinical trials of anti-angiogenic therapies.

Serum vascular endothelial growth factor (VEGF) and interleukin-8 (IL-8) levels in small cell lung cancer

This study was conducted to determine the value of the angiogenic serum factors, vascular endothelial growth factor (VEGF) and interleukin-8 (IL-8), in patients with small cell lung cancer (SCLC). These serum angiogenic factors were measured of 34 SCLC patients on the before and after chemotherapy in comparison with 20 healthy controls using ELISA method. Serum levels of VEGF and IL-8 were significantly increased in SCLC patients compared with healthy controls (p < 0.001). No statistically significant relationships was found between investigated elevated serum angiogenic parameters and various characteristics of patients and disease such as disease stage and tumor burden. Likewise, we also found no correlation between serum angiogenic factors. Cytotoxic therapy of patients was accompanied by unchanged serum levels of angiogenic factors. Contrary to serum IL-8, elevated serum levels of VEGF was determined as a prognostic factor for survival by univariate analysis (p = 0.05). Multivariate analysis revealed that independent prognostic factors of overall survival included only response to chemotherapy and weight loss (p < 0.001 for both). In conclusion, our data suggest that the angiogenic serum factors, VEGF and IL-8, are useful diagnostic factors, but not predictive and prognostic markers for overall survival in SCLC patients.

Placenta growth factor overexpression inhibits tumor growth, angiogenesis, and metastasis by depleting vascular endothelial growth factor homodimers in orthotopic mouse models

The role of placenta growth factor (PlGF) in pathologic angiogenesis is controversial. The effects of PlGF on growth, angiogenesis, and metastasis from orthotopic tumors are not known. To this end, we stably transfected three human cancer cell lines (A549 lung, HCT116 colon, and U87-MG glioblastoma) with human plgf-2 full-length cDNA. Overexpression of PlGF did not affect tumor cell proliferation or migration in vitro. The growth of PlGF-overexpressing tumors grown orthotopically or ectopically was impaired in all three tumor models. This decrease in tumor growth correlated with a decrease in tumor angiogenesis. The PlGF-overexpressing tumors had decreased vessel density and increased vessel diameter, but vessel permeability was not different from the parental tumors. Tumors overexpressing PlGF exhibited higher levels of PlGF homodimers and PlGF/vascular endothelial growth factor (VEGF) heterodimers but decreased levels of VEGF homodimers. Our study shows that PlGF overexpression decreases VEGF homodimer formation and inhibits tumor progression.

Vascular endothelial growth factor increases in serum and protects against the organ injuries in severe acute pancreatitis

BACKGROUND

We have demonstrated that apoptosis was detected in liver and kidney cells in severe acute pancreatitis and that cellular injury because of apoptosis may be involved in the mechanism of multiple organ dysfunction syndrome. Vascular endothelial growth factor (VEGF) is a glycoprotein with potent angiogenic, mitogenic, and vascular permeability-enhancing activities specific for endothelial cells. It has been reported that VEGF is implicated in many diseases such as cancer and inflammation.

METHODS

Serum VEGF concentrations were determined in patients with acute pancreatitis at the time of admission, and the relationships with severity, blood biochemical parameters on admission, organ dysfunction during the clinical course, and prognosis were analyzed. Moreover, to clarify the role of VEGF in acute pancreatitis, effects of VEGF were investigated in experimental severe acute pancreatitis.

RESULTS

Serum VEGF levels were significantly elevated in patients with acute pancreatitis. Serum VEGF levels were not related to severity or prognosis. In male patients, among the various blood biochemical parameters, serum lactate dehydrogenase, and blood urea nitrogen levels were positively correlated with serum VEGF levels. Serum VEGF levels with organ dysfunction (liver and kidney) were higher than those without organ dysfunction. In rat experimental severe acute pancreatitis, serum VEGF levels were significantly elevated. Recombinant VEGF did not affect the lung water content, volume of ascitic fluid, hematocrit, or serum amylase, but improved the hepatic and renal dysfunctions. Apoptosis of liver and kidney was significantly inhibited by the administration of VEGF.

CONCLUSIONS

These results suggest that VEGF is closely related to organ dysfunction in severe acute pancreatitis, and that VEGF may function as not a vascular permeability factor, but a protective factor via the anti-apoptotic effect against the organ injuries in this disease.

Angiogenesis in non-small cell lung cancer: The prognostic impact of neoangiogenesis and the cytokines VEGF and bFGF in tumours and blood

BACKGROUND

Due to a dismal prognosis of advanced lung cancer, novel screening tools and more effective treatments are clearly needed. Lately, an increasing number of tumour-released angiogenic cytokines which affect vessel formation, tumour growth, invasion, and metastasis have been identified. Vascular endothelial growth factors (VEGFs) and basic fibroblast growth factor (bFGF) are among the most important angiogenic factors. Based on available literature, we have explored the mechanisms of angiogenesis and its prognostic significance in non-small cell lung cancer, estimated by microvessel density (MVD) and the presence of VEGF and bFGF in the tumour and blood from NSCLC patients.

METHODS

Several comprehensive Pubmed searches for the period January 1993 to May 2005 were performed using strategic combinations of the terms non-small cell lung cancer, angiogenesis, vascular endothelial growth factor, basic fibroblast growth factor, tumour expression, microvessel density, circulating, and serum.

RESULTS

NSCLC neoangiogenesis, as measured by MVD, and tumour expression of VEGF are poor prognostic factors for survival (MVD, HR 1.8-2.0; VEGF, HR 1.5). bFGF tumour expression is also associated with poor survival and more aggressive disease. When evaluating the prognostic impact of elevated VEGF levels in blood, 10 of 16 studies (63%) indicated a negative prognostic impact. Of five studies on the prognostic value of circulating bFGF, three studies reported a negative prognostic impact, while one indicated bFGF as a good prognostic factor and one was inconclusive.

CONCLUSION

Angiogenic factors are poor prognostic indicators for tumour aggressiveness and survival in NSCLC. Assessments of circulating levels of VEGF and possibly bFGF may be valuable future tools for treatment planning and monitoring of treatment effect and relapse. First, however, these blood tests need to be standardised and validated in large-scale prospective clinical trials.

Alteration of protein expression pattern of vascular endothelial growth factor (VEGF) from soluble to cell-associated isoform during tumourigenesis

Background

Vascular endothelial growth factor (VEGF) is a potent mitogen for endothelial cells, and its expression has been correlated with increased tumour angiogenesis. Although numerous publications dealing with the measurement of circulating VEGF for diagnostic and therapeutic monitoring have been published, the relationship between the production of tissue VEGF and its concentration in blood is still unclear. The aims of this study were to determine: 1) The expression pattern of VEGF isoforms at the protein level in colorectal and lung adenocarcinoma in comparison to the pattern in corresponding adjacent normal tissues 2) The relationship between the expression pattern of VEGF and total level of circulating VEGF in the blood to clarify whether the results of measuring circulating VEGF can be used to predict VEGF expression in tumour tissues.

Methods

Ninety-four tissue samples were obtained from patients, 76 colorectal tumour tissues and 18 lung tumour tissues. VEGF protein expression pattern and total circulating VEGF were examined using western blot and capture ELISA, respectively.

Results

Three major protein bands were predominately detected in tumour samples with an apparent molecular mass under reducing conditions of 18, 23 and 26 kDa. The 18 kDa VEGF protein was expressed equally in both normal and colorectal tumour tissues and predominately expressed in normal tissues of lung, whereas the 23 and 26 kDa protein was only detected at higher levels in tumour tissues. The 18, 23 and 26 kDa proteins are believed to represent the VEGF₁₂₁, the VEGF₁₆₅ and the VEGF₁₈₉, respectively. There was a significant correlation of the expression of VEGF₁₆₅ with a smaller tumour size maximum diameter <5 cm (p < 0.05), and there was a significant correlation of VEGF₁₈₉ with advanced clinical stage of colorectal tumours. The measurement of total circulating VEGF in serum revealed that cancer patients significantly (p < 0.001) possessed a higher level of circulating VEGF (1081 ± 652 pg/ml in colorectal and 1,251 ± 568 pg/ml in lung) than a healthy volunteer group (543 ± 344 pg/ml). No correlation between the level of circulating VEGF and the pathologic features of tumours was observed.

Conclusion

Our findings indicate that the expression patterns of VEGF isoforms are altered during tumourigenesis as certain isoform overexpression in tumour tissues correlated with tumour progression indicating their important role in tumour development. However, measurement of VEGF in the circulation as a prognostic marker needs to be carefully evaluated as the cell-associated isoform (VEGF₁₈₉), but not the soluble isoform (VEGF₁₂₁ and VEGF₁₆₅) appears to play important role in tumour progression.