Vascular endothelial growth factor gene polymorphisms are associated with prognosis in ovarian cancer

An Investigation of the Association Between Vascular Endothelial Growth Factor +405 G/C Polymorphism and Acute Liver Transplant Rejection in Iranian Liver Transplant Recipients

OBJECTIVES

Vascular endothelial growth factor is an endothelial-specific growth factor that promotes endothelial cell proliferation, differentiation, and survival; mediates endothelium-dependent vasodilatation; induces microvascular hyperpermeability; and participates in interstitial matrix remodeling. The aim of the present study was to investigate the association between +405 G/C polymorphism of vascular endothelial growth factor and the risk of liver rejection in liver transplant recipients.

MATERIALS AND METHODS

The present study included 124 patients with liver disease that led to liver transplant. There were 22 patients who experienced histologically proven acute liver rejection, and the other 102 patients showed no rejection. Both groups were matched for sex and age. The VEGF+405 G/C polymorphism was evaluated by the polymerase chain reaction-restriction fragment-length polymorphism method.

RESULTS

Our analyses showed no significant relationships between genotypes and alleles of +405 G/C and risk of acute liver transplant rejection.

CONCLUSIONS

Our report indicated that there was no association between the carrier states of +405 G/C gene polymorphism of vascular endothelial growth factor and acute rejection or nonrejection of liver transplant.

Polyphenols Extracted from Chinese Hickory (Carya cathayensis) Promote Apoptosis and Inhibit Proliferation through the p53-Dependent Intrinsic and HIF-1α-VEGF Pathways in Ovarian Cancer Cells

Ovarian cancer is the second most common gynecologic cancer with an estimated 13,940 mortalities across the United States in 2020. Natural polyphenols have been shown to double the survival time of some cancer patients due to their anticancer properties. Therefore, the effect of polyphenols extracted from Chinese hickory seed skin Carya cathayensis (CHSP) on ovarian cancer was investigated in the present study. Cell viability results showed that CHSP is more effective in inhibiting ovarian cancer cells than normal ovarian cells, with the IC50 value for inhibition of cell proliferation of Ovarian cancer cells (OVCAR-3) being 10.33 ± 0.166 μg/mL for a 24 h treatment. Flow cytometry results showed that the apoptosis rate was significantly increased to 44.21% after 24 h treatment with 20 μg/mL of CHSP. Western blot analysis showed that CHSP induced apoptosis of ovarian cancer cells through a p53-dependent intrinsic pathway. Compared with control values, levels of VEGF excreted by OVCAR-3 cancer cells were reduced to 7.87% with a 40 μg/mL CHSP treatment. Consistent with our previous reports, CHSP inhibits vascular endothelial growth factor (VEGF) secretion by regulating the HIF-1α-VEGF pathway. In addition, we also found that the inhibitory effect of CHSP on ovarian cancer is related to the up-regulation of Phosphatase and tension homolog (PTEN) and down-regulation of nuclear factor kappa-B (NF-kappa B). These findings provide some evidence of the anti-ovarian cancer properties of CHSP and support the polyphenols as potential candidates for ovarian cancer adjuvant therapy.

Association of Genetic Variants in ANGPT/TEK and VEGF/VEGFR with Progression and Survival in Head and Neck Squamous Cell Carcinoma Treated with Radiotherapy or Radiochemotherapy

Angiogenesis is essential for growth, progression, and metastasis of solid tumors. Vascular endothelial growth factor (VEGF)/VEGF receptor (VEGFR) and angiopoietin (ANGPT)/ tyrosine kinase endothelial (TEK) signaling plays an important role in regulating angiogenesis. Very little is known about the effects of single-nucleotide polymorphisms (SNPs) in angiogenesis-related genes on treatment outcome in head and neck squamous cell carcinoma (HNSCC). Therefore, we evaluated the association between SNPs in ANGPT1, ANGPT2, TEK, VEGF, VEGFR1, and VEGFR2 genes and five clinical endpoints in 422 HNSCC patients receiving radiotherapy alone or combined with chemotherapy. Multivariate analysis showed an association of ANGPT2 rs3739391, rs3020221 and TEK rs639225 with overall survival, and VEGF rs2010963 with overall and metastasis-free survival. VEGFR2 rs1870377 and VEGF rs699947 affected local recurrence-free survival in all patients. In the combination treatment subgroup, rs699947 predicted local, nodal, and loco-regional recurrence-free survival, whereas VEGFR2 rs2071559 showed an association with nodal recurrence-free survival. However, these associations were not statistically significant after multiple testing correction. Moreover, a strong cumulative effect of SNPs was observed that survived this adjustment. These SNPs and their combinations were independent risk factors for specific endpoints. Our data suggest that certain germline variants in ANGPT2/TEK and VEGF/VEGFR2 axes may have predictive and prognostic potential in HNSCC treated with radiation or chemoradiation.

In-Vitro Anti-Proliferative, Apoptotic and Antioxidative Activities of Medicinal Herb Kalonji (Nigella sativa)

BACKGROUND

Natural product with apoptotic activity could serve as a potential new source for anti-cancer medicine. Numerous phytochemicals from plants have shown to exert antineoplastic effects via programmed cell death (apoptosis). Cancer is one of the leading causes of death in prosperous countries. The subject study was intended to evaluate the anticancer properties of Kalonji extracts against cancer cell lines HeLa and HepG2 and normal cell lines BHK and VERO were used as normal controls.

MATERIALS & METHODS

For the evaluation of anti-proliferative effects, cell viability and cell death in all groups of cells were evaluated via MTT, crystal violet and trypan blue assays. For the evaluation of angiogenesis, Immunocytochemistry and ELISA of VEGF were done. Immunocytochemistry and ELISA of Annexin-V and p53 were performed for the estimation of apoptosis in all groups of cells. Furthermore, LDH assay, antioxidant enzymes activity (GSH, APOX, CAT and SOD) and RT-PCR with proliferative and apoptotic markers along with internal control were also performed. Cancer cells of both cell lines HepG2 and HeLa cells showed reduced viability, angiogenesis and proliferation with increased apoptosis when treated with Kalonji extracts. Whereas anti-oxidative enzymes show enhanced levels in treated cancer cells as compared to untreated ones.

CONCLUSION

It was observed that Kalonji extracts have the ability to induce apoptosis and improve the antioxidant status of HeLa and HepG2 cells. They can also inhibit the proliferation and angiogenesis in both these cancer cell lines.

Analysis of VEGF gene polymorphisms and serum VEGF protein levels contribution in polycystic ovary syndrome of patients

Vascular endothelial growth factor (VEGF) is a well-known factor in reproductive function and contributes to the pathogenesis of polycystic ovary syndrome (PCOS). Genetic variations in VEGFA gene were suggested to contribute alterations in VEGF secretion and PCOS. This study evaluated the association of VEGFA SNPs with altered VEGF secretion level and PCOS among ethnically-matched control women. This prospective case-control study was conducted from 2016 to 2018 and comprised of 55 women with PCOS and 52 control subjects. ELISA was used to measure VEGF levels; and various other related bio chemicals whereas the genotyping of VEGFA variants was performed through the analysis of nine SNPs of VEGF. PRL, E2, PRGE testosterone and glucose level were found to be insignificantly different. The levels of FSH, LH, LH/FSH, TT, insulin, SHBG and HOMA-IR were significantly higher in the study group. Among the nine tested variants of VEGF SNPs, two SNPs rs3025020 and rs833061, consisted of TT (Recessive and Dominant homozygous, respectively) which were marginally higher in test. The SNP rs1570360 had significantly higher GG allele (32.73%) which was recessive homozygous. There was no significant difference observed in genotype frequencies related to higher value of VEGF. The genotype frequencies for the studied SNPs were in alignment with Hardy-Weinberg equilibrium (HWE). The mean serum VEGF levels got significantly increased in PCOS group. No significant association was found between VEGF genotypes and its serum levels. VEGF levels in rs699947 (AA-major homozygous), rs3025039 (CC-major homozygous) and rs833061 (TT & CC-major & minor homozygous) genotypes were significantly higher in PCOS. The study results evidently proved that the allelic variants in genes may be a factor for PCOS and VEGF serum levels with respect to few SNP variants only. These findings indicated that VEGF may be involved in PCOS status and confirmed the previous association between genetic variants in VEGF, serum level of VEGF protein and PCOS.

Vascular Endothelial Growth Factor (VEGF) Polymorphisms and Serum VEGF Levels in Women With Epithelial Ovarian Cancer, Benign Tumors, and Healthy Ovaries

OBJECTIVE

This study analyzed the relation of 5 single-nucleotide polymorphisms (SNPs) in the VEGF (vascular endothelial growth factor) gene in patients with epithelial ovarian cancer (EOC), compared with patients carrying benign tumors or healthy ovaries. We studied serum VEGF levels and the relation with SNPs and association between VEGF SNPs and haplotypes with progression-free survival (PFS) in patients with cancer.

METHODS

The genotyping of VEGF gene polymorphisms (-2578 C/A, -1154 G/A, -460 T/C, +405 G/C, +936 C/T) was performed in DNA isolated from blood samples of 100 women. The different genotypes were evaluated by quantitative real-time polymerase chain reaction. Vascular endothelial growth factor protein concentration was assessed in serum using solid-phase sandwich enzyme-linked immunosorbent assay.

RESULTS

We found statistically significant differences in the distribution of VEGF genotypes among the 3 groups of patients: -2578 C/A between those with EOC and healthy ovary (P = 0.04), -460 T/C between those with EOC and healthy ovary (P = 0.03), and -460 T/C between those with benign tumors and healthy ovary (P = 0.02). Vascular endothelial growth factor serum levels were analyzed in patients with EOC. Higher levels were found in patients with clear cell carcinoma compared with those with serous, mucinous, or endometrioid tumors (P < 0.05). No clear association was observed between VEGF SNPs and serum VEGF levels. There was no significant correlation between VEGF SNPs and PFS. In haplotype analysis, CGTCT and CGTGT showed worse prognosis without reaching the statistical significance. CGCGC and AGTGC haplotypes had statistically significant differences among patients with EOC, benign tumors, and healthy ovaries (Ps = 0.046 and 0.041, respectively).

CONCLUSIONS

The distribution of VEGF genotypes was different in patients with EOC, compared with those with benign tumors or women with healthy ovaries. Vascular endothelial growth factor serum levels were higher in patients with clear cell carcinoma. No correlation was found with improved PFS, but CGTCT and CGTGT haplotypes showed worse prognosis.

Dietary Compound Proanthocyanidins from Chinese bayberry (Myrica rubra Sieb. et Zucc.) leaves inhibit angiogenesis and regulate cell cycle of cisplatin-resistant ovarian cancer cells via targeting Akt pathway

Ovarian cancer is the leading cause of death from gynecological malignancy and natural products have drawn great attention for cancer treatment. Chinese bayberry leaves proanthocyanidin (BLPs) with epigallocatechin-3-O-gallate (EGCG) as its terminal and major extension units is unusual in the plant kingdom. In the present study, BLPs showed strong growth inhibitory effects on cisplatin-resistant A2780/CP70 cells by inhibiting angiogenesis and inducing G1 cell cycle arrest. BLPs reduced the tube formation in HUVECs and attenuated the wound healing ability in A2780/CP70 cells. BLPs further reduced the level of ROS and targeted Akt/mTOR/p70S6K/4E-BP-1 pathway to reduce the expression of HIF-1α and VEGF, and thus inhibited angiogenesis. Furthermore, BLPs induced G1 cell cycle arrest by reducing the expressions of c-Myc, cyclin D1 and CDK4, which was also in accordance with the flow cytometry analysis. Overall, these results indicated that BLPs could be a valuable resource of natural compounds for cancer treatment.

Genetic variants as ovarian cancer first-line treatment hallmarks: A systematic review and meta-analysis

BACKGROUND

The potential predictive value of genetic polymorphisms in ovarian cancer first-line treatment is inconsistently reported. We aimed to review ovarian cancer pharmacogenetic studies to update and summarize the available data and to provide directions for further research.

METHODS

A systematic review followed by a meta-analysis was conducted on cohort studies assessing the involvement of genetic polymorphisms in ovarian cancer first-line treatment response retrieved through a MEDLINE database search by November 2016. Studies were pooled and summary estimates and 95% confidence intervals (CI) were calculated using random or fixed-effects models as appropriate.

RESULTS

One hundred and forty-two studies gathering 106871 patients were included. Combined data suggested that GSTM1-null genotype patients have a lower risk of death compared to GSTM1-wt carriers, specifically in advanced stages (hazard ratio (HR), 0.68; 95% CI, 0.48-0.97) and when submitted to platinum-based chemotherapy (aHR, 0.61; 95% CI, 0.39-0.94). ERCC1 rs11615 and rs3212886 might have also a significant impact in treatment outcome (aHR, 0.67; 95% CI, 0.51-0.89; aHR, 1.28; 95% CI, 1.01-1.63, respectively). Moreover, ERCC2 rs13181 and rs1799793 showed a distinct ethnic behavior (Asians: aHR, 1.41; 95% CI, 0.80-2.49; aHR, 1.07; 95% CI, 0.62-1.86; Caucasians: aHR, 0.10; 95% CI, 0.01-0.96; aHR, 0.18; 95% CI, 0.05-0.68, respectively).

CONCLUSION(S)

The definition of integrative predictive models should encompass genetic information, especially regarding GSTM1 homozygous deletion. Justifying additional pharmacogenetic investigation are variants in ERCC1 and ERCC2, which highlight the DNA Repair ability to ovarian cancer prognosis. Further knowledge could aid to understand platinum-treatment failure and to tailor chemotherapy strategies.

Prognostic significance of vascular endothelial growth factor polymorphisms in colorectal cancer patients

AIM

To investigate the associations of the genetic polymorphisms of vascular endothelial growth factor A (VEGF-A) -1498C>T and -634G>C, with the survival of patients with colorectal cancer (CRC).

METHODS

A prospective cohort consisting of 131 Brazilians patients consecutively operated on with a curative intention as a result of sporadic colorectal carcinoma was studied. DNA was extracted from peripheral blood and its amplification and allelic discrimination for each genetic polymorphism was performed using the technique of polymerase chain reaction (PCR) in real-time. The real-time PCR technique was used to identify the VEGF-A -1498C>T (rs833031) and -634G>C (rs2010963) polymorphisms. Genotyping was validated for VEGF-A -1498C>T polymorphism in 129 patients and for VEGF-A -634G>C polymorphism in 118 patients. The analysis of association between categorical variables was performed using logistic regression, survival by Kaplan-Meier method and multivariate analysis by the Cox regression method.

RESULTS

In the univariate analysis there was a significant association (OR = 0.32; P = 0.048) between genotype CC of the VEGF-A -1498C>T polymorphism and the presence of CRC liver metastasis. There was no association between VEGF-A -1498C>T polymorphism and VEGF-A -634G>C polymorphism with further clinical or anatomopathologic variables. The genotype CC of the VEGF-A -1498C>T polymorphism was significantly correlated with the 5-year survival (P = 0.032), but not significant difference (P = 0.27) was obtained with the VEGF-A -634G>C polymorphism with the 5-year survival in the univariate analysis. The genotype CT (HR = 2.79) and CC (HR = 4.67) of the polymorphism VEGF-A -1498C>T and the genotype CC (HR = 3.76) of the polymorphism VEGF-A -634C>G acted as an independent prognostic factor for the risk of death in CRC patients.

CONCLUSION

The CT and CC genotypes of the VEGF-A -1498C>T and the CC genotype of the VEGF-A -634C>G polymorphisms are prognostic factors of survival in Brazilians patients with sporadic colorectal carcinoma.

Analysis of VEGFA Variants and Changes in VEGF Levels Underscores the Contribution of VEGF to Polycystic Ovary Syndrome

Background

Vascular endothelial growth factor (VEGF) contributes to the pathogenesis of polycystic ovary syndrome (PCOS), and genetic variations in VEGFA gene were suggested to contribute to VEGF secretion and PCOS.

Aim

To evaluate the association of altered VEGF levels, stemming from the presence of specific VEGFA variants, with altered risk of PCOS.

Subjects and Methods

Retrospective case-control study, performed between 2012–2015. Study subjects comprised 382 women with PCOS, and 393 control subjects. ELISA measured VEGF levels; genotyping of VEGFA variants was done by allelic exclusion.

Results

Among the 12 tested VEGFA SNPs, minor allele frequency of only rs3025020 was significantly higher in PCOS cases than control women. Increased and reduced PCOS risk was seen with rs3025020 and rs2010963 genotypes, respectively. Increases and reduction in VEGF levels were associated with rs3025020 and rs2010963, respectively. Increased fasting insulin and HOMA-IR, and bioactive testosterone were linked with rs3025020, while carriage of rs2010963 was linked with reduction in fasting insulin, and free and bioactive testosterone. Of the 12 VEGFA variants, 9 were in LD, thus allowing construction of 9-locus haplotypes. Increased frequency of CAACAGCGA haplotype was seen in PCOS cases, after controlling for BMI, free and bioactive testosterone, SHBG, free insulin and HOMA-IR.

Conclusion

This study confirms the contribution of altered VEGF secretion, resulting from genetic variation in VEGFA gene into the pathogenesis of PCOS. This supports a role for VEGF as PCOS candidate locus.

The Different Effect of VEGF Polymorphisms on the Prognosis of Non-Small Cell Lung Cancer according to Tumor Histology

Vascular endothelial growth factor (VEGF) contributes to tumor angiogenesis. The role of VEGF single nucleotide polymorphisms (SNPs) in lung cancer susceptibility and its prognosis remains inconclusive and controversial. This study was performed to investigate whether VEGF polymorphisms affect survival outcomes of patients with early stage non-small cell lung cancer (NSCLC) after surgery. Three potentially functional VEGF SNPs (rs833061T>C, rs2010963G>C, and rs3025039C>T) were genotyped. A total of 782 NSCLC patients who were treated with surgical resection were enrolled. The association of the SNPs with overall survival (OS) and disease free survival (DFS) was analyzed. In overall population, none of the three polymorphisms were significantly associated with OS or DFS. However, when the patients were stratified by tumor histology, squamous cell carcinoma (SCC) and adenocarcinoma (AC) had significantly different OS (Adjusted hazard ratio [aHR] = 0.76, 95% CI = 0.56-1.03 in SCC; aHR = 1.33, 95% CI = 0.98-1.82 in AC; P for heterogeneity = 0.01) and DFS (aHR = 0.75, 95% CI = 0.58-0.97 in SCC; aHR = 1.26, 95% CI = 1.00-1.60 in AC; P for heterogeneity = 0.004) according to the rs833061T>C genotypes. Our results suggest that the prognostic role of VEGF rs833061T>C may differ depending on tumor histology.

VEGF gene polymorphisms and outcome of epithelial ovarian cancer patients

AIM

Since VEGF polymorphisms were associated with variable protein production, we analyzed herein their roles in outcome of epithelial ovarian cancer (EOC) patients.

METHODS

Genotypes of 85 patients with primary EOC were identified in DNA by real-time PCR. Progression-free survival and overall survival were analyzed using Kaplan-Meier method, univariate Cox model and bootstrap resampling study.

RESULTS

At 60 months of follow-up, progression-free survival was shorter in patients with VEGF c.-2578 CC genotype compared with others (52.7 vs 82.2%; p = 0.04). Those patients had 2.15 more chance of presenting disease progression than others (p = 0.04); bootstrap study validated the result (p = 0.03).

CONCLUSION

Our data suggest that VEGF c.-2578C>A polymorphism acts as a prognostic factor in EOC.

Role of five small nucleotide polymorphisms in the VEGF gene on the susceptibility to osteosarcoma and overall survival of patients

The present study aimed to investigate the association between five common small nucleotide polymorphisms (SNPs) in the VEGF gene and the risk of osteosarcoma. An additional aim was to investigate the role of these five SNPs on the prognosis of osteosarcoma. A total of 186 patients with osteosarcoma and 186 age- and sex-matched healthy controls were enrolled into the present study. A polymerase chain reaction-restriction fragment length polymorphism assay was conducted to determine the incidence of the VEGF-2578 C/A, -1156 G/A, +1612 G/A, +936 C/T and -634 G/C polymorphisms. Conditional logistic regression analyses revealed that individuals carrying the -634 GG genotype possessed a significantly increased risk of osteosarcoma, with an adjusted odds ratio [(95% confidence interval (CI)] of 2.00 (1.07-3.75). In the Cox proportional hazards model, subsequent to adjusting for potential confounding factors, patients with osteosarcoma carrying the -634 GG genotype were found to demonstrate a shorter overall survival time (hazard ratio, 3.10; 95% CI, 1.17-8.38). The VEGF-634 G/C polymorphism may therefore be used as a genetic marker for the prediction of the risk and clinical outcome of osteosarcoma.

Dietary compounds galangin and myricetin suppress ovarian cancer cell angiogenesis

Galangin and myricetin are flavonoids isolated from vegetables and fruits which exhibit anti-proliferative activity in human cancer cells. In this study, their anti-angiogenic effects were investigated with in vitro (HUVEC) and in vivo (CAM) models, which showed that galangin and myricetin inhibited angiogenesis induced by OVCAR-3 cells. The molecular mechanisms through which galangin and myricetin suppress angiogenesis were also studied. It was observed that galangin and myricetin inhibited secretion of the key angiogenesis mediator vascular endothelial growth factor (VEGF) and decreased levels of p-Akt, p-70S6K and hypoxia-inducible factor-1α (HIF-1α) proteins in A2780/CP70 and OVCAR-3 cells. Transient transfection experiments showed that galangin and myricetin inhibited secretion of VEGF by the Akt/p70S6K/ HIF-1α pathway. Moreover, a novel pathway, p21/HIF-1α/VEGF, was found to be involved in the inhibitory effect of myricetin on angiogenesis in OVCAR-3 cells. These data suggest that galangin and myricetin might serve as potential anti-angiogenic agents in the prevention of ovarian cancers dependent on new blood vessel networks.

A vascular endothelial growth factor gene polymorphism predicts malignant potential in intraductal papillary mucinous neoplasm

OBJECTIVES

The aim of this study was to evaluate the clinical relevance of vascular endothelial growth factor (VEGF) single nucleotide polymorphisms (SNPs) in intraductal papillary mucinous neoplasms (IPMNs).

METHODS

A total of 169 IPMN and 108 pancreatic ductal adenocarcinoma patients who underwent curative resection were enrolled, and VEGF +405G/C and -460C/T SNPs were investigated.

RESULTS

Vascular endothelial growth factor +405C/C was found more frequently in malignant IPMNs compared with +405G/G (odds ratio [OR], 2.7; P = 0.04), and +405C allele was associated with malignant IPMNs compared with +405G (P = 0.055). In branch duct IPMNs, VEGF +405C/C was significantly associated with malignant transformation (CC vs GG: OR, 4.0; P = 0.03; CC vs CG + GG: OR, 3.3; P = 0.04), and there was a trend of VEGF +405C/C associated with malignant transformation of gastric-type IPMNs (CC vs GG: OR, 3.0; P = 0.07). When the survival outcomes were analyzed based on VEGF +405G/C SNPs, however, there was no relationship between VEGF SNPs and overall survival in patients with both IPMNs and pancreatic ductal adenocarcinomas.

CONCLUSIONS

Vascular endothelial growth factor +405G/C SNP was significantly associated with malignant transformation in IPMNs, especially branch duct and gastric-type IPMNs. Vascular endothelial growth factor +405G/C SNP might be helpful in predicting clinical course in pancreatic disease with potential for malignant transformation.

The flavonoid nobiletin inhibits tumor growth and angiogenesis of ovarian cancers via the Akt pathway

Despite its importance, the death rate of ovarian cancer has remained unchanged over the past five decades, demanding an improvement in prevention and treatment of this malignancy. With no known carcinogens, targeted prevention is currently unavailable, and efforts in early detection of this malignancy by screening biomarkers have failed. The inhibition of angiogenesis, also known as angioprevention, is a promising strategy to limit the growth of solid tumors, including ovarian cancers. Nobiletin, a polymethoxy flavonoid compound isolated from the tiansheng plant, has been shown to inhibit the growth of multiple types of human cancers. However, there are no reports involving the effect on nobiletin on human ovarian cancer. The present report shows that nobiletin potently decreases the viability of ovarian cancer cells in vitro. However, nobiletin does not affect the viability of normal ovarian epithelial cells at <40 μM. The antitumor activity of nobiletin was also observed in athymic mouse models and in chicken chorioallantoic membrane (CAM) models. The anti-neoplastic activity of nobiletin was due to its ability to inhibit angiogenesis. We also studied the molecular mechanisms by which nobiletin suppresses angiogenesis. We observed that nobiletin inhibits secretion of the key angiogenesis mediators, Akt, HIF-1α, NF-κB and vascular epithelial growth factor (VEGF) by ovarian cancer cells. Transient transfection experiments showed that nobiletin inhibits production of HIF-1α by downregulation of Akt. Such decreased levels of HIF-1α were responsible for nobiletin-induced suppression of VEGF. Our data suggest that nobiletin may be a promising anti-angiogenic agent relevant for therapy of ovarian cancers.

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.

Predictive value of vascular endothelial growth factor polymorphisms on the clinical outcome of renal cell carcinoma patients

A cohort study was conducted to investigate the association between vascular endothelial growth factor (VEGF) polymorphisms −2578C/A, −1154G/A and −634C/G and the clinical outcome of renal cell carcinoma (RCC), as well as the interaction of VEGF polymorphisms with tumor stage, metastasis and size. A total of 310 RCC patients were recruited from the First Affiliated Hospital of Zhengzhou University (Zhengzhou, China) between January 2006 and December 2007, and were followed up until December 2012. The association between the three single nucleotide polymorphisms and the overall survival of RCC patients was estimated using Cox’s proportional hazard regression model. The median follow-up duration was 34.7 months and 74 of the RCC patients succumbed due to cancer during the follow-up period. The frequency of the VEGF −2578 AA genotype was significantly higher in patients classed as tumor stages III–IV (odds ratio [OR], 0.47; 95% confidence interval [CI], 0.24–0.95) and larger tumors (longest diameter, >4 cm; OR, 0.44; 95% CI, 0.22–0.89). Furthermore, the frequency of VEGF −634 GG was significantly higher in patients with larger tumors (longest diameter, >4 cm; OR, 0.68; 95% CI, 0.48–0.97). The VEGF −2578 AA genotype was correlated with a 2.96-fold increase in the risk of RCC-associated mortality and was associated with a five-year survival rate of ~25%. Therefore, the present study identified that the VEGF −2578C/A polymorphism may be associated with the prognosis of RCC patients, and may interact with the tumor stage and size.

Association of +405C>G and +936C>T polymorphisms of the vascular endothelial growth factor gene with sporadic breast cancer in North Indians

BACKGROUND

Vascular endothelial growth factor (VEGF), an endothelial cell specific mitogen, has been implicated as a critical factor influencing tumor related angiogenesis. The aim of present study was to evaluate the relationship between VEGF +936C>T and +405C>G polymorphisms of VEGF with risk of breast cancer in Punjab, India.

MATERIALS AND METHODS

We screened DNA samples of 192 sporadic breast cancer patients and 192 unrelated healthy, gender and age matched control individuals for VEGF +936C>T and +405C>G polymorphisms using the PCR-RFLP method.

RESULTS

For the VEGF +405C>G polymorphism, we observed significantly increased frequency of GG genotype in cases as compared to controls and strong association of +405GG genotype was observed with three fold risk for breast cancer (OR=3.07; 95%CI 1.41-6.65; p=0.003). For the +936C>T polymorphism, significant associations of CT and combined CT+TT genotypes were observed with elevated risk of breast cancer (p=0.021; 0.023). The combined genotype combinations of GG-CC and GG- CT of +405C>G and +936C>T polymorphisms were found to be significantly associated with increased risk of breast cancer (p=0.04; 0.0064).

CONCLUSIONS

The findings of the present study indicated significant associations of VEGF +936C>T and +405C>G polymorphisms with increased breast cancer risk in patients from Punjab, North India.

C936T polymorphism of the VEGF gene in relation to the risk and the clinical and biological characteristics of sporadic colorectal adenocarcinoma

Background

One of the main glycoproteins responsible for angiogenesis is the vascular endothelial growth factor. It is believed that C936T polymorphism, located in the VEGF gene, is correlated with susceptibility towards development of sporadic colorectal adenocarcinoma. The aim of this study was to identify the frequencies of the genotypes of C936T polymorphism of the VEGF gene in patients with sporadic colorectal adenocarcinoma, in comparison with controls, and whether this correlates with the degree of tumor invasion, lymph node involvement and occurrence of metastases at the time of the diagnosis. The analysis was done on 261 patients with sporadic colorectal adenocarcinoma and 261 controls. The genotypes of C936T polymorphism were evaluated by means of the polymerase chain reaction and enzyme digestion, using peripheral blood samples.

Results

The occurrences of genotype 936CC were similar in the two groups (80.5% versus 78.5%, p = 0.2288). In relation to tumor location, lymph node involvement, infiltration and tumor metastasis, no statistically significant results were obtained (p = 0.3116, p = 0.8485, p = 0.9408 and p = 0.2861, respectively).

Conclusion

C936T polymorphism of the VEGF gene did not influence the occurrence of sporadic colorectal adenocarcinoma development and did not correlated with the degree of tumor invasion, lymph node involvement and occurrence of metastases.

Single-nucleotide polymorphisms in the vascular endothelial growth factor pathway and outcomes of patients treated with first-line cytotoxic chemotherapy combined with bevacizumab for advanced colorectal cancer

OBJECTIVE

The aim of this study was to evaluate the association between the efficacy of first-line cytotoxic chemotherapy plus bevacizumab and single-nucleotide polymorphisms (SNPs) of angiogenic genes in patients with advanced colorectal cancer (CRC).

METHODS

DNA was extracted from blood samples of 125 patients, and 12 SNPs were evaluated for association with the objective response rate (ORR), progression-free survival (PFS), and overall survival (OS).

RESULTS

The vascular endothelial growth factor A (VEGFA) rs833061 T/T was associated with superior ORR compared to its alternative genotypes (75.9 vs. 50.8%; p = 0.008), and the interleukin 8 rs4073 A/A genotype tended to be associated with poor ORR (45.0 vs. 66.0%; p = 0.067). The median PFS and OS were superior in patients with the fms-related tyrosine kinase 1 (FLT1) rs9513070 A/A genotype (8.7 vs. 6.6 months; p = 0.001 and 26.4 vs. 16.1 months; p = 0.038, respectively). The kinase insert domain receptor rs1531289 G/G genotype tended to be associated with improved PFS (8.0 vs. 7.1 months; p = 0.069). In haplotype analysis, the FLT1 rs9513070/rs9554320/rs9582036 GCA haplotype was associated with inferior PFS and OS (p = 0.004 and p = 0.041, respectively).

CONCLUSION

The VEGFA rs833061 SNP is associated with the ORR, and the FLT1 rs9513070 SNP and FLT1 GCA haplotypes are associated with PFS and OS in advanced CRC patients treated with cytotoxic chemotherapy plus bevacizumab.

Association of vascular endothelial growth factor polymorphisms with clinical outcome of renal cell carcinoma patients

We investigated the association of three single nucleotide polymorphisms (SNPs) in VEGF gene with the prognosis of renal cell carcinoma (RCC) and its association with clinical characteristics of RCC, such as tumor stages, metastasis, and tumor size. Polymerase chain reaction (PCR) restriction fragment length polymorphism analysis was used to genotype specimens for three polymorphisms (-2578C/A, -1154G/A, and -634G/C) in the VEGF gene. Hazard ratios (HRs) and their confidence intervals (CIs) were used to analyze the association of three SNPs in the VEGF gene with survival time using a multivariate Cox proportional hazards model. Frequencies of VEGF-2578AA genotype and A allele were significantly higher in patients with III-IV tumor stage or larger tumor size when compared with CC genotype. Moreover, frequencies of VEGF-634CC genotype and C allele were significantly higher in patients with tumor size >4 cm when compared with -634GG genotype. By Cox proportional hazards model, patients carrying VEGF-2578AA genotype and A allele significantly increased the risk of death from RCC, with the adjusted HRs (95 % CI) of 2.23 (1.15-4.36) and 1.55 (1.11-2.17), respectively. Our study suggests that VEGF-2578C/A and VEGF-634G/C polymorphisms may have effects on the prognosis of RCC. This finding might help in clarifying the mechanisms of RCC development and progression.

Association between VEGF -634G/C polymorphism and diseases

Vascular endothelial growth factor (VEGF) is a special heparin-binding growth factor, and can significantly stimulate vasculogenesis and angiogenesis in both cancer and healthy tissues. There have been many studies confirming that the single nucleotide polymorphisms (SNP) of VEGF have a close relationship with the occurrence, development, and prognosis of diseases. According to statistics, the human VEGF gene has at least 30 SNP loci, among which VEGF -634C/G, -936C/T and -2578C/A mutations have been proved to regulate the VEGF plasma levels. Here we review the recent advances in understanding the association between VEGF -634G/C polymorphism and diseases.

VEGF pathway polymorphisms as prognostic and pharmacogenetic factors in cancer: a 2013 update

With the recent advances in genomic medicine and the development of targeted antiangiogenic therapy for cancer patients, there has been an increased interest in the role of predictive and prognostic markers for antiangiogenic therapy. Here, we provide a summary of the angiogenesis pathway, the role of predictive and prognostic markers in cancer and a summary of the current literature and studies on predictive and prognostic markers for antiangiogenic therapy. Our aim is to summarize those studies that are currently in the literature with an emphasis on the future directions of the field from 2013 and beyond. We conclude by providing our perspective on the future directions of this growing field, as well as possible challenges and pitfalls along the way.

Endothelial progenitor cells contribute to the development of ovarian carcinoma tumor blood vessels

Only a few studies in the literature have reported the contribution of endothelial progenitor cells (EPCs) in ovarian tumors, and with regard to malignant tumors, the data on the pre-existing endothelium insertion rate and the extent to which these cells contribute to tumor angiogenesis is controversial. The present study demonstrated the existence of EPCs and evaluated the expression of two markers, AC133 (also known as cluster of differentiation 133 or prominin) and tyrosine kinase with immunoglobulin-like and EGF-like domains 2 (Tie2), signaling the presence of EPCs in the pre-existing endothelium. In total, 62 female patients who were diagnosed with ovarian tumors were retrospectively selected over a four-year period. Immunohistochemical analyses used Tie2 and AC133 as primary antibodies. In total, 27.4% of ovarian tumor cases expressed AC133 and Tie2 in blood vessel endothelial cells. The expression of these two markers did not correlate with the clinicopathological prognostic parameters, histological type, vascular microdensity or vessel type. The expression of AC133 and Tie2 in blood vessel endothelial cells contributes to angiogenesis progression in cases where the budding process is reduced or absent, as shown by the inverse correlation with the rate of proliferation of the endothelial cells.

Clinical significance of vascular endothelial growth factor and vascular endothelial growth factor receptor-2 gene polymorphisms in patients with gastrointestinal stromal tumors

AIM

The vascular endothelial growth factor (VEGF) or its family might play role in tumor-related angiogenesis in gastrointestinal stromal tumors (GIST), thereby affecting the prognosis. Accordingly, the present study analyzed the impact of VEGF and VEGF receptor-2 (VEGFR-2) gene polymorphisms on the prognosis for GIST patients.

METHODS

In all, 213 consecutive patients with GIST from five medical centers were enrolled in the present study. The genomic DNA was extracted from paraffin-embedded tumor tissue, and four VEGF (-2578C/A, -1498C/T, -634G/C, and +936C/T) and one VEGFR-2 (+1416A/T) gene polymorphisms were determined using a Sequenom MassARRAY system.

RESULTS

With a median follow up of 18.4 months, the estimated 5-year relapse-free survival and overall survival rates were 70 and 87%, respectively. In a multivariate analysis including age, sex, primary site of disease, pathology and risk stratification, no significant association was observed between the polymorphism of the VEGF and VEGFR-2 genes and survival.

CONCLUSION

None of the five VEGF and VEGFR-2 gene polymorphisms investigated in this study was found to be an independent prognostic marker for Korean patients with surgically resected GIST. However, further studies on a larger scale are warranted to clarify the role of VEGF and VEGFR gene polymorphisms as a prognostic biomarker for GIST patients.

Prevalence of +405G>C,-1154G>A Vascular Endothelial Growth Factor Polymorphism in Breast Cancer

Vascular endothelial growth factor (VEGF) plays an important role in the development of Breast Cancer. The aim of this study was to investigate the association of polymorphisms in the VEGF gene on prognosis of Breast Cancer patients. This study comprised 200 patients with histologically confirmed cases of Breast cancer and 200 controls. Genotyping of the VEGF gene polymorphisms at +405G>C,-1154G>A, were performed by PCR-RFLP analysis. Preoperative plasma VEGF levels were determined by ELISA. Amongst both cases and controls, the genotypic distribution of the individual SNPs were all in Hardy-Weinberg equilibrium. Mean VEGF level was significantly elevated in cases compared to controls (t = 8.248; P < 0.001). No significant association was found between +405G>C,-1154G>A VEGF polymorphism and Breast Cancer. Logistic regression analysis revealed that 405GG & 1154GG were associated with higher levels of VEGF.

Influence of vascular endothelial growth factor single nucleotide polymorphisms on non-small cell lung cancer tumor angiogenesis

Vascular endothelial growth factor (VEGF) plays an important role in tumor angiogenesis. Several studies have reported that genomic VEGF polymorphisms may influence VEGF synthesis. To evaluate the role of VEGF single nucleotide polymorphisms (SNPs), we examined the expression of several angiogenesis-related proteins [VEGF, hypoxia-inducible factor-1α (HIF-1α) and delta-like ligand 4 (Dll4)] and the spread of microvessels in resected non-small cell lung cancer (NSCLC). Blood and tumor tissue from 83 patients with NSCLC were examined for VEGF −460T/C (rs833061) and VEGF +405G/C (rs2010963) SNPs using the SNaPshot method. Immunohistochemical staining was performed to measure protein expression and microvessel density (MVD). VEGF −460T/C and +405G/C SNPs showed no association with VEGF or HIF-1α expression and MVD. Patients with VEGF −460TT and the TC genotype had significantly higher MVD compared to those with the CC genotypes. Furthermore, patients with the VEGF −460TT genotype had significantly higher Dll4 expression compared to those with the TC or CC genotypes, while the VEGF +405G/C SNP displayed no association with Dll4 expression and MVD. These findings indicate that the VEGF −460T/C SNP may have a functional influence on tumor angiogenesis in NSCLC. We hypothesize that VEGF SNPs may influence angiogenesis through Dll4.

Vascular endothelial growth factor pathway polymorphisms as prognostic and pharmacogenetic factors in cancer: a systematic review and meta-analysis

Angiogenesis is an important host process that interacts with cancer cells to promote growth, invasion, and metastasis. Numerous therapeutic agents targeting the VEGF pathway have been developed. Host variability in VEGF pathway can influence angiogenesis-dependent signaling, altering sensitivity to antiangiogenic drugs and prognosis. A systematic review and meta-analysis was conducted (May 1990-July 2011). Eligible studies involved cancer patients and compared polymorphisms in the VEGF pathway [VEGF and molecules directly interacting with VEGF: KDR, FLT1, FGF, FGF2, FGFR, NRP1, endostatin (encoded by COL18A1)], and reported one of the following outcomes: overall survival, progression-free survival, time to recurrence, disease-free survival, response rate, or drug toxicity. We identified 48 cancer studies assessing prognosis and 12 cancer studies exploring pharmacogenetics of anti-VEGF therapy across various VEGF pathway polymorphisms. There was marked inter- and intradisease site heterogeneity in the effect of polymorphisms on both outcome and response to therapy. Meta-analyses of 5 VEGF polymorphisms (+936C>T, -460T>C, +405G>C, -1154G>A, and -2578C>A) identified a significant prognostic relationship: VEGF +405G>C variants showed a highly statistically significant improvement in overall survival [HR, 0.74; 95% confidence interval, 0.60-0.91; P = 0.004]. Variants (heterozygotes and/or homozygotes) of VEGF +405G>C were significantly associated with improved survival in a meta-analysis of multiple cancer sites.

Ovarian cancer: emerging molecular-targeted therapies

With about 22,000 new cases estimated in 2012 in the US and 15,500 related deaths, ovarian cancer is a heterogeneous and aggressive disease. Even though most of patients are sensitive to chemotherapy treatment following surgery, recurring disease is almost always lethal, and only about 30% of the women affected will be cured. Thanks to a better understanding of the molecular mechanisms underlying ovarian cancer malignancy, new therapeutic options with molecular-targeted agents have become available. This review discusses the rationale behind molecular-targeted therapies and examines how newly identified molecular targets may enhance personalized therapies for ovarian cancer patients.

Targeting the insulin growth factor and the vascular endothelial growth factor pathways in ovarian cancer

Antiangiogenic therapy is emerging as a highly promising strategy for the treatment of ovarian cancer, but the clinical benefits are usually transitory. The purpose of this study was to identify and target alternative angiogenic pathways that are upregulated in ovarian xenografts during treatment with bevacizumab. For this, angiogenesis-focused gene expression arrays were used to measure gene expression levels in SKOV3 and A2780 serous ovarian xenografts treated with bevacizumab or control. Reverse transcription-PCR was used for results validation. The insulin growth factor 1 (IGF-1) was found upregulated in tumor and stromal cells in the two ovarian xenograft models treated with bevacizumab. Cixutumumab was used to block IGF-1 signaling in vivo. Dual anti-VEGF and IGF blockade with bevacizumab and cixutumumab resulted in increased inhibition of tumor growth. Immunohistochemistry measured multivessel density, Akt activation, and cell proliferation, whereas terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) assay measured apoptosis in ovarian cancer xenografts. Bevacizumab and cixutumumab combination increased tumor cell apoptosis in vivo compared with therapy targeting either individual pathway. The combination blocked angiogenesis and cell proliferation but not more significantly than each antibody alone. In summary, IGF-1 activation represents an important mechanism of adaptive escape during anti-VEGF therapy in ovarian cancer. This study provides the rationale for designing bevacizumab-based combination regimens to enhance antitumor activity.

Significance of vascular endothelial growth factor in growth and peritoneal dissemination of ovarian cancer

Vascular endothelial growth factor (VEGF) is a key regulator of angiogenesis which drives endothelial cell survival, proliferation, and migration while increasing vascular permeability. Playing an important role in the physiology of normal ovaries, VEGF has also been implicated in the pathogenesis of ovarian cancer. Essentially by promoting tumor angiogenesis and enhancing vascular permeability, VEGF contributes to the development of peritoneal carcinomatosis associated with malignant ascites formation, the characteristic feature of advanced ovarian cancer at diagnosis. In both experimental and clinical studies, VEGF levels have been inversely correlated with survival. Moreover, VEGF inhibition has been shown to inhibit tumor growth and ascites production and to suppress tumor invasion and metastasis. These findings have laid the basis for the clinical evaluation of agents targeting VEGF signaling pathway in patients with ovarian cancer. In this review, we will focus on VEGF involvement in the pathophysiology of ovarian cancer and its contribution to the disease progression and dissemination.

Role of common genetic variants in ovarian cancer susceptibility and outcome: progress to date from the Ovarian Cancer Association Consortium (OCAC)

In this article, we review the current knowledge of the inherited genetics of epithelial ovarian cancer (EOC) susceptibility and clinical outcome. We focus on recent developments in identifying low-penetrance susceptibility genes and the role of the Ovarian Cancer Association Consortium (OCAC) in these discoveries. The OCAC was established to facilitate large-scale replication analyses for reported genetic associations for EOC. Since its inception, the OCAC has conducted both candidate gene and genome-wide association studies (GWAS); the latter has identified six established loci for EOC susceptibility, most of which showed stronger association with the serous histological subtype. Future GWAS and sequencing studies are likely to result in the discovery of additional susceptibility loci and may result in established associations with clinical outcome. Additional rare and uncommon ovarian cancer loci will likely be uncovered from high-throughput next-generation sequencing studies. Applying these novel findings to establish improved preventative and clinical intervention strategies will be one of the major challenges of future work.

Ovarian cancer: opportunity for targeted therapy

Ovarian cancer is a common cause of cancer mortality in women with limited treatment effectiveness in advanced stages. The limitation to treatment is largely the result of high rates of cancer recurrence despite chemotherapy and eventual resistance to existing chemotherapeutic agents. The objective of this paper is to review current concepts of ovarian carcinogenesis. We will review existing hypotheses of tumor origin from ovarian epithelial cells, Fallopian tube, and endometrium. We will also review the molecular pathogenesis of ovarian cancer which results in two specific pathways of carcinogenesis: (1) type I low-grade tumor and (2) type II high-grade tumor. Improved understanding of the molecular basis of ovarian carcinogenesis has opened new opportunities for targeted therapy. This paper will also review these potential therapeutic targets and will explore new agents that are currently being investigated.

Genetic polymorphisms as predictive and prognostic biomarkers in gynecological cancers: a systematic review

PURPOSE

Numerous studies have explored the potential role of genetic polymorphisms as predictive or prognostic biomarkers in gynecologic malignancies. A systematic review for all eligible polymorphisms has not yet been reported. The aim of this study was to summarize the current status of the field and provide direction for future research.

DESIGN

We searched literature databases (MEDLINE, EMBASE, Cochrane) from 2006 to April 2011 to identify studies evaluating the association between gene polymorphisms and clinical outcome in ovarian, endometrial, cervical, or vulvar cancer. The main outcome measures were overall survival (OS) and progression-free survival (PFS). Studies reporting relationships between polymorphisms and toxicity were also included.

RESULTS

Sixty two studies met the inclusion criteria. The median sample size was 140. Most of the included studies (n=50, 81%) were conducted in ovarian cancer patients. Almost a third assessed potential predictive associations between gene polymorphism and outcome in ovarian cancer. The most commonly evaluated genes were ERCC1, VEGF, ABCB1 (MDR), and GSTP1. Most studies (n=44, 71%) were observational case-series. Only four studies (6%) included a validation arm and patient population ethnicity was explicitly stated only in 27% of included studies.

CONCLUSION

No consistent association between any gene polymorphism and clinical outcome in gynecological cancers has been found across studies. There is incomplete adherence to the REMARK guidelines and inadequate methodology reporting in most studies. Moving forward, analysis of large trial-based clinical samples; adherence to the highest methodological standards, and focus on validation analyses are necessary to identify clinically useful pharmacogenomic biomarkers of outcome.

Utility of vascular endothelial growth factor inhibitors in the treatment of ovarian cancer: from concept to application

Despite recent advances in the management of ovarian cancer, it remains the most lethal gynecologic malignancy. Vascular endothelial growth factor (VEGF) has been shown to play a pivotal role in the progression of ovarian cancer leading to the eventual development of malignant ascites. On this basis, agents rendering VEGF ineffective by neutralizing VEGF (bevacizumab), blocking its receptors (aflibercept), or interfering with the postreceptor signaling pathways (sunitinib) provide us with the rational treatment options. These agents are generally used in combination with the standard chemotherapeutic drugs. Here, we discuss the basis of and the logic behind the use of these agents in the treatment of epithelial ovarian cancer, as well as their evaluation in different preclinical and clinical studies.

Intraoperative imaging in ovarian cancer: fact or fiction?

Tumor-targeted fluorescence imaging for cancer diagnosis and treatment is an evolving field of research that is on the verge of clinical implementation. As each tumor has its unique biologic profile, selection of the most promising targets is essential. In this review, we focus on target finding in ovarian cancer, a disease in which fluorescence imaging may be of value in both adequate staging and in improving cytoreductive efforts, and as such may have a beneficial effect on prognosis. Thus far, tumor-targeted imaging for ovarian cancer has been applied only in animal models. For clinical implementation, the five most prominent targets were identified: folate receptor α, vascular endothelial growth factor, epidermal growth factor receptor, chemokine receptor 4, and matrix metalloproteinase. These targets were selected based on expression rates in ovarian cancer, availability of an antibody or substrate aimed at the target approved by the Food and Drug Administration, and the likelihood of translation to human use. The purpose of this review is to present requirements for intraoperative imaging and to discuss possible tumor-specific targets for ovarian cancer, prioritizing for targets with substrates ready for introduction into the clinic.

Targeting angiogenesis in ovarian cancer

Results of standard chemotherapy in ovarian cancer are hampered by the development of drug resistance leading to disease recurrence. This prompted interest in the development of therapies targeting critical pathways responsible for tumor progression. Angiogenesis is a key process that enables ovarian cancer growth and metastasis in the peritoneal space. Its regulation relies on signaling mechanisms initiated by the vascular endothelial growth factor, the platelet-derived growth factor, the fibroblast growth factor, angiopoietins, and others. These pathways are not only important to the modulation of the tumor microenvironment and vasculature, but also control cancer cell proliferation and survival. In this review, we discuss preclinical evidence supporting the rationale for inhibiting these pathways and provide an overview for the clinical development of agents targeting them. Clinical trials evaluating such agents alone and in combination with chemotherapy are ongoing. Early clinical results position antiangiogenic therapy at the forefront of change to the standard treatment of difficult to treat ovarian cancer.

Predictive value of VEGF gene polymorphisms for metastatic colorectal cancer patients receiving first-line treatment including fluorouracil, irinotecan, and bevacizumab

PURPOSE

The aim of this study is to evaluate the influence of germline vascular endothelial growth factor (VEGF) gene polymorphisms (VGPs) on the efficacy of the anti-VEGF antibody bevacizumab (Bev) in metastatic colorectal cancer (MCRC) patients.

METHODS

Forty MCRC patients eligible for a first-line therapy were enrolled in this prospective trial and treated with FOLinate/Fluorouracil/Irinotecan (FOLFIRI) + Bev (male/female = 22:18, age (median) = 61 years). Eight VGPs within the promoter/5'UTR region were evaluated in patient blood samples. Primary endpoint was association between VGPs and median progression-free survival (mPFS). Overall radiological response rate (ORR), overall survival (OS), and toxicity were assessed as secondary outcomes.

RESULTS

VGPs -2578, -1512, -1451, -1411, and -460 were in complete linkage disequilibrium and therefore analyzed as haplotype (two variants: Haplo1: A-18 bp insertion-T-4G-C and Haplo2: C-18 bp deletion-C-5G-T, respectively). Seventeen patients Haplo2/Haplo2 had significantly shorter mPFS compared to 23 patients Haplo1/Haplo1 or Haplo1/Haplo2 (mPFS, 9 vs. 15.4 months, respectively, p = 0.02; hazard ratio (HR), 2.64). Also, VGPs -152 (G/G vs. G/A + A/A) and -1154 (G/G vs. G/A + A/A) were significantly associated with PFS (mPFS, 8.9 vs. 15.4 months, p = 0.007; HR, 3.53 and 9.8 vs. 16 months, p = 0.03, HR, 2.32, respectively). In the multivariate analysis including also biochemical variables known to influence prognosis, VGP -1154 retained an independent predictive value for mPFS (G/G over G/A + A/A = HR, 4.43; p = 0.02). With regard to ORR, only VGP -634 was significantly associated with response (G/G vs. G/C + C/C = 64% vs. 14%, p = 0.03). No significant influence on OS and toxicity by the investigated VGPs was observed.

CONCLUSIONS

Although these data need to be confirmed in larger trials, investigation of germline VGPs may help identify patients who are more sensitive to anti-VEGF agents.

Association of vascular endothelial growth factor gene polymorphisms with susceptibility to epithelial ovarian cancer

BACKGROUND

Vascular endothelial growth factor (VEGF) is a major angiogenic factor involved in a number of pathological processes, including neovascularization, a crucial step in the development of solid malignancies. The aim of this study was to investigate the association of polymorphisms in the VEGF gene with susceptibility to epithelial ovarian cancer (EOC).

METHODS

This case-control study included 303 EOC patients and 303 healthy controls. Genotyping of the VEGF gene polymorphisms at j460C/T, j1154G/A, j2578C/A, and +936C/T were performed by polymerase chain reaction and restriction fragment length polymorphism analysis.

RESULTS

No significant difference was found in allele and genotype distributions of the -460C/T, +936C/T, and -2578C/A polymorphisms between patients and controls. However, the frequencies of -1154G/A genotype and allele were significantly different between the two groups (P = 0.037, P = 0.013). Compared with the G/A + A/A genotype, the G/G genotype could significantly increase the risk of developing EOC (odds ratio, 1.64; 95% confidence interval, 1.12Y2.39). The haplotype analysis suggested that the -460T/ -1154A/ -2578C haplotype exhibited a decrease in the risk of developing EOC compared with the -460T/ -1154G/ -2578C haplotype (odds ratio, 0.644; 95% confidence interval, 0.415-0.999).

CONCLUSIONS

The study suggested a possible association between the VEGF -1154G/A polymorphism with susceptibility to EOC, but there is no support for an association of the VEGF -460C/T, +936C/T, and -2578C/A polymorphisms with the risk for EOC.

Evaluation of vascular endothelial growth factor as a prognostic marker for local relapse in early-stage breast cancer patients treated with breast-conserving therapy

PURPOSE

Vascular endothelial growth factor (VEGF) is an important protein involved in the process of angiogenesis that has been found to correlate with relapse-free and overall survival in breast cancer, predominantly in locally advanced and metastatic disease. A paucity of data is available on the prognostic implications of VEGF in early-stage breast cancer; specifically, its prognostic value for local relapse after breast-conserving therapy (BCT) is largely unknown. The purpose of our study was to assess VEGF expression in a cohort of early-stage breast cancer patients treated with BCT and to correlate the clinical and pathologic features and outcomes with overexpression of VEGF.

METHODS AND MATERIALS

After obtaining institutional review board approval, the paraffin specimens of 368 patients with early-stage breast cancer treated with BCT between 1975 and 2005 were constructed into tissue microarrays with twofold redundancy. The tissue microarrays were stained for VEGF and read by a trained pathologist, who was unaware of the clinical details, as positive or negative according the standard guidelines. The clinical and pathologic data, long-term outcomes, and results of VEGF staining were analyzed.

RESULTS

The median follow-up for the entire cohort was 6.5 years. VEGF expression was positive in 56 (15%) of the 368 patients. Although VEGF expression did not correlate with age at diagnosis, tumor size, nodal status, histologic type, family history, estrogen receptor/progesterone receptor status, or HER-2 status, a trend was seen toward increased VEGF expression in the black cohort (26% black vs. 13% white, p=.068). Within the margin-negative cohort, VEGF did not predict for local relapse-free survival (RFS) (96% vs. 95%), nodal RFS (100% vs. 100%), distant metastasis-free survival (91% vs. 92%), overall survival (92% vs. 97%), respectively (all p>.05). Subset analysis revealed that VEGF was highly predictive of local RFS in node-positive, margin-negative patients (86% vs. 100%, p=.029) on univariate analysis, but it did not retain its significance on multivariate analysis (hazard ratio, 2.52; 95% confidence interval, 0.804-7.920, p=.113). No other subgroups were identified in which a correlation was found between VEGF expression and local relapse.

CONCLUSION

To our knowledge, our study is the first to assess the prognostic value of VEGF with the endpoint of local relapse in early-stage breast cancer treated with BCT, an important question given the recent increased use of targeted antiangiogenic agents in early-stage breast cancer. Our study results suggest that VEGF is not an independent predictor of local RFS after BCT, but additional, larger studies specifically analyzing the endpoint of VEGF and local relapse are warranted.

Vascular endothelial growth factor gene polymorphisms and ovarian cancer survival

OBJECTIVES

We sought to evaluate the effect of polymorphisms in the VEGF (Vascular Endothelial Growth Factor) gene on overall survival in ovarian cancer patients.

METHODS

A sample of 319 women diagnosed with primary invasive epithelial ovarian cancer in Australia between 1985 and 1997, recruited as incident cases, were genotyped for four VEGF single nucleotide polymorphisms (three tagSNPs and one functional SNP) using the Sequenom MassARRAY platform. A SNP found to be associated with ovarian cancer survival in this sample set was then evaluated in two independent datasets in an attempt to replicate the association.

RESULTS

VEGF tagSNPs rs3025033 and rs2146323 were not associated with ovarian cancer survival in the Australian sample. Ovarian cancer patients homozygous for tagSNP rs833068 or the functional SNP rs2010963 displayed significantly shortened overall survival in the Australian sample (HR 2.09, 95% CI 1.16-3.78), an effect most apparent in the first 5years after diagnosis. This association was not replicated in two independent datasets.

CONCLUSIONS

Findings from this study provide no evidence that rs3025033 and rs2146323 VEGF polymorphisms are associated with ovarian cancer survival. Although homozygous carriers of the tagSNP rs833068 experienced significantly worse survival in our Australian dataset, we were unable to replicate this in two independent datasets.

VEGF polymorphisms in early cervical cancer susceptibility, angiogenesis, and survival

OBJECTIVE

Vascular endothelial growth factor (VEGF) plays an important role in cervical carcinogenesis. We hypothesized that VEGF genetic polymorphisms may affect cancer susceptibility, angiogenesis, and survival in patients with early cervical cancer.

METHODS

Among 215 healthy subjects and 199 early cervical cancer patients who were treated with surgical resection, we specifically investigated four genetic polymorphisms within the VEGF gene (-2578C>A, -460 T>C, +405G>C, and +936C>T). VEGF and CD31 microvessel density (MVD) were measured using tissue microarrays constructed from 117 patients who had available tissue.

RESULTS

Risk of cervical cancer was decreased in subjects with the VEGF -2578A/A genotype (adjusted OR=0.39, 95% CI 0.16-0.96). Angiogenesis measured by CD31 MVD was significantly decreased in patients with the VEGF +405C/C genotype and VEGF -2578C - -460 T - +405C haplotype (recessive model; adjusted OR=0.32, 95% CI 0.11-0.99, equally). Moreover, VEGF +405C/C and VEGF -2578C - -460 T - +405C haplotype were significantly related to shorter disease-free survival (adjusted HR=3.18, 95% CI 1.13-8.94, equally) and overall survival (adjusted HR=8.86, 95% CI 1.40-56.08, equally) by multiple Cox regression analysis.

CONCLUSION

Polymorphisms of VEGF genes may affect cancer susceptibility and survival of early cervical cancer by modulating tumor angiogenesis. Prospective study among homogeneously treated patients is warranted.