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

Current and emerging biomarkers in ovarian cancer diagnosis; CA125 and beyond

Ovarian cancer (OC) is one of the most common causes of cancer-related death in women worldwide. Its five-year survival rates are worse than the two most common gynecological cancers, cervical and endometrial. This is because it is asymptomatic in the early stages and usually detected in the advanced metastasized stage. Thus, survival is increasingly dependent on timely diagnosis. The delay in detection is contributed partly by the occurrence of non-specific clinical symptoms in the early stages and the lack of effective biomarkers and detection approaches. This underlines the need for biomarker identification and clinical validation, enabling earlier diagnosis, effective prognosis, and response to therapy. Apart from the traditional diagnostic biomarkers for OC, several new biomarkers have been delineated using advanced high-throughput molecular approaches in recent years. They are currently being clinically evaluated for their true diagnostic potential. In this chapter, we document the commonly utilized traditional screening markers and recently identified emerging biomarkers in OC diagnosis, focusing on secretory and protein biomarkers. We also briefly reviewed the recent advances and prospects in OC diagnosis.

Circulating vascular endothelial growth factor and cancer risk: A bidirectional mendelian randomization

In observational studies, circulating vascular endothelial growth factor (VEGF) has been reported to be associated with certain types of cancer. The purpose of this study was to verify whether there is a causal relationship between circulating VEGF and different types of cancer and the direction of the causal relationship. Summary statistical data were obtained from the corresponding genome-wide association studies (GWASs) to investigate the causal relationship between circulating VEGF and the risk of several cancers, including breast cancer, ovarian cancer, lung cancer, colorectal cancer, anus and anal canal cancer, prostate cancer, esophageal cancer, kidney cancer, bladder cancer, thyroid cancer, malignant neoplasm of the brain and malignant neoplasm of the liver and intrahepatic bile ducts. A two-sample bidirectional Mendelian randomization (MR) analysis and sensitivity tests were used to evaluate the validity of causality. A causal relationship was detected between circulating VEGF and colorectal cancer (OR 1.21, 95% CI 1.11–1.32, p < 0.000) and colon adenocarcinoma (OR 1.245, 95% CI 1.10–1.412, p < 0.000). Suggestive evidence of association was detected in VEGF on malignant neoplasms of the rectum (OR 1.16, 95% CI 1.00–1.34, p = 0.049). No causal relationship was found between circulating VEGF and other types of cancer, nor was there a reverse causal relationship from tumors to VEGF (p > 0.05). Circulating VEGF has a causal relationship with specific types of cancer. Our findings highlight and confirm the importance of circulating VEGF in the prevention and treatment of colorectal cancer.

Histone Methyltransferase KMT2D Regulates H3K4 Methylation and is Involved in the Pathogenesis of Ovarian Cancer

To investigate the function of histone-lysine N-methyltransferase 2D (KMT2D) on the methylation of H3 lysine 4 (H3K4) in the progression of Ovarian cancer (OV). KMT2D, ESR1 and H3K4me expressions in surgical resected tumors and tumor adjacent tissues of OV from 198 patients were determined using immunohistochemistry (IHC). Human OV cell lines including SKOV3, HO-8910 cells and normal ovarian epithelial cell line IOSE80 were employed for in vitro experiment, and BALB/C female nude mice were used for in vivo study. qRT-PCR and Western blotting were implemented for measuring the KMT2D, ESR1, PTGS2, STAT3, VEGFR2, H3K4me and ELF3 levels. Chromatin immunoprecipitation (ChIP) analysis was used for studying the binding between ESR1 and H3K4me. Edu staining assay was executed to determine cell viability, and colony formation and cell invasion assay. The immunofluorescence method was utilized for the visualization of protein expression and distribution in cells. In this study, KMT2D, ESR1 and H3K4me were found upregulated in OV progression. Mutated H3K4me could inhibit the proliferation, colony formation and invasion ability of OV cells. Mutated H3K4me could also hinder the ESR1 in SKOV3 expressions and HO-8910 cells, which would further mediate PTGS2/STAT3/VEGF pathway. In vivo studies also demonstrated that mutated H3K4me inhibited OV progression via targeting ESR1. All the ChIP-PCR analysis indicated the moderator effect of H3K4me on ESR1. Our findings indicated that ESR1 played an important role in the OV progression. Besides, H3K4me could promote cell proliferation and inhibit apoptosis of OV cells. Meanwhile, it could also targets the ESR1 production to enhance the migration and invasion of OV cells, which was through the activation of ESR1-ELF3-PTGS2-STAT3-VEGF cascade signaling pathway.

Association of Variants in Vascular Endothelial Growth Factor A Gene and VEGFA Serum Levels with the Risk of Primary Ovarian Insufficiency: A Case-Control Study

OBJECTIVE

The study aimed at investigating the association between the vascular endothelial growth factor A (VEGFA) genetic variants, the VEGFA serum level, and the primary ovarian insufficiency (POI) risk in Chinese Han women.

DESIGN

An age-matched case-control study was implemented in the West China Second Hospital of Sichuan University. Participants/Materials, Setting, Methods: Blood samples and clinical information were collected from 240 patients with POI and 261 healthy controls between December 2012 and December 2018 at the West China Second Hospital of Sichuan University. Mutations of VEGFA gene -2578C/A, -1154G/A, 936C/T, and -634C/G were identified by PCR-RFLP. Moreover, VEGFA serum levels in the 2 groups were measured by the enzyme-linked immunosorbent assay (ELISA).

RESULTS

The -1154G>A and 936C>T variants of the VEGFA gene were significantly associated with POI (the adjusted odds ratio [OR] = 2.17 and 95% confidence interval [CI] = 1.07-4.43 for the former; the adjusted OR = 2.74 and 95% CI = 1.18-6.34 for the latter), whereas no significant difference was found in the genotype distribution of -2578C>A and -634C>G variants between patients and controls (p > 0.05). Moreover, the combined -1154G>A and 936C>T genotype was associated with a significantly increased risk of POI (the adjusted OR = 21.98, 95% CI = 2.78-173.78 among subjects carrying 3 or more variants), particularly when patients aged ≥35 years (the adjusted OR = 20.58, and 95% CI = 2.58-164.25). The POI group exhibited an obviously lower VEGFA serum level (45.15 ± 1.25 pg/mL) than the control group. Compared with the control, the expression of VEGFA was significantly decreased in the POI group (279.90 ± 5.71 pg/mL; p < 0.05). Moreover, the serum VEGFA levels are lower in the -1154AA genotype than those of AG/GG genotypes.

LIMITATIONS

The main limitation is that all participants enrolled in this study were Chinese. As genotype and allelotype frequencies tend to differ between ethnic populations, extrapolation of the results to other ethnic groups should be cautiously considered.

CONCLUSIONS

Our study indicates an association between the VEGFA -1154G/A, 936C/T variants, and susceptibility to POI in Chinese Han women. Reduced levels of VEGFA may be a potential mechanism for the de-velopment of POI.

Expression of vascular endothelial growth factor C in renal cell carcinoma and its correlation with pathological parameters and prognosis

BACKGROUND

Renal cell carcinoma (RCC) is a common malignant tumor of the urinary system. This study aimed to analyze the expression of vascular endothelial growth factor C (VEGF-C) in RCC and its relationship with pathological parameters and prognosis.

METHODS

The clinical data of 68 patients who underwent surgical treatment and confirmed to be RCC by pathology from February 2012 to January 2014 were collected. The specimens of carcinoma tissues of the 68 patients were collected, among which 20 patients were collected from normal tissue specimens adjacent to the cancer more than 5 cm away from the tumor as controls. The VEGF-C expression level was detected by immunohistochemistry, and the relationship between VEGF-C expression and clinical pathological parameters and prognosis of RCC was analyzed.

RESULTS

The positive expression rate of VEGF-C in cancer tissues of RCC patients was significantly higher than the adjacent tissues (85.29% vs. 15.00%) (P<0.05). The positive expression rate of VEGF-C in cancer tissues of RCC patients with low-to- moderate differentiation, stage III-IV, and lymph node metastasis was higher than that of RCC patients with high differentiation, stage I-II, and no lymph node metastasis (P<0.05). The survival rates of RCC patients at 1-, 3- and 5-year follow-up were 82.35% (56/68), 54.41% (37/68), and 32.35% (22/68), and the survival time of patients with positive VEGF-C expression was shorter than patients with negative expression (P<0.05). There was no significant difference in the 5-year survival rate among RCC patients according to sex or presence of muscular infiltration (P>0.05). Meanwhile, the 5-year survival rate was higher in patients with tumor diameter <5 cm, high differentiation, stage I-II, no lymph node metastasis, VEGF-C-negative expression, and aged <55 years old (P<0.05). The Cox regression model analysis showed that differentiation degree, clinical stage, lymph node metastasis, and VEGF-C expression were all independent risk factors affecting the prognosis of RCC patients (P<0.05).

CONCLUSIONS

VEGF-C is highly expressed in cancer tissues of RCC patients, and is related to clinical stage, pathological differentiation, and lymph node metastasis, which maybe an effective factor of prognosis prediction.

Plasma levels of M-CSF and VEGF in laboratory diagnostics and differentiation of selected histological types of cervical cancers

Background

The search of useful serum biomarkers for the early detection of cervical cancers has been of a high priority. The activation of Macrophage-Colony Stimulating Factor (M-CSF) and Vascular Endothelial Growth Factor (VEGF) is likely involved in the pathogenesis and spread of cancer. We compared the plasma levels of M-CSF and VEGF to the ones of commonly accepted tumor markers CA 125and SCC-Ag in three groups of patients: 1. the cervical cancer group (patients with either squamous cell carcinoma or adenocarcinoma); 2. the cervical dysplasia group; 3. the control group.

Methods

This cohort study included 100 patients with cervical cancer and 55 patients with cervical dysplasia. The control group consisted of 50 healthy volunteers. The plasma levels of VEGF and M-CSF were determined using ELISA, while CA 125 and SCC-Ag concentrations were obtained by the chemiluminescent microparticle immunoassay (CMIA).

Results

The median levels of M-CSF and VEGF as well as CA 125 and SCC-Ag in the entire group of cervical cancer patients, were significantly different compared to the healthy women group. In case of both the squamous cell carcinoma and the adenocarcinoma groups, plasma levels of M-CSF and VEGF were higher compared to the control group. No significant differences in the studied parameters between the squamous cell carcinoma and the adenocarcinoma group were observed. The highest sensitivity and specificity were obtained for VEGF (81.18 and 76.00%, respectively) and SCC-Ag (81.18%; 74.00%) in the squamous cell carcinoma group and for VEGF (86.67%; 76.00%) in the adenocarcinoma group. The area under the ROC curve for VEGF was the largest in the adenocarcinoma group followed by the squamous cell carcinoma group (0.9082 and 0.8566 respectively).

Conclusions

Obtained results indicate a possible clinical applicability and a high diagnostic power for the combination of MSC-F, VEGF, CA 125 and SCC-Ag in the diagnosis of both studied types of cervical cancer.

SiRNA-Mediated RRM2 Gene Silencing Combined with Cisplatin in the Treatment of Epithelial Ovarian Cancer In Vivo: An Experimental Study of Nude Mice

Introduction: We aimed to explore small interfering (si)RNA silencing of ribonucleotide reductase M2 (RRM2) gene combined with cisplatin for the treatment of human ovarian cancer in nude mice models of subcutaneous transplantation of tumor cells. Methods: After conventional cultivation of human ovarian cancer cell line SKOV3 in vitro, SKOV3 cells were injected into the right back of nude mice by subcutaneous injection to establish the subcutaneous tumor models. Twenty-four tumor-burdened rats were randomly divided into four groups (n=6): siRNA group, siRNA in combination with cisplatin group, cisplatin group, and control group. Intraperitoneal injection of cisplatin and subcutaneous injection of siRNA were performed weekly. Tumor volume was measured, and tumor growth inhibition rate was calculated. RRM2 expression at the mRNA and protein levels was detected by reverse transcription-polymerase chain reaction and immunohistochemistry. Results: In the siRNA group, the tumor volume and tumor growth inhibition rate were 249.60±20.46 mm³ and 36.39%, respectively. The tumor growth inhibition rate and tumor volume were significantly different between the siRNA and control groups (p<0.05). In the cisplatin group, the tumor volume and tumor growth inhibition rate were 249.86±12.46 mm³ and 41.10%, respectively. The tumor growth inhibition rate and tumor volume were significantly different between the cisplatin and control groups (p<0.05). In the siRNA + cisplatin group, the tumor volume reduced to 180.84±16.25 mm³ and the tumor growth inhibition rate was increased to 64.33%, which were significantly different compared with the control group (p<0.01). Significant downregulation of RRM2 mRNA and protein expression in the tumor tissues was detected by reverse transcription polymerase chain reaction and immunohistochemistry assay (p<0.05). Discussion: siRNA alone or combined with cisplatin can effectively inhibit the growth of human ovarian cancer in nude mice models of subcutaneous transplantation of tumor cells. RRM2 gene silencing may be a potential treatment regimen for ovarian cancer in future.