Vascular endothelial growth factor-C (VEGF-C) expression in human colorectal cancer tissues

Eltrombopag Inhibits Metastasis in Breast Carcinoma by Targeting HuR Protein

Eltrombopag is a small molecule TPO-R agonist that has been shown in our previous studies to inhibit tumor growth by targeting Human antigen R (HuR) protein. HuR protein not only regulates the mRNA stability of tumor growth-related genes, but it also regulates the mRNA stability of a variety of cancer metastasis-related genes, such as Snail, Cox-2, and Vegf-c. However, the role and mechanisms of eltrombopag in breast cancer metastasis have not been fully investigated. The purpose of this study was to investigate whether eltrombopag can inhibit breast cancer metastasis by targeting HuR. Our study first found that eltrombopag can destroy HuR-AU-rich element (ARE) complexes at the molecular level. Secondly, eltrombopag was found to suppress 4T1 cell migration and invasion and inhibit macrophage-mediated lymphangiogenesis at the cellular level. In addition, eltrombopag exerted inhibitory effects on lung and lymph node metastasis in animal tumor metastasis models. Finally, it was verified that eltrombopag inhibited the expressions of Snail, Cox-2, and Vegf-c in 4T1 cells and Vegf-c in RAW264.7 cells by targeting HuR. In conclusion, eltrombopag displayed antimetastatic activity in breast cancer in an HuR dependent manner, which may provide a novel application for eltrombopag, hinting at the multiple effects of HuR inhibitors in cancer therapy.

Lymphatic Tissue Bioengineering for the Treatment of Postsurgical Lymphedema

Lymphedema is characterized by progressive and chronic tissue swelling and inflammation from local accumulation of interstitial fluid due to lymphatic injury or dysfunction. It is a debilitating condition that significantly impacts a patient's quality of life, and has limited treatment options. With better understanding of the molecular mechanisms and pathophysiology of lymphedema and advances in tissue engineering technologies, lymphatic tissue bioengineering and regeneration have emerged as a potential therapeutic option for postsurgical lymphedema. Various strategies involving stem cells, lymphangiogenic factors, bioengineered matrices and mechanical stimuli allow more precisely controlled regeneration of lymphatic tissue at the site of lymphedema without subjecting patients to complications or iatrogenic injuries associated with surgeries. This review provides an overview of current innovative approaches of lymphatic tissue bioengineering that represent a promising treatment option for postsurgical lymphedema.

Molecular Mechanisms of Tumor Immunomodulation in the Microenvironment of Colorectal Cancer

Colorectal cancer remains one of the most important health challenges in our society. The development of cancer immunotherapies has fostered the need to better understand the anti-tumor immune mechanisms at play in the tumor microenvironment and the strategies by which the tumor escapes them. In this review, we provide an overview of the molecular interactions that regulate tumor inflammation. We particularly discuss immunomodulatory cell-cell interactions, cell-soluble factor interactions, cell-extracellular matrix interactions and cell-microbiome interactions. While doing so, we highlight relevant examples of tumor immunomodulation in colorectal cancer.

Effect of bevacizumab combined with first-line chemotherapy on metastatic colorectal cancer

BACKGROUND

To investigate the effect of bevacizumab combined with chemotherapy on the metastasis response rate, survival time of patients with metastatic colorectal cancer (mCRC), the incidence of complications, and the efficacy and safety of bevacizumab for mCRC were recorded.

METHODS

Of 87 patients with mCRC, 42 were treated without bevacizumab (control group, CG) and 45 were treated with bevacizumab (observation group, OG). Baseline characteristics, resectability of metastases, quality of life (QOL), and short- and long-term curative effect were compared to evaluate the safety of the treatment plan in the two groups.

RESULTS

After 6 months of treatment, the overall response rate (ORR) and disease control rate (DCR) of the CG were 28.57% and 59.52%, respectively, whereas the ORR and DCR of the OG were notably higher at 48.89% and 86.67%, respectively (P < 0.05). The resectability rate of metastases in the OG increased from 8.89% pretreatment to 40.00% posttreatment, whereas that of metastases in the CG increased from 11.90% pretreatment to 23.81% posttreatment. In the OG, the median survival time was 23.0 (range, 19.7-26.3) months, and the median progression-free survival (PFS) was 11.0 (range, 9.4-12.6) months. These results were all superior to those of the CG, which were 14.0 (range, 12.6-15.4) months and 6.0 (range, 4.9-7.2) months, respectively.

CONCLUSION

Bevacizumab combined with first-line chemotherapy can significantly prolong survival and PFS, improve QOL, increase the resectability rate of metastases, and improve survival outcomes of patients with mCRC.

An origami paper-based nanoformulated immunosensor detects picograms of VEGF-C per milliliter of blood

Detecting vascular endothelial growth factor C (VEGF-C), a kind of tumor biomarker, is of significant clinical importance in evaluating the prognosis of patients with cancer. However, laboratory analyses are usually not suitable for point-of-care testing because they are expensive and time consuming. In response to these challenges, we fabricated an origami paper-based microfluidic electrochemical device. To improve the specificity of VEGF-C detection, nanocomposites, synthesized by new methylene blue (NMB), amino-functional single-walled carbon nanotubes (NH₂-SWCNTs), and gold nanoparticles (AuNPs), were used to modify the surface of working electrodes. Results of electrochemical detection showed that the immunosensor had excellent linearity, ranging from 0.01 to 100 ng mL⁻¹ (R² = 0.988), and the limit of detection was 10 pg mL⁻¹. To confirm the high specificity of the device under real-world conditions, we evaluated the device using clinical serum samples from our hospital. The results demonstrated that the device had an excellent performance and could provide a platform for real-time detection of cancers.

Sun, Wang et al. report an origami paper-based immunosensor for the electrochemical detection of the VEGF-C biomarker in blood serum. The immunosensor is made by modifying the surface of working electrodes with new methylene blue, amino-functional single-walled carbon nanotubes, and gold nanoparticles and demonstrates excellent performance with a limit of detection in the range of picograms per milliliter.

Emerging Roles of Mast Cells in the Regulation of Lymphatic Immuno-Physiology

Mast cells (MCs) are abundant in almost all vascularized tissues. Furthermore, their anatomical proximity to lymphatic vessels and their ability to synthesize, store and release a large array of inflammatory and vasoactive mediators emphasize their significance in the regulation of the lymphatic vascular functions. As a major secretory cell of the innate immune system, MCs maintain their steady-state granule release under normal physiological conditions; however, the inflammatory response potentiates their ability to synthesize and secrete these mediators. Activation of MCs in response to inflammatory signals can trigger adaptive immune responses by dendritic cell-directed T cell activation. In addition, through the secretion of various mediators, cytokines and growth factors, MCs not only facilitate interaction and migration of immune cells, but also influence lymphatic permeability, contractility, and vascular remodeling as well as immune cell trafficking through the lymphatic vessels. In summary, the consequences of these events directly affect the lymphatic niche, influencing inflammation at multiple levels. In this review, we have summarized the recent advancements in our understanding of the MC biology in the context of the lymphatic vascular system. We have further highlighted the MC-lymphatic interaction axis from the standpoint of the tumor microenvironment.

Immunohistochemical expression and prognostic significance of VEGF-C in well-differentiated thyroid cancer

Context

Neoangiogenesis and lymphangio-genesis are essential for the growth of tumor and progression of malignancy.

Objective

The study examined the significance of VEGF-C expression in comparison to classical prognostic factors in differentiated thyroid carcinoma (DTC), as well as an independent prognostic marker in DTC.

Design

The study included 81 patients with DTC allocated in two groups according to the type of cancer (follicular versus papillary) and then compared to expression of VEGF-C and clinicopathological features.

Methods

Expression of VEGF-C was identified with anti-VEGF-C antibody using tris-EDTA buffer Antigen Retrieval Protocol. Each specimen was scored with a semi-quantitative score system (H-score).

Results

The analysis of T staging system showed a linear correlation between the size of a tumor, expression of VEGF-C and recurrence of a disease, with a statistical significance (p < 0.0001). There was a clear and significant correlation between VEGF-C expression and T stage in patients with papillary carcinoma (p = 0.0294). Analysis of invasion of a surgical margin demonstrated significant positivity in patients with papillary thyroid cancers who expressed VEGF-C (p = 0.0207) indicating the worse prognosis of a disease. Also a statistically significant correlation was between VEGF-C and extrathyroid extension, indicating the worse prognosis (p = 0.0133) in papillary cancers. The level of VEGF-C expression was statistically significant in patients with papillary thyroid cancer (p = 0.039).

Conclusions

This study undoubtedly demonstrates that VEGF-C expression is an evident negative prognostic factor in patients with papillary thyroid carcinoma, along with the classic prognostic factors, such as a larger tumor size, tumor margin involvement, extrathyroid extension, i.e. local aggressiveness.

HMGB1: an overview of its versatile roles in the pathogenesis of colorectal cancer

BACKGROUND

In recent years, the high mobility group box-1 (HMGB1) protein, a damage-associated molecular pattern (DAMP) molecule, has been found to play multifunctional roles in the pathogenesis of colorectal cancer. Although much attention has been given to the diagnostic and prognostic values of HMGB1 in colorectal cancer, the exact functional roles of the protein as well as the mechanistic pathways involved have remained poorly defined. This systematic review aims to discuss what is currently known about the roles of HMGB1 in colorectal cancer development, growth and progression, and to highlight critical areas for future investigations. To achieve this, the bibliographic databases Pubmed, Scopus, Web of Science and ScienceDirect were systematically screened for articles from inception till June 2018, which address associations of HMGB1 with colorectal cancer.

CONCLUSIONS

HMGB1 plays multiple roles in promoting the pathogenesis of colorectal cancer, despite a few contradicting studies. HMGB1 may differentially regulate disease-related processes, depending on the redox status of the protein in colorectal cancer. Binding of HMGB1 to various protein partners may alter the impact of HMGB1 on disease progression. As HMGB1 is heavily implicated in the pathogenesis of colorectal cancer, it is crucial to further improve our understanding of the functional roles of HMGB1 not only in colorectal cancer, but ultimately in all types of cancers.

Two Birds, One Stone: Double Hits on Tumor Growth and Lymphangiogenesis by Targeting Vascular Endothelial Growth Factor Receptor 3

Vascular endothelial growth factor receptor 3 (VEGFR3) has been known for its involvement in tumor-associated lymphangiogenesis and lymphatic metastasis. The VEGFR3 signaling is stimulated by its main cognate ligand, vascular endothelial growth factor C (VEGF-C), which in turn promotes tumor progression. Activation of VEGF-C/VEGFR3 signaling in lymphatic endothelial cells (LECs) was shown to enhance the proliferation of LECs and the formation of lymphatic vessels, leading to increased lymphatic metastasis of tumor cells. In the past decade, the expression and pathological roles of VEGFR3 in tumor cells have been described. Moreover, the VEGF-C/VEGFR3 axis has been implicated in regulating immune tolerance and suppression. Therefore, the inhibition of the VEGF-C/VEGFR3 axis has emerged as an important therapeutic strategy for the treatment of cancer. In this review, we discuss the current findings related to VEGF-C/VEGFR3 signaling in cancer progression and recent advances in the development of therapeutic drugs targeting VEGF-C/VEGFR3.

Correlation of Vascular Endothelial Growth Factor subtypes and their receptors with melanoma progression: A next-generation Tissue Microarray (ngTMA) automated analysis

INTRODUCTION

Finding new markers to assess prognosis of melanoma without the necessity to perform a surgical interventions is an important goal in melanoma research. The current study aimed to assess the correlation of clinical course and prognosis of primary and metastatic melanoma with expression of VEGF family and their receptors.

METHODS

A ngTMA block was made from the randomly selected paraffin tissue blocks of the patients with melanocytic nevi, primary and metastatic melanoma. Then sections cut from ngTMA-block were immunohistochemically stained with proper antibodies. Expression of these proteins was investigated using automated image analysis and compared among the study groups.

RESULTS

We analyzed the tissue of 238 patients with following diagnoses: 101 (42.4%) with a diagnosis of nevus, 86 (36.1%) Malignant melanoma and 51 (21.4%) metastasis. Median follow-up time for the malignant lesions was 5.71 years. Among the tested antigen, VEGF-C (p = 0.016), VEGF-R2 (p<0.001) and VEGF-R3 (p = 0.002) were significantly higher expressed in the metastatic tissues. When these scores were assessed in multiple regression models, the only independent factor linked to patient's diagnosis was VEGF-R2 (p<0.001). In addition, groups of highly correlated variables (VEGF-C and VEGF-R3, VEGF-A and VEGF-R1) were found to form separate sub-clusters. On the other side, high values of VEGF-C were associated with both overall and disease-free survival with a statically significant HR of 2.76 (95% CI: 1.27, 5.98; p = 0.01) and 2.82 (95%CI: 1.62, 4.91; p<0.001), respectively.

CONCLUSIONS

This study shows that VEGF-C and VEGF-R2 might represent new prognostic marker in MM. However, further prospective studies are warranted to test their real efficacy as a prognostic marker.

The effect of vascular endothelial growth factor-1 expression on survival of advanced colorectal cancer patients

Colorectal cancer is third leading cause of cancer mortality. About 60% of patients had already developed metastasis at the time of diagnosis. Vascular endothelial growth factor (VEGF) is crucial for the development of neovascularization and hence metastasis. This study aimed at investigating the relation between the expression of VEGF in biopsies from surgically dissected colon cancer and the survival of those patients. Biopsies were collected from 86 patients with advanced colon cancer and sections were stained by immunohistochemistry for VEGF. Patients received chemotherapy after the operation and were followed up for disease progression and survival. The clinical data were statistically analyzed with respect to the immunohistochemistry results. The survival of the patients was significantly longer in the patients for whom biopsies showed negative or weak expression of VEGF in comparison to those with moderate to high expression (p-value = 0.04). The expression of VEGF was more frequent in the patients who died as a consequence of the disease in comparison to the 10-year survivors. In conclusion, VEGF could be related to the survival of the patients with colorectal carcinoma and should be considered as a predictor of the prognosis.

Lipopolysaccharide increases the release of VEGF-C that enhances cell motility and promotes lymphangiogenesis and lymphatic metastasis through the TLR4- NF-κB/JNK pathways in colorectal cancer

Lipopolysaccharide (LPS) exists in the outer membrane of Gram-negative bacteria. Colorectal normal epithelium and colorectal cancer cells in situ are continuously exposed to LPS from intestinal bacteria, while little is known about the influence of LPS on colorectal cancer progression and metastasis. In this study, we investigated the potential role of LPS on colorectal cancer progression and metastasis as well as the underlying mechanisms. We measured higher LPS concentration in colorectal cancer tissues and even higher LPS concentration in colorectal cancer tissues with lymph node metastasis. LPS significantly enhanced cancer cell motility and promoted human dermal lymphatic endothelial cells' (HDLECs') capacity of tube-like formation in vitro, as well as accelerates lymphangiogenesis and lymph node metastasis in nude mice. Furthermore, we demonstrated LPS notably increased the expression of VEGF-C in a time-dependent and concentration-dependent manner. VEGF-C is a key regulator for lymphangiogenesis and lymph node metastasis. By constructing lentivirus-mediated shVEGF-C cells, VEGF-C down-regulation suppressed LPS' promotive effect on cancer cell motility and HDLEC tube-like formation capacity. In addition, we found TLR4- NF-κB/JNK signal pathways were important for LPS to increase VEGF-C expression. All these result suggested a critical role for LPS in migration, invasion, lymphangiogenesis and lymph node metastasis of colorectal cancer, providing evidence that LPS increased VEGF-C secretion to promote cell motility and lymphangiogenesis via TLR4- NF-κB/JNK signaling.

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.

The mechanisms of IL-17A on promoting tumor metastasis

In recent decades, extensive studies have indicated that IL-17A plays an important role in tumor progression and metastasis, but the underlying mechanisms are not immediately clear. In this review, we examined the literature from the recent years concerning the study of IL-17A in four kinds of tumor transfer paths, including hematogenous metastasis, lymphatic metastasis, local invasion and transcoelomic metastasis, to summarize the roles and underlying mechanisms of IL-17A on tumor metastasis.

Intestinal lymphatic vasculature: structure, mechanisms and functions

The mammalian intestine is richly supplied with lymphatic vasculature, which has functions ranging from maintenance of interstitial fluid balance to transport of antigens, antigen-presenting cells, dietary lipids and fat-soluble vitamins. In this Review, we provide in-depth information concerning the organization and structure of intestinal lymphatics, the current view of their developmental origins, as well as molecular mechanisms of intestinal lymphatic patterning and maintenance. We will also discuss physiological aspects of intestinal lymph flow regulation and the known and emerging roles of intestinal lymphatic vessels in human diseases, such as IBD, infection and cancer.

Autocrine mechanisms of cancer chemoresistance

An ever-increasing number of studies highlight the role of cancer secretome in the modification of tumour microenvironment and in the acquisition of cancer cell resistance to therapeutic drugs. The knowledge of the mechanisms underlying the relationship between cancer cell-secreted factors and chemoresistance is becoming fundamental for the identification of novel anticancer therapeutic strategies overcoming drug resistance and novel prognostic secreted biomarkers. In this review, we summarize the novel findings concerning the regulation of secreted molecules by cancer cells compromising drug sensitivity. In particular, we highlight data from available literature describing the involvement of cancer cell-secreted molecules determining chemoresistance in an autocrine manner, including: i) growth factors; ii) glycoproteins; iii) inflammatory cytokines; iv) enzymes and chaperones; and v) tumor-derived exosomes.

Structural alterations in tumor-draining lymph nodes before papillary thyroid carcinoma metastasis

BACKGROUND

The purpose of this study was to define and characterize the thyroid tumor-draining lymph nodes in genetically engineered mice harboring thyroid-specific expression of oncogenic Braf^V600E with and without Pten insufficiency.

METHODS

After intratumoral injection of methylene blue, the lymphatic drainage of the thyroid gland was visualized in real time. The thyroid gland/tumor was resected en bloc with the respiratory system for histological analysis.

RESULTS

Although mice harboring Braf^V600E mutations were smaller in body size compared with their wild-type (WT) littermates, the size of their thyroid glands and deep cervical lymph nodes were significantly larger. Additionally, the tumor-draining lymph nodes showed increased and enlarged lymphatic sinuses that were distributed throughout the cortex and medulla. Tumor-reactive lymphadenopathy and histiocytosis, but no frank metastases, were observed in all mice harboring Braf^V600E mutations.

CONCLUSIONS

The tumor-draining lymph nodes undergo significant structural alterations in immunocompetent mice, and this may represent a primer for papillary thyroid carcinoma (PTC) metastasis.

Association between VEGF-A, C and D expression and lymph node involvement in breast cancer: a meta-analysis

BACKGROUND

Metastasis is the primary cause of death in patients with breast cancer. Although VEGF-A, C and D are considered to be prime factors in lymph node metastasis in breast cancer, the published studies have conflicting conclusions.

METHODS

To resolve this conflict, we conducted a meta-analysis of 37 studies (n = 5,001 patients) evaluating the correlation between VEGF-A, C and D immunohistochemical expression and lymph node metastasis (LNM). The meta-analysis included 22 studies of VEGF-A, 17 of VEGF-C, and 6 of VEGF-D. The relationships between VEGF-A, C and D and clinicopathological parameters were also examined.

RESULTS

The results showed a significant association between VEGF-A or VEGF-C overexpression and LNM (risk ratio [RR] = 1.28 [95% CI 1.04-1.58], p = 0.02; and RR = 1.36 [95% CI 1.07-1.72], p = 0.01, respectively). Subgroup evaluation showed a significant association between VEGF-A, C and D overexpression and LNM when analyses were limited to Asian patients (RR = 1.78 [95% CI 1.28-2.46], p = 0.0005; RR = 1.38 [95% CI 1.04-1.84], p = 0.03, and RR = 2.62 [95% CI 1.35-5.09], p = 0.004, respectively). VEGF-A overexpression was significantly associated with lymph vessel invasion (RR = 1.86 [95% CI 1.33-2.60], p = 0.0003). Overexpression of VEGF-C or VEGF-D was significantly associated with HER-2 positivity (RR = 1.30 [95% CI 1.06-1.59], p = 0.01; and RR = 1.75 [95% CI 1.01-3.03], p = 0.05, respectively).

CONCLUSIONS

With some limitations, our meta-analysis indicated that VEGF-A and C could predict LNM in patients with breast cancer, particularly Asian patients.

Vasohibin-1 suppresses colon cancer

Vasohibin-1 (VASH1) is an endogenous angiogenesis inhibitor.However, the clinical relevance of VASH1 in colon cancer and its regulations on cancer angiogenesis and cancer cell biological characteristics are still unknown. Here we showed that stromal VASH1 levels were negatively correlated with tumor size, advanced clinical stage and distant metastases in colon cancer patients. Overexpression of VASH1 in colon cancer cells induced apoptosis and senescence, inhibiting cancer cell growth and colony formation in vitro and tumor growth in vivo. In addition, knockdown of VASH1 in cancer cells promoted cell growth, adhesion and migration in vitro, and enhanced tumorigenesis and metastasis in vivo.

Clinicopathological significance of lymphangiogenesis detected by immunohistochemistry using D2-40 monoclonal antibody in breast cancer

To elucidate the association between the lymphangiogenesis and clinicopathological factors including the survival in breast cancer, 91 Japanese patients with breast cancer were investigated.　The lymphangiogenesis was evaluated by the count of lymph vessel density (LVD) with immunohistochemical method using D2-40 monoclonal antibody, a specific marker for lymphatic endothelial cells.D2-40-positive lymph vessels were detected in 87 of 91 cases, and were mainly distributed in the peritumoral lesions or around the tumor edge.　There was a significant difference in disease-free survival (DFS) and overall survival (OS) between patients with high LVD and with low LVD (p=0.02, 0.01, respectively, log-rank test).　In addition, LVD significantly correlated with the following clinicopathological factors: menopausal status (p<0.01), tumor size (p<0.01), lymph-node status (p=0.01) lymphatic vessel invasion (LVI) (p<0.01), blood vessel invasion (BVI) (p=0.03) and estrogen receptor status (ER) (p=0.02).Those data suggest that D2-40 monoclonal antibody is a useful marker for evaluating the LVD and its evaluation is helpful to predict the survival in breast cancer.

Prognostic significance of VEGF-C immunohistochemical expression in colorectal cancer: A meta-analysis

BACKGROUND

We sought to comprehensively summarize available evidence for the use of VEGF-C protein to evaluate the clinicopathological and prognostic role of VEGF-C in colorectal cancer.

METHODS

Electronic databases from inception to February 2016 were used to search without language restrictions for original articles. A meta-analysis was undertaken to assess the relationship between VEGF-C expression and overall survival (OS) in colorectal cancer.

RESULTS

Twenty-seven studies were included in the final meta-analysis. We aggregated 13 trials (n=1.428 patients) that evaluated the correlation between OS and VEGF-C overexpression. Statistics were performed for OS (HR=1.95; 95%CI=1.31-2.92, P=0.007). When the studies were stratified by the pathological variables, including T stage (n=383 patients; OR=1.79; 95%CI=1.14-2.81), lymph node metastasis (n=3212 patients; OR=4.21; 95%CI=3.49-5.08), M stage (n=1106 patients; OR=4.46; 95%CI=2.96-6.70), vascular invasion(n=1471 patients; OR=2.18; 95%CI=1.65-2.88), lymph invasion (n=831 patients; OR=3.95; 95%CI=2.80-5.56), histo-differentiation (n=1695 patients; OR=1.34; 95%CI=1.00-1.79) and Duke's stage(n=778 patients; OR=4.90; 95%CI=3.55-6.75), TNM stage (n=808 patients; OR=1.73; 95%CI=1.18-2.54) provided critical and comprehensive prognostic information.

CONCLUSION

Our results demonstrated that VEGF-C overexpression was associated with OS in colorectal cancer.

VEGF-C expression is not a prognostic factor in locally advanced colon adenocarcinoma

Aim of the study

Evaluation of the relationships between increased expression of VEGF-C (vascular endothelial growth factor-C) and vessel density in the tumour-surrounding stroma, patient survival, and other conventional prognostic factors in patients with pT3-4 colon cancer.

Material and methods

Expression of VEGF-C and vessel density were immunohistochemically assessed in 104 specimens of primary, locally advanced (pT3-4) colon adenocarcinoma after surgical resection.

Results

A significant relationship was found between the expression of VEGF-C and increased vessel density in the tumour-surrounding stroma (p = 0.03). A relationship between VEGF-C expression and location of the tumour in the left side of the colon was also found (p = 0.003). Expression of VEGF-C was likely to occur in well-differentiated tumours. No relationship between patient overall survival and the expression level of VEGF-C in locally advanced colon cancer was observed.

Conclusions

The study results indicate that expression of VEGF-C in cells of locally advanced pT3-4 adenocarcinoma of the colon does not affect the survival time of the patients. Increased expression of VEGF-C is accompanied by a significant increase in vessel density in the pT3-4 tumour stroma. Increased expression of VEGF-C in cancer cells is related to the tumour location in the left side of the colon and better tumour differentiation.

Influence of Cancer-Associated Endometrial Stromal Cells on Hormone-Driven Endometrial Tumor Growth

Cancer-associated fibroblasts have been shown to inhibit or stimulate tumor growth depending on stage, grade, and tumor type. It remains unclear, however, the effect of endometrial-cancer-associated fibroblasts on hormone-driven responses in endometrial cancer. In this study, we investigated the effect of normal and cancer-associated stromal cells from patients with and without endometrial cancer on endometrial tumor growth in response to estradiol (E2) and progesterone (P4). Compared to benign endometrial stromal cells, the low-grade and high-grade cancer-associated stromal cells exhibited a blunted hormone response for proliferation as well as IGFBP1 secretion. Additional analysis of the influence of stromal cells on hormone-driven tumor growth was done by mixing stromal cells from benign, low-grade, or high-grade tumors, with Ishikawa cells for subcutaneous tumor formation. The presence of both benign and high-grade cancer-associated stromal cells increased estradiol-driven xenografted tumor growth compared to Ishikawa cells alone. Low-grade cancer-associated stromal cells did not significantly influence hormone-regulated tumor growth. Addition of P4 attenuated tumor growth in Ishikawa + benign or high-grade stromal cells, but not in Ishikawa cells alone or with low-grade stromal cells. Using an angiogenesis focused real-time array TGFA, TGFB2 and TGFBR1 and VEGFC were identified as potential candidates for hormone-influenced growth regulation of tumors in the presence of benign and high-grade stromal cells. In summary, endometrial-cancer-associated cells responded differently to in vitro hormone treatment compared to benign endometrial stromal cells. Additionally, presence of stromal cells differentially influenced hormone-driven xenograft growth in vivo depending on the disease status of the stromal cells.

The relevance of cell type- and tumor zone-specific VEGFR-2 activation in locally advanced colon cancer

Background

For the successful therapeutic use of inhibitors of the vascular endothelial growth factor receptor (VEGFR) pathway detailed knowledge of the mechanisms leading to tumor progression is indispensable. The main goal of this study was to determine the relevance of the VEGFR-2 activating pathway for colon carcinoma (CC) metastasis. The initial event is ligand-induced receptor activation through tyrosine autophosphorylation.

Methods

VEGFR-2, its ligands VEGF-C and VEGF-D and the phosphorylated (activated) receptor forms pVEGFR-2^Tyr1175 and pVEGFR-2^Tyr1214 were investigated immunohistochemically in different tumor compartments (intratumoral (zone 1) - invasive front (zone 2) – extratumoral soft tissue (zone 3)) and various cell types (tumor cells, inflammatory cells, macro- and microvasculature) in 84 non-metastatic, lymphogenous-metastatic and haematogenous-metastatic CC.

Results

VEGF-D produced by tumor cells has an autocrine affinity for its receptor VEGFR-2. In tumor budding regions VEGF-D-induced receptor activation by autophosphorylation at Tyr1214 seems to be a possible initial event of the VEGFR-2-mediated signaling pathway, but without effect on metastatic behaviour. In inflammatory cells of almost all CC VEGFR-2 phosphorylation at Tyr 1175 and Tyr 1214 was detectable without accompanying receptor expression, suggesting receptor activation without cell surface expression. Peritumoral inflammatory cells also expressed paracrine acting VEGF-C. The autocrine VEGF-D/VEGFR-2 signaling axis and receptor autophosphorylation at Tyr1214 appear to be main events for capillaries in all three tumor zones and for small vessels in zone 1 and 2. Independent of the metastatic status a large number of cases with capillary immunopositivity in the angiogenically active invasive front was documented, especially for VEGF-D, VEGFR-2 and pVEGFR-2^Tyr1214. VEGFR-2 positive extratumoral capillaries were significantly more common in distant metastatic CC. In all tumor compartments the investigated biomolecules were also detected in different frequencies in the macrovasculature, which is responsible for sufficient tumor vascularization. In addition, vascular paracrine-acting VEGF-C production was widely detected, but without zone and vessel-type dependence.

Conclusions

The VEGFR-2 activating pathway is closely involved in tumor cell-associated, vessel-mediated and immuno-inflammatory processes in colon carcinoma and appears to contribute to tumor survival and growth as well as maintenance of the infiltrative phenotype rather than to promote metastasis.

miR-101 suppresses vascular endothelial growth factor C that inhibits migration and invasion and enhances cisplatin chemosensitivity of bladder cancer cells

Background

The microRNA miR-101 is downregulated in several cancers, including bladder cancer. However, miR-101’s role in the invasion, metastasis, and chemosensitivity of bladder cancer cells remains unclear. This study was conducted to determine miR-101’s role on the lymphangiogenic molecule vascular endothelial growth factor C (VEGF-C) and their effects upon bladder cancer cell migration, invasion, and chemosensitivity to cisplatin.

Methods

Two bladder cancer cell lines (T24 and 5637) and the tool cell line 293T were employed here. Bladder cancer cells were transfected with either a miR-101 overexpression vector or a scrambled-sequence lentivirus, both of which exhibited a high transfection efficiency. Non-transfection was used as a mock negative control. Wound healing and Transwell assays were performed to measure cell migration and invasiveness. A luciferase reporter assay was performed to validate miR-101’s interaction with VEGF-C’s 3′ untranslated region followed by RT-PCR and Western blot confirmation. An MTS assay was used to evaluate the cisplatin sensitivity of the cell lines.

Results

miR-101 overexpression significantly inhibited the migration and invasiveness while significantly enhancing cisplatin sensitivity. miR-101 negatively regulated VEGF-C protein expression, and VEGF-C overexpression rescued the effects of miR-101 overexpression, indicating that miR-101 negatively regulates VEGF-C protein expression post-transcriptionally. miR-101 and VEGF-C interference independently enhanced cisplatin cytotoxicity in bladder cancer cells.

Conclusions

miR-101 suppresses VEGF-C expression, inhibits cell migration and invasion, and increases cisplatin sensitivity in bladder cancer cells. This study provides new insight into miR-101’s role in bladder cancer and shows miR-101’s promise as a potential molecular target for bladder cancer.

Association between VEGFR-3 expression and lymph node metastasis in non-small-cell lung cancer

Vascular endothelial growth factor receptor (VEGFR)-3 is considered to be associated with lymphangiogenesis. The aim of the present study was to identify the clinical significance of VEGFR-3 expression and lymph node metastasis in patients with non-small-cell lung cancer (NSCLC). Lung tumor tissue samples and 196 lymph nodes from 52 patients with NSCLC were analyzed. In addition, lung tissue samples and 8 lymph nodes from 10 patients with lung diseases other than cancer were included as controls. Semiquantitative multiplex reverse transcription technology was applied to measure the mRNA expression levels of VEGFR-3, while VEGFR-3 protein expression levels were assessed immunohistochemically. The total number of lymphatic vessels was counted and the microlymphatic vessel density (MLVD) was calculated. The results indicated that the VEGFR-3 mRNA expression level in lymph node tissue from the group with lymph node metastasis was significantly lower compared with the group without lymph node metastasis (0.281±0.166 vs. 0.158±0.158; t=4.849; P<0.001). The VEGFR-3 mRNA expression levels in the lung tumor tissue of the NSCLC patients exhibited no statistically significant difference between the lymph node metastasis and lymph node non-metastasis groups (0.139±0.137 vs. 0.142±0.123; t=0.08; P>0.05). In addition, in the lymph node metastasis group, there was no statistically significant difference between the metastasis-positive and -negative lymph nodes (0.158±0.158 vs. 0.123±0.115; t=0.993; P>0.05) with regard to VEGFR-3 mRNA expression. Morphologically, VEGFR-3 immunoreactivity was primarily localized in the cytoplasm of the lymphatic endothelial cells, as well as a number of the cancer cells. MLVD was much higher in the lung tissue surrounding the tumor than in the tumor tissue, and was significantly higher in the lymph node metastasis group than in the lymph node non-metastasis group. VEGFR-3 expression levels were shown to correlate with lymph node metastasis in NSCLC patients, thus, may be a useful biomarker for lymph node metastasis prediction in NSCLC. MLVD is a key indictor of lymphatic vessel metastasis in NSCLC. An enhanced MLVD indicates lymphangiogenesis and lymphatic node metastasis, and may be an important predictor for tumor monitoring and prognosis.

Impact of the prolymphangiogenic crosstalk in the tumor microenvironment on lymphatic cancer metastasis

Lymphangiogenesis is a very early step in lymphatic metastasis. It is regulated and promoted not only by the tumor cells themselves, but also by cells of the tumor microenvironment, including cancer associated fibroblasts, mesenchymal stem cells, dendritic cells, or macrophages. Even the extracellular matrix as well as cytokines and growth factors are involved in the process of lymphangiogenesis and metastasis. The cellular and noncellular components influence each other and can be influenced by the tumor cells. The knowledge about mechanisms behind lymphangiogenesis in the tumor microenvironmental crosstalk is growing and offers starting points for new therapeutic approaches.

Associations of nm23H1, VEGF-C, and VEGF-3 receptor in human prostate cancer

We studied the expression of the non-metastatic clone 23 type 1 (nm23H1) gene, vascular endothelial growth factor (VEGF)-C, and its receptor VEGFR-3 using an in situ hybridization technique and immunohistochemical analyses with prostate cancer tissues and adjacent benign tissues of 52 human archival cases. The association between VEGF-C expression, microlymphatic count (MLC), and staining intensity for nm23H1 and VEGFR-3 was used to evaluate tumor metastasis and survival rate. MLC values were significantly higher in tumorous tissue than in non-cancerous tissue. VEGF-C mRNA, VEGFR-3, and nm23H1 were highly expressed in tumorous tissue. VEGFR-3 expression was greater in VEGF-C mRNA-positive tumors than in VEGF-C mRNA-negative tumors. The association of VEGFR-3 expression with VEGF-C mRNA and MLC suggested that the poor prognosis and tumor metastasis associated with VEGFR-3 expression may be due, in part, to its role in promoting angiogenesis. VEGF-C expression was significantly associated with tumor lymphangiogenesis, angiogenesis, and immune response as a potent multifunctional stimulating factor in prostate cancer. Expression of nm23H1 was significantly inversely correlated with lymph node metastasis. Furthermore, there was a strong negative correlation between the expression of nm23H1, VEGF-C mRNA, and MLC. These findings provide important information for prophylactic, diagnostic, and therapeutic strategies for prostate cancer.

Prognostic value of vascular endothelial growth factors A and C in oral squamous cell carcinoma

BACKGROUND

Vascular endothelial growth factor (VEGF) family members play a major role in angiogenesis and vascularization. VEGF-A promotes tumor angiogenesis by stimulating the growth of tumor vascular endothelial cells. In addition, VEGF-C has been identified as a potent inducer of lymphangiogenesis in tumor and lymph node metastasis. Previous studies have investigated the association between clinicopathological factors and the expression of VEGF-A and VEGF-C in oral squamous cell carcinoma cancer (OSCC), but the results are contradictory. In this study, we investigated the relationship between VEGF-A and VEGF-C expression and OSCC clinicopathological factors and prognosis.

METHODS

Expression of VEGF-A and VEGF-C was evaluated in surgical specimens from 61 patients with OSCC and three human oral cancer cell lines (OSC-19, OSC-20 and HOC313) by immunohistochemical staining and enzyme-linked immunosorbent assay, respectively. We also determined the relationship between the 5-year survival rate and clinicopathological factors, such as TNM classification (Union for International Cancer Control, UICC), lymph node metastasis, recurrence, histological differentiation, location, and mode of invasion.

RESULTS

VEGF-A expression correlated significantly with lymph node metastasis. VEGF-C expression was associated with lymph node metastasis, recurrence, and a poorer 5-year survival rate. A multivariate analysis demonstrated that VEGF-C is an independent prognostic factor for patients with OSCC. VEGF-C expression was significantly up-regulated in HOC313 cells compared to OSC-19 and OSC-20 cells.

CONCLUSIONS

These results indicate that VEGF-C may be a predictive factor for OSCC outcome, lymph node metastasis, and recurrence. Moreover, VEGF-C may be an important factor in the development of new therapies for OSCC patients.

Slit2N and Robo4 regulate lymphangiogenesis through the VEGF-C/VEGFR-3 pathway

Background

Signaling through vascular endothelial growth factor C (VEGF–C) and VEGF receptor 3 (VEGFR-3) plays a central role in lymphangiogenesis and the metastasis of several cancers via the lymphatics. Recently, the Slit2/Robo4 pathway has been recognized as a modulator of vascular permeability and integrity. Signaling via the Robo receptor inhibits VEGF-mediated effects; however, its effects on lymphatic endothelial cell function have not been well characterized.

Results

We found that pretreatment with Slit2N, an active fragment of Slit2, inhibited VEGF-C-mediated lung-derived lymphatic endothelial cell (L-LEC) proliferation, migration, and in vitro tube formation. Slit2N induced the internalization of VEGFR-3, which blocked its activation, and inhibited the activation of the PI3K/Akt pathway by VEGF-C in L-LECs. Moreover, we found that inhibition of VEGF-C-induced effects by Slit2N was Robo4-dependent.

Conclusion

These results indicate that Slit2N/Robo4 modulates several key cellular functions, which contribute to lymphangiogenesis, and identify this ligand-receptor pair as a potential therapeutic target to inhibit lymphatic metastasis of VEGF-C-overexpressing cancers and manage lymphatic dysfunctions characterized by VEGF-C/VEGFR-3 activation.

VEGF-C mediates RhoGDI2-induced gastric cancer cell metastasis and cisplatin resistance

Rho GDP dissociation inhibitor 2 (RhoGDI2) expression is correlated with tumor growth, metastasis and chemoresistance in gastric cancer. However, the mechanisms by which RhoGDI2 promotes tumor cell survival and metastasis remain unclear. In this study, we clearly demonstrate that RhoGDI2 upregulates VEGF-C expression and RhoGDI2 expression is positively correlated with VEGF-C expression in human gastric tumor tissues as well as parental gastric cancer cell lines. VEGF-C depletion suppressed RhoGDI2-induced gastric cancer metastasis and sensitized RhoGDI2-overexpressing cells to cisplatin-induced apoptosis in vitro and in vivo. Secreted VEGF-C enhanced gastric cancer cell invasion and conferred cisplatin resistance to RhoGDI2-overexpressing cells. We also show that RhoGDI2 positively regulates Rac1 activity in gastric cancer cells. Inhibition of Rac1 expression suppressed RhoGDI2-induced VEGF-C expression, and this inhibition was associated with decreased invasiveness and increased sensitivity to cisplatin in RhoGDI2-overexpressing cells. Our results indicate that RhoGDI2 might be a potential therapeutic target for simultaneously reducing metastasis risk and enhancing chemotherapy efficacy in gastric cancer.

VEGF targets the tumour cell

The function of vascular endothelial growth factor (VEGF) in cancer is not limited to angiogenesis and vascular permeability. VEGF-mediated signalling occurs in tumour cells, and this signalling contributes to key aspects of tumorigenesis, including the function of cancer stem cells and tumour initiation. In addition to VEGF receptor tyrosine kinases, the neuropilins are crucial for mediating the effects of VEGF on tumour cells, primarily because of their ability to regulate the function and the trafficking of growth factor receptors and integrins. This has important implications for our understanding of tumour biology and for the development of more effective therapeutic approaches.

VEGF-C and VEGF-D overexpression is more common in left-sided and well-differentiated colon adenocarcinoma

Tumour vessel network formation, including blood and lymph vessels, is a major step involved in the process of carcinogenesis. The discovery of vascular growth factors has led to a better understanding of tumour biology, thus, creating new possibilities for cancer treatment that targets angiogenesis within tumour-associated stroma, including therapy for colon cancer patients. The present study evaluated the relationships between increased expression of lymphangiogenic factors (VEGF-C and VEGF-D) and vessel density in the tumour-surrounding stroma, patient survival and other standard prognostic factors. The expression of VEGF-C and VEGF-D and vessel density were immunohistochemically assessed in 114 primary tumour specimens from colon adenocarcinoma patients after surgical resection between January 1, 2003 and December 31, 2008. Concomittant overexpression of VEGF-C and VEGF-D was found in 51 (44.7%) colon tumours and low expression was observed in 63 (55.3%) cases. Mean vessel density was 52.87/field. A significant correlation was found between the expression of factors influencing lymph vessel growth and increased vessel density in the tumour-surrounding stroma (p=0.03). A relationship between lymphangiogenic factor overexpression and left-sided tumour location was also found (p=0.00002). Overexpression of these factors was likely to occur in well-differentiated tumours (p=0.003). No association between patient survival and the expression levels of lymphangiogenic factors was observed. The study results indicate that the overexpression of lymphangiogenic factors tends to be associated with tumours of favourable prognosis, i.e. well-differentiated and those localized in the left-side of the colon.

MT1-MMP in breast cancer: induction of VEGF-C correlates with metastasis and poor prognosis

BACKGROUND

Recent evidence suggests that vascular endothelial growth factor-C (VEGF-C)- dependent tumour production promotes lymphangiogenesis, while membrane-type matrix 1 metalloproteinase (MT1-MMP) is involved in the critical steps leading to carcinogenesis. However, the role of MT1-MMP in lymphangiogenesis and lymphatic metastasis remains poorly understood. In the present study, we investigated the relationship between MT1-MMP and VEGF-C in human breast cancer and correlated MT1-MMP and VEGF-C expression with lymphangiogenesis and prognosis.

METHODS

MT1-MMP and VEGF-C levels were compared in five breast carcinoma cell lines. We used a membrane invasion assay to assess the effect of MT1-MMP and VEGF-C expression, as well as anti-MT1-MMP and VEGF-C antibodies, on cancer cell invasion. We further assessed MT1-MMP and VEGF-C immunoreactivity and lymph vessels in a cohort of human breast cancer specimens (n = 106) and associated MT1-MMP and VEGF-C expression with clinicopathological parameters, such as lymphatic vessel density (LVD), and patient prognosis.

RESULTS

MT1-MMP and VEGF-C expression differed among the five breast cancer cell lines and MT1-MMP and VEGF-C expression were correlated with tumour cell invasion. VEGF-C mRNA expression levels and invasive activity of MDA-MB-231 cells was inhibited by an anti-MT1-MMP antibody in a concentration-dependent manner. A significant correlation was found between the expression of MT1-MMP and VEGF-C in breast cancer patient samples and elevated MT1-MMP and VEGF-C expression was associated with higher LVD, lymph node metastasis, cancer stage, and a decline in overall survival rates.

CONCLUSIONS

Our data demonstrate that MT1-MMP expression is closely correlated with VEGF-C expression, and that MT1-MMP promotes lymphangiogenesis by up-regulating VEGF-C expression in human breast cancer. Thus, elevated MT1-MMP may serve as a significant prognostic factor in breast cancer.

A practical and sensitive method of quantitating lymphangiogenesis in vivo

To address the inadequacy of current assays, we developed a directed in vivo lymphangiogenesis assay (DIVLA) by modifying an established directed in vivo angiogenesis assay. Silicon tubes (angioreactors) were implanted in the dorsal flanks of nude mice. Tubes contained either growth factor-reduced basement membrane extract (BME)-alone (negative control) or BME-containing vascular endothelial growth factor (VEGF)-D (positive control for lymphangiogenesis) or FGF-2/VEGF-A (positive control for angiogenesis) or a high VEGF-D-expressing breast cancer cell line MDA-MD-468LN (468-LN), or VEGF-D-silenced 468LN. Lymphangiogenesis was detected superficially with Evans Blue dye tracing and measured in the cellular contents of angioreactors by multiple approaches: lymphatic vessel endothelial hyaluronan receptor-1 (Lyve1) protein (immunofluorescence) and mRNA (qPCR) expression and a visual scoring of lymphatic vs blood capillaries with dual Lyve1 (or PROX-11 or Podoplanin)/Cd31 immunostaining in cryosections. Lymphangiogenesis was absent with BME, high with VEGF-D or VEGF-D-producing 468LN cells and low with VEGF-D-silenced 468LN. Angiogenesis was absent with BME, high with FGF-2/VEGF-A, moderate with 468LN or VEGF-D and low with VEGF-D-silenced 468LN. The method was reproduced in a syngeneic murine C3L5 tumor model in C3H/HeJ mice with dual Lyve1/Cd31 immunostaining. Thus, DIVLA presents a practical and sensitive assay of lymphangiogenesis, validated with multiple approaches and markers. It is highly suited to identifying pro- and anti-lymphangiogenic agents, as well as shared or distinct mechanisms regulating lymphangiogenesis vs angiogenesis, and is widely applicable to research in vascular/tumor biology.

Lymphangiogenesis and prognostic significance of vascular endothelial growth factor C in gastro-oesophageal junction adenocarcinoma

Vascular endothelial growth factor C (VEGF-C) is a crucial regulator of the development of lymphatic vessels and is involved in the lymph node metastasis of cancer. The levels of VEGF-C expression and lymphatic vessel density (LVD) in 128 gastro-oesophageal junction adenocarcinoma (GEJA) tissues were examined by immunohistochemistry and analysed for their association with clinicopathological features and disease-free survival. We found that 75.0% of tumour samples displayed strong immunoreactivity to VEGF-C. The levels of VEGF-C expression in the tumour tissues were associated with the stages of the clinical tumours and the lymph node metastasis status, but not with the age, gender and the size and type of tumours in the cohort. Similarly, LVD, as evaluated by anti-D2-40 staining, was also associated with the clinical stages of GEJA. The values of LVD were positively correlated with the levels of VEGF-C expression in these samples (r = 0.3760, P = 0.0001). High levels of VEGF-C expression and high values of LVD were associated with shorter periods of disease-free survival (DFS) in patients with GEJA (P < 0.001). In addition, GEJA at N1 and N2 stages, at T4 stage, chemotherapy after surgery, high levels of VEGF-C expression and lower marginal resection were independent factors for the prognosis of DFS in patients with GEJA. Our data indicate that VEGF-C may promote the lymphangiogenesis and lymphatic metastasis of GEJA and that VEGF-C may be a valuable biomarker for the diagnosis of lymphatic metastasis and a prognostic factor of the survival of patients with GEJA.

The role of the VEGF-C/VEGFRs axis in tumor progression and therapy

Vascular endothelial growth factor C (VEGF-C) has been identified as a multifaceted factor participating in the regulation of tumor angiogenesis and lymphangiogenesis. VEGF-C is not only expressed in endothelial cells, but also in tumor cells. VEGF-C signaling is important for progression of various cancer types through both VEGF receptor-2 (VEGFR-2) and VEGF receptor-3 (VEGFR-3). Likewise, both receptors are expressed mainly on endothelial cells, but also expressed in tumor cells. The dimeric VEGF-C undergoes a series of proteolytic cleavage steps that increase the protein binding affinity to VEGFR-3; however, only complete processing, removing both the N- and C-terminal propeptides, yields mature VEGF-C that can bind to VEGFR-2. The processed VEGF-C can bind and activate VEGFR-3 homodimers and VEGFR-2/VEGFR-3 heterodimers to elicit biological responses. High levels of VEGF-C expression and VEGF-C/VEGFRs signaling correlate significantly with poorer prognosis in a variety of malignancies. Therefore, the development of new drugs that selectively target the VEGF-C/VEGFRs axis seems to be an effective means to potentiate anti-tumor therapies in the future.

The prognostic and predictive value of mRNA expression of vascular endothelial growth factor family members in breast cancer: a study in primary tumors of high-risk early breast cancer patients participating in a randomized Hellenic Cooperative Oncology Group trial

INTRODUCTION

The main prognostic variables in early breast cancer are tumor size, histological grade, estrogen receptor/progesterone receptor (ER/PgR) status, number of positive nodes and human epidermal growth factor receptor 2 (HER2) status. The present study evaluated the prognostic and/or predictive value of vascular endothelial growth factor (VEGF) family members in high-risk early breast cancer patients treated with adjuvant chemo-hormonotherapy.

METHODS

RNA was isolated from 308 formalin-fixed paraffin-embedded primary tumor samples from breast cancer patients enrolled in the HE10/97 trial, evaluating adjuvant dose-dense sequential chemotherapy with epirubicin followed by cyclophosphamide, methotrexate, fluorouracil (CMF) with or without paclitaxel (E-T-CMF versus E-CMF). A fully automated method based on magnetic beads was applied for RNA extraction, followed by one-step quantitative RT-PCR for mRNA analysis of VEGF-A, -B, -C and vascular endothelial growth factor receptor (VEGFR) 1, 2, 3.

RESULTS

With a median follow-up of 8 years, 109 patients (35%) developed a relapse and 80 patients (26%) died. In high VEGF-C and VEGFR1 mRNA expressing tumors, ER/PgR-negative tumors (Fisher's exact test, P = 0.001 and P = 0.021, respectively) and HER2-positive tumors (P <0.001 and P = 0.028, respectively) were more frequent than in low VEGF-C and VEGFR1 expressing tumors, respectively. From the VEGF family members evaluated, high VEGFR1 mRNA expression (above the 75th percentile) emerged as a significant negative prognostic factor for overall survival (OS; hazard ratio (HR) = 1.60, 95% confidence interval (CI): 1.01 to 2.55, Wald's P = 0.047) and disease-free survival (DFS; HR = 1.67, 95% CI: 1.13 to 2.48, P = 0.010), when adjusting for treatment group. High VEGF-C mRNA expression was predictive for benefit from adjuvant treatment with paclitaxel (E-T-CMF arm) for OS (test for interaction, Wald's P = 0.038), while in multivariate analysis the interaction of VEGF-C with taxane treatment was significant for both OS (Wald's P = 0.019) and DFS (P = 0.041) and continuous VEGF-B mRNA expression values for OS (P = 0.019).

CONCLUSIONS

The present study reports, for the first time, that VEGF-C mRNA overexpression, as assessed by qRT-PCR, has a strong predictive value in high-risk early breast cancer patients undergoing adjuvant paclitaxel-containing treatment. Further studies are warranted to validate the prognostic and/or predictive value of VEGF-B, VEGF-C and VEGFR1 in patients treated with adjuvant therapies and to reveal which members of the VEGF family could possibly be useful markers in identifying patients who will benefit most from anti-VEGF strategies.

TRIAL REGISTRATION

Australian New Zealand Clinical Trials Registry (ANZCTR) ACTRN12611000506998.

Lymphangiogenesis and cancer

Historically, lymphatic vessels were considered passive participants in tumor metastasis by simply providing channels for tumor cells to transit to draining lymph nodes. The discovery of several key lymphatic-specific molecular markers and an increased availability of in vitro and in vivo experimental systems to study lymphatic biology have however highlighted a much more complex, active role for the lymphatic vasculature in metastatic tumor spread. This review will briefly describe the lymphatic system and lymphangiogenesis and then focus on the role of the lymphatic system in cancer metastasis. The progression of our understanding from the lymphatic system as a somewhat passive conduit for metastasis to an active participant in metastatic tumor dissemination, regulated by a complex array of lymphangiogenic factors, chemokines, and immune cell subsets, will be described.

Guggulsterone enhances antitumor activity of gemcitabine in gallbladder cancer cells through suppression of NF-κB

PURPOSE

Patients with gallbladder cancer usually have a poor prognosis, and effective standard chemotherapeutic regimens have not been established. The anticancer activities of guggulsterone have been demonstrated in various cancer cells. The aims of the study were to determine the effect of guggulsterone on gallbladder cancer cells and to investigate whether treatment with guggulsterone influences the antitumor activities of gemcitabine.

METHODS

The Dojindo Cell Counting Kit-8 assay was used to determine the inhibition of proliferation by drugs in TGBC1 and TGBC2 cells. Cell migration and invasion were examined using 24-well inserts and Matrigel™-coated invasion chambers. The activities of NF-κB p65, VEGF-C, and MMP-2 were measured by ELISA.

RESULTS

Guggulsterone inhibited the proliferation and suppressed migration and invasion of gallbladder cancer cells in a dose-dependent manner. Guggulsterone significantly decreased NF-κB p65, VEGF-C, and MMP-2 activities in the gallbladder cancer cells examined. Gallbladder cancer cells treated with a combination of guggulsterone and gemcitabine demonstrated significant inhibition of cell proliferation and invasion when compared to treatment with gemcitabine alone. In addition, NF-κB p65 activation decreased significantly in cells treated with a combination of guggulsterone and gemcitabine when compared to treatment with gemcitabine alone.

CONCLUSIONS

Guggulsterone exhibits anticancer activities and enhances the antitumor activities of gemcitabine through the suppression of NF-κB activation in gallbladder cancer cells. These results suggest that guggulsterone could be a potential therapeutic option for patients with gallbladder cancer.

Expression and clinical significance of extracellular matrix protein 1 and vascular endothelial growth factor-C in lymphatic metastasis of human breast cancer

BACKGROUND

Extracellular matrix protein 1 (ECM1) and vascular endothelial growth factor-C (VEGF-C) are secretory glycoproteins that are associated with lymphangiogenesis; these proteins could, therefore, play important roles in the lymphatic dissemination of tumors. However, very little is known about their potential roles in lymphangiogenesis. The aim of this study was to investigate whether correlations exist between ECM1 and VEGF-C in human breast cancer, lymphangiogenesis, and the clinicopathological characteristics of the disease.

METHODS

ECM1 and VEGF-C mRNA and protein expression levels in 41 patients were investigated using real-time reverse transcriptase polymerase chain reaction (RT-PCR), or immunohistochemical (IHC) staining of breast cancer tissue, matched noncancerous breast epithelial tissues, and suspicious metastatic axillary lymph nodes. D2-40 labelled lymph vessels and lymphatic microvessel density (LMVD) were counted. Correlations between ECM1 or VEGF-C protein expression levels, LMVD, and clinicopathological parameters were statistically tested.

RESULTS

The rate of ECM1 positive staining in breast cancer tissues was higher (31/41, 75.6%) than that in the corresponding epithelial tissues (4/41, 9.8%, P < 0.001) and lymph nodes (13/41, 31.7%, P < 0.001). Similarly, the VEGF-C expression rate in cancer specimens was higher (33/41, 80.5%) than in epithelial tissues (19/41, 46.3%, P < 0.01) or lymph nodes (15/41, 36.6%, P < 0.01). Higher ECM1 and VEGF-C mRNA expression levels were also detected in the tumor tissues, compared to the non-cancerous tissue types or lymph nodes (P < 0.05). ECM1 protein expression was positively correlated with the estrogen receptor status (P < 0.05) and LMVD (P < 0.05). LMVD in the ECM1- and VEGF-C-positive tumor specimens was higher than that in the tissue types with negative staining (P < 0.05).

CONCLUSIONS

Both ECM1 and VEGF-C were overexpressed in breast cancer tissue samples. ECM1 expression was positively correlated with estrogen responsiveness and the metastatic properties of breast cancer. We conclude, therefore, that ECM1 and VEGF-C may have a synergistic effect on lymphangiogenesis to facilitate lymphatic metastasis of breast cancer.

Tacrolimus enhances the invasion potential of hepatocellular carcinoma cells and promotes lymphatic metastasis in a rat model of hepatocellular carcinoma: involvement of vascular endothelial growth factor-C

PURPOSE

The purpose of this study was to elucidate the effect of tacrolimus treatment on tumor growth and metastasis of hepatocellular carcinoma (HCC).

METHODS

The effect of tacrolimus was investigated on tumor growth and lymph node metastasis in a rat model of HCC. Angiogenesis and lymphangiogenesis were assessed by CD31 and vascular endothelial growth factor receptor 3 (VEGFR-3) immunostaining. Cell proliferation and invasion were monitored in vitro using the Cell Counting Kit-8 (CCK8) and Matrigel Invasion Chambers, respectively. Levels of vascular endothelial growth factor-C (VEGF-C) expression were measured using quantitative real-time polymerase chain reaction (qRT-PCR), immunohistochemisty and Western blots.

RESULTS

Tacrolimus had no effect on the proliferation of HCC in vitro or in vivo. Treatment with tacrolimus resulted in a dose-dependent increase in the invasive potential of HCC cells in vitro, in the density of peritumoral lymphatic vessels, and in the number and volume of metastatic lymph nodes in August Copenhagen Irish (ACI) rats. qRT-PCR, immunohistochemisty, and Western blot revealed that tacrolimus increased the levels of expression of VEGF-C in HCC.

CONCLUSIONS

Tacrolimus enhanced the invasive potential of HCC cells, facilitating HCC lymphangiogenesis and promoting lymphatic metastasis in a rat model of HCC. This influence may be the result of an increase in VEGF-C expression by HCC cells. Targeting the VEGF-C/Fms-related tyrosine kinase 4 axis may be a novel treatment for HCC patients after liver transplantation.

Vascular endothelial growth factor receptor 2 (VEGFR-2) signalling activity in paediatric pilocytic astrocytoma is restricted to tumour endothelial cells

AIMS

Tumours depend on angiogenesis for enhanced tumour cell survival and progression. Vascular endothelial growth factor receptor (VEGFR) signalling plays a major part in this process. Previously, we evaluated tyrosine kinase activity in paediatric brain tumour tissue lysates using a peptide microarray containing 144 different tyrosine kinase peptide substrates. When applied to paediatric pilocytic astrocytoma tissue, this analysis revealed extensive phosphorylation of VEGFR-derived peptides. The aim of the current study was to validate this result and determine the presence of VEGFR-2 activity in paediatric pilocytic astrocytoma as the main VEGFR in terms of mitogenic signalling. In addition, the localization of VEGFR1-3 mRNA expression was assessed.

METHODS

VEGFR-2 phosphorylation was determined by adopting a proximity ligation assay approach. Enrichment of endothelial markers and VEGFRs in tumour endothelium was determined by quantitative polymerase chain reaction (qPCR) analysis of laser-microdissected blood vessels.

RESULTS

Proximity ligation assays on tumour cryosections showed the presence of phosphorylation of VEGFR-2, which primarily localized to vascular endothelium. qPCR analysis of endothelial markers and VEGFRs showed a 13.6-fold average enrichment of VEGFR-2 expression in the laser-microdissected endothelium compared to whole tumour. Also the expression of VEGFR-1 and -3 was highly enriched in the endothelium fraction with an average fold-enrichment of 16.5 and 50.8 respectively.

CONCLUSIONS

Phosphorylated VEGFR-2 is detected on endothelial cells in paediatric pilocytic astrocytoma. Furthermore, endothelial cells are the main source of VEGFR1-3 mRNA expression. This suggests a crucial role for VEGF/VEGFR-induced angiogenesis in the progression and maintenance of these tumours.