Targeting Vascular Endothelial Growth factor-C Research Articles

Anti-Vascular Endothelial Growth Factor C Antibodies Efficiently Inhibit the Growth of Experimental Clear Cell Renal Cell Carcinomas.

Despite improvement during the last ten years in the longevity of patients with metastatic clear cell renal cell carcinoma (mccRCC) the disease remains incurable. Hence, new therapeutic strategies are urgently needed. Relapse following anti-angiogenic treatment depends on the over-expression of vascular endothelial growth factor C (VEGFC), one of the main drivers of lymphangiogenesis. Therefore, we developed specific mouse monoclonal antibodies and evaluated their therapeutic efficacy in vitro and in vivo. Immunization of mice with the domain of VEGFC that stimulates the VEGF receptor 3 (VEGFR3) led to the selection of one hybridoma producing specific anti-VEGFC monoclonal antibodies. The selected 1E9 antibodies were sequenced, and the corresponding variable light and heavy chains were subcloned into expression vectors in frame with sequences encoding the human IgG1 constant heavy and light chains. CHO cells were stably transfected and cloned to produce chimeric antibodies. These antibodies inhibited the activation of VEGFR3 signaling, and therefore the proliferation and migration of VEGFC-stimulated endothelial cells. Moreover, they inhibited the proliferation of VEGFC-expressing renal cancer cells through NRP2 signaling. 1E9 antibodies inhibited the growth of experimental RCC, and their therapeutic efficacy was enhanced by the anti-VEGF antibody bevacizumab. Hence, our results suggest that targeting VEGFC could have a relevant therapeutic impact on mccRCC that relapse following anti-angiogenic treatment.

Long Noncoding RNA ASLNC07322 Functions in VEGF-C Expression Regulated by Smad4 during Colon Cancer Metastasis

Deletion and mutation of the Smad4 gene are favorable events for the progression of colon cancer, which is related to the negative regulation of vascular endothelial growth factor C (VEGF-C). However, the regulatory mechanism between Smad4 and VEGF-C remains unclear. We reported first that Smad4 can increase the transcription of miR-128-3p, a microRNA targeting VEGF-C mRNA, resulting in a negative correlation between Smad4 and VEGF-C. Moreover, we found that Smad4 combined with Smad3 can positively regulate VEGF-C during colon cancer metastasis through binding to VEGF-C gene promoter. Further, results revealed a mechanism that long noncoding RNA (lncRNA) ASLNC07322 increased specifically in metastatic colon cancer and decreased miR-128-3p as a sponge, leading to a subsequent elevation of VEGF-C. In a word, there are two pathways in the progression of colon cancer, including Smad4/miR-128-3p/VEGF-C and Smad4/VEGF-C pathways in non-metastatic and metastatic colon cancer, respectively. ASLNC07322 crucially controlled this negative and positive regulatory transformation between them. Additionally, ASLNC07322 knockdown combined with Smad4 overexpression could efficiently inhibit lymphatic endothelial cells (LECs) proliferation and tube formation in vitro, as well as tumor growth and lymphangiogenesis in vivo. These data explained the underlying mechanism of Smad4 contribution on VEGF-C expression during metastasis where ASLNC07322 functions vitally as a switch in colon cancer.

VEGFC acts as a double-edged sword in renal cell carcinoma aggressiveness.

Hypoxic zones are common features of metastatic tumors. Due to inactivation of the von Hippel-Lindau gene (VHL), renal cell carcinomas (RCC) show constitutive stabilization of the alpha subunit of the hypoxia-inducible factor (HIF). Thus, RCC represents a model of chronic hypoxia. Development of the lymphatic network is dependent on vascular endothelial growth factor C (VEGFC) and lies at the front line of metastatic spreading. Here, we addressed the role of VEGFC in RCC aggressiveness and the regulation of its expression in hypoxia.Methods: Transcriptional and post transcriptional regulation of VEGFC expression was evaluated by qPCR and with reporter genes. The involvement of HIF was evaluated using a siRNA approach. Experimental RCC were performed with immuno-competent/deficient mice using human and mouse cells knocked-out for the VEGFC gene by a CRISPR/Cas9 method. The VEGFC axis was analyzed with an online available data base (TCGA) and using an independent cohort of patients.Results: Hypoxia induced VEGFC protein expression but down-regulated VEGFC gene transcription and mRNA stability. Increased proliferation, migration, over-activation of the AKT signaling pathway and enhanced expression of mesenchymal markers characterized VEGFC-/- cells. VEGFC-/- cells did not form tumors in immuno-deficient mice but developed aggressive tumors in immuno-competent mice. These tumors showed down-regulation of markers of activated lymphocytes and M1 macrophages, and up-regulation of M2 macrophages markers and programmed death ligand 1 (PDL1). Over-expression of lymphangiogenic genes including VEGFC was linked to increased disease-free and overall survival in patients with non-metastatic tumors, whereas its over-expression correlated with decreased progression-free and overall survival of metastatic patients.Conclusion: Our study revisited the admitted dogma linking VEGFC to tumor aggressiveness. We conclude that targeting VEGFC for therapy must be considered with caution.

CCL5 promotes VEGF-C production and induces lymphangiogenesis by suppressing miR-507 in human chondrosarcoma cells.

Chondrosarcoma is the second most frequently occurring type of bone malignancy that is characterized by the distant metastasis propensity. Vascular endothelial growth factor-C (VEGF-C) is the major lymphangiogenic factor, and makes crucial contributions to tumor lymphangiogenesis and lymphatic metastasis. Chemokine CCL5 has been reported to facilitate angiogenesis and metastasis in chondrosarcoma. However, the effect of chemokine CCL5 on VEGF-C regulation and lymphangiogenesis in chondrosarcoma has largely remained a mystery. In this study, we showed a clinical correlation between CCL5 and VEGF-C as well as tumor stage in human chondrosarcoma tissues. We further demonstrated that CCL5 promoted VEGF-C expression and secretion in human chondrosarcoma cells. The conditioned medium (CM) from CCL5-overexpressed cells significantly induced tube formation of human lymphatic endothelial cells (LECs). Mechanistic investigations showed that CCL5 activated VEGF-C-dependent lymphangiogenesis by down-regulating miR-507. Moreover, inhibiting CCL5 dramatically reduced VEGF-C and lymphangiogenesis in the chondrosarcoma xenograft animal model. Collectively, we document for the first time that CCL5 induces tumor lymphangiogenesis by the induction of VEGF-C in human cancer cells. Our present study reveals miR-507/VEGF-C signaling as a novel mechanism in CCL5-mediated tumor lymphangiogenesis. Targeting both CCL5 and VEGF-C pathways might serve as the potential therapeutic strategy to block cancer progression and metastasis in chondrosarcoma.

MiRNA-27b targets vascular endothelial growth factor C to inhibit tumor progression and angiogenesis in colorectal cancer.

Colorectal cancer (CRC) is one of the most prevalent cancers globally and is one of the leading causes of cancer-related deaths due to therapy resistance and metastasis. Understanding the mechanism underlying colorectal carcinogenesis is essential for the diagnosis and treatment of CRC. microRNAs (miRNAs) can act as either oncogenes or tumor suppressors in many cancers. A tumor suppressor role for miR-27b has recently been reported in neuroblastoma, while no information about miR-27b in CRC is available. In this study, we demonstrated that miR-27b expression is decreased in most CRC tissues and determined that overexpression of miR-27b represses CRC cell proliferation, colony formation and tumor growth in vitro and in vivo. We identified vascular endothelial growth factor C (VEGFC) as a novel target gene of miR-27b and determined that miR-27b functioned as an inhibitor of tumor progression and angiogenesis through targeting VEGFC in CRC. We further determined that DNA hypermethylation of miR-27b CpG islands decreases miR-27b expression. In summary, an anti-tumor role for miR-27b and its novel target VEGFC in vivo could lead to tumor necrosis and provide a rationale for developing miR-27b as a therapeutic agent.

RNAi-mediated gene silencing of vascular endothelial growth factor-C inhibits tumor lymphangiogenesis and growth of gastric cancer in vivo in mice

Overexpression of vascular endothelial growth factor-C (VEGF-C) has been implicated as a critical molecular signal in tumor development by promoting intratumoral lymphangiogenesis. The aim of this study was to explore whether small hairpin RNA (shRNA) targeting VEGF-C could inhibit gastric cancer lymphangiogenesis and tumor growth. Plasmid-mediated expression of VEGF-C-shRNA was employed to silence VEGF-C gene expression in human SGC-7901 cell lines. The inhibition of the target gene expression was quantified by real-time quantitative polymerase chain reaction, Western blotting, and enzyme-linked immunosorbent assay. In vitro, the cell viability was determined by MTT assay, flow cytometry analysis, and migration assay. After VEGF-C knockdown was confirmed, the stable cells were inoculated into nude mice. Tumor growth, lymph vessel density (LVD), and microvascular density were compared for mice administered either VEGF-C-shRNA or control. VEGF-C-shRNA causes effective and specific downregulation of VEGF-C expression (P<0.05). The migration activity of SGC-7901 cells was attenuated in vitro (P<0.05). Tumor growth rate and LVD was suppressed in vivo (P<0.05). VEGF-C-shRNA effectively suppressed gastric cancer cell migration in vivo, retards tumorigenicity, and lymphangiogenesis in nude mice.

Expression of vascular endothelial growth factor C in esophageal carcinoma and its clinical significance

Objective To investigate the expression of vascular endothelial growth factor C (VEGF-C) in human esophageal squamous cell carcinoma (ESCC) and its clinical significance.Methods The expression of VEGF-C in ESCC and its correlation with lymph node metastasis were detected by using immunohistochemistry (IHC) and in situ hybridization (ISH).Three small interfering RNA (siRNA) expression vectors targeting VEGF-C were constructed and transformed into EC9706 cells.The inhibitory effect of siRNA on the expression of VEGF-C protein and mRNA in tranfected cells was analyzed by using Western blotting and reverse transcription-polymerase chain reaction (RT-PCR).Stably transfected cells were transplanted in nude mice later.The expression of VEGF-C in transplant tumor was detected by using IHC and ISH.Results VEGF-C was up-expressed in ESCC.Its expression was correlated significantly with lymph node metastasis.The positive expression rate of VEGF-C in lymph node metastasis group and non-lymph node metastasis group was 90.0％ and 62.1％ respectively (P ＜0.01 ).VEGF-C-targeted siRNA could decrease the expression of VEGF-C mRNA and protein in EC9706 cells effectively.There was significant difference between transfected group (0.32 ± 0.02) and un-transfected group (0.91 ± 0.09,P ＜0.01 ).Correspondingly,the expression of VEGF-C was 9.26 ±0.95,8.94 ±0.81,9.19 ±0.92 and 32.47 ±3.25 respectively.There was significant difference among them (P ＜0.01 ).Conclusion Targeting VEGF-C siRNA can inhibit VEGF-C expression of EC9706 in vivo and in vitro effectively. Key words: Esophageal neoplasm; Vascular endothelial growth factor C

RNA Interference-Mediated Vascular Endothelial Growth Factor-C Reduction Suppresses Malignant Progression and Enhances Mitomycin C Sensitivity of Bladder Cancer T24 Cells

Vascular endothelial growth factor-C (VEGF-C) has been found to be significantly associated with lymphangiogenesis and regional lymph node metastasis in various human tumors. The present work was aimed to explore the role of VEGF-C in malignant progression of human bladder cancer T24 cell line. First, the expression of VEGF-C in T24 cells was detected by western blotting. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay was employed to measure the cellular proliferation after treatment with various concentrations of recombinant human VEGF-C (rhVEGF-C). Then, lentivirus vector-based RNA interference (RNAi) was used to inhibit VEGF-C expression of T24 cells. The alterations of T24 cells regarding proliferation, invasiveness, and the apoptosis induced by mitomycin C (MMC) were evaluated. The results showed that the proliferation rate of T24 cells rose from 27.3% to 65.0%, with increasing rhVEGF-C concentration. T24 cells stably transfected with VEGF-C small interference RNA showed 85% reduction in VEGF-C mRNA expression (p < 0.05). The VEGF-C protein level was significantly downregulated (p < 0.05) and the growth and invasiveness were also inhibited (p < 0.05) compared with the control group. Further, the inhibition of VEGF-C expression markedly enhanced the apoptosis of T24 cells induced by MMC (p < 0.05). These were associated with the decreased ratio of Bcl-2/Bax, activation of Caspase-3, decreased expression of MMP-9, as well as the downregulation of phosphorylated p38 MAPK and Akt. The present study suggests that VEGF-C can enhance the proliferation and invasiveness of bladder cancer T24 cells, which is due to suppression of apoptosis and facilitation of migration, accompanied with upregulation of p38 MAPK and Akt phosphorylation. RNAi targeting VEGF-C could effectively suppress malignant progression and enhance chemosensitivity of T24 cells. Thus, inhibition of VEGF-C expression is a potential and promising therapeutic strategy for bladder cancer.

VEGF-C promotes the development of esophageal cancer via regulating CNTN-1 expression

Vascular endothelial growth factor C (VEGF-C) is a key regulator of angiogenesis and lymphangiogenesis. VEGF-C is also implicated in the development of esophageal cancer. We investigated the mRNA levels of VEGF-C and its receptors in 38 esophageal squamous cell carcinoma specimens (ESCCs) and matched adjacent normal esophageal tissues via real-time PCR. The mRNA levels of VEGF-C, VEGFR-2 and VEGFR-3 were significantly upregulated in ESCCs versus respective side normal tissues. To explore the influence of VEGF-C on esophageal cancer progression, the expression of VEGF-C was manipulated in esophageal cancer cell lines TE-1 and Eca-109. VEGF-C transcription, translation and secretion were significantly enhanced in cells stably transfected with a VEGF-C overexpression vector or attenuated in VEGF-C shRNA-transfected cell lines. In vitro, TE-1 cells stably transfected with a VEGF-C overexpression vector exhibited an increased rate of cell proliferation, migration and focus formation, whereas knockdown of VEGF-C inhibited cell proliferation, migration and focus formation. Similar results were obtained for Eca-109 cells. VEGF-C mediated biological function through transcription of CNTN-1, which is implicated in tumor invasion and metastasis. The expression of VEGF-C was correlated with that of CNTN-1 and cell proliferation and migration induced by VEGF-C were reversed by silencing of CNTN-1. In addition, nude mice inoculated with VEGF-C shRNA-transfected cells exhibited a significantly decreased tumor size in vivo via reduced VEGFR-2 and VEGFR-3 phosphorylation and microvessel formation. VEGF-C upregulation may be involved in esophageal tumor progression. Vector-based RNA interference (RNAi) targeting VEGF-C is a potential therapeutic method for human esophageal carcinoma.

Abstract 2442: VGX-100, a novel therapeutic monoclonal antibody targeting VEGF-C that inhibits tumor growth

Abstract Angiogenesis and lymphangiogenesis are important contributors to the growth and metastasis of a wide variety of tumor types. Therapeutic targeting of the angiogenic vascular endothelial growth factor (VEGF) is now an FDA-approved treatment for several cancers. Vascular endothelial growth factor-C (VEGF-C) has also been demonstrated to stimulate angiogenesis and lymphangiogenesis in a number of experimental systems, and is essential for development of the lymphatic system during embryogenesis. In addition, expression of VEGF-C drives tumor progression and metastasis in mouse models of cancer, and is associated with poor prognosis in many human cancers. Targeting VEGF-C is therefore a highly promising strategy for novel therapeutics, with the potential to disrupt both angiogenesis and lymphangiogenesis. VGX-100 is a highly specific, fully human monoclonal antibody for VEGF-C that does not bind to other members of the VEGF family. In vitro testing demonstrates that VGX-100 blocks binding of VEGF-C to both VEGF receptor-2 and VEGF receptor-3, and inhibits the proliferation of blood vascular (HUVEC) and lymphatic endothelial cells in response to VEGF-C stimulation. Here we demonstrate anti-tumor efficacy through the use of xenograft models of human cancer, with VGX-100 treatment significantly inhibiting tumor growth in several models. These findings demonstrate that VGX-100 has great potential for development as a new cancer therapeutic, with potential clinical utility in combination with existing therapies or in patients refractory to existing anti-angiogenic agents. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 2442.

Role of short haipin RNA targeting vascular endothelial growth factor-C on biological characteristics of human breast cancer cell MCF-7

To study the effect of short haipin RNA (shRNA) on expression of vascular endothelial growth factor C (VEGF-C) and proliferation and invasion behavior of human breast cancer cell MCF-7. The recombinant vector (pSIREN-VEGF-C) was transfected into the human breast cancer cell MCF-7 by liposome and the positive transfected cell clones were screened with puromycin. Expression of VEGF-C in MCF-7 cells after gene transfer was detected by real-time quantitative PCR and Western blot assay, respectively. Proliferation and invasion ability of transfected cells were analyzed by MTT and Transwell filter. The expressions of VEGF-C mRNA and protein were decreased markedly compared with the control group after the transfection and the inhibitive ratio was 95% and 100% respectively (P<0.05). The proliferation of MCF-7 cells transfected by pSIREN-VEGF-C, measured with MTT assays, was significantly decended (P<0.05). The invasion ability of passing through the Transwell filter of MCF-7 cells transfected by pSIREN-VEGF-C were declined evidently (P<0.05). The recombinant vector (pSIREN-VEGF-C) have been proved not only to be effective and specific for down-regulation of VEGF-C, but also can inhibit the proliferation and invasion of MCF-7 cells significantly.

Vector-based RNA interference against vascular endothelial growth factor-C inhibits tumor lymphangiogenesis and growth of colorectal cancer in vivo in mice

RNA interference (RNAi) technology is emerging as a very potent tool to generate a cellular knockdown of a desired gene. The aim of this study was to explore whether RNAi targeting vascular endothelial growth factor-C (VEGF-C) could inhibit colorectal tumor lymphangiogenesis and tumor growth. We used vector-based RNAi to inhibit VEGF-C expression in colon cancer in vitro and in vivo. VEGF-C expression was quantified by real-time polymerase chain reaction and Westen blotting. To establish LoVo cell tumor xenografts in mice, we subcutaneously inoculated 1.0 x 10(6) LoVo cells in nude mice; after injection, tumors were allowed to grow for 4 weeks until the volume reached (75.8+/-55.8) mm(3). The mice were then randomly divided into two groups: (1) the VEGF-C-siRNA group (n=10) received direct injection of "therapeutic" plasmid 50 microg of LoVo-VEGF-C-siRNA into the tumor mass; (2) the control group (n=10) were injected with LoVo-control in 20 microl of sterile 0.9% NaCl solution into the tumor mass. Tumor growth, microlymphatics and microvessels were compared for mice administered either systemic VEGF-C-siRNA or control over 4 weeks. The mRNA and protein expression of VEGF-C in the colon tumor cell line, LoVo, stably transfected with a VEGF-C-siRNA vector, were significantly downregulated 45.3% and 35.3% respectively. In vivo, four weeks after injection, the tumor volume were significantly smaller in VEGF-C-siRNA group than in LoVo-control group ((314.8+/-54.8) mm(3) vs (553.9+/-90.1) mm(3)); the incidences of lymph node metastasis (30%) in VEGF-C-siRNA were significantly inhibited compared with LoVo-control group (70%); in VEGF-C-siRNA group, the number of microlymphatics per microscopic field was (5.3+/-0.7) and the number of microvessels per microscopic field was (24.2+/-6.5) decreased compared with LoVo-control group (12.5+/-6.9) and (42.1+/-7.4) (all P<0.001). Inhibition of VEGF-C expression using siRNA-mediated gene silencing vectors reduced lymphangiogenesis and lymph node metastasis and enhanced survival.

Calcium carbonate nanoparticle delivering vascular endothelial growth factor-C siRNA effectively inhibits lymphangiogenesis and growth of gastric cancer in vivo

A nonviral gene carrier, calcium carbonate (CaCO3) nanoparticle, was evaluated for efficient in vitro and in vivo delivery of small interfering RNA (siRNA) targeting vascular endothelial growth factor-C (VEGF-C). The chemically synthesized CaCO3 nanoparticle has a 58 nm diameter and +28.6 mV positive surface charge. It is capable of forming a CaCO3 nanoparticle-DNA complex and transferring DNA into targeted cells with high transfection efficiency while effectively protecting the encapsulated DNA from degradation. Furthermore, the CaCO3 nanoparticle-DNA complex has no obvious cytotoxicity for SGC-7901 cells, while a liposome-DNA complex exhibited measurable cytotoxicity. SGC-7901 cells transfected with a VEGF-C-targeted siRNA via CaCO3 nanoparticle exhibit significantly reduced VEGF-C expression as measured by real-time PCR and enzyme-linked immunosorbent assay; whereas no decrease in VEGF-C expression is observed in cells treated by control transfection. Transfection of SGC-7901 cells with VEGF-C siRNA via CaCO3 nanoparticle also dramatically suppresses tumor lymphangiogenesis, tumor growth and regional lymph-node metastasis in subcutaneous xenografts. Significant downregulation of VEGF-C messenger RNA expression in a subcutaneous xenograft derived from VEGF-C siRNA-treated SGC-7901 cells was confirmed by real-time PCR as compared to controls. We conclude that CaCO3 nanoparticle is a novel and nonviral system for effective delivery of siRNA for cancer gene therapy.

RNA interference (RNAi)-mediated vascular endothelial growth factor-C (VEGF-C) reduction interferes with lymphangiogenesis and enhances Epirubicin sensitivity of breast cancer cells

It has been reported that over-expression of vascular endothelial growth factor-C (VEGF-C) in tumors leads to increased lymphangiogenesis and resistance to chemotherapy. Therefore, we hypothesized that VEGF-C would be a good molecular target for cancer gene therapy. In this study, we silenced the expression of VEGF-C with the highly specific post-transcriptional suppression of RNA interference (RNAi) in human breast cancer MCF-7 cell line. The expression of VEGF-C was examined by reverse transcription-polymerase chain reaction (RT-PCR) and enzyme-linked immunosorbent assay (ELISA), and the effect of plasmid on human lymphatic endothelial cells (HLECs) in vitro was analyzed by migration and 3-(4, 5-dimethylt-hiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay. The sensitivity to anticancer agents was evaluated by MTT and apoptosis assay, and apoptosis-related genes bcl-2/bax ratio was determined by Western Blotting. Results showed that of three siRNA-expressing vectors, P-1/siRNA most significantly suppressed the expression of VEGF-C mRNA and protein (38.1% of control and 117.8 +/- 24.2 pg/ml, respectively) and interfered with proliferation and migration of HLECs in vitro. Moreover, transfection of VEGF-C/siRNA combined with Epirubicin markedly decreased breast cancer cells viability, reaching up to 38.5%, and increased apoptosis rate from 13.1% to 38.9%, as determined by decrease of bcl-2/bax ratio. In summary, VEGF-C would be a good molecular target, and a combination of Epirubicin and RNAi targeting VEGF-C could be an effective means for suppressing lymphatic metastasis and enhancing chemosensitivity of human breast cancer cells.