RUNX3 inhibits the expression of vascular endothelial growth factor and reduces the angiogenesis, growth, and metastasis of human gastric cancer.

PURPOSE: Recent studies indicated that RUNX3 exhibits potent antitumor activity. However, the underlying molecular mechanisms of this activity remain unclear. In the present study, we used a gastric cancer model to determine the effect of RUNX3 expression on tumor angiogenesis. EXPERIMENTAL DESIGN: The effects of increased RUNX3 expression on vascular endothelial growth factor (VEGF) expression in and angiogenic potential of human gastric cancer cells were determined in vitro and in animal models. RUNX3 and VEGF expression was determined in 120 human gastric cancer specimens and their relationship was analyzed. RESULTS: RUNX3 gene transfer suppressed VEGF expression in human gastric cancer cells. Down-regulation of VEGF expression correlated with a significantly impaired angiogenic potential of human gastric cancer cells. Furthermore, RUNX3 restoration inhibited tumor growth and metastasis in animal models, which was consistent with inhibition of angiogenesis as determined by evaluating VEGF expression and tumor microvessel formation. In gastric cancer specimens, loss or decrease in RUNX3 expression inversely associated with increased VEGF expression and elevated microvessel formation. CONCLUSIONS: Our clinical and experimental data provide a novel molecular mechanism for the antitumor activity of RUNX3 and may help design effective therapy targeting RUNX3 pathway to control gastric cancer growth and metastasis.     

beta-Catenin regulates vascular endothelial growth factor expression in colon cancer

To evaluate whether beta-catenin signaling has a role in the regulation of angiogenesis in colon cancer, a series of angiogenesis-related gene promoters was analyzed for beta-catenin/TCF binding sites. Strikingly, the gene promoter of human vascular endothelial growth factor (VEGF, or VEGF-A) contains seven consensus binding sites for beta-catenin/TCF. Analysis of laser capture microdissected human colon cancer tissue indicated a direct correlation between up-regulation of VEGF-A expression and adenomatous polyposis coli (APC) mutational status (activation of beta-catenin signaling) in primary tumors. In metastases, this correlation was not observed. Analysis by immunohistochemistry of intestinal polyps in mice heterozygous for the multiple intestinal neoplasia gene (Min/+) at 5 months revealed an increase and redistribution of VEGF-A in proximity to those cells expressing nuclear beta-catenin with a corresponding increase in vessel density. Transfection of normal colon epithelial cells with activated beta-catenin up-regulated levels of VEGF-A mRNA and protein by 250-300%. When colon cancer cells with elevated beta-catenin levels were treated with beta-catenin antisense oligodeoxynucleotides, VEGF-A expression was reduced by more than 50%. Taken together, our observations indicate a close link between beta-catenin signaling and the regulation of VEGF-A expression in colon cancer.     

Interleukin-8 increases vascular endothelial growth factor and neuropilin expression and stimulates ERK activation in human pancreatic cancer

Interleukin-8 (IL-8) is associated with tumorigenesis by promoting angiogenesis and metastasis. Although up-regulation of IL-8 is indicated in many cancers, its function in pancreatic cancer has not been well characterized. In this study we examined the expression of IL-8 on pancreatic cancer cells and clinical tissue specimens, and investigated the effect of exogenous IL-8 on gene expression, and signaling in human pancreatic cancer cells. We found that pancreatic cancer cells expressed higher amount of IL-8 mRNA than normal human pancreatic ductal epithelium cells. IL-8 mRNA was also substantially overexpressed in 11 of 14 (79%) clinical pancreatic-adenocarcinoma samples compared with that in their surrounding normal tissues. Exogenous IL-8 up-regulated the expression of vascular endothelial growth factor₁₆₅, and neuropilin (NRP)-2 in BxPC-3 cells, one of human pancreatic cancer cell lines. IL-8 expression was inducible by hypoxia mimicking reagent cobalt chloride. In addition, IL-8 activated extracellular signal-regulated kinase (ERK)1/2 signaling pathway in BxPC-3 cells. Our studies suggest that IL-8 might be a malignant factor in human pancreatic cancer by induction of vascular endothelial growth factor and NRP-2 expression and ERK activation. Targeting IL-8 along with other antiangiogenesis therapy could be an effective treatment for this malignancy. ( Cancer Sci 2008, 99: 733–737)     

Tenascin-C regulates angiogenesis in tumor through the regulation of vascular endothelial growth factor expression

In order to verify whether tenascin-C (TN-C) is involved in angiogenesis as an extracellular signal molecule during tumorigenesis, cancerous cell transplantation experiments and coculture experiments were carried out, focusing on the regulation of vascular endothelial growth factor (VEGF). The A375 human melanoma cells introduced the GFP gene (A375-GFP), implanted subcutaneously into BALB/cA nude (WT) and TN-C knockout BALB/cA nude (TNKO) congenic mice. Furthermore, coculture experiments between A375-GFP and embryonic mesenchyme, which was prepared from both genotypes, were carried out to investigate the molecular mechanism in the cell-cell interactions. Both the content of TN-C and that of VEGF in the tumor and the conditioned medium were analyzed by the sandwich ELISA method. Seven days after transplantation of the A375-GFP, capillary nets became far more abundant in the tumors grown in WT mice than those in TNKO mice. Interestingly, VEGF and TN-C expressions showed antithetical expression patterns between the tumors in WT mice and those in TNKO mice. This peculiar phenomenon seems to be caused by a time lag prior to the onset of the mesenchymal regulation for the TN-C expression of A375-GFP. The coculture experiments revealed that WT mesenchyme had a much stronger effect than TNKO mesenchyme on both TN-C and VEGF expression. However, the defects of TNKO mesenchyme were restored in all cases by additional TN-C. These results clearly indicated that the expressions of both TN-C and VEGF depend on the surrounding mesenchyme, and that the function of mesenchyme is regulated by its own mesenchymal TN-C. In conclusion, the present data suggest that the matrix microenvironment organized by the host mesenchyme is very important for angiogenesis in tumor development.     

Melatonin inhibits the expression of vascular endothelial growth factor in pancreatic cancer cells

Objective:To investigate the effects of melatonin on cellular proliferation and endogenous vascular endothelial growth factor(VEGF) expression in pancreatic carcinoma cells(PANC-1).Methods:PANC-1 cells were cultured for this study.The secreted VEGF concentration in the culture medium was determined using ELISA method,VEGF production in the tumor cells was detected by immunocytochemistry,and VEGF mRNA expression was determined by RT-PCR.Results:Higher melatonin concentrations significantly inhibited cellular proliferation,with 1 mmol/L concentration exhibiting the highest inhibitory effect(P<0.01).VEGF concentrations in the cell culture supernatants and intra-cellules were all significantly reduced after melatonin(1 mmol/L) incubation(P<0.05).VEGF mRNA expression decreased markedly in a time-dependent manner during the observation period(P<0.05).Conclusions:High melatonin concentrations markedly inhibited the proliferation of pancreatic carcinoma cells.The endogenous VEGF expression was also suppressed by melatonin incubation.     

Cyclooxygenase-2 upregulates vascular endothelial growth factor expression and angiogenesis in human gastric carcinoma

Although gastric cancer with cyclooxygenase (COX)-2 overexpression is associated with poor prognosis, the mechanistic pathway remains unknown. We examined the associations between expressions of COX-2 and vascular endothelial growth factor (VEGF) in both gastric cancer cells and in human gastric cancer. The gastric cell line, Kato III, was transiently transfected with cox-2 expressing vector. The levels of COX-2, prostaglandin (PG) E2 and VEGF expression were measured post-transfection. Additionally, expressions of COX-2 and VEGF in human gastric cancer were determined by immunohistochemistry in archive gastrectomy specimens. Tumor angiogenesis was assessed by the microvessel density (MVD), which was determined by anti-CD34 immunostaining. Transient transfection of Kato III with cox-2 was associated with increased COX-2 expression, higher PGE2 production and upregulated VEGF expressions. Treatment with NS398, a specific COX-2 inhibitor, reduced VEGF expression in COX-2 expressing Kato III cells by 25%. Among the 67 gastric cancers examined, COX-2 overexpression was found in 45 (67%) cases whereas increased VEGF expression was detected in 46 (69%) cases. There was a significant association between COX-2 and VEGF expressions in gastric cancer (r=0.25, p=0.041). Additionally, tumor MVD was associated with both COX-2 (r=0.32, p=0.008) and VEGF (r=0.39, p=0.001) expressions. Our results showed that overexpression of COX-2 in both gastric cells and primary gastric cancer is associated with upregulation of VEGF and angiogenesis. Future studies should evaluate the potential anti-angiogenic effect of COX-2 inhibitors on human gastric cancer.     

Akt3 controls vascular endothelial growth factor secretion and angiogenesis in ovarian cancer cells

The PI3 kinase/Akt pathway is commonly deregulated in human cancers, functioning in such processes as proliferation, glucose metabolism, survival and motility. We have previously described a novel function for one of the Akt isoforms (Akt3) in primary endothelial cells: the control of VEGF-induced mitochondrial biogenesis. We sought to determine if Akt3 played a similar role in carcinoma cells. Because the PI3 kinase/Akt pathway has been strongly implicated as a key regulator in ovarian carcinoma, we tested the role of Akt3 in this tumor type. Silencing of Akt3 by shRNA did not cause an overt reduction in mitochondrial gene expression in a series of PTEN positive ovarian cancer cells. Rather, we find that blockade of Akt3, results in smaller, less vascularized tumors in a xenograft mouse model that is correlated with a reduction in VEGF expression. We find that blockade of Akt3, but not Akt1, results in a reduction in VEGF secretion and retention of VEGF protein in the endoplasmic reticulum (ER). The reduction in secretion under conditions of Akt3 blockade is, at least in part, due to the down regulation of the resident golgi protein and reported tumor cell marker, RCAS1. Conversely, over-expression of Akt3 results in an increase in RCAS1 expression and in VEGF secretion. Silencing of RCAS1 using siRNA inhibits VEGF secretion. These findings suggest an important role for Akt3 in the regulation of RCAS1 and VEGF secretion in ovarian cancer cells.     

Effect of the vascular endothelial growth factor receptor-2 antibody DC101 plus gemcitabine on growth,metastasis and angiogenesis of human pancreatic cancer growing orthotopically in nude mice

Vascular endothelial growth factor (VEGF) is the major pro-angiogenic factor for most tumors. VEGF expression has been shown to be associated with a poor prognosis in human pancreatic cancer. The purpose of our study was to determine the effect of blockade of VEGF receptor-2 activity with or without gemcitabine on tumor growth and metastasis in an orthotopic model of human pancreatic cancer in nude mice. Therapy with gemcitabine or DC101, a VEGF receptor-2 antibody, resulted in a significant reduction of primary pancreatic tumor growth compared to untreated controls. The combination of DC101 and gemcitabine inhibited primary pancreatic tumor growth and lymphatic metastasis to a greater degree than either agent alone. Treatment with DC101 decreased vessel counts and increased the area of hypoxic tumor tissue compared to controls. Immunofluorescent double staining for apoptotic endothelial cells demonstrated a significant increase in the number apoptotic endothelial cells 24 days after initiation of therapy with DC101 plus gemcitabine. DC101 plus gemcitabine also increased tumor cell death and decreased tumor cell proliferation in pancreatic tumors. These findings indicate that blockade of VEGF receptor activation interferes with the survival of tumor endothelial cells, resulting in a reduction of primary pancreatic tumor growth in nude mice. Furthermore, the data demonstrate that anti-VEGF receptor-2 therapy potentiates the tumoricidal effect of gemcitabine in this model. Anti-VEGF receptor-2 therapy in combination with gemcitabine may be a novel therapeutic approach for advanced pancreatic cancer.     

Site-dependent expression of vascular endothelial growth factor, angiogenesis and proliferation in human gastric carcinoma

To determine the role of site of tumor implantation on tumor angiogenesis, we implanted gastric cancer cells in the orthotopic (stomach) and ectopic (subcutaneous) locations in nude mice. Tumors in the stomach demonstrated greater vascularization, higher levels of vascular endothelial growth factor (VEGF) expression, and greater proliferation compared with tumors in the subcutaneous tissues. These data suggest that the relationships among the expression of VEGF, vascularization, and proliferation of human gastric cancer cells are regulated by the organ microenvironment. In addition, VEGF may provide a target for anti-angiogenic therapy for gastric cancers.     

大肠癌血管内皮生长因子的表达与转移的相关性研究

目的　探讨大肠癌组织中血管内皮生长因子 (VEGF)的表达与间质微血管密度 (MVD)及转移的相关性。方法　应用免疫组化 S- P法 ,检测 87例大肠癌中 VEGF的表达 ,同时选用 CD34进行微血管标记并计数。结果　大肠癌中 VEGF的表达与间质 MVD呈正相关 (r=0 .70 2 )。转移组 VEGF的表达与 MVD均高于未转移组 (P<0 .0 5 )。结论　 VEGF的表达及 MVD增高与大肠癌转移有关 ,可作为大肠癌转移危险度的预测     

Targeting vascular endothelial growth factor and angiogenesis for the treatment of colorectal cancer

Angiogenesis, the development and proliferation of new blood vessels, is critical for the growth of tumors. The process of new blood vessel formation is under complex control from a variety of pro- and anti-angiogenesis factors. By identifying and understanding these factors, new therapies have been developed to inhibit tumor growth and survival by blocking tumor-related angiogenesis. Recent success with the monoclonal antibody against vascular endothelial growth factor (VEGF; bevacizumab) in a large, randomized, phase III study has provided a critical proof of principle for this therapeutic area. This review will outline the biology of angiogenesis in colorectal cancer and discuss the current status of angiogenesis inhibition in its treatment.     

VEGF及其受体KDR在非小细胞肺癌中的表达及与肿瘤血管形成关系

目的：探讨血管内皮生长因子（VEGF）及其受体（KDR）的表达与非小细胞肺癌（NSCLC）血管形成的关系。方法：分别应用免疫组织化学S-P法和原位分子杂交法检测62例NSCLC组织和16例肺的良性瘤样病变组织中的VEGF和KDR mRNA的表达，并对血管进行染色、计数。结果：62例肺癌组织中46例有VEGF的表达（占74．29％），阳性表达位于肿瘤细胞胞膜及胞质；KDR mRNA在49例中有阳性表达（占79．03％），阳性表达位于肿瘤血管内皮细胞、肿瘤细胞胞膜及胞质。VEGF和KDR mRNA的表达与有无淋巴结转移和临床病理分期密切相关；VEGF和KDR mRNA阳性表达组微血管密度明显高于阴性表达组，P〈0．01。结论：VEGF和KDR的表达与NSCLC的发生、发展和转移可能密切相关，可作为评估NSCLC患者预后的一项指标。     

VEGF及其受体KDR在非小细胞肺癌中的表达及与肿瘤血管形成关系

目的:探讨血管内皮生长因子(VEGF)及其受体(KDR)的表达与非小细胞肺癌(NSCLC)血管形成的关系。方法:分别应用免疫组织化学S-P法和原位分子杂交法检测62例NSCLC组织和16例肺的良性瘤样病变组织中的VEGF和KDRmRNA的表达,并对血管进行染色、计数。结果:62例肺癌组织中46例有VEGF的表达(占74·29%),阳性表达位于肿瘤细胞胞膜及胞质;KDR mRNA在49例中有阳性表达(占79·03%),阳性表达位于肿瘤血管内皮细胞、肿瘤细胞胞膜及胞质。VEGF和KDR mRNA的表达与有无淋巴结转移和临床病理分期密切相关;VEGF和KDR mRNA阳性表达组微血管密度明显高于阴性表达组,P<0·01。结论:VEGF和KDR的表达与NSCLC的发生、发展和转移可能密切相关,可作为评估NSCLC患者预后的一项指标。     

CD133 expression is correlated with lymph node metastasis and vascular endothelial growth factor-C expression in pancreatic cancer

Although CD133 has been shown to be a marker for cancer stem cells in various tumours, its expression in pancreatic cancer has not yet been clinically reported. In this study, we investigated the relationship between CD133 expression and clinicopathological factors in pancreatic cancer. Pancreatic head carcinoma specimens from 80 patients who underwent surgical resection were immunohistochemically assessed for CD133, vascular endothelial growth factor (VEGF)-C, CXCR4, CD34, Ki-67, and cytokeratin (CK) expressions. Sixty percentage (48/80) of specimens were CD133-positive, with less than 15% cells per specimen expressing the marker. CD133-positive cells were found at the peripheral site of adenocarcinoma glandular structures and were negative for CK. There was a significant correlation between CD133 expression and clinicopathological factors, including histological type, lymphatic invasion, and lymph node metastasis (P=0.0215, 0.0023, and 0.0024, respectively). Vascular endothelial growth factor-C expression was also significantly correlated with CD133 expression (P=0.0002). Consequently, the 5-year survival rate of CD133-positive patients was significantly lower than that of CD133-negative patients (P=0.0002) and multivariate analysis revealed that CD133 expression was an independent prognostic factor (P=0.0103). These results suggest that CD133 expression in pancreatic cancer was significantly associated with lymphatic metastasis, VEGF-C expression, and prognosis.