Expression of lymphangiogenic factors and evidence of intratumoral lymphangiogenesis in pancreatic endocrine tumors.
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Lymphangiogenesis is thought to promote the progression of malignant tumors. Because the lymphangiogenic factors vascular endothelial factor (VEGF)-C and -D are expressed in endocrine cells, we investigated their expression in pancreatic endocrine tumors (PETs) and correlated these data and intratumoral lymph vessel density (iLVD) with clinicopathological features. Lymph vessels were identified with anti-podoplanin antiserum and with podoplanin/proliferating cell nuclear antigen double labeling. PETs (n = 104) were investigated by immunohistochemical staining for VEGF, basic fibroblast growth factor, and VEGF-C expression. VEGF-C and VEGF-D mRNA were quantified by real-time reverse transcriptase-polymerase chain reaction. PETs showed higher iLVD than normal pancreata, but iLVD did not discriminate between benign and malignant PETs. In PETs proliferating lymph vessels were identified. High iLVD was associated with lymph vessel invasion and it was more frequent in angioinvasive/metastatic tumors than in grossly invasive tumors. VEGF-C expression correlated with iLVD as well as with glucagon and pancreatic polypeptide expression. PETs show intratumoral lymphangiogenesis, which is associated with VEGF-C expression in tumor cells. The association between iLVD and lymph vessel invasion and angioinvasive/metastatic features in PETs suggests that lymphangiogenesis may promote malignant progression of PETs. PET is the first human tumor entity in which VEGF-C-related intratumoral lymphangiogenesis has been demonstrated. (+info)
Angiogenic profile of breast carcinoma determines leukocyte infiltration.
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To study the relationship between the angiogenic profile and leukocyte infiltration of tumors, single cell suspensions of archival frozen medullary and ductal breast cancer tissues were analyzed by flow cytometry. The amount of leukocytes and endothelial cells was measured, as well as the expression of intercellular adhesion molecule-1 (ICAM-1) on the endothelial cell fraction. A significantly higher number (3.2-fold) of infiltrating leukocytes was observed in medullary carcinoma. The composition of this infiltrate was similar to that seen in ductal carcinomas. The more intense infiltrate was explained by the approximately 3-fold enhanced endothelial ICAM-1 expression in medullary carcinoma. The angiogenic profile of all tumors was assessed by quantitative real-time reverse transcription-PCR analysis. Vascular endothelial growth factor (VEGF)-C and VEGF-D, but not VEGF-A, basic fibroblast growth factor, placental growth factor, and angiopoietins 1, 2, and 3 showed a relatively higher level of expression in ductal carcinoma than in medullary carcinoma. In vitro, both VEGF-C and VEGF-D were found to decrease endothelial ICAM-1 expression in the presence of basic fibroblast growth factor. These data suggest that in vivo angiogenic stimuli prevent the formation of an effective leukocyte infiltrate in tumors by suppressing endothelial ICAM-1 expression. (+info)
Loss of neural cell adhesion molecule induces tumor metastasis by up-regulating lymphangiogenesis.
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Reduced expression of neural cell adhesion molecule (NCAM) has been implicated in the progression to tumor malignancy in cancer patients. Previously, we have shown that the loss of NCAM function causes the formation of lymph node metastasis in a transgenic mouse model of pancreatic beta cell carcinogenesis (Rip1Tag2). Here we show that tumors of NCAM-deficient Rip1Tag2 transgenic mice exhibit up-regulated expression of the lymphangiogenic factors vascular endothelial growth factor (VEGF)-C and -D (17% in wild-type versus 60% in NCAM-deficient Rip1Tag2 mice) and, with it, increased lymphangiogenesis (0% in wild-type versus 19% in NCAM-deficient Rip1Tag2 mice). Repression of VEGF-C and -D function by adenoviral expression of a soluble form of their cognate receptor, VEGF receptor-3, results in reduced tumor lymphangiogenesis (56% versus 28% in control versus treated mice) and lymph node metastasis (36% versus 8% in control versus treated mice). The results indicate that the loss of NCAM function causes lymph node metastasis via VEGF-C- and VEGF-D-mediated lymphangiogenesis. These results also establish Rip1Tag2;NCAM-deficient mice as a unique model for stochastic, endogenous tumor lymphangiogenesis and lymph node metastasis in immunocompetent mice. (+info)
The lymphangiogenic vascular endothelial growth factors VEGF-C and -D are ligands for the integrin alpha9beta1.
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Mice homozygous for a null mutation of the integrin alpha9 subunit die 6-12 days after birth from bilateral chylothoraces suggesting an underlying defect in lymphatic development. However, until now the mechanisms by which the integrin alpha9beta1 modulates lymphangiogenesis have not been described. In this study we show that adhesion to and migration on the lymphangiogenic vascular endothelial growth factors (VEGF-C and -D) are alpha9beta1-dependent. Mouse embryonic fibroblasts and human colon carcinoma cells (SW-480) transfected to express alpha9beta1 adhered and/or migrated on both growth factors in a concentration-dependent fashion, and both adhesion and migration were abrogated by anti-alpha9beta1 function-blocking antibody. In SW-480 cells, which lack cognate receptors for VEGF-C and -D, both growth factors induced alpha9beta1-dependent Erk and paxillin phosphorylation. Human microvascular endothelial cells, which express both alpha9beta1 and VEGF-R3, also adhered to and migrated on both growth factors, and both responses were blocked by anti-alpha9beta1 antibody. Furthermore, in a solid phase binding assay recombinant VEGF-C and -D bound to purified alpha9beta1 integrin in a dose- and cation-dependent fashion showing that VEGF-C and VEGF-D are ligands for the integrin alpha9beta1. The interaction between alpha9beta1 and VEGF-C and/or -D may begin to explain the abnormal lymphatic phenotype of the alpha9 knock-out mice. (+info)
Dual role of carcinoembryonic antigen-related cell adhesion molecule 1 in angiogenesis and invasion of human urinary bladder cancer.
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Here, we show that carcinoembryonic antigen-related cell adhesion molecule 1 (CEACAM1) is expressed in umbrella cells of bladder urothelium but is down-regulated in superficial bladder cancer, such as histologic tumor stage a (pTa) and transitional cell carcinoma in situ (pTis). Concurrently, CEACAM1 is up-regulated in the endothelia of adjacent angiogenic blood vessels. Mimicking the CEACAM1 down-regulation in the urothelium, CEACAM1 was silenced in bladder cancer cell lines 486p and RT4 using the small interfering RNA technique. CEACAM1 down-regulation was confirmed at the protein level by Western blot analyses. CEACAM1 silencing leads to a significant up-regulation of vascular endothelial growth factor (VEGF)-C and VEGF-D in quantitative reverse transcription-PCR. Correspondingly, supernatants from the CEACAM1-overexpressing bladder cancer cell lines reduce, but those from CEACAM1 silencing induce endothelial tube formation and potentiate the morphogenetic effects of VEGF. These data suggest that the epithelial down-regulation of CEACAM1 induces angiogenesis via increased expression of VEGF-C and VEGF-D. Inversely, CEACAM1 is up-regulated in endothelial cells of angiogenic blood vessels. This in turn is involved in the switch from noninvasive and nonvascularized to invasive and vascularized bladder cancer. CEACAM1 appears to be a promising endothelial target for bladder cancer therapy. (+info)
Impact of vascular endothelial growth factor-C and -D expression in human pancreatic cancer: its relationship to lymph node metastasis.
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PURPOSE: The aim of this study was to evaluate the expression of vascular endothelial growth factor (VEGF)-C and -D in pancreatic cancer and to reveal its relation to lymph node metastasis. EXPERIMENTAL DESIGN: Formalin-fixed, paraffin-embedded blocks were obtained from 58 patients with pancreatic head cancer. All of the patients underwent a curative resection. The total number of resected lymph nodes was 1,058. The expressions of VEGF-C and -D were evaluated by immunohistochemical staining. To evaluate the relation to lymph node metastasis, the expressions of VEGF-C and -D between the marginal and central portions in the tumor were compared. When >25% of the tumor cells showed distinct staining, the portion was judged as high expression. RESULTS: The two groups with high expression of VEGF-C (P = 0.015) and VEGF-D (P = 0.020) in the marginal portion had a significantly higher incidence of lymph node metastasis compared with the groups with low expression, respectively. Furthermore, the group with high expression of both VEGF-C and -D in the marginal portion had a higher incidence of lymph node metastasis compared with the group with low expression (P = 0.007). The 5-year survival rate of patients with high expression of both VEGF-C and -D in the marginal portion was significantly lower than that of patients with low expression of both VEGF-C and -D (P = 0.017). CONCLUSIONS: VEGF-C and -D expression in tumor cells in the marginal portion of the tumor significantly associated with lymphatic metastasis and prognosis in patients with pancreatic head cancer. (+info)
Pathogenesis of persistent lymphatic vessel hyperplasia in chronic airway inflammation.
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Edema occurs in asthma and other inflammatory diseases when the rate of plasma leakage from blood vessels exceeds the drainage through lymphatic vessels and other routes. It is unclear to what extent lymphatic vessels grow to compensate for increased leakage during inflammation and what drives the lymphangiogenesis that does occur. We addressed these issues in mouse models of (a) chronic respiratory tract infection with Mycoplasma pulmonis and (b) adenoviral transduction of airway epithelium with VEGF family growth factors. Blood vessel remodeling and lymphangiogenesis were both robust in infected airways. Inhibition of VEGFR-3 signaling completely prevented the growth of lymphatic vessels but not blood vessels. Lack of lymphatic growth exaggerated mucosal edema and reduced the hypertrophy of draining lymph nodes. Airway dendritic cells, macrophages, neutrophils, and epithelial cells expressed the VEGFR-3 ligands VEGF-C or VEGF-D. Adenoviral delivery of either VEGF-C or VEGF-D evoked lymphangiogenesis without angiogenesis, whereas adenoviral VEGF had the opposite effect. After antibiotic treatment of the infection, inflammation and remodeling of blood vessels quickly subsided, but lymphatic vessels persisted. Together, these findings suggest that when lymphangiogenesis is impaired, airway inflammation may lead to bronchial lymphedema and exaggerated airflow obstruction. Correction of defective lymphangiogenesis may benefit the treatment of asthma and other inflammatory airway diseases. (+info)
Stage-specific characterization of the vascular endothelial growth factor axis in prostate cancer: expression of lymphangiogenic markers is associated with advanced-stage disease.
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PURPOSE: The vascular endothelial growth factor (VEGF) family plays a critical role in tumor angiogenesis and lymphangiogenesis. We characterized, at the mRNA and protein levels, the expression of VEGF-A and VEGF-D and their cognate receptors, VEGFR-1, VEGFR-2, and VEGFR-3 in early- and advanced-stage prostate cancer specimens. EXPERIMENTAL DESIGN: The levels of VEGF-A and VEGF-D mRNA in early- and advanced-stage specimens were compared using an angiogenic gene array and were confirmed by quantitative real-time PCR. Receptor protein levels and activation status were determined by immunoblotting. Spatial expression of the proteins was evaluated using immunohistochemistry with fresh and archival tissues from benign prostatic hypertrophy specimens, early-stage prostate specimens, and advanced-stage metastatic specimens. Circulating plasma levels of these growth factors were measured using ELISAs. RESULTS: We observed that expression patterns of VEGF isotypes corresponded to the prostate cancer stage: high expression of angiogenic growth factor VEGF-A was observed in early-stage prostate specimens, whereas high expression of lymphangiogenic growth factor VEGF-D was associated with advanced-stage metastatic disease. All VEGF receptors were present at variable levels in all specimens, but their activation states varied in a stage-specific manner. VEGFR-1 and, to a limited extent, VEGFR-2 were activated in early-stage specimens, whereas VEGFR-2 and VEGFR-3 were activated in advanced-stage specimens. CONCLUSIONS: Our results suggest that lymphangiogenic markers, such as VEGF-D and VEGFR-2 and VEGFR-3, may be better than angiogenic markers as targets of therapeutic intervention in advanced-stage prostate disease. (+info)