VEGFR-3在肿瘤淋巴管转移中的作用

VEGFR-3主要在成熟组织的淋巴管内皮细胞上表达,肿瘤分泌的VEGF-C、VEGF-D与之结合后可诱导淋巴管内皮细胞增殖和迁移,刺激淋巴管的新生,介导肿瘤淋巴道的转移.通过竞争性抑制VEGFR-3的信号转导可有效阻止肿瘤淋巴管的转移,最终达到提高治疗肿瘤的作用.     

Vascular endothelial growth factor-C expression in human prostatic carcinoma and its relationship to lymph node metastasis.

Lymph node dissemination is a major prognostic factor in human cancer. However, the molecular mechanisms underlying lymph node metastasis are poorly understood. Recently, vascular endothelial growth factor-C (VEGF-C) was identified as a ligand for VEGF receptor-3 (VEGFR-3/Flt-4) and the expression of VEGFR-3 was found to be highly restricted to the lymphatic endothelial cells. In this report, we investigated the expression of VEGF-C and VEGFR-3 in human prostatic carcinoma tissue by using in situ hybridization and immunohistochemical staining respectively. Expression of VEGF-C mRNA in prostatic carcinoma was significantly higher in lymph node-positive group than in lymph node-negative group. In addition, the number of VEGFR-3-positive vessels was increased in stroma surrounding VEGF-C-positive prostatic carcinoma cells. These results suggest that the expression of VEGF-C in prostatic carcinoma cells is implicated in the lymph node metastasis.     

Vascular endothelial growth factor expression predicts outcome and lymph node metastasis in squamous cell carcinoma of the esophagus.

Vascular endothelial growth factor (VEGF) expression and tumor microvessel density (MVD) were examined by immunohistochemical staining in 117 cases of thoracic esophageal squamous cell carcinoma. Thirty-six (31%) of the 117 cases were evaluated as VEGF-positive. The average number of metastatic lymph nodes at surgery was 5.6 in the VEGF-positive cases and 3.0 in the VEGF-negative cases and was significantly higher in those with VEGF-positive cases (P = 0.04). The incidence of pathological tumor (PT)2-4 cases among the high-MVD cases was significantly higher than among the low-MVD cases (P = 0.01). MVD was 59.4 +/- 4.7 (mean +/- SE)/mm2 in the VEGF-positive cases and 47.9 +/- 3.8/mm2 in the VEGF-negative cases. The MVD of the VEGF-positive tumors was higher than that of VEGF-negative tumors, but the difference was not significant (P = 0.08). The survival rate of the patients with high-MVD tumors was significantly poorer than those with low-MVD tumors, and the survival rate of those patients with VEGF-positive tumors was significantly poorer than in those with VEGF-negative tumors (P = 0.009 and P = 0.04, respectively). The cumulative survival rates in the VEGF-positive groups were found to be significantly poorer in the pT3 and pathological node (pN)1 groups when stratified according to pT factor (pathological T category) and pN factor (pathological N category) in the tumor-node-metastasis (TNM) classification. VEGF expression had the second highest hazard ratio in the multivariate analysis, after pN factor. These results indicate that VEGF is a useful marker for predicting the outcome in patients with more advanced esophageal squamous cell carcinoma. It seems that TNM factors and VEGF expression are important factors in the selection of appropriate treatments.     

Vascular endothelial growth factor C expression and lymph node metastasis are regulated by the type I insulin-like growth factor receptor

Vascular endothelial growth factor (VEGF)-C is a lymphangiogenic factor implicated in lymphatic metastasis. In this study, we investigated the role of the type I insulin-like growth factor receptor (IGF-IR) in the regulation of VEGF-C expression. We used Lewis lung carcinoma subline M-27 cells transfected with human IGF-IR cDNA. These cells, but not the wild-type cells, expressed VEGF-C mRNA, produced a M(r) 58,000 VEGF-C precursor protein, and secreted a M(r) 29,000 processed form in response to IGF-I. In vivo, they acquired a lymph node metastasizing potential. VEGF-C induction was abolished in cells expressing an IGF-IR with tyrosine-phenylalanine substitutions in the kinase domain, but not in the COOH-terminal domain. The induction was phosphatidylinositol 3'-kinase dependent and, to a lesser extent, mitogen-activated protein kinase signaling dependent, as determined by the use of the respective inhibitors LY294002 (84.6% reduction) and PD98059 (38% reduction). The results identify the IGF-IR as a positive regulator of VEGF-C expression and implicate it in the control of lymphatic metastasis.     

Role of vascular endothelial growth factor C expression in the development of lymph node metastasis in gastric cancer.

Neogenesis of lymphatic vessel and lymphatic invasion is frequently found in the stroma of cancers, but the mechanisms of this phenomenon remain unclear. Vascular endothelial growth factor C (VEGF-C) is known to be the only growth factor for the lymphatic vascular system, and its receptor has been identified as Flt4. To clarify the mechanism of lymphatic invasion in cancer, we studied the expression of VEGF-C and flt4 genes in gastric cancer tissues. VEGF-C mRNA was mainly expressed in primary tumors (15 of 32; 47%), but the frequency of VEGF-C mRNA expression was low in normal mucosa (4 of 32; 13%). In primary tumors, there was a significant relationship between VEGF-C and flt4 mRNA expression. In contrast, Flt4 was mainly expressed on the lymphatic endothelial cells but not in cancer cells. A strong correlation was found between VEGF-C expression and lymph node status, lymphatic invasion, venous invasion, and tumor infiltrating patterns. Cancer cells in the lymphatic vessels frequently showed intracytoplasmic VEGF-C immunoreactivity. Furthermore, there was a close correlation between VEGF-C tissue status and the grade of lymph node metastasis. Patients with high expression of VEGF-C protein had a significantly poorer prognosis than did those in low VEGF-C expression group. By the Cox regression model, depth of wall invasion, lymph node metastasis, and VEGF-C tissue status emerged as independent prognostic parameters, and the VEGF-C tissue status was ranked third as an independent risk factor for death. These results strongly suggest that cancer cells producing VEGF-C may induce the proliferation and dilation of lymphatic vessels, resulting in the development of invasion of cancer cells into the lymphatic vessel and lymph node metastasis.     

Vascular endothelial growth factor C (VEGF-C) in esophageal cancer correlates with lymph node metastasis and poor patient prognosis

Background

The diagnosis of lymph node metastasis in esophageal cancer by the presence and number of metastatic lymph nodes is an extremely important prognostic factor. In addition, the indication of non-surgical therapy is gaining more attention. Vascular endothelial growth factor C (VEGF-C) is potentially lymphangiogenic and selectively induces hyperplasia of the lymphatic vasculature. In this study, we investigated the expression of VEGF-C and whether it correlated with various clinico-pathologic findings.

Methods

KYSE series of esophageal cancer cell lines and 106 patients with primary esophageal squamous cell carcinomas who had undergone radical esophagectomy were analyzed. VEGF-C mRNA expression was determined by quantitative RT-PCR.

Results

High expression of VEGF-C was detected in most of the KYSE cell lines, especially KYSE410, yet, in an esophageal normal epithelium cell line, Het-1A, VEGF-C was not detected. In the clinical specimen, the expression of VEGF-C in the cancerous tissue was higher than in the corresponding noncancerous esophageal mucosa (p = 0.026). The expression of VEGF-C was found to be higher in Stage2B-4A tumors than in Stage0-2A tumors (p = 0.049). When the patients were divided into two groups according to their expression levels of VEGF-C (a group of 53 cases with high expression and a group of 53 cases with low expression), the patients with high VEGF-C expression had significantly shorter survival after surgery than the patients with low expression (p = 0.0065). Although univariate analysis showed that high expression of VEGF-C was a statistically significant prognostic factor, this was not shown in multivariate analysis. In the subgroup of patients with Tis and T1 tumors, the expression of VEGF-C was higher in N1 tumors than in N0 tumors (p = 0.029). The survival rate of patients from the high expression group (n = 10) was lower than that in the low expression group (n = 11), and all the patients in the low VEGF-C expression group survived.

Conclusions

The expression of VEGF-C correlates with lymph node metastasis and poor prognosis. In patients with Tis and T1 esophageal tumors, the expression of VEGF-C may be a good diagnostic factor for determining metastasis of the lymph node.     

Expression of hepatoma-derived growth factor is correlated with lymph node metastasis and prognosis of gastric carcinoma.

PURPOSE: Hepatoma-derived growth factor (HDGF) is a unique nuclear/growth factor and might play an important role in the development and progression of carcinomas. In the present study, association of HDGF expression with recurrence and prognosis of gastric carcinoma was examined. PATIENTS AND METHODS: HDGF expression in 317 patients with gastric carcinoma (233 males and 84 females) with ages ranging from 26 to 81 years (median, 60 years) was analyzed by immunohistochemistry. Samples with >90% of tumor cells to express positive immunoreactivity similar to or stronger than that in endothelial cells both for nucleus and cytoplasm were regarded as HDGF index level 2, and others as HDGF index level 1. RESULTS: One hundred and eighty-two cases showed level 1 HDGF expression, whereas 135 cases showed level 2 HDGF expression. Patients with level 2 expression showed higher rates of proximal tumor location (P < 0.0001), large tumor size (P < 0.0001), infiltrative tumor growth (P < 0.0001), presence of vascular and lymphatic invasion (P < 0.0001 for both), presence of lymph node metastasis (P < 0.0001), deep tumor invasion (P < 0.0001), and poorer disease-free and overall survival (P < 0.0001 for both) compared to those with level 1 expression. Multivariate analysis revealed HDGF expression level as an independent prognosticator for disease-free and overall survival. CONCLUSION: HDGF expression level was shown to be a prognostic factor for gastric carcinoma.     

Vascular endothelial growth factor C promotes tumor lymphangiogenesis and intralymphatic tumor growth

Many solid tumors produce vascular endothelial growth factor C (VEGF-C), and its receptor, VEGFR-3, is expressed in tumor blood vessels. To study the role of VEGF-C in tumorigenesis, we implanted MCF-7 human breast carcinoma cells overexpressing recombinant VEGF-C orthotopically into severe combined immunodeficient mice. VEGF-C increased tumor growth, but unlike VEGF, it had little effect on tumor angiogenesis. Instead, VEGF-C strongly promoted the growth of tumor-associated lymphatic vessels, which in the tumor periphery were commonly infiltrated with the tumor cells. These effects of VEGF-C were inhibited by a soluble VEGFR-3 fusion protein. Our data suggest that VEGF-C facilitates tumor metastasis via the lymphatic vessels and that tumor spread can be inhibited by blocking the interaction between VEGF-C and its receptor.     

Increased expression of vascular endothelial growth factor C in papillary thyroid carcinoma correlates with cervical lymph node metastases.

PURPOSE: Despite recent studies showing that vascular endothelial growth factor C (VEGF-C) mRNA is up-regulated in papillary thyroid carcinoma (PTC), the role of VEGF-C in lymph node metastasis is still unclear. The aim of this study is to investigate the expression pattern of VEGF-C immunoreactive protein in PTC and its relationship with cervical lymph node metastasis. EXPERIMENTAL DESIGN: Tissue samples were obtained from 39 specimens of PTC (20 with and 19 without lymph node metastasis) as well as 20 benign thyroid nodules. Overexpression of the VEGF-C protein was evaluated by immunoblotting with specific anti-VEGF-C antibody in paired tumor and nontumor tissues from PTC. The data were compared with patients' clinicopathologic features and lymph node metastasis. Immunohistochemical staining was done on selected paraffin sections to determine cellular localization of VEGF-C and to assess flt-4 (or VEGFR-3)-positive vessel density in PTC lesions. RESULTS: Overexpression of VEGF-C was detected in 69% of the PTC and in 5% of the benign thyroid specimens. When comparing between the metastatic and nonmetastatic groups of PTC, a higher expression level of VEGF-C was detected in both the tumor (P = 0.004) and adjacent nontumor tissues (P = 0.011). Positive immunostaining for VEGF-C was confirmed in PTC tumor tissues and metastatic lymph nodes, which correlated with flt-4-positive vessel density in tumor and peritumor tissues. The increased expression of VEGF-C protein in PTC is associated with lymph node metastasis (P = 0.004) and lymphovascular permeation (P = 0.001) but is independent of other clinicopatholgic variables. CONCLUSIONS: The VEGF-C immunoreactive protein is overexpressed in PTC lesions, which correlates with lymph node metastases. VEGF-C expression may play a role in lymphangiogenesis of PTC and further study is necessary to evaluate the clinical application of VEGF-C as a molecular marker for tumor metastases to cervical lymph nodes.     

Overexpression of vascular endothelial growth factor C is related to lymphogenous metastasis in early gastric carcinoma

Vascular endothelial growth factor C (VEGF-C) is considered to be potentially lymphangiogenic and can selectively induce hyperplasia of the lymphatic vasculature. In this study, we clarified the clinicopathological features of early gastric carcinoma (EGC) that has metastasized to the lymph nodes, as well as the correlation between lymphogenous metastases in EGC and the expression of VEGF-C and VEGF. We selected 35 cases of lymph node metastasis-positive [n(+)] EGC and 70 cases of lymph node metastasis-negative [n(-)] EGC for the present study. The expression of VEGF and VEGF-C was investigated with immunohistochemical staining using monoclonal antibodies against VEGF and VEGF-C. Clinicopathologically, there were significant differences in median size (4.1 +/- 2.4 vs. 2.4 +/- 1.7 cm), lymphatic invasion (54 vs. 4%) and venous invasion (23 vs. 3%) between n(+) EGC and n(-) EGC. Immunohistochemically, the incidence of positive expression of VEGF-C in lymphatic invasion-positive EGC (36%) was significantly higher than that in lymphatic invasion-negative EGC (14%). The incidence of positive expression of VEGF-C in n(+) or venous invasion-positive EGC tended to be higher than that in n(-) or venous invasion-negative EGC. In conclusion, lymphatic invasion was significantly increased in VEGF-C-positive EGC.     

血管内皮生长因子-C、-D与肿瘤淋巴道转移研究进展

恶性肿瘤淋巴道转移的机制和抗肿瘤淋巴道转移的治疗是目前的研究热点之一,不少研究表明血管内皮生长因子－C（cvscular endothelial growth factor-C VEGF-C)和血管内皮生长因子－D（VEGF-D)与恶性肿瘤的淋巴道转移密切相关,本文主要综述VEGF－C,VEGF－D的结构。功能特点,在肿瘤淋巴道转移中的可能机制及由此而引发出的抗肿瘤淋巴道转移治疗的有关进展。     

Vascular endothelial growth factor-a promotes peritumoral lymphangiogenesis and lymphatic metastasis

Metastases are commonly found in the lymphatic system. The molecular mechanism of lymphatic metastasis is, however, poorly understood. Here we report that vascular endothelial growth factor (VEGF)-A stimulated lymphangiogenesis in vivo and that overexpression of VEGF-A in murine T241 fibrosarcomas induced the growth of peritumoral lymphatic vessels, which occasionally penetrated into the tumor tissue. As a result of peritumoral lymphangiogenesis, metastases in lymph nodes of mice were detected. VEGF-A-overexpressing tumors contained high numbers of infiltrating inflammatory cells such as macrophages, which are known to express VEGF receptor (VEGFR)-1. It seemed that in the mouse cornea, VEGF-A stimulated lymphangiogenesis through a VEGF-C/-D/VEGFR-3-independent pathway as a VEGFR-3 antagonist selectively inhibited VEGF-C-induced, but not VEGF-A-induced, lymphangiogenesis. Our data show that VEGF-A contributes to lymphatic mestastasis. Thus, blockage of VEGF-A-induced lymphangiogenesis may provide a novel approach for prevention and treatment of lymphatic metastasis.     

Apelin promotes lymphangiogenesis and lymph node metastasis

Whereas the role of the G-protein-coupled APJ receptor and its ligand, apelin, in angiogenesis has been well documented, the ability of the apelin/APJ system to induce lymphangiogenesis and lymphatic metastasis has been largely unexplored. To this end, we first show that APJ is expressed in lymphatic endothelial cells (LECs) and, moreover, that it responds to apelin by activating the apelinergic signaling cascade. We find that although apelin treatment does not influence the proliferation of LECs in vitro, it enhances their migration, protects them against UV irradiation-induced apoptosis, increases their spheroid numbers in 3D culture, stimulates their in vitro capillary-like tube formation and, furthermore, promotes the invasive growth of lymphatic microvessels in vivo in the matrigel plug assay. We also demonstrate that apelin overexpression in malignant cells is associated with accelerated in vivo tumor growth and with increased intratumoral lymphangiogenesis and lymph node metastasis. These results indicate that apelin induces lymphangiogenesis and, accordingly, plays an important role in lymphatic tumor progression. Our study does not only reveal apelin as a novel lymphangiogenic factor but might also open the door for the development of novel anticancer therapies targeting lymphangiogenesis.     

Vascular endothelial growth factor expression correlates with hematogenous metastasis and prognosis in colorectal carcinoma

We investigated the expression of vascular endothelial growth factor (VEGF) in 175 colorectal carcinomas by immunohistochemistry. VEGF expression was correlated with advanced TNM stage (III, IV), advanced T stage (T3, T4), vessel involvement, lymph node metastasis, and liver metastasis. With regard to the prognosis, both overall and relapse-free survival was significantly poorer, and furthermore, the hematogenous recurrences were significantly more commonly found in the patients with VEGF-positive tumors. VEGF expresion in colorectal carcinomas may have a substantial value in predicting those patients at high risk for hematogenous recurrence after surgery.