Expression of VEGF-C and VEGF-D as significant markers for assessment of lymphangiogenesis and lymph node metastasis in non-small cell lung cancer.

Vascular endothelial growth factor (VEGF)-C and VEGF-D induce lymphangiogenesis through activation of VEGF receptor 3 (VEGFR-3) and have been implicated in tumor spread to the lymphatic system. Lymph node dissemination critically determines clinical outcome and therapeutic options of patients with non-small cell lung cancer (NSCLC). However, the relationship of VEGF-C, VEGF-D, and lymph node metastasis in cancers, including NSCLC, is still controversial. To evaluate the relationship between lymphangiogenesis and lymph node metastasis, the expression of VEGF-C and VEGF-D in NSCLC tumors were detected by immunohistochemistry and quantitative real-time polymerase chain reaction (QRT-PCR). QRT-PCR revealed that in marginal region VEGF-C and VEGF-D mRNA was significantly higher than in tumor center, and VEGF-D mRNA was also higher than that in peritumoral lung tissue. Immunohistochemically, we observed the same heterogeneous expression of VEGF-C and VEGF-D proteins. The group with high expression of VEGF-C and VEGF-D in marginal region had a higher incidence of lymph node metastasis compared with the group with low expression. Furthermore, the group with high expression of VEGF-D in marginal region had a higher incidence of lymphatic invasion. The group with high peritumoral lymphatic vessel density (LVD) had higher expression of VEGF-C and VEGF-D mRNA compared with the group with low peritumoral LVD. Our studies suggested that the expression of VEGF-C and VEGF-D at invasive edge was significantly associated with lymph node metastasis or lymphatic invasion in patients with NSCLC and may be involved in regulation of lymphangiogenesis and lymph node metastasis in NSCLC.

Feng Y ，Wang W ，Hu J ，Ma J ，Zhang Y ，Zhang J ... -  《-》

The balance of VEGF-C and VEGFR-3 mRNA is a predictor of lymph node metastasis in non-small cell lung cancer.

A positive association between vascular endothelial growth factor-C (VEGF-C) expression and lymph node metastasis has been reported in several cancers. However, the relationship of VEGF-C and lymph node metastasis in some cancers, including non-small cell lung cancer (NSCLC), is controversial. We evaluated the VEGF-C and vascular endothelial growth factor receptor-3 (VEGFR-3) expression in NSCLC samples from patients who had undergone surgery between 1998 and 2002 using real-time quantitative RT-PCR and immunohistochemical staining. We failed to find a positive association between VEGF-C and VEGFR-3 mRNA expression and lymph node metastasis in NSCLC. An immunohistological study demonstrated that VEGF-C was expressed not only in cancer cells, but also in macrophages in NSCLC, and that VEGFR-3 was expressed in cancer cells, macrophages, type II pneumocytes and lymph vessels. The VEGF-C/VEGFR-3 ratio of the node-positive group was significantly higher than that of the node-negative group. Immunohistochemical staining showed that VEGFR-3 was mainly expressed in cancer cells. The immunoreactivity of VEGF-C and VEGFR-3 was roughly correlated to the mRNA levels of VEGF-C and VEGFR-3 in real-time PCR. VEGF-C mRNA alone has no positive association with lymph node metastasis in NSCLC. The VEGF-C/VEGFR-3 ratio was positively associated with lymph node metastasis in NSCLC. This suggests that VEGF-C promotes lymph node metastasis while being influenced by the strength of the VEGF-C autocrine loop, and the VEGF-C/VEGFR-3 ratio can be a useful predictor of lymph node metastasis in NSCLC.

Takizawa H ，Kondo K ，Fujino H ，Kenzaki K ，Miyoshi T ，Sakiyama S ，Tangoku A ... -  《-》

Lymphangiogenesis and its relationship with lymphatic metastasis and prognosis in malignant melanoma.

Regional lymph node metastasis is one of the important indicators of cutaneous malignant melanoma. Newly formed lymphatic vessels are considered to provide a route whereby tumor cells can migrate to the lymph nodes. Both vascular endothelial growth factors (VEGF) -C and -D have been confirmed to participate in tumor lymphangiogenesis, but the prognostic significance of VEGF-C, VEGF-D, and lymphangiogenesis in cutaneous malignant melanoma remains controversial. To clarify the effects of these factors and to evaluate the relationships between lymphangiogenesis, lymph node metastasis, and prognosis in patients with malignant melanoma, the expressions of VEGF-C, VEGF-D, and their receptor (VEGFR) -3 were detected by immunohistochemistry and reverse transcriptase-polymerase chain reaction. The expressions of both VEGF-C and VEGF-D proteins were concomitantly detected in the cytoplasm of the malignant cells. VEGF-C and VEGF-D expressions were associated with VEGFR-3 expression and were significantly correlated with both peritumoral lymphangiogenesis and lymph node metastasis. The incidence of peritumoral lymphatic vessels was significantly higher in lymph node metastatic melanomas than that in nonmetastatic melanomas. Univariate and multivariate analyses indicated that VEGF-C and VEGF-D were independent prognostic factors for overall survival and disease-free survival in patients with malignant melanoma. This study suggests that both VEGF-C and VEGF-D are involved in peritumoral lymphangiogenesis and lymphatic metastasis. VEGF-C and VEGF-D expression may be clinically useful indicators for prognostic evaluation in patients with cutaneous malignant melanoma.

Liu B ，Ma J ，Wang X ，Su F ，Li X ，Yang S ，Ma W ，Zhang Y ... -  《-》

Expression of vascular endothelial growth factors A, B, C, and D and their relationships to lymph node status in lung adenocarcinoma.

Vascular endothelial growth factors (VEGFs) C and D are novel members of the VEGF family that show some selectivity toward lymphatic endothelial cells. Recent studies suggest that VEGF-C may be involved in lymphangiogenesis and spread of cancer cells via lymphatic vessels. However, whether other VEGF family members play a role in lymph node metastasis is largely unknown. The aim of the present study was to explore whether expressions of VEGF-A, VEGF-B, VEGF-C, and VEGF-D are correlated with lymph node status in lung adenocarcinoma. Total RNA was isolated from 60 surgical specimens of lung adenocarcinoma with (n = 27) or without (n = 33) lymph node metastasis. The relative mRNA abundance of VEGF-A, VEGF-B, VEGF-C, and VEGF-D was measured by real-time reverse transcription-PCR analysis based on TaqMan fluorescence methodology. We found that, as single factors, expression of none of the four VEGF family members clearly correlated with the presence of lymph node metastasis. The only tendency noted was for higher VEGF-B and VEGF-C and lower VEGF-D levels in the node-positive group. However, two-way scatterplot analysis revealed that tumors with lymph node metastasis were associated with a pattern of low VEGF-D and high VEGF-A, VEGF-B, or VEGF-C, such that the ratios of VEGF-D:VEGF-A, VEGF-D:VEGF-B, or VEGF-D:VEGF-C were significantly lower in the node-positive group. Strikingly, none of the 11 tumors with high VEGF-D levels metastasized to lymph nodes. Furthermore, a low VEGF-D:VEGF-C ratio correlated with the presence of lymphatic invasion, and six of seven tumors with a pattern of very high expression of VEGF-C and low expression of VEGF-D displayed lymph vessel invasion that extended along the bronchovascular tree beyond the main tumor. Finally, levels of VEGF-A, but not VEGF-B or VEGF-C, were higher in tumors with large nodal metastasis (> or = 1 cm) than in those with small (< 1 cm) nodal metastasis. These results support the hypothesis that two VEGF family members are involved in lymph node metastasis at two distinct steps; VEGF-C facilitates entry of cancer cells into the lymph vasculature, whereas VEGF-A promotes the growth of metastatic tumor through angiogenesis. The results also suggest that the balance between VEGF-C and VEGF-D could be important rather than the level of VEGF-C alone. Whether a low VEGF-D level plays a causative role in lymph node metastasis requires further investigation.

Niki T ，Iba S ，Tokunou M ，Yamada T ，Matsuno Y ，Hirohashi S ... -  《CLINICAL CANCER RESEARCH》

Correlation between lymph node metastasis and the expression of VEGF-C, VEGF-D and VEGFR-3 in T1 lung adenocarcinoma.

Vascular endothelial growth factor (VEGF)-C and VEGF-D influence lymphangiogenesis through the activation of the vascular endothelial growth factor receptor (VEGFR)-3. They have been implicated in lymphatic tumor spread, which is an important prognostic factor in patients with non-small cell lung carcinoma (NSCLC). Whether or not the expression of VEGF-C, -D, and VEGFR-3 correlates with clinicopathological factors in patients with T1 lung adenocarcinoma was analysed. The tumor specimens were homogenized to determine the protein expression of VEGF-C, -D, and VEGFR-3 by enzyme-linked immunosorbent assay (ELISA). RNA fractions extracted from the tumor tissues were subjected to real-time reverse transcription-polymerase chain reaction (RT-PCR) to assess the mRNA levels of VEGF-C, -D, and VEGFR-3. The expression of VEGF-D protein and mRNA levels in patients without lymph node metastasis were significantly higher than those with metastasis (p=0.013, p=0.0494, respectively). However, the protein and mRNA levels of VEGF-C and VEGFR-3 were not significantly different in patients with or without metastasis. The 5-year survival rates of the patients with high VEGF-D levels were significantly higher than those of patients with low levels (p =0.0221). No significant difference in the survival rates was observed for VEGF-C and VEGFR-3. VEGF-D may be downregulated in NSCLC tissues in comparison to adjacent normal tissue, resulting in lymph node metastasis and poor prognosis.

Maekawa S ，Iwasaki A ，Shirakusa T ，Enatsu S ，Kawakami T ，Kuroki M ，Kuroki M ... -  《ANTICANCER RESEARCH》