CCM3 Loss-Induced Lymphatic Defect Is Mediated by the Augmented VEGFR3-ERK1/2 Signaling

OBJECTIVE

Cerebral cavernous malformations (CCMs) can happen anywhere in the body, although they most commonly produce symptoms in the brain. The role of CCM genes in other vascular beds outside the brain and retina is not well-examined, although the 3 CCM-associated genes (CCM1, CCM2, and CCM3) are ubiquitously expressed in all tissues. We aimed to determine the role of CCM gene in lymphatics. Approach and Results: Mice with an inducible pan-endothelial cell (EC) or lymphatic EC deletion of Ccm3 (Pdcd10ECKO or Pdcd10LECKO) exhibit dilated lymphatic capillaries and collecting vessels with abnormal valve structure. Morphological alterations were correlated with lymphatic dysfunction in Pdcd10LECKO mice as determined by Evans blue dye and fluorescein isothiocyanate(FITC)-dextran transport assays. Pdcd10LECKO lymphatics had increased VEGFR3 (vascular endothelial growth factor receptor-3)-ERK1/2 (extracellular signal-regulated kinase 1/2) signaling with lymphatic hyperplasia. Mechanistic studies suggested that VEGFR3 is primarily regulated at a transcriptional level in Ccm3-deficient lymphatic ECs, in an NF-κB (nuclear factor κB)-dependent manner. CCM3 binds to importin alpha 2/KPNA2 (karyopherin subunit alpha 2), and a CCM3 deletion releases KPNA2 to activate NF-κB P65 by facilitating its nuclear translocation and P65-dependent VEGFR3 transcription. Moreover, increased VEGFR3 in lymphatic EC preferentially activates ERK1/2 signaling, which is critical for lymphatic EC proliferation. Importantly, inhibition of VEGFR3 or ERK1/2 rescued the lymphatic defects in structure and function.

CONCLUSIONS

Our data demonstrate that CCM3 deletion augments the VEGFR3-ERK1/2 signaling in lymphatic EC that drives lymphatic hyperplasia and malformation and warrant further investigation on the potential clinical relevance of lymphatic dysfunction in patients with CCM.

Two methods of extracorporeal shock-wave therapy in a rat model of secondary lymphedema: a pilot study

Objectives

To compare the effectiveness of two methods of extracorporeal shock-wave therapy (ESWT) in a rat model of forelimb lymphedema, induced by axillary lymph node dissection.

Methods

Sprague–Dawley rats were randomly allocated to a group that received 500 ESWT shocks only in the lymphedematous forelimb (Forelimb/ESWT) and a group that received 300 ESWT shocks in the axilla and 200 shocks in the lymphedematous forelimb (Axilla+Forelimb/ESWT). The circumferences of each limb were then measured. Immunohistochemistry for a pan-endothelial marker (cluster of differentiation [CD]31) and lymphatic vessel endothelial hyaluronan receptor-1, and western blot analysis for vascular endothelial growth factor receptor-3 (VEGFR3) and VEGF-C were performed.

Results

The circumferences of the limbs showed significant effects of group and time following surgery. The circumferences at the carpal joint and 2.5 cm above were smallest in the naïve limbs, larger in the Axilla+Forelimb/ESWT group, and the largest in the control group. VEGFR3 tended to be expressed at a higher level in the Axilla+Forelimb/ESWT group (1.96-fold) than in the Forelimb/ESWT group (1.20-fold) versus the opposite non-edematous forelimbs, although this difference was not statistically significant.

Conclusions

These data suggest that ESWT protocols have differential effects on angiogenesis and lymphangiogenesis in lymphedematous limbs.

Vascular endothelial growth factor receptor-3 regulates astroglial glutamate transporter-1 expression via mTOR activation in reactive astrocytes following pilocarpine-induced status epilepticus

Recent evidence has shown that the vascular endothelial growth factor (VEGF) system plays a crucial role in several neuropathological processes. We previously reported an upregulation of VEGF-C and its receptor, VEGFR-3, in reactive astrocytes after the onset of status epilepticus (SE). However, it remains unknown, which molecules act as downstream signals following VEGFR-3 upregulation, and are involved in reactive astrogliosis after SE. Therefore, we investigated whether VEGFR-3 upregulation within reactive astrocytes is associated with the activation of mammalian target of rapamycin (mTOR) signaling, which we confirmed by assaying for the phosphorylated form of S6 protein (pS6), and whether VEGFR-3-mediated mTOR activation induces astroglial glutamate transporter-1 (GLT-1) expression in the hippocampus after pilocarpine-induced SE. We found that spatiotemporal expression of pS6 was consistent with VEGFR-3 expression in the hippocampus after SE, and that both pS6 and VEGFR-3 were highly expressed in SE-induced reactive astrocytes. Treatment with the mTOR inhibitor rapamycin decreased astroglial VEGFR-3 expression and GLT-1 expression after SE. Treatment with a selective inhibitor for VEGFR-3 attenuated astroglial pS6 expression as well as suppressed GLT-1 expression and astroglial reactivity in the hippocampus after SE. These findings demonstrate that VEGFR-3-mediated mTOR activation could contribute to the regulation of GLT-1 expression in reactive astrocytes during the subacute phase of epilepsy. In conclusion, the present study suggests that VEGFR-3 upregulation in reactive astrocytes may play a role in preventing hyperexcitability induced by continued seizure activity.

Phomaketide A Inhibits Lymphangiogenesis in Human Lymphatic Endothelial Cells

Lymphangiogenesis is an important biological process associated with cancer metastasis. The development of new drugs that block lymphangiogenesis represents a promising therapeutic strategy. Marine fungus-derived compound phomaketide A, isolated from the fermented broth of Phoma sp. NTOU4195, has been reported to exhibit anti-angiogenic and anti-inflammatory effects. However, its anti-lymphangiogenic activity has not been clarified to date. In this study, we showed that phomaketide A inhibited cell growth, migration, and tube formation of lymphatic endothelial cells (LECs) without an evidence of cytotoxicity. Mechanistic investigations revealed that phomaketide A reduced LECs-induced lymphangiogenesis via vascular endothelial growth factor receptor-3 (VEGFR-3), protein kinase Cδ (PKCδ), and endothelial nitric oxide synthase (eNOS) signalings. Furthermore, human proteome array analysis indicated that phomaketide A significantly enhanced the protein levels of various protease inhibitors, including cystatin A, serpin B6, tissue factor pathway inhibitor (TFPI), and tissue inhibitor matrix metalloproteinase 1 (TIMP-1). Importantly, phomaketide A impeded tumor growth and lymphangiogenesis by decreasing the expression of LYVE-1, a specific marker for lymphatic vessels, in tumor xenograft animal model. These results suggest that phomaketide A may impair lymphangiogenesis by suppressing VEGFR-3, PKCδ, and eNOS signaling cascades, while simultaneously activating protease inhibitors in human LECs. We document for the first time that phomaketide A inhibits lymphangiogenesis both in vitro and in vivo, which suggests that this natural product could potentially treat cancer metastasis.

Experimental and clinicopathological analysis of HOXB9 in gastric cancer

The association between homeobox (HOX)B9 expression and tumor malignancy was identified recently. It was reported that HOXB9 induced tumor angiogenesis, and associated with poor prognosis in patients with breast and colon cancer. On the other hand, regional lymph nodes are the most common site of tumor spread, and lymph node metastasis is a major prognostic factor in gastric cancer. It was hypothesized that HOXB9 promotes tumor lymphangiogenesis and induces tumor progression, invasion and metastasis in gastric cancer. The aim of the present study was to evaluate the correlation between HOXB9 expression, prognosis and clinicopathologic factors in patients with gastric cancer, and to assess the contribution of HOXB9 expression to tumor cell lymphangiogenesis in vitro. HOXB9 expression was evaluated by immunohistochemistry in resected tumor tissues from 58 patients with gastric cancer, and the association between prognosis and clinicopathologic factors was determined. HOXB9 gene was overexpressed in human gastric cancer TMK-1 cells and the effect of HOXB9 overexpression on the expression of vascular endothelial growth factor (VEGF)-C, VEGF-D and VEGF receptor (R)-3 was determined. It was demonstrated that the depth of tumor invasion, the number of node metastases, lymphatic invasion and vascular invasion were significantly associated with HOXB9 expression. Overall survival was decreased in patients with HOXB9 expression. The mRNA expression of VEGF-D but not of VEGF-C and VEGFR-3 was increased in HOXB9-overexpressing TMK-1 cells compared with control cells. In conclusion, HOXB9 expression was positively correlated with gastric cancer progression and lymphangiogenesis marker expression. HOXB9 may be associated with lymphogenic metastasis.

Immunohistochemical characterization of lymphangiogenesis-related biomarkers in primary and recurrent gliomas: A STROBE compliant article

Glial tumors constitute the majority of primary intracranial brain tumors. The expression of specific markers of lymphangiogenesis in gliomas still remains unclear.A total of 40 surgical specimens from 20 patients with recurrent gliomas were included in the study. The expression of D2-40, vascular endothelial growth factor (VEGF)-C, VEGF-D, and VEGF receptor-3 (VEGR-3) was detected by immunohistochemistry (IHC). The clinicopathologic data (p53 and Ki67) were also collected and analyzed.At relapse malignant transformation rate was 65% (13/20 cases). D2-40, VEGF-C, VEGF-D, and VEGFR-3 were expressed in 20%, 30%, 60%, and 20% of primary and 45%, 30%, 75%, and 35% of recurrent glioma tumors (P < .01, P = 1.00, P = .03, P = .03). In 13 cases with increased malignancy grade, the expression of Ki67 and p53 were higher at relapse compared with the primary tumors (P = .001, P = .045). Multivariate survival analysis showed VEGF-D was an independent prognostic factor for malignant transformation (HR = 0.376, P = .045).Glioma is easy to relapse with tumor progression. VEGF-D was an independent prognostic factor for malignant transformation.

Enhancing Renal Lymphatic Expansion Prevents Hypertension in Mice

RATIONALE

Hypertension is associated with renal infiltration of activated immune cells; however, the role of renal lymphatics and immune cell exfiltration is unknown.

OBJECTIVE

We tested the hypotheses that increased renal lymphatic density is associated with 2 different forms of hypertension in mice and that further augmenting renal lymphatic vessel expansion prevents hypertension by reducing renal immune cell accumulation.

METHODS AND RESULTS

Mice with salt-sensitive hypertension or nitric oxide synthase inhibition-induced hypertension exhibited significant increases in renal lymphatic vessel density and immune cell infiltration associated with inflammation. Genetic induction of enhanced lymphangiogenesis only in the kidney, however, reduced renal immune cell accumulation and prevented hypertension.

CONCLUSIONS

These data demonstrate that renal lymphatics play a key role in immune cell trafficking in the kidney and blood pressure regulation in hypertension.

Novel function of E26 transformation-specific domain-containing protein ELK3 in lymphatic endothelial cells

Lymphatic endothelial cells (LEC) are major components of the tumor microenvironment and, due to the relative leakiness of lymphatic vessels compared with blood vessels, are essential for tumor dissemination and metastasis. In the present study, small interfering RNA-mediated suppression of E26 transformation-specific domain-containing protein Elk-3 (ELK3) inhibited the proliferation, migration and tube-forming ability of LEC. Suppression of ELK3 decreased vascular endothelial-cadherin expression levels and increased the phosphorylation of β-catenin. Furthermore, vascular endothelial growth factor receptor-3 (VEGFR-3) mRNA and protein expression levels were suppressed by the transfection of LEC with siELK3. As VEGFR-3 serves a major role in lymphangiogenesis, ELK3 may be a novel therapeutic target to inhibit tumor dissemination through the lymphatic system.

Lymphatic System in Cardiovascular Medicine

The mammalian circulatory system comprises both the cardiovascular system and the lymphatic system. In contrast to the blood vascular circulation, the lymphatic system forms a unidirectional transit pathway from the extracellular space to the venous system. It actively regulates tissue fluid homeostasis, absorption of gastrointestinal lipids, and trafficking of antigen-presenting cells and lymphocytes to lymphoid organs and on to the systemic circulation. The cardinal manifestation of lymphatic malfunction is lymphedema. Recent research has implicated the lymphatic system in the pathogenesis of cardiovascular diseases including obesity and metabolic disease, dyslipidemia, inflammation, atherosclerosis, hypertension, and myocardial infarction. Here, we review the most recent advances in the field of lymphatic vascular biology, with a focus on cardiovascular disease.

Inflammatory biomarkers and spontaneous preterm birth among obese women

OBJECTIVE

To identify associations between second-trimester serum inflammatory biomarkers and preterm birth among obese women.

METHODS

In this nested case-control study, we compared 65 serum inflammatory biomarkers in obese women whose pregnancies resulted in early spontaneous preterm birth (<32 weeks gestation, n = 34) to obese women whose pregnancies resulted in term birth (n = 34). These women were selected from a larger population-based California cohort. Random forest and classification and regression tree techniques were employed to identify biomarkers of importance, and adjusted odds ratios (aORs) and 95% confidence intervals (CI) were estimated using logistic regression.

RESULTS

Random forest and classification and regression tree techniques found that soluble vascular endothelial growth factor receptor-3 (sVEGFR3), soluble interleukin-2 receptor alpha-chain (sIL-2RA) and soluble tumor necrosis factor receptor-1 (sTNFR1) were related to preterm birth. Using multivariable logistic regression to compare preterm cases and term controls, decreased serum levels of sVEGFR3 and increased serum levels of sIL-2RA and sTNFR1 were associated with increased risk of preterm birth among obese women, aOR = 3.2 (95% CI: 1.0-9.9), aOR = 2.8 (95% CI: 0.9-9.0), and aOR = 4.1 (95% CI: 1.2-14.1), respectively.

CONCLUSIONS

In this pilot study, we identified three serum biomarkers indicative of inflammation to be associated with spontaneous preterm birth among obese women: sVEGFR3, sIL-2RA and sTNFR1.

Fenofibrate inhibits the expression of VEGFC and VEGFR-3 in retinal pigmental epithelial cells exposed to hypoxia

The aim of the present study was to examine the mechanisms through which fenofibrate inhibits the ability of human retinal pigment epithelial cells (RPE cells) exposed to hypoxia to stimulate the proliferation and migration of human umbilical vein endothelial cells (HUVECs). For this purpose, RPE cells and HUVECs were divided into the following groups: RPE-normoxia, RPE + fenofibrate, RPE-hypoxia, RPE hypoxia + fenofibrate; HUVECs normal culture and HUVECs + RPE-hypoxia culture supernatant. RPE cell hypoxia was induced by cobalt(II) chloride (CoCl₂). A superoxide anion probe was used to measure the production of superoxide anion, which is indicative of hypoxic conditions. Cell proliferation was assessed by MTT assay, and the expression of vascular endothelial growth factor C (VEGFC) and vascular endothelial growth factor receptor-3 (VEGFR-3) in the RPE cell culture supernatant was measured by enzyme-linked immunosorbent assay (ELISA). The migration ability of the HUVECs was determined by scratch-wound assay, and the angiogenic ability of the HUVECs was examined by measuring cell lumen formation. The mRNA and protein expression levels of VEGFC and VEGFR-3 in the RPE cells were measured by RT-qPCR and western blot analysis, respectively. Our results revealed that fenofibrate inhibited the increase in the expression and release of VEGFC and VEGFR-3 into the RPE cell culture supernatant induced by exposure to hypoxia. The culture of HUVECs in medium supernatant of RPE cells epxosed to hypoxia enhanced the viability and migration ability of the HUVECs and promoted lumen formation; these effects were inhibited by fenofibrate. In conclusion, our data demonstrated that the exposure of RPE cells to hypoxia induced the expression and release of VEGFC and VEGFR-3 into the cell culture supernatant. The culture of HUVECs in conditioned medium from RPE cells exposed to hypoxia increased VEGFC and VEGFR-3 expression, and promoted the proliferation and migration of the HUVECs, as well as capillary tube formation, suggesting that RPE cells play an important role in the formation of choroidal neovascularization resulting from hypoxia. Fenofibrate inhibited the upregulation of VEGFC and VEGFR-3 in the RPE cells exposed to hypoxia, and thus reduced the ability of HUVECs to form new blood vessels.

Immunohistochemical study of vascular endothelial growth factor-C/vascular endothelial growth factor receptor-3 expression in oral tongue squamous cell carcinoma: Correlation with the induction of lymphangiogenesis

The aim of the present study was to elucidate the associations between the expression of the vascular endothelial growth factor-C (VEGF-C)/VEGF receptor-3 (VEGFR-3) axis and lymphangiogenesis, regional lymph node metastasis and clinicopathological factors in oral tongue squamous cell carcinoma (OTSCC) using immunohistochemistry. The expression of VEGF-C, VEGFR-3 and podoplanin was immunohistochemically evaluated in specimens obtained from 65 patients with OTSCC (T1-2, N0) who had undergone radical surgery alone. The associations between the expression of VEGF-C, VEGFR-3 and podoplanin, and lymphangiogenesis, regional lymph node metastasis and clinocopathological factors were determined by immunohistochemical analysis. VEGF-C, VEGFR-3 and combined VEGF-C/VEGFR-3 expression was significantly higher in cases with regional recurrence compared with those without lymph node involvement (P<0.001). As regards lymphangiogenesis, a significant correlation was observed between podoplanin expression and VEGF-C, VEGFR-3 and combined VEGF-C/VEGFR-3 expression (P<0.001). Therefore, lymphangiogenesis in the peritumoral stroma was associated with lymph node metastasis. However, podoplanin expression did not exhibit a significant correlation with the progression of lymph node metastasis. The results of the present study suggest that the VEGF-C/VEGFR-3 axis may be associated with lymph node metastasis through lymphangiogenesis. Determining the VEGF-C/VEGFR-3 expression status may help predict which patients will develop regional recurrence and provide novel targets for therapies to suppress lymph node metastasis in the treatment of OTSCC.

VEGF-C-VEGFR3/Flt4 axis regulates mammary tumor growth and metastasis in an autocrine manner

PURPOSE

Lymphangiogenic factors, such as vascular endothelial growth factor-C (VEGF-C) and VEGFC-D, and their receptor, VEGF receptor-3 (VEGFR3), play a pivotal role in the promotion of metastasis to regional lymph nodes. In the present study we explored the role of VEGF-C as an autocrine growth factor for breast cancer cells.

METHODS

We examined the expression of VEGF-C and VEGFR3 in mammary tumor cells lines and examined whether blocking the VEGF-C-VEGFR3/Flt4 pathway using a VEGFR3 antagonist would inhibit proliferation of mammary tumor cells resulting in a decrease in tumor growth and metastasis.

RESULTS

We report expression of VEGF-C and its receptor VEGFR3 by mammary tumor cells, and their association with aggressiveness. Inhibition of VEGF-C-VEGFR3/Flt4 in mammary tumor cells decreased their proliferation and survival. Mammary tumor bearing mice treated with a VEGFR3 antagonist showed a significant decrease in tumor growth and the extent of spontaneous and experimental lung metastases.

CONCLUSION

These findings demonstrate the VEGF-C-VEGFR3/Flt4 autocrine signaling pathway regulates mammary tumor cell survival and proliferation and that neutralization of VEGFR3 signaling might lead to development of a novel therapeutic approach for malignant breast cancer.

Association between VEGFR-3 expression and lymph node metastasis in non-small-cell lung cancer

Vascular endothelial growth factor receptor (VEGFR)-3 is considered to be associated with lymphangiogenesis. The aim of the present study was to identify the clinical significance of VEGFR-3 expression and lymph node metastasis in patients with non-small-cell lung cancer (NSCLC). Lung tumor tissue samples and 196 lymph nodes from 52 patients with NSCLC were analyzed. In addition, lung tissue samples and 8 lymph nodes from 10 patients with lung diseases other than cancer were included as controls. Semiquantitative multiplex reverse transcription technology was applied to measure the mRNA expression levels of VEGFR-3, while VEGFR-3 protein expression levels were assessed immunohistochemically. The total number of lymphatic vessels was counted and the microlymphatic vessel density (MLVD) was calculated. The results indicated that the VEGFR-3 mRNA expression level in lymph node tissue from the group with lymph node metastasis was significantly lower compared with the group without lymph node metastasis (0.281±0.166 vs. 0.158±0.158; t=4.849; P<0.001). The VEGFR-3 mRNA expression levels in the lung tumor tissue of the NSCLC patients exhibited no statistically significant difference between the lymph node metastasis and lymph node non-metastasis groups (0.139±0.137 vs. 0.142±0.123; t=0.08; P>0.05). In addition, in the lymph node metastasis group, there was no statistically significant difference between the metastasis-positive and -negative lymph nodes (0.158±0.158 vs. 0.123±0.115; t=0.993; P>0.05) with regard to VEGFR-3 mRNA expression. Morphologically, VEGFR-3 immunoreactivity was primarily localized in the cytoplasm of the lymphatic endothelial cells, as well as a number of the cancer cells. MLVD was much higher in the lung tissue surrounding the tumor than in the tumor tissue, and was significantly higher in the lymph node metastasis group than in the lymph node non-metastasis group. VEGFR-3 expression levels were shown to correlate with lymph node metastasis in NSCLC patients, thus, may be a useful biomarker for lymph node metastasis prediction in NSCLC. MLVD is a key indictor of lymphatic vessel metastasis in NSCLC. An enhanced MLVD indicates lymphangiogenesis and lymphatic node metastasis, and may be an important predictor for tumor monitoring and prognosis.

Expression of vascular endothelial growth factor-C and vascular endothelial growth factor receptor-3 in esophageal squamous cell carcinoma

Lymph node metastasis is one of the most important prognostic factors in esophageal squamous cell carcinoma (ESCC). Vascular endothelial growth factor (VEGF)-C and its receptor, VEGF receptor-3 (VEGFR-3), are key in the process of lymphangiogenesis. The present study immunohistochemically examined the expression of VEGF-C, VEGFR-3 and D2-40 in 119 patients with ESCC, and microlymphatic vessel density (MLVD) was calculated based on D2-40 expression counts. Positive expression of VEGF-C was found to correlate significantly with depth of tumor invasion, lymphatic invasion and lymph node metastasis (P<0.001, P<0.0001 and P<0.0001, respectively). Patients with deeper tumor invasion showed higher positivity of VEGFR-3 expression (P<0.05), while patients with lymph node metastasis showed higher MLVD (P<0.05). When patients were divided into three groups according to the expression of VEGF-C and VEGFR-3, patients with coexpression of VEGF-C and VEGFR-3 exhibited poorer prognosis and higher MLVD. The VEGF-C/VEGFR-3 axis is important in tumor lymphangiogenesis.

AIP1 mediates vascular endothelial cell growth factor receptor-3-dependent angiogenic and lymphangiogenic responses

OBJECTIVE

To investigate the novel function of ASK1-interacting protein-1 (AIP1) in vascular endothelial cell growth factor receptor (VEGFR)-3 signaling, and VEGFR-3-dependent angiogenesis and lymphangiogenesis.

APPROACH AND RESULTS

AIP1, a signaling scaffold protein, is highly expressed in the vascular endothelium. We have previously reported that AIP1 functions as an endogenous inhibitor in pathological angiogenesis by blocking VEGFR-2 activity. Surprisingly, here we observe that mice with a global deletion of AIP1-knockout mice (AIP1-KO) exhibit reduced retinal angiogenesis with less sprouting and fewer branches. Vascular endothelial cell (but not neuronal)-specific deletion of AIP1 causes similar defects in retinal angiogenesis. The reduced retinal angiogenesis correlates with reduced expression in VEGFR-3 despite increased VEGFR-2 levels in AIP1-KO retinas. Consistent with the reduced expression of VEGFR-3, AIP1-KO show delayed developmental lymphangiogenesis in neonatal skin and mesentery, and mount weaker VEGF-C-induced cornea lymphangiogenesis. In vitro, human lymphatic endothelial cells with AIP1 small interfering RNA knockdown, retinal endothelial cells, and lymphatic endothelial cells isolated from AIP1-KO all show attenuated VEGF-C-induced VEGFR-3 signaling. Mechanistically, we demonstrate that AIP1 via vegfr-3-specific miR-1236 increases VEGFR-3 protein expression and that, by directly binding to VEGFR-3, it enhances VEGFR-3 endocytosis and stability.

CONCLUSION

Our in vivo and in vitro results provide the first insight into the mechanism by which AIP1 mediates VEGFR-3-dependent angiogenic and lymphangiogenic signaling.

Correlation of vascular endothelial growth factor-D expression and VEGFR-3-positive vessel density with lymph node metastasis in gastric carcinoma

Lymph node metastasis is an important prognostic factor in gastric cancer. Vascular endothelial growth factor-D (VEGF-D) is a lymphangiogenic growth factor that activates VEGF receptor (VEGFR)-3, a receptor expressed in the lymphatic endothelium. We investigated the clinical value of VEGF-D expression and VEGFR-3 positive vessel density in gastric carcinoma with regard to lymphangiogenesis. Immunohistochemical staining was used to determine the expression of VEGF-D and VEGFR- 3 in specimens from 104 cases of resected gastric cancer. VEGF-D expression was observed in 62.5% of the gastric cancers and in 9.6% of the non-neoplastic gastric tissue. The VEGFR-3-positive vessel density was significantly greater in the VEGFD positive group than the negative group. VEGF-D expression was significantly associated with lymph node metastasis, increased serum CEA levels, and the nonsignet ring cell type. The VEGFR-3-positive vessel density was correlated with tumor size, lymphatic invasion, and lymph node metastasis. The VEGF-D expression and high VEGFR-3-positive vessel density were significant poor prognostic factors for relapse-free survival. These results suggest that VEGF-D and VEGFR-3-positive vessel density are potential molecular markers that predict lymphatic involvement in gastric carcinoma.

Clinicopathological Significance of VEGF-C, VEGFR-3 and Cyclooxygenase-2 in Early-Stage Cervical Cancer

To investigate the roles of VEGF-C, VEGFR-3 and cyclooxygenase-2 (COX-2) in tumor progression and lymph node metastasis. The expression of VEGF-C, VEGFR-3 and COX-2 were examined in 93 cases of surgical speciments of cervical diseases by immunohistochemical staining. The correlation between expression of these factors and tumor aggressiveness was evaluated. The expression levels of VEGF-C and COX-2 were much higher in cervical cancer than in cervical intraepithelial neoplasia (CIN) and in chronic cervicitis. VEGF-C expression correlated with lymph node metastases (P<0.01). Multivariate analysis indicated that lymph vessel density (LVD) was associated with the coexpression of VEGF-C and COX-2. Expression of VEGF-C and VEGFR-3 were both in coincidence with lymph node metastasis. VEGF-C and COX-2 may promote the canceration of cervical cancer and that VEGF-C/ VEGFR-3 system had a significant association with the lymphagiogenesis and lymph node metastasis.