Expression of eukaryotic initiation factor 4E, vascular endothelial growth factor and Cyclin D1 in gastric carcinoma and their significances

AIM: To investigate the expression of eukaryotic initiation factor 4E (eIF4E), vascular endothelial growth factor (VEGF) and Cyclin D1 in gastric cancerous tissues and their correlations with the clinical pathology.

METHODS: Immunohistochemistry was used to detect the expression of eIF4E, VEGF and Cyclin D1 in 91 specimens of gastric cancer and 30 specimens of normal gastric tissues. The corresponding clinical data were analyzed retrospectively.

RESULTS: In comparison with those in normal gastric mucosa, the expression of eIF4E, VEGF and Cyclin D1 were significantly increased (95.6%, 68.1%, 84.6% vs 0.0%, all P < 0.01), which were significantly correlated with the depth of invasion, lymph node metastasis and clinical stages (P < 0.05), but not with the age, sex of patients and tumor differentiation. There was a positive correlation between eIF4E and VEGF expression (r = 0.407, P < 0.05) as well as between eIF4E and Cyclin D1 expression (r = 0.780, P < 0.01).

CONCLUSION: The expression of eIF4E, VEGF and Cyclin D1 are closely correlated with the invasion and metastasis of gastric carcinoma, and moreover, eIF4E expression is positively correlated with VEGF and Cyclin D1 expression.

Inhibitory effect of saikosaponin-d on the angiogenesis of experimental hepatocarcinoma in rats

AIM: To investigate the effect of saikosaponin-d (SSd) on the expressions of cycloxygenase-2 (COX-2), vascular endothelial cell growth factor (VEGF) and CD34 during hepatocellular carcinogenesis induced by diethylinitrosamine (DEN).

METHODS: Ninety male SD rats were randomly divided into 5 groups: control group (n = 10), model group (n = 20) and three treatment groups (n = 20 in each group). Except for the control group, the other groups were administered (ig) with 2 g/L DEN at a dose of 10 mg/kg body weight (5 times/wk for 16 wk). At the same time, the rats in the treatment groups were injected intraperitoneally with SSd at different doses (1.0, 1.5 and 2.0 mg/kg) once per day for 16 wk. The rats were anesthetized and killed at 6, 12, and 16 wk. Hematoxylin and eosin (HE) staining was used to examine the changes of liver pathology and the expression of COX-2, VEGF and CD34 in liver tissues were dynamically monitored by SABC immunohistochemistry.

RESULTS: During 6, 12, and 16 wk of experiment, typical pathological changes such hepatocyte injury, hyperplasia, cirrhosis, and carcinogenesis appeared in the rats of model group. Both the volume and the number of tumors were significantly reduced in 3 SSd treatment groups. Under microscope, the cancer cells in the rats of model group showed polymorphic and abnormal shape. In contrast, the cancer cells in the rats of SSd treatment groups were well differentiated. Immunohistochemistry demonstrated that the expression of COX-2 and VEGF and the value of microvessel density (MVD) in the model group were low in the early stage of carcinogenesis, but they were all remarkably increased in the stage of carcinoma. Whereas, the expression of COX-2 and VEGF and MVD value were all reduced in every stage of carcinogenesis after SSd treatment, especially in the stage of carcinoma after high-dose SSd treatment. There was a highly positive correlation between COX-2 and VEGF expression (r = 0.815, P < 0.01), VEGF expression and MVD value (r = 0.862, P < 0.01) and between COX-2 expression and MVD value (r = 0.726, P < 0.01).

CONCLUSION: SSd has inhibitory effect on the angiogenesis during DEN-induced hepatocarcinogenesis in rats, which may be related to the down-regulation of COX-2 expression and VEGF activity.

Inhibition of CXCR4 activity with AMD3100 decreases invasion of human colorectal cancer cells in vitro

AIM: To investigate the effect and mechanism of blockade of the CXC chemokine receptor-4 (CXCR4) signaling pathway by AMD3100, a small non-peptide CXCR4 inhibitor, on invasion and metastasis of colorectal cancer cells in vitro.

METHODS: Human colorectal cancer cell line SW480 was treated with AMD3100 at different final concentrations. 3-(4,5-dimethylthiazol-2-yl)-2.5-dipheny-tetrazolium bromide (MTT) assay was used to detect the effect of AMD3100 on cell proliferation. The invasion ability of SW480 cells was determined by cell invasion assay kit. In the presence of AMD3100, the CXCL12-mediated migratory response of SW480 cells was tested by classical chemotaxis assays. RT-PCR analysis and Western blotting were used to detect the expression of vascular endothelial growth factor (VEGF), matrix metalloproteinase-2 (MMP-2) and -9 (MMP-9) in SW480 cells.

RESULTS: Cell viability was significantly suppressed by AMD3100 in a dose-dependent manner. AMD3100 (100 and 1000 ng/mL) significantly inhibited the invasion ability of SW480 cells. Treatment with AMD3100 markedly reduced the expression of VEGF and MMP-9 but not MMP-2 in SW480 cells.

CONCLUSION: The CXCL12/CXCR4 system is an important mediator of proliferation and invasion of CXCR4-expressing colorectal cancer cells. AMD3100 inhibited invasion and metastasis activity of the colorectal cancer cell line SW480 through down-regulation of VEGF and MMP-9 expression.

Vascular endothelial growth factor attenuates hepatic sinusoidal capillarization in thioacetamide-induced cirrhotic rats

AIM: To investigate the effect of vascular endothelial growth factor (VEGF) transfection on hepatic sinusoidal capillarization.

METHODS: Enhanced green fluorescent protein (EGFP)/VEGF transfection was confirmed by immunofluorescence microscopy and immunohistoche-mistry both in primary hepatocytes and in normal liver. Cirrhotic rats were generated by thioacetamide (TAA) administration and then divided into a treatment group, which received injections of 400 &mgr;g of plasmid DNA encoding an EGFP-VEGF fusion protein, and a blank group, which received an equal amount of normal saline through the portal vein. The portal vein pressure was measured in the normal and cirrhotic state, in treated and blank groups. The average number of fenestrae per hepatic sinusoid was determined using transmission electron microscopy (TEM), while the relative abundance of VEGF transcripts was examined by Gene array.

RESULTS: Green fluorescent protein was observed in the cytoplasms of liver cells under immunofluorescence microscopy 24 h after transfection with EGFP/VEGF plasmid in vitro. Staining with polyclonal antibodies against VEGF illustrated that hepatocytes expressed immunodetectable VEGF both in vitro and in vitro. There were significant differences in the number of fenestrae and portal vein pressures between normal and cirrhotic rats (7.40 ± 1.71 vs 2.30 ± 1.16 and 9.32 ± 0.85 cmH₂O vs 17.92 ± 0.90 cmH₂O, P < 0.01), between cirrhotic and treated rats (2.30 ± 1.16 cmH₂O vs 4.60 ± 1.65 and 17.92 ± 0.90 cmH₂O vs 15.52 ± 0.93 cmH₂O, P < 0.05) and between the treatment group and the blank group (4.60 ± 1.65 cmH₂O vs 2.10 ± 1.10 cmH₂O and 15.52 ± 0.93 cmH₂O vs 17.26 ± 1.80 cmH₂O, P < 0.05). Gene-array analysis revealed that the relative abundance of transcripts of VEGF family members decreased in the cirrhotic state and increased after transfection.

CONCLUSION: Injection of a plasmid encoding VEGF through the portal vein is an effective method to induce the formation of fenestrae and decrease portal vein pressure in cirrhotic rats. Therefore, it may be a good choice for treating hepatic cirrhosis and portal hypertension.

Prognostic significance of S100A4 and vascular endothelial growth factor expression in pancreatic cancer

AIM: To investigate the expression of vascular endothelial growth factor (VEGF) and calcium-binding protein S100A4 in pancreatic cancer and their relationship to the clinicopathological parameters and prognosis of pancreatic cancer.

METHODS: Expression status of VEGF and S100A4 was examined in 62 surgical specimens of primary pancreatic cancer by immunohistochemistry. Correlation between the expression of VEGF and S100A4 and clinicopathological parameters was analyzed.

RESULTS: Thirty-eight of 62 (61.3%) specimens of primary pancreatic cancer were positive for S100A4. Thirty-seven (59.7%) specimens showed positive expression of VEGF. The positive correlation between S100A4 and VEGF expression was significant in cancer tissues (P < 0.001). S100A4 expression was significantly correlated with tumor size, TNM stage and poorer prognosis. VEGF expression had a significant correlation with poorer prognosis. The prognosis of 17 S100A4- and VEGF-negative cancer patients was significantly better than that of other patients (P < 0.05). Distant metastasis (P = 0.001), S100A4- (P = 0.008) and VEGF-positive expression (P = 0.016) were significantly independent prognostic predictors (P < 0.05).

CONCLUSION: Over-expression of S100A4 and VEGF plays an important role in the development of pancreatic cancer. Combined examination of the two molecules might be useful in evaluating the outcome of patients with pancreatic cancer.

Clinical significance of matrix metalloproteinases-9 and vascular endothelial growth factor expression in the invasion and metastasis of pancreatic carcinoma

AIM: To study the expression of vascular endothelial growth factor (VEGF) and matrix metalloproteinases-9 (MMP-9) in pancreatic carcinoma (PC) and validate the significance and distinction of angiogenesis in vascular invasion and metastasis.

METHODS: VEGF, MMP-9 expression and microvessel density (MVD) were detected by immunohistochemistry in surgically resected specimens (cancer tissues, cancer-adjacent tissues and normal tissues) from 35 PC patients, and the results were analyzed combined with clinical pathologic characteristics.

RESULTS: VEGF and MMP-9 expression were higher in PC tissues than those in the cancer-adjacent and normal pancreatic tissues (VEGF: 77.14% vs 5.71%, 12.86%, P < 0.01; MMP-9: 68.57% vs 8.57%, 5.71%, P < 0.01). The positive rates of VEGF and MMP-9 expression were related to the tumor size (< 2 cm, 2-4 cm and > 4 cm in diameter, VEGF: 42.86%, 92.86% and 78.57%; MMP-9: 28.57%, 75.00% and 83.33%; all P < 0.05) and the tumor differentiation (high, moderate and low differentiation, VEGF: 71.43%, 70.59% and 90.91%, MMP-9: 71.43%, 64.71% and 72.73%; all P < 0.05). VEGF and MMP-9 expression in metastasis-positive group were 100% and 95.24%, respectively. The mean values of MVD were significantly different between VEGF- or MMP-positive group (t = 3.23, P < 0.01; t = 3.89, P < 0.01).

CONCLUSION: MMP-9 and VEGF expression are associated with high angiogenesis in PC, so VEGF and MMP-9 may serve as new target proteins to resist the invasion and metastasis of PC.

Lipopolysaccharide-squamous cell carcinoma-monocyte interactions induce cancer-supporting factors leading to rapid STAT3 activation

Oral and oro-pharyngeal squamous cell carcinomas (OSCC) exhibit surface breach, and recent studies have demonstrated bacterial contamination of primary and metastatic OSCC. Increasing concentrations of inflammatory products, such as interleukin (IL)-6 and vascular endothelial growth factor (VEGF), correlate with, and contribute to, cancer progression, but their regulation in OSCC is poorly understood. We hypothesized that monocyte-lineage cells and bacterial contamination may contribute important inflammatory products that can support OSCC progression. We found that relative to non-specific chronic mucositis, oral carcinoma-in-situ/superficially-invasive OSCC contained more monocyte-lineage cells. In vitro, we used lipopolysaccharide (LPS) to model bacterial contamination, and evaluated the effects of oral and oropharyngeal (O)SCC-monocyte interactions and of LPS on OSCC cells and on the production of IL-6 and VEGF. OSCC cell lines varied in constitutive cytokine and chemokine production, and OSCC-monocyte interactions in the absence of LPS stimulated IL-6 and VEGF occasionally, while LPS-OSCC-monocyte interactions were always strongly stimulatory. Importantly, LPS independently stimulated some OSCC lines to secrete monocyte-dendritic cell chemoattractants CCL2 and/or CCL20, as well as IL-6 and/or VEGF. While very little constitutive Y705-STAT3 phosphorylation (pY705-STAT3) was detectable in HNSCC lines, IL-6 rapidly induced pY705-STAT3 in OSCC lines that produced little IL-6 constitutively. Supernatants from LPS-OSCC-monocyte co-cultures always rapidly and strongly activated STAT3, which was partly due to IL-6. We conclude that monocytes and microbial contamination have the potential to contribute to OSCC progression, as STAT3 activation in OSCC cells depends on soluble factors, which are consistently available through LPS-OSCC-monocyte interactions.

Prokineticin 2/Bv8 is expressed in Kupffer cells in liver and is down regulated in human hepatocellular carcinoma

AIM: To study the implication of prokineticin 1 (PK1/EG-VEGF) and prokineticin 2 (PK2/Bv8) in hepatocellular carcinoma angiogenesis.

METHODS: The gene induction of PK1/EG-VEGF and PK2/Bv8 was investigated in 10 normal, 28 fibrotic and 28 tumoral livers by using real time PCR. Their expression was compared to the expression of VEGF (an angiogenesis marker), vWF (an endothelial cell marker) and to CD68 (a monocyte/macrophage marker). Furthermore, the mRNA levels of PK1/EG-VEGF, PK2/Bv8, prokineticin receptor 1 and 2 were evaluated by real time PCR in isolated liver cell populations. Finally, PK2/Bv8 protein was detected in normal liver paraffin sections and in isolated liver cells by immunohistochemistry and immunocytochemistry.

RESULTS: PK2/Bv8 mRNA but not PK1/EG-VEGF was expressed in all types of normal liver samples examined. In the context of liver tumor development, we reported that PK2/Bv8 correlates only with CD68 and showed a significant decrease in expression as the pathology evolves towards cancer. Whereas, VEGF and vWF mRNA were significantly upregulated in both fibrosis and HCC, as expected. In addition, out of all isolated liver cells examined, only Kupffer cells (liver resident macrophages) express significant levels of PK2/Bv8 and its receptors, prokineticin receptor 1 and 2.

CONCLUSION: In normal liver PK2/Bv8 and its receptors were specifically expressed by Kupffer cells. PK2/Bv8 expression decreased as the liver evolves towards cancer and did not correlate with HCC angiogenesis.

Correlation of integrin β3 mRNA and vascular endothelial growth factor protein expression profiles with the clinicopathological features and prognosis of gastric carcinoma

AIM: To investigate integrin β3 mRNA and vascular endothelial growth factor (VEGF) protein expression in gastric carcinoma, and its correlation with microvascular density, growth-pattern, invasion, metastasis and prognosis.

METHODS: In situ hybridization (ISH) of integrin β3 mRNA and immunohistochemistry of VEGF and CD34 protein were performed on samples from 118 patients with gastric cancer.

RESULTS: The positive rate of integrin β3 mRNA in non-tumor gastric mucosa (20%) was significantly lower than that of the gastric cancer tissue (52.5%, χ² = 10.20, P < 0.01). In patients of infiltrating type, stage T₃-T₄, vessel invasion, lymphatic metastasis, hepatic or peritoneal metastasis, the positive expression rates of integrin β3 mRNA were significantly higher than those in patients of expanding type (P < 0.01), stage T₁-T₂ (P < 0.01), non-vessel invasion (P < 0.01), without lymphatic metastasis (P < 0.01), without hepatic and peritoneal metastasis (P < 0.01), respectively. In patients of infiltrating type, stage T₃-T₄, vessel invasion, lymphatic metastasis, hepatic or peritoneal metastasis, the positive expression rates of VEGF protein were significantly higher than those in patients of expanding type (P < 0.01), stage T₁-T₂ (P < 0.01), non-vessel invasion (P < 0.01), without lymphatic metastasis (P < 0.01), without hepatic and peritoneal metastasis (P < 0.01), respectively. In patients of infiltrating type, stage T₃-T₄, vessel invasion, lymphatic metastasis, hepatic or peritoneal metastasis, the mean MVD were significantly higher than those in patients of expanding type (P < 0.01), stage T₁-T₂ (P < 0.01), non-vessel invasion (P < 0.01), without lymphatic metastasis (P < 0.01), without hepatic and peritoneal metastasis (P < 0.01), respectively. It was found that the positive expression rate of integrin β3 mRNA was positively related to that of VEGF protein (P < 0.01) and MVD (P < 0.05), meanwhile the positive expression rate of VEGF protein was positively related to MVD (P < 0.05). The mean survival period in patients with positive expression of integrin β3 mRNA and VEGF, and MVD ≥ 54.9/mm² was significantly shorter than that in patients with negative expression of integrin β3 mRNA (P < 0.05) and VEGF (P < 0.01), and MVD < 54.9/mm² (P < 0.01). Five-year survival rate in patients with positive expression of integrin β3 mRNA and VEGF, and MVD ≥ 54.9/mm² was significantly lower than those with negative expression of integrin β3 mRNA (P < 0.05), VEGF (P < 0.05), and MVD < 54.9/mm² (P < 0.01).

CONCLUSION: Integrin β3 and VEGF expression can synergistically enhance tumor angiogenesis, and may play a crucial role in invasion and metastasis of gastric carcinoma. Therefore, they may be prognostic biomarkers and novel molecular therapeutic targets.

Clinical significance and relationship between gastric bare area involved in gastric carcinoma and expression of CD34, VEGF and VEGF-C

AIM: To detect the expression of CD34, vascular endothelial growth factor (VEGF) and vascular endothelial growth factor C (VEGF-C) in gastric carcinoma, and to investigate the clinical significance and relationship between the gastric bare area (GBA) involved in gastric carcinoma and expression of CD34, VEGF and VEGF-C.

METHODS: Seventy-two cases of gastric carcinoma were divided into GBA involved and non-involved groups. Expression of CD34, VEGF and VEGF-C was detected by immunohistochemistry.

RESULTS: In gastric carcinoma, there was no significant difference in the expression of VEGF (27/32 vs 28/40), CD34(61.67 ± 21.33 vs 60.79 ± 22.04) or VEGF-C (23/32 vs 26/40) in GBA involved and non-involved groups. In proximal gastric carcinoma, there was no significant difference in the expression of VEGF (23/30 vs 6/9), CD34 (62.48 ± 20.12 vs 61.79 ± 23.68) and VEGF-C (20/30 vs 6/9) in GBA involved and non-involved groups.

CONCLUSION: There was no relationship between the GBA involved in gastric carcinoma and expression of CD34, VEGF and VEGF-C. The anatomical structure of the GBA may result in poor prognosis of gastric carcinoma.

Antitumor and antiangiogenic activities of anti-vascular endothelial growth factor hairpin ribozyme in human hepatocellular carcinoma cell cultures and xenografts

AIM: To study the effectiveness and mechanisms of anti- human vascular endothelial growth factor (hVEGF) hairpin ribozyme on angiogenesis, oncogenicity and tumor growth in a hepatocarcinoma cell line and a xenografted model.

METHODS: The artificial anti-hVEGF hairpin ribozyme was transfected into hepatocarcinoma cell line SMMC-7721 and, subsequently, polymerase chain reaction (PCR) and reverse transcription polymerase chain reaction (RT-PCR) were performed to confirm the ribozyme gene integration and transcription. To determine the effects of ribozyme ,VEGF expression was detected by semiquantitative RT-PCR and enzyme liked immunosorbent assay (ELISA). MTT assay was carried out to measure the cell proliferation. Furthermore,the transfected and control cells were inoculated into nude mice respectively, the growth of cells in nude mice and angiogenesis were observed.

RESULTS: VEGF expression was down-regulated sharply by ribozyme in transfected SMMC-7721 cells and xenografted tumor. Compared to the control group, the transfected cells grew slower in cell cultures and xenografts, and the xenograft formation was delayed as well. In addition, the microvessel density of the xenografted tumor was obviously declined in the transfected group. As demonstrated by microscopy,reduction of VEGF production induced by ribozyme resulted in a significantly higher cell differentiation and less proliferation vigor in xenografted tumor.

CONCLUSION: Anti-hVEGF hairpin ribozyme can effectively inhibit VEGF expression and growth of hepatocarcinoma in vitro and in vivo. VEGF is functionally related to cell proliferation, differentiation and tumori-genesis in hepatocarcinoma.

Angiogenesis and vascular malformations: Antiangiogenic drugs for treatment of gastrointestinal bleeding

Treatment of gastrointestinal bleeding in patients with angiodysplasias and Osler’s disease (hereditary hemorrhagic telangiectasia) is clinically challenging. Frequently, vascular malformations occur as multiple disseminated lesions, making local treatment an unfavorable choice or impossible. After local therapy, lesions often recur at other sites of the intestine. However, as there are few therapeutic alternatives, repeated endoscopic coagulations or surgical resections are still performed to prevent recurrent bleeding. Hormonal therapy has been employed for more than 50 years but has recently been shown to be ineffective. Therefore, new therapeutic strategies are required. Understanding of the pathophysiology of angiogenesis and vascular malformations has recently substantially increased. Currently, multiple inhibitors of angiogenesis are under development for treatment of malignant diseases. Experimental and clinical data suggest that antiangiogenic substances, which were originally developed for treatment of malignant diseases, may also represent long-awaited specific drugs for the treatment of vascular malformations. However, antiangiogenics display significantly different actions and side-effects. Although antiangiogenics like thalidomide seem to inhibit gastrointestinal bleeding, other substances like bevacizumab can cause mucosal bleeding. Therefore differential and cautious evaluation of this therapeutic strategy is necessary.

Expression of matrix metalloproteinase-10 and vascular endothelial growth factor in gastric carcinoma and its relationship with angiogenesis

AIM: To investigate the expression of matrix metalloproteinase-10 (MMP-10) and vascular endothelial growth factor (VEGF) and microvascular density (MVD) in gastric carcinoma and its relationship with the clinical characteristics of tumors.

METHODS: CD31 was used as the standard of MVD. 60 examples of gastric carcinoma tissue by immunohistochemistry for MMP-10, VEGF and CD31 were investigated, and were compared the results with those in 60 normal tissues.

RESULTS: The expression positive rates for MMP-10 and VEGF in the 60 gastric carcinoma tissues were 81.7% and 76.7%, respectively. They were much higher than those in normal tissue samples (11.7% and 8.3%, respectively). The differences were statistically significant (P < 0.05). The expression of MMP-10 and VEGF was related with MVD, and tumor grade, TNM classification, lymphatic metastasis, and degree of invasion.

CONCLUSION: The high expression of MMP-10 and VEGF in gastric carcinoma is closely related to metastasis of gastric carcinoma and angiogenesis. It can be used as an important factor in judging the metastasis prognosis of gastric carcinoma.

RNA interference-mediated gene silencing of vascular endothelial growth factor in colon cancer cells

AIM: To inhibit the expression of vascular endothelial growth factor (VEGF) in colon cancer cell line by RNA interference (RNAi).

METHODS: Followed the service of E-RNAi, we designed and constructed two kinds of shRNA expression vectors aiming at the VEGF gene, then transfected them into colon cancer HT29 cells by lipofectamine^TM 2000. The level of VEGF mRNA was investigated by RT-PCR and Northern blotting. The protein expression of VEGF was observed by immunofluoresence staining and Western blotting.

RESULTS: We got two kinds of VEGF specific shRNA expression vectors which could efficiently inhibit the expression of VEGF in HT29 cells. RT-PCR, Northern blotting, immunofluoresence staining and Western blotting showed that inhibition rate for VEGF expression was up to 42%, 89%, 73% and 82%, respectively.

CONCLUSION: The expression of VEGF can be inhibited by RNA interference in HT29 cells.

Expression of cyclooxygenase-2 and vascular endothelial growth factor in carcinoma of the gastric cardia and its correlation with angiogenesis

AIM: To investigate the expression of cycloo-xygenase (COX)-2 and vascular endothelial growth factor (VEGF) in carcinoma of the gastric cardia, and to evaluate the relationship between COX-2, VEGF expression and angiogenesis, and clinicopathological features of carcinoma of the gastric cardia.

METHODS: Forty-six resected tumor specimens were obtained from patients with carcinoma of the gastric cardia, and 21 corresponding paracancerous normal tissues were randomly selected as a control group. Immunohistochemical staining was used for detecting the expression of COX-2 and VEGF. Monoclonal antibody against CD34 was used for visualizing vascular endothelial cells, and microvascular density (MVD) was determined by counting the number of CD34-positive vascular endothelial cells. The correlation between COX-2, VEGF expression and MVD and clinicopathological features of the patients was analyzed.

RESULTS: The positive expression rate for COX-2, VEGF and MVD in the cancerous tissue was 80.4%, 76.1% and 31.95 ± 3.87 respectively, which was significantly higher than that in the controls (14.3%, 19.1% and 16.28 ± 1.55, respectively; P < 0.01). The mean positive expression rate for COX-2, VEGF and MVD was associated with clinical TNM classification (90.3% vs 60.0%, χ² = 5.91, P < 0.05; 96.8% vs 46.7%, χ² = 16.13, P < 0.01; 33.43 ± 3.34 vs 28.90 ± 3.08, t = 4.42, P < 0.01) and lymph node metastasis (94. 1% vs 41.7%, χ² = 15.51, P < 0.01; 91.2% vs 50.0%, χ² = 9.56, P < 0.01; 33.53 ± 3.21 vs 27.48 ± 1.03, t = 6.38, P < 0.01). The Spearman rank correlation test showed that tumor MVD was closely associated with COX-2 (r = 0.823, P < 0.01) and VEGF (r = 0.892, P < 0.01) expression.

CONCLUSION: Overexpression of COX-2 and VEGF is related to tumor invasion and lymph node metastasis in carcinoma of the gastric cardia. COX-2 contributes to development of carcinoma of the gastric cardia by promoting VEGF expression and angiogenesis.

Effects of NM-3-containing serum on endothelial growth factor and its receptors KDR and Flt-1 in human gastric cancer SGC-7901 cell line

AIM: To study the inhibitory effect of anti-angiogenesis agent NM-3-containing serum on human gastric cancer SGC-7901 cell line.

METHODS: Human gastric cancer SGC-7901 cell line was cultured with high, medium and low doses of NM-3-containing serum, and two control groups were cultured with medium alone and medium with serum. Cell cycle distribution and apoptosis rate were determined by flow cytometry. After 72 hours incubation, mRNA for vascular endothelial growth factor (VEGF) and its receptors, including KDR and Flt-1, was detected by reverse-transcriptase polymerase chain reaction (RT-PCR).

RESULTS: The apoptosis rate in the high- (25.20% ± 0.86%, 43.62% ± 3.53%, 54.35% ± 5.42%) and medium-dose (16.80% ± 0.40%, 26.95% ± 3.25%, 39.85% ± 4.10%) groups was significantly increased compared with that in the two control groups were cultured with meduim alone (5.34% ± 0.28%, 6.91% ± 1.06%; 6.87% ± 1.24%) and meduim with serum (5.66% ± 0.72%, 8.90% ± 0.86%, 8.06% ± 0.78%) after 6, 24 and 72 hours culture. The apoptosis rate was increased with prolongation of incubation time and NM-3 dose. The apoptosis rate in the high-dose group was higher than in the medium and low dose groups (P < 0.05). After 72 hours in the high-dose group, the proportion of cells in G₀/G₁ phase was higher, and the number in S, G₂/M phase was lower than that in the medium- and low-dose groups. There were significant differences between the proportion of cells in G₀/G₁, S and G₂/M phase in the high- and medium-dose groups and the two control groups (P < 0.01). mRNA of VEGF and its receptors KDR and Flt-1 decreased in SGC-7901 cells in the high-, medium- and low-dose NM-3 groups after 72 hours. Compared with the two control groups, the high-dose group significantly inhibited mRNA transcription for VEGF and its receptors KDR and Flt-1 (P < 0.01), and the medium- and low-dose groups obviously inhibited mRNA transcription (P < 0.05).

CONCLUSION: NM-3-containing serum can inhibit vascular formation in gastric carcinoma, and can induce apoptosis of human gastric carcinoma cells.

Expression and clinical significance of estrogen receptor β and vascular endothelial growth factor in colorectal carcinoma

AIM: To investigate the expression of estrogen receptor β (ERβ) and vascular endothelial growth factor (VEGF) in colorectal cancer tissue, and to determine their relationship with histological type.

METHODS: Expression of ERβ and VEGF was detected using an immunohistochemistry SP method in 45 cases of colorectal cancer. Normal colorectal mucosa from 10 patients was used as a control. The relationship between colorectal cancer and the expression of ERβ and VEGF was investigated.

RESULTS: ERβ and VEGF expression was detected in 23 (51.11%) and 33 (73.33%) of the 45 cases, respectively. ERβ and VEGF expression was significantly correlated with the histological type (P = 0.024, and P = 0.005), but there was no correlation with disease stage (P = 0.289, P = 0.173). There was a significant difference on the VEGF expression between the group positive and negative for ERβ (56.52% vs 90.90%, P < 0.05).

CONCLUSION: The positive expression of ERβ is closely correlated with the development of carcinogenesis and prognosis of colorectal carcinoma. Detection of both ERβ and VEGF appears to be a valuable tumor marker and prognostic factor for colorectal carcinoma.

Influence of radiofrequency ablation on vascular endothelial growth factor and fetal liver kinase 1 in transplanted liver cancer in rats

AIM: To study the influence of radiofrequency ablation (RFA) on vascular endothelial growth factor (VEGF) and fetal liver kinase 1 (Flk-1) in a rat transplanted liver cancer model.

METHODS: A rat liver cancer model was established by injecting Walker carcinosarcoma 256 tumor cells into the livers of the rats. After tumor growth had proceeded for about 9 or 10 days, we surgically treated the rats with RFA. Rats were randomly divided into control and RFA groups. After treatment, rats were randomly divided into two groups, and were killed after 1 or 3 days to obtain liver specimens. Expression of VEGF and Flk-1 was observed in the tumor and adjacent tissues by an immunohistochemical Elivision method at 1 and 3 days after RFA.

RESULTS: The expression of VEGF in adjacent tissues was higher (P = 0.014, and P = 0.013) and the expression of VEGF in remnant tumors was lower at 1 and 3 days after RFA than that before RFA (P = 0.015, P = 0.013). The expression of Flk-1 1 day after RFA in the adjacent tissues was higher than that in controls (P = 0.008).

CONCLUSION: RFA can repress the expression of VEGF in carcinoma near areas of necrosis, but this treatment may also induce expression of VEGF in adjacent tissues. The effect of RFA on Flk-1 needs further investigation.

Effects of an extract from Scutellaria barbatae D.DON on tumor angiogenesis in vitro

AIM: To explore the effects of the extract flavonoid A06 from Scutellaria barbatae D.DON on tumor angiogenesis in vitro.

METHODS: Human umbilical venous endothelial cells (HUVECs) were treated with different concentrations of the flavonoid A06 (25, 50 and 100 mg/L). The effect of flavonoid A06 on the formation and migration of tubules in cultured HUVECs was evaluated by tube formation assay and Transwell chambers. The effect of flavonoid A06 on protein expression of vascular endothelial growth factor (VEGF) and nitric oxide (NO) in human cervical carcinoma Hela cells was detected by enzyme-linked immunosorbent assay and the nitrate reductase method.

RESULTS: Flavonoid A06 extract from Scutellaria barbatae D.DON at two concentrations (50 and 100 mg/L) effectively inhibited migration (37.7% ± 10.7%, 13.7% ± 6.0% vs 68.0% ± 8.2%, both P < 0.01) and tubule formation in HUVECs (9.7% ± 4.5%, 1.8% ± 1.2% vs 30.2% ± 5.4%, both P < 0.05) after 24 h. Flavonoid A06 also decreased the protein expression of VEGF and NO in Hela cells after 24 h (VEGF, 135.6 ± 14.6 ng/L, 108.3 ± 7.7 ng/L vs 231.1 ± 6.4 ng/L, both P < 0.01; NO, 42.3 ± 2.3 mmol/L, 25.9 ± 5.2 mmol/L vs 70.1 ± 8.1 mmol/L, both P < 0.01).

CONCLUSION: Flavonoid A06 inhibits tumor angiogenesis in vitro. Its mechanism may be related to the inhibition of the expression of VEGF and NO, endothelial cell migration and tubule formation.

Expression of macrophage inhibitory cytokine-1, vascular endothelial growth factor and P53 and its clinical significance in rectal cancer

AIM: To investigate the expression of macrophage inhibitory cytokine-1 (MIC-1), vascular endothelial growth factor (VEGF) and P53 in rectal cancer, and its relationship to clinicopathological parameters.

METHODS: Expression of MIC-1, VEGF and P53 in 73 cases of rectal cancer was assessed by immunohistochemistry, and its correlation with clinicopathological factors was statistically analyzed.

RESULTS: Expression of MIC-1, VEGF and P53 had a significant correlation with clinical stage (χ²_MIC-1 = 37.534, χ²_VEGF = 54.451, χ²_P53 = 16.834, respectively; P < 0.01). There was a significant linear relationship between the levels of the three oncoproteins and clinical stage in patients with rectal cancer (r = 0.918, P = 0.000). The expression of MIC-1 also had a positive correlation with the expression of VEGF and P53 (r = 0.808, r = 0.369, respectively; P < 0.01).

CONCLUSION: MIC-1, VEGF and P53 have synergetic and mutual regulation in the occurrence and development of rectal cancer. The combined detection of their expression may help to determine progression and metastasis in rectal cancer.

Expression of Cyclooxygenase-2 and Vascular endothelial growth factor in precancerous lesions and colon carcinoma tissue

AIM: To determine the clinical significance of expression of cyclooxygenase-2 (COX-2) and vascular endothelial growth factor (VEGF) in normal colon epithelium near colon carcinoma, and in precursors and colon carcinoma.

METHODS: Immunohistochemistry (ABC) was utilized to detect the expression of COX-2 and VEGF in 40 normal colon epithelium, 27 adenomatous polyposis of the colon, and 40 colon carcinoma tissues.

RESULTS: Immunoreactivity of COX-2 and VEGF in adenomatous polyposis of the colon and colon carcinoma was much higher than that in normal tissues (COX-2, 63.0 and 77.5% vs 0.0 and 0.0%; VEGF, 70.4 and 80.0% vs 25.0 and 25.0%, respectively; P < 0.05). The relationship between COX-2 and VEGF was statistically significant (r = 0.411, P < 0.05).

CONCLUSION: COX-2 and VEGF expression is up-regulated in adenomatous polyposis of the colon and colon carcinoma.

Infiltrating dendritic cells in the development of gastric cancer and an association with tumor angiogenesis

AIM: To investigate the potential role of infiltrating dendritic cells (DCs) in the biological behavior of gastric cancer and any association with tumor angiogenesis.

METHODS: Immunohistological identification of DCs in gastric cancer using monoclonal antibody recognizing S-100 protein was undertaken in 35 primary gastric cancers (PGC) and 23 lymphoid metastatic gastric cancers (LMGC). Antibodies recognizing vascular endothelial growth factor (VEGF) and CD34 were employed to detect VEGF expression and microvascular density (MVD), respectively.

RESULTS: The density of S-100⁺DCs was obviously decreased along with progressive cancer invasion of the gastric wall; a statistically significant decrease was seen in gastric cancer with serosal invasion (P = 0.04). Further, a statistically negative correlation between the density of S-100⁺DCs and the degree of invasion was shown in gastric cancer (P = 0.023). The density of S-100⁺DCs in PGC with lymphatic metastasis was clearly lower than that in PGC with no lymphatic metastasis, though this difference was not statistically significant. However, the density of S-100⁺DCs in lymph nodes with carcinomatosis showed a marked decrease corresponding to the increase in the percentage of metastasis; a significantly negative correlation was shown between them (r = -0.923, P < 0.01). The density of S-100⁺DCs in VEGF-positive PGC was lower than that in VEGF-negative PGC (P = 0.157). There was a negative association of the density of S-100⁺DCs with VEGF expression in PGC, but it was not statistically significant (r = -0.128, P = 0.464). MVD in PGC with lower infiltration of S-100⁺DCs was significantly higher than that in PGC with higher infiltration (P = 0.013). Similarly, the density of S-100+DCs in PGC with higher MVD was also lower than that in PGC with lower MVD, thus showing a significantly negative association of the density of S-100⁺DCs with MVD (r = -0.322, P = 0.059).

CONCLUSION: Biological behaviors of gastric cancer cells such as invasive growth and lymphatic metastasis were closely associated with the level of infiltrating S-100⁺DCs. The infiltration of DCs might be affected by the ability of cancer cell-induced angiogenesis. Thus, pro-angiogenic factors such as VEGF released from tumor cells might be one of the molecular mechanisms of tumor orientated immune escape in gastric cancer.

Elevation of vascular endothelial growth factor production and its effect on revascularization and function of graft islets in diabetic rats

AIM: To determine whether the elevated vascular endothelial growth factor (VEGF) expression produced by the transfected vascular endothelial cells (VECs) could stimulate angiogenesis of the graft islets and exert its effect on the graft function.

METHODS: Thirty diabetic recipient rats were divided into three groups (n = 10 per group). In the control group, 300 IEQ islets were transplanted in each rat under the capsule of the right kidney, which were considered as marginal grafts. In the VEC group, VEC together with the islets were transplanted in each rat. In the VEGF group, VEC transfected by pIRES2-EGFP/VEGF165 plasmid and the islets were transplanted in each rat. Blood glucose and insulin levels were evaluated every other day after operation. Intravenous glucose tolerance test (IVGTT) was performed 10 d after the transplantation. Hematoxylin and eosin (HE) staining was used to evaluate the histological features of the graft islets. Immunohistochemical staining was used to detect insulin-6, VEGF and CD34 (MVD) expression in the graft islets.

RESULTS: Blood glucose and insulin levels in the VEGF group restored to normal 3 d after transplantation. In contrast, diabetic rats receiving the same islets with or without normal VECs displayed moderate hyperglycemia and insulin, without a significant difference between these two groups. IVGTT showed that both the amplitude of blood glucose induction and the kinetics of blood glucose in the VEGF group restored to normal after transplantation. H&E and immunohistochemical staining showed the presence of a large amount of graft islets under the capsule of the kidney, which were positively stained with insulin-6 and VEGF antibodies in the VEGF group. In the cell masses, CD34-stained VECs were observed. The similar masses were also seen in the other two groups, but with a fewer positive cells stained with insulin-6 and CD34 antibodies. No VEGF-positive cells appeared in these groups. Microvessel density (MVD) was significantly higher in the VEGF group compared to the other two groups.

CONCLUSION: Elevated VEGF production by trans-fected vascular endothelial cells in the site of islet transplantation stimulates angiogenesis of the islet grafts. The accelerated islet revascularization in early stage could improve the outcome of islet transplantation, and enhance the graft survival.

Cyclooxygenase-2 expression after preoperative chemoradiotherapy correlates with more frequent esophageal cancer recurrence

AIM: To investigate the relationship between cycloo-xygenase-2 (COX-2), and vascular endothelial growth factor (VEGF), and to determine the clinical significance of this relationship in esophageal cancer patients undergoing chemoradiotherapy (CRT).

METHODS: Immunohistochemical staining was used to evaluate COX-2 and VEGF expression in 40 patients with histologically-confirmed esophageal squamous carcinoma (ESCC) who were undergoing preoperative CRT.

RESULTS: Fourteen out of 40 ESCC patients showed a pathological complete response (CR) after CRT. COX-2 and VEGF protein expressions were observed in the cytoplasm of 17 and 13 tumors, respectively, with null expression in 9 and 13 tumors, respectively. COX-2 expression was strongly correlated with VEGF expression (P < 0.05). There were also significant associations between COX-2 expression, tumor recurrence, and lymph-node involvement (P = 0.0277 and P = 0.0095, respectively). COX-2 expression and VEGF expression had significant prognostic value for disease-free survival (log-rank test; P = 0.0073 and P = 0.0341, respectively), but not for overall survival, as assessed by univariate analysis.

CONCLUSION: Our results suggest that COX-2 expression correlates with VEGF expression and might be a useful prognostic factor for more frequent tumor recurrence in ESCC patients undergoing neoadjuvant CRT. These findings support the use of anti-angiogenic COX-2 inhibitors in the treatment of ESCC.

Therapeutic and prophylactic thalidomide in TNBS-induced colitis: Synergistic effects on TNF-α, IL-12 and VEGF production

AIM: To evaluated the therapeutic and prophylactic effect of thalidomide on 2, 4, 6-trinitrobenzene sulfonic acid (TNBS)-induced colitis. Thalidomide has been reported to downregulate the expression of tumor necrosis factor α (TNF-α), IL-12, and vascular endothelial growth factor (VEGF), hallmarks of intestinal inflammation in Crohn’s disease (CD).

METHODS: Male Wistar rats were divided in five groups of ten animals each. Four groups received a rectal infusion of TNBS in ethanol. The first group was sacrificed 7 d after colitis induction. The second and third groups received either thalidomide or placebo by gavage and were sacrificed at 14 d. The fourth group received thalidomide 6 h before TNBS administration, and was sacrificed 7 d after induction. The fifth group acted as the control group and colitis was not induced. Histological inflammatory scores of the colon were performed and lamina propria CD4+ T cells, macrophages, and VEGF+ cells were detected by immunohistochemistry. TNF-α and IL-12 were quantified in the supernatant of organ cultures by ELISA.

RESULTS: Significant reduction in the inflammatory score and in the percentage of VEGF+ cells was observed in the group treated with thalidomide compared with animals not treated with thalidomide. Both TNF-α and IL-12 levels were significantly reduced among TNBS induced colitis animals treated with thalidomide compared with animals that did not receive thalidomide. TNF-α levels were also significantly reduced among the animals receiving thalidomide prophylaxis compared with untreated animals with TNBS-induced colitis. Intestinal levels of TNF-α and IL-12 were significantly correlated with the inflammatory score and the number of VEGF+ cells.

CONCLUSION: Thalidomide significantly attenuates TNBS-induced colitis by inhibiting the intestinal production of TNF-α, IL-12, and VEGF. This effect may support the use of thalidomide as an alternate approach in selected patients with CD.

Effects of vascular endothelial growth factor antisense oligodeoxynucleotide on the mRNA expression of vascular endothelial growth factor, fms-like tyrosine kinase-1 and kinase insert domain-containing receptor and vascular endothelial growth factor protein excretion of gallbladder carcinoma GBC-SD cells in vitro

AIM: To investigate the effect of oligofectamine-mediated vascular endothelial growth factor (VEGF) antisense oligodeoxynucleotide (ASODN) transfection on the mRNA expression of VEGF, fms-like tyrosine kinase-1 (Flt-1) and kinase insert domain-containing receptor (KDR) as well as VEGF protein excretion of gallbladder carcinoma GBC-SD cells in vitro.

METHODS: Gallbladder carcinoma GBC-SD cells were transfected with VEGF ASODN and scrambled oligodeoxynucleotide (SODN) by Oligofectamine mediation. The mRNA expression of VEGF, Flt-1 and KDR in GBC-SD cells of each group were detected by semi-quantitive reverse transcription-polymerase chain reaction (RT-PCR) and the excretion of VEGF protein was measured by enzyme-linked immunosorbent assay (ELISA).

RESULTS: Semi-quantitive RT-PCR revealed that VEGF, Flt-1 and KDR mRNA expression in groups of ASODN (VEGF165: 0.686 ± 0.033, 0.569 ± 0.049, 0.489 ± 0.036, 0.716 ± 0.017; VEGF165: 0.462 ± 0.046, 0.338 ± 0.034, 0.219 ± 0.022, 0.471 ± 0.038; Flt-1: 0.694 ± 0.019, 0.562 ± 0.045, 0.435 ± 0.042, 0.724 ± 0.026; KDR: 0.667 ± 0.063, 0.490 ± 0.033, 0.301 ± 0.029, 0.665 ± 0.068) and ASODN + Oligofectamine (VEGF165: 0.601 ± 0.021, 0.465 ± 0.042, 0.416 ± 0.023, 0.662 ± 0.035; VEGF121: 0.408 ± 0.014, 0.286 ± 0.019, 0.157 ± 0.021, 0.418 ± 0.037; Flt-1: 0.609 ± 0.018, 0.442 ± 0.049, 0.314 ± 0.015, 0.614 ± 0.029; KDR: 0.523 ± 0.048, 0.432 ± 0.027, 0.218 ± 0.036, 0.524 ± 0.037) were significantly inhibited 24, 48, 72 and 96 h after transfection in comparison with those in the control group (P < 0.05), and the inhibitory effect of ASODN + Oligofectamine was stronger (P > 0.05). ELISA results discovered that VEGF protein excretion was markedly decreased in the culture media of ASODN (281.26 ± 18.62, 526.44 ± 34.95, 791.13 ± 20.99) and ASODN + Oligofectamine (250.7 ± 14.57, 506.09 ± 19.14, 711.79 ± 19.91) group (P < 0.05) as compared with that in the control group, and ASODN + Oligofectamine was more efficient (P > 0.05).

CONCLUSION: VEGF ASODN can inhibit VEGF, Flt-1 and KDR mRNA expression and VEGF protein excretion of GBC-SD cells, and the effect may be strengthened by Oligofectamine mediation.

Upregulation of hypoxia inducible factor 1α mRNA is associated with elevated vascular endothelial growth factor expression and excessive angiogenesis and predicts a poor prognosis in gastric carcinoma

AIM: To investigate the implication of the hypoxia inducible factor HIF-1α mRNA in gastric carcinoma and its relation to the expression of vascular endothelial growth factor (VEGF) protein, tumor angiogenesis invasion/metastasis and the patient's survival.

METHODS: In situ hybridization was used to examine expression of HIF-1α mRNA, and immunohistochemical staining was used to examine expression of VEGF protein and CD34 in 118 specimens from patients with gastric carcinoma.

RESULTS: The positive rates of HIF-1α mRNA and VEGF protein were 49.15% and 55.92%, respectively. Positive expressions of HIF-1α and VEGF in stage T₃-T₄ tumors and those with vessel invasion, lymph node metastasis and distant metastasis were dramatically stronger than stage T₁-T₂ cases and those without vessel invasion, lymph node metastasis and distant metastasis. The mean microvascular density (MVD) in stage T₃-T₄ tumors and those with vessel invasion, lymph node metastasis and distant metastasis was significantly higher than stage T₁-T₂ tumors and those without vessel invasion, lymph node metastasis and distant metastasis. The mean MVD in tumors with positive HIF-1α and VEGF expression was significantly higher than that in tumors with negative HIF-1α and VEGF expression. The expression of HIF-1α was positively correlated with VEGF protein. There were positive correlations between MVD and expression of HIF-1α and VEGF. The mean survival time and the 5-year survival rate in cases with positive expression HIF-1α and VEGF and MVD value ≥ 41.5/0.72 mm² were significantly lower than those with negative expression of HIF-1α and VEGF and MVD value < 41.5/0.72 mm².

CONCLUSION: Overexpression of HIF-1α is found in gastric carcinoma. HIF-1α may induce the angiogenesis in gastric carcinoma by upregulating the transcription of VEGF gene, and take part in tumor invasion and metastasis. They can be used as prognostic markers of gastric cancer in clinical practice.

Effect of vascular endothelial growth factor gene on its receptor-2 expression and proliferation of human gastric carcinoma cell in vitro

AIM: To amplify and purify the recombinant adenovirus vector carrying vascular endothelial growth factor 165 (Ad-VEGF₁₆₅), and to investi-gate its effect of on the expression of VEGF receptor-2 (VEGFR-2) and the proliferation of human gastric adenocarcinoma cell line BGC-823 in vitro.

METHODS: The adenoviruses were packaged and amplified in human embryonic kidney 293 cells. Then human gastric adenocarcinoma cell line BGC-823 was transfected with the resultant adenoviruses. The proliferation and expression of VEGFR-2 were measured by MTT assay and immunocytochemistry, respectively.

RESULTS: The recombinant adenovirus vector carrying VEGF₁₆₅ or GFP (control virus) was amplified and purified successfully. The viral titer of VEGF₁₆₅ or GFP was 3.2 × 10¹³ and 2.0 × 10¹³ pfu/L, respectively. The transfection rate almost reached 100% in BGC-823 cells when the multiplicity of infection (MOI) was 20. The proliferation of BGC-823 cells (shown by absorbency) transfected with Ad-VEGF₁₆₅ was significantly higher than that of the cells transfected with Ad-GFP (24 h: 0.960 ± 0.01 vs 0.737 ± 0.01, P < 0.01; 48 h: 1.321 ± 0.03 vs 0.981 ± 0.02, P < 0.01; 72 h: 1.663 ± 0.03 vs 1.207 ± 0.01, P < 0.01) or the controlled cells (24 h: 0.960 ± 0.01 vs 0.724 ± 0.03, P < 0.01; 48 h: 1.321 ± 0.03 vs 0.968 ± 0.01, P < 0.01; 72 h: 1.663 ± 0.03 vs 1.185 ± 0.02, P < 0.01). Moreover, the expression of VEGFR-2 was expressed was markedly higher in BGC-823 cells transfected with Ad-VEGF₁₆₅ than that in Ad-GFP-transfected cells (62.5% vs 37.6%, P < 0.01) and the controlled cells (62.5% vs 34.1%, P < 0.01).

CONCLUSION: VEGF can promote the proliferation and increase VEGFR-2 expression of BGC-823 cells in vitro.

Advancement of the relationship between vascular endothelial growth factor receptors and angiogenesis of hepatocellular carcinoma

Angiogenesis is the basis of tumor growth and metastasis. Hepatocellular carcinoma is a kind of typical multivessel tumor, whose generation, progression and invasion are closely related with the angiogenesis. The angiogenesis is mainly regulated by angiogenins and anti-angiogenins, of which vascular endothelial growth factor (VEGF) and its receptor (VEGFR) are the most important. Different kinds of VEGFR have various functions in vivo, and VEGFR-1 (flt-1) and VEGFR-2 (flk-1) are involved in the angiogenesis HCC. Satisfactory effects have been obtained by the anti-angiogenic therapies targeting on VEGFR in laboratory studies, some of which have been launched in clinical experiments.

(-)-Epigallocatechin-3-gallate inhibits growth of gastric cancer by reducing VEGF production and angiogenesis

AIM: To investigate the effect of (-)-epigallocatechin-3-gallate (EGCG) on growth of gastric cancer and its possible mechanism.

METHODS: Heterotopic tumors were induced by subcutaneously injection of SGC-7901 cells in nude mice. Tumor growth was measured by calipers in two dimensions. Tumor angiogenesis was determined with tumor microvessel density (MVD) by immunohistology. Vascular endothelial growth factor (VEGF) protein level and activation of signal transducer and activator of transcription 3 (Stat3) were examined by Western blotting. VEGF mRNA expression was determined by RT-PCR and VEGF release in tumor culture medium by ELISA. VEGF-induced cell proliferation was studied by MTT assay, cell migration by gelatin modified Boyden chamber (Transwell) and in vitro angiogenesis by endothelial tube formation in Matrigel.

RESULTS: Intraperitoneal injection of EGCG inhibited the growth of gastric cancer by 60.4%. MVD in tumor tissues treated with EGCG was markedly reduced. EGCG treatment reduced VEGF protein level in vitro and in vivo. Secretion and mRNA expression of VEGF in tumor cells were also suppressed by EGCG in a dose-dependent manner. This inhibitory effect was associated with reduced activation of Stat3, but EGCG treatment did not change the total Stat3 expression. EGCG also inhibited VEGF-induced endothelial cell proliferation, migration and tube formation.

CONCLUSION: EGCG inhibits the growth of gastric cancer by reducing VEGF production and angiogenesis, and is a promising candidate for anti-angiogenic treatment of gastric cancer.

Effect of non-anticoagulant N-desulfated heparin on expression of vascular endothelial growth factor, angiogenesis and metastasis of orthotopic implantation of human gastric carcinoma

AIM: To investigate the effect of N-desulfated heparin on tumor metastasis and angiogenesis, and expression of vascular endothelial growth factor (VEGF) of orthotopic implantation of human gastric carcinoma in male severe combined immune deficiency (SCID) mice.

METHODS: Human gastric cancer SGC-7901 cells were orthotopically implanted into the stomach of SCID mice. The mice were randomly divided into normal saline group and N-desulfated heparin group. One week after operation, the mice in N-desulfated heparin group received i.v. injections of N-desulfated heparin (Shanghai Institute of Cell Biology, Chinese Academy of Sciences, 10 mg/kg.d) twice weekly for 3 wk. The mice in normal saline group received i.v. injections of normal saline (100 μL) twice weekly for 3 wk. The mice were sacrificed six weeks after implantation. Tumor metastasis was evaluated histologically for metastasis under microscope. Intratumoral microvessel density (MVD) and VEGF expression were evaluated immuohistochemically. VEGF mRNA expression in gastric tissue of SCID mice was detected by real time PCR.

RESULTS: The tumor metastasis rate was 80% in normal saline group and 20% in N-desulfated heparin group (P < 0.05). MVD was 8.0 ± 3.1 in normal saline group and 4.3 ± 1.8 in N-desulfated heparin group (P < 0.05). VEGF positive immunostaining was found in cytoplasm of cancer cells. The rate of VEGF positive expression was higher in normal saline group than in N-desulfated heparin treated group (90% vs 20%, P < 0.05). VEGF mRNA expression was significantly inhibited by N-desulfated heparin and was higher in normal saline group than in N-desulfated heparin group (Ct value 19.51 ± 1.01 vs 22.55 ± 1.36, P < 0.05). N-desulfated heparin significantly inhibited the expression of VEGF mRNA in cancer cells. No bleeding occurred in N-desulfated heparin group.

CONCLUSION: N-desulfated heparin can inhibit metastasis of gastric cancer by suppressing tumor VEGF expression and tumor angiogenesis, but has no obvious anticoagulant activity.

Expression of midkine and vascular endothelial growth factor and their significances in gastric carcinoma

AIM: To investigate the expression vascular endothelial growth factor (VEGF) and midkine (MK) and their significances in gastric carcinoma.

METHODS: Immunohistochemistry was performed to detect the expression of MK, VEGF and CD34 in gastric carcinoma (n = 64) and adjacent normal tissues (n = 20).

RESULTS: The positive rates of MK and VEGF expression were significantly higher in gastric cancer tissues than those in the normal ones (76.6%, 79.7% vs 0, 15.0%, both P < 0.01). The expression of MK and VEGF had marked correlations with the invasion depth (χ² = 7.111, P = 0.008; χ² = 7.590, P = 0.006), lymph node metastasis (χ² = 4.814, P = 0.028; χ² = 6.207, P = 0.013), and clinical stages (χ² = 13.971, P = 0.001;χ² = 18.554, P = 0.000). The value of MVD in patients with positive MK expression was notably higher than that in ones with negative MK expression (31.745 ± 8.592 vs 24.680 ± 8.938, P < 0.01), and there was a positive correlation between MK and VEGF expression (χ² = 4.447, P < 0.05).

CONCLUSION: MK and VEGF may play synergistic roles in the growth, invasion and metastasis of gastric carcinoma, and their co-expression may be a useful indicator for the prognosis of gastric carcinoma.

Clinical significance of serum leptin, vascular endothelial growth factor and alpha-fetoprotein expression in hepatocelluar carcinoma

AIM: To explore the expression of serum leptin (Lep), vascular endothelial growth factor (VEGF) and alpha-fetoprotein (AFP) and their clinical significances in hepatocelluar carcinoma (HCC).

METHODS: Enzyme-linked immunosorbent assay (ELISA) was used to detect serum Lep, VEGF and AFP levels in 146 patients with HCC, 31 patients with liver cirrhosis and 30 healthy controls. The correlations Lep, VEGF, and AFP expression with clinical indexes were analyzed.

RESULTS: The serum Lep level was correlated with body mass index (BMI) in HCC patients (r = 0.64, P < 0.01), and significantly lower than that in cirrhotic patients and healthy controls (19 μg/L vs 35, 27 μg/L, P < 0.05). The serum Lep level in HCC patients was significantly decreased with upgrade of TNM stages, metastasis and recurrence (P < 0.05). In comparison with that in cirrhotic patients and healthy controls, the serum VEGF level in HCC patients was significantly increased (398 ng/Lvs 179, 167 ng/L, P < 0.01). There was no correlation between VEGF and AFP expression. The sensitivity and specificity of VEGF were 71.2% and 80.6%, and those of AFP were 73.3% and 83.9%, respectively, in the diagnosis of HCC. However, the sensitivity was increased to 91.8%, while the accuracy reached 90.4% after the combined detection of VEGF and AFP was used. There was a relationship beween the level of serum VEGF and tumor size (<3 cm: 237 ± 96 ng/L, >3 cm: 398 ± 124 ng/L, P < 0.01). As compared with that of TNMⅠ, Ⅱ stage, the serum VEGF of TNM Ⅲ, Ⅳstage was obviously higher (346 ± 131, 401 ± 152 ng/L vs 228 ± 89, 259 ± 102 ng/L, P < 0.01), and it also showed a significant elevation in the patients with metastasis and recurrent HCC (P < 0.01).

CONCLUSION: Nutrition status and prognosis of patients with HCC can be judged by serum Lep level, and the combined detection of serum VEGF and AFP may provide a significant marker for HCC diagnosis and prognosis.

Steroids reduce local inflammatory mediator secretion and mucosal permeability in collagenous colitis patients

AIM: To study the effect of oral steroids upon clinical response and rectal mucosa secretion of eosinophil cationic protein (ECP), myeloperoxidase (MPO), basic fibroblast growth factor (bFGF), vascular endothelial growth factor (VEGF) and albumin in patients with collagenous colitis (CC).

METHODS: A segmental perfusion technique was used to collect perfusates from rectum of CC patients once before and twice (one and four weeks) after the start of steroid treatment. Clinical data was monitored and ECP, MPO, bFGF, VEGF and albumin concentrations were analyzed by immunochemical methods in perfusates and in serum.

RESULTS: Steroids reduced the number of bowel movements by more than five times within one week and all patients reported improved subjective well-being at wk 1 and 4. At the same time, the median concentrations of ECP, bFGF, VEGF and albumin in rectal perfusates decreased significantly. MPO values were above the detection limit in only 3 patients before treatment and in none during treatment. VEGF, bFGF, ECP and albumin concentrations correlated with each other with the exception of ECP and albumin. A decrease of serum ECP and VEGF concentrations was also seen even if the overtime reduction was not significant.

CONCLUSION: Oral steroid treatment in CC patients induced a simultaneous reduction of bowel movements and rectal release of ECP, bFGF, VEGF and albumin, suggesting that these polypeptides and increased mucosal permeability are important components of the pathophysiology in collagenous colitis.

Role of hypoxia-inducible factor-1α in pancreatic cancer

AIM: To study the level changes of hypoxia-inducible factor-1α (HIF-1α), vascular endothelial growth factor (VEGF), glucose transporter 1 (GLUT1) and multidrug resistance gene (MDR1) in pancreatic carcinoma cells SW1990 exposed to hypoxia, and to explore the possible molecular mechanism.

METHODS: CoCl₂ was used to induce chemical hypoxia, and SW1990 cells were divided into normal oxygen group and hypoxia group. The expression of HIF-1α, VEGF, GLUT1 and MDR1 at the mRNA and protein levels were analyzed by reverse transcription-polymerase chain reaction (RT-PCR) and Western-blot, respectively, in the above groups 24 h after treatment with hypoxia and transfected with plasmid HIF-1α/PCDNA3.

RESULTS: Chemical hypoxia induced significant expression of HIF-1α protein (P = 0.0089), but not mRNA (P = 0.057). After exposure to hypoxia, the expression of VEGF (P = 0.046, 0.039), GLUT1 (P = 0.0024, 0.036) and MDR1 (P = 0.021, 0.038) were significantly increased at the mRNA and protein level. Furthermore, the mRNA and protein expression of HIF-1α, VEGF, GLUT1 and MDR1 were all elevated to some extent after transfection with plasmid HIF-1α/PCDNA3.

CONCLUSION: HIF-1α plays an important role in promoting the progression, relapse and resistance to chemotherapeutics of pancreatic carcinoma by up-regulating the expression of the related genes such as VEGF, GLUT1 and MDR1.

Expression of vascular endothelial growth factor and nuclear factor kappa B and their significances inHelicobacter pylori-associated gastric ulcer and gastric cancer

AIM: To probe the expression of vascular endothelial growth factor (VEGF), nuclear factor kappa B (NF-κB) in H. pylori-associated gastric ulcer (GU) and gastric cancer (GC) tissues and their correlations, and further investigate the mechanism of H. pylori-induced GU and GC.

METHODS: SABC immunohistochemical technique was used to detect the expression of H. pylori, VEGF, and NF-κB in pathological samples of GU (n = 36) and GC (n = 52).

RESULTS: The incidence rate of GU existed significant difference between H. pylori positive and negative group (78% vs 22%,P < 0.05). The expression of VEGF or NF-κΒ in H. pylori positive GU tissues was markedly higher than that in H. pylori negative ones (53.6% vs 12.5%, P < 0.05; 39.3% vs 0, P < 0.05). The expression of VEGF or NF-κΒ in H. pylori positive GC tissues was notably higher than that in H. pylori negative ones (84% vs 40.7%, P < 0.05; 80% vs 48.1%, P < 0.05). There existed significant correlations between the expression of NF-κΒ and VEGF in GC and GU tissues (r = 0.997, P < 0.05).

CONCLUSION: H. pylori infection is closely related to the expression of VEGF and NF-κB in GU and GC. H. pylori infection may be the initiating factor, and the activation of NF-κB may be the key event in the pathogenesis of GU and GC. H. pylori infection, NF-κB activation, and VEGF expression play synergic roles in the occurrence of GU and GC.

Expression of vascular endothelial growth factor and its receptors VEGFR-1 and 2 in gastrointestinal stromal tumors, leiomyomas and schwannomas

AIM: To investigate the role of vascular endothelial growth factor (VEGF) and its receptors VEGFR-1 and 2 in the growth and differentiation of gastrointestinal stromal tumors (GISTs).

METHODS: Thirty-three GISTs, 15 leiomyomas and 6 schwannomas were examined by immunohistochemistry in this study.

RESULTS: VEGF protein was expressed in the cytoplasm of tumor cells, and VEGFR-1 and 2 were expressed both in the cytoplasm and on the membrane of all tumors. Immunohistochemical staining revealed that 26 GISTs (78.8%), 9 leiomyomas (60.0%) and 3 schwannomas (50.0%) were positive for VEGF; 24 GISTs (72.7%), 12 leiomyomas (80.0%) and 4 schwannomas (66.7%) were positive for VEGFR-1; 30 GISTs (90.9%), 5 leiomyomas (33.3%) and 4 schwannomas (66.7%) were positive for VEGFR-2. VEGFR-2 expression was statistically different between GISTs and leiomyomas (P < 0.0001). However, there was no correlation between the expression of VEGF pathway componenets and the clinical risk categories.

CONCLUSION: Our results suggest that the VEGF pathway may play an important role in the differentiation of GISTs, leiomyomas and schwannomas.

Inhibitory effect of arsenic trioxide on angiogenesis and expression of vascular endothelial growth factor in gastric cancer

AIM: To investigate the inhibitory effect of As₂O₃ on angiogenesis of tumor and expression of vascular endothelial growth factor (VEGF) in tumor cells in vivo and in vitro.

METHODS: The solid tumor model was formed in nude mice with the gastric cancer cell line SGC-7901. The animals were randomly divided into three groups. As₂O₃ was injected into the arsenic-treated groups (2.5 mg/kg and 5 mg/kg) and the same volume of saline solution was injected into the control group. Microvessel density (MVD) and expression of VEGF were detected with immunofluorescence laser confocal technology. Further expression of VEGF protein and VEGF mRNA was measured with Western bloting and fluorescence quantitative RT- PCR in SGC-7901 cells treated with As₂O₃.

RESULTS: In nude mice, after treatment with 5 mg/kg and 2.5 mg/kg As₂O₃ respectively, about 50% and 30% tumor growth inhibition were observed correspondingly (P < 0.05, P < 0.05). Decrease in MVD appeared in As2O3-treated tumors compared with control group (P < 0.001, P < 0.001). MVD in tumors was significantly lower in 5 mg/kg group than in 2.5 mg/kg group (P < 0.01). The fluorescence intensity levels of VEGF in tumor cells were significantly lowered in the arsenic-treated groups (P < 0.01, P < 0.01). The fluorescence intensity level of VEGF in 5 mg/kg group was lower than that in 2.5 mg/kg group (P < 0.01). In vitro, the expression of VEGF protein decreased in dose- and time-dependent manner after the treatment with As₂O₃, but in VEGF mRNA no significant difference was found between the control group and the treated groups.

CONCLUSION: As₂O₃ can inhibit solid tumor growth by inhibiting the formation of new blood vessels. One of the mechanisms is that As₂O₃ can inhibit VEGF protein expression.

Effects of prostaglandin E2 on expression of vascular endothelial growth factor in human gastric cancer cell line MKN28

AIM: To investigate the expression of vascular endothelial growth factor (VEGF) in human gastric cell line MKN28 in vitro, and identify whether exogenous prostaglandin E₂ (PGE₂) can increase the expression of VEGF.

METHODS: Human gastric cell line MKN28 was culture in vitro and then treated with 0.1, 1, 5, and 10 μmol/L PGE₂ for 3 h. Real-time polymerase chain reaction (PCR) and Western blot were used to detect the expression of VEGF mRNA and protein, respectively.

RESULTS: The transcription of VEGF mRNA increased in a dose-dependent manner after PGE₂ treatment, and the difference between the groups of 0.1, 1, 5, 10 μmol/L PGE₂ treatment and the control group had statistical significances (0.67 ± 0.093, 0.74 ± 0.13, 0.87 ± 0.07, 1.49 ± 0.15 vs 0.42 ± 0.10, P < 0.05 or P < 0.01). PGE₂ also up-regulated the expression of VEGF protein in a dose-dependent manner, and except 0.1 μmol/L PGE₂ treatment group, the difference between the groups of 1, 5, 10 μmol/L PGE₂ treatment and the control group had statistical significances (51.02 ± 2.16, 66.69 ± 9.85, 136.49 ± 6.89 vs 26.87 ± 3.98, P < 0.05 or P < 0.01).

CONCLUSION: PGE₂ can promote VEGF mRNA transcription and protein expression in human gastric cancer cell line MKN28.

Increased expression of angiogenin in gastric carcinoma in correlation with tumor angiogenesis and proliferation

AIM: To investigate the implication of angiogenin (ANG) in the neovascularizaton and growth of human gastric carcinoma (HGC).

METHODS: ANG mRNA expression in HGC specimens obtained by surgical resection from patients with HGC were examined by RT-PCR. ANG, Ki-67, VEGF protein expression and microvessel density (MVD) in HGC specimens were detected by immunohistochemistry.

RESULTS: RT-PCR showed significantly higher ANG mRNA expression (0.482 ± 0.094) in HGC tissues than in the surrounding nontumorous tissues (0.276 ± 0.019, P = 0.03). MVD within tumorous tissues increased significantly with ANG mRNA expression (r = 0.380, P = 0.001) and ANG protein expression (P < 0.01). The ANG expression levels of cancer tissues were positively correlated with VEGF (P < 0.01) and the proliferation index of cancer cells (P < 0.01).

CONCLUSION: ANG is one of the neovascularization factors of HGC. ANG may work in coordination with VEGF, and promote the proliferation of HGC cells.

Post-transcriptional regulation of vascular endothelial growth factor: Implications for tumor angiogenesis

Vascular endothelial growth factor (VEGF) is a potent secreted mitogen critical for physiologic and tumor angiogenesis. Regulation of VEGF occurs at several levels, including transcription, mRNA stabilization, translation, and differential cellular localization of various isoforms. Recent advances in our understanding of post-transcriptional regulation of VEGF include identification of the stabilizing mRNA binding protein, HuR, and the discovery of internal ribosomal entry sites in the 5'UTR of the VEGF mRNA. Monoclonal anti-VEGF antibody was recently approved for use in humans, but suffers from the need for high systemic doses. RNA interference (RNAi) technology is being used in vitro and in animal models with promising results. Here, we review the literature on post-transcriptional regulation of VEGF and describe recent progress in targeting these mechanisms for therapeutic benefit.

Expression of vascular endothelial growth factor and basic fibroblast growth factor in gastric carcinoma and their significances

AIM: To investigate the expression of vascular endothelial growth factor (VEGF), basic fibro-blast growth factor (bFGF) in serum and tissues of gastric cancer patients and the clinical charac-teristics of gastric cancer.

METHODS: Avidin-biotin system enzyme-linked immunosorbent assay (ABC-ELISA) was used to examine the serum expression of VEGF and bFGF in preoperative gastric cancer patients (n = 73) and healthy individuals (n = 20). Meanwhile, immunohistochemistry was used to detect the expression of VEGF and bFGF in the cancer and cancer-adjacent tissues.

RESULTS: The serum expression of VEGF and bFGF in gastric cancer patients were significantly higher than those in the healthy controls (VEGF: 101.8 ± 53.3 ng/L vs 16.1 ± 22.5 ng/L, P < 0.05; bFGF: 152.9 ± 42.7 ng/L vs 25.0 ± 11.4 ng/L, P < 0.05). The serum expression of VEGF and bFGF were significantly correlated with the depth of invasion, TNM staging, lymph node metastasis and distant metastasis, but not with the age, sex of patients, and pathological types (P < 0.05). The positive rates of VEGF and bFGF expression in gastric cancer tissues were significantly higher than those in the cancer-adjacent tissues (χ² = 32.1, P < 0.05; χ² = 17.7, P < 0.05). The tissue expression of VEGF and bFGF were also correlated with the depth of invasion, TNM staging, lymph node metastasis and distant metastasis (P < 0.05), but not with the age, sex of patients, and pathological types. There existed positive correlations between serum and tissue expression of VEGF and bFGF (in serum: r = 0.439, P < 0.01; in tissue: r = 0.391, P < 0.01). The correlation between serum and tissue expression was also significantly positive (VEGF: r = 0.346, P < 0.01; bFGF: r = 0.304, P < 0.01).

CONCLUSION: VEGF and bFGF play important roles in the oncogenesis, progression, metastasis and prognosis of gastric cancer, which may become new tumor markers for preoperative diagnosis, postoperative following-up, metastasis or recurrence monitoring, assessment of anti-angiogenesis drugs.

Expression of angiopoietins, Tie2 and vascular endothelial growth factor in angiogenesis and progression of hepatocellular carcinoma

AIM: To investigate the significance of angiopoietins, Tie2 and vascular endothelial growth factor (VEGF) expression in the angiogenesis and progress of hepatocellular carcinoma (HCC).

METHODS: Fresh surgically resected specimens of HCC and noncancerous liver (NCL) tissue from 38 patients with HCC were obtained, and expression of angiopoietin-1 (Ang-1), angiopoietin-2 (Ang-2), Tie2, and VEGF messenger RNA (mRNA) was examined by real-time quantitative reverse transcription-polymerase chain reaction (RT-PCR). Expression pattern of each gene in HCC and NCL tissue specimens was compared and the potential role and interaction in angiogenesis of HCC were analyzed. Genes’ expression level and its relationship with tumor’s clinicopathological parameters were also investigated. Immunohistochemical staining of CD34 was performed to determine the microvessel density (MVD) and Ang-2/Ang-1 ratio was calculated. Relationships between Ang-2/Ang-1 ratio, VEGF and MVD and clinicopathological features were also tested so as to evaluate their significance in the progression of HCC.

RESULTS: Ang-2 and VEGF mRNAs in HCC were significantly higher than those in NCL tissue (P < 0.05), whereas the Ang-1 and Tie2 mRNAs showed no statistical significance (P > 0.05), though slightly lower level of Ang-1 mRNA in HCC was observed. Ang-2/Ang-1 ratio and VEGF were both positively correlated to MVD. The Ang-2/ Ang-1 ratio, Ang-2 and VEGF were all associated with tumor’s clinicopathological parameters (P < 0.05) except for histological grades (P > 0.05). Ang-1 and Tie2 levels in different clinicopathological groups were not significantly different (P > 0.05).

CONCLUSION: Dominant Ang-2 expression against Ang-1 through Tie2 receptor in the presence of VEGF plays a critical role in initiating early neovascularization and transformation of noncancerous liver to hepatocellular carcinoma. Its consequently constant operation in formed HCC induces further angiogenesis and progression of HCC.

Correlative studies on uPA mRNA and uPAR mRNA expression with vascular endothelial growth factor, microvessel density, progression and survival time of patients with gastric cancer

AIM: To investigate the correlations between the expression of urokinase-type plasminogen activator (uPA) mRNA, uPA receptor (uPAR) mRNA and vascular endothelial growth factor (VEGF) protein and clinicopathologic features, microvessel density (MVD) and survival time.

METHODS: In situ hybridization and immuno-histochemistry techniques were used to study the expressions of uPA mRNA, uPAR mRNA, VEGF and CD34 protein in 105 gastric carcinoma specimens.

RESULTS: Expressions of uPA mRNA, uPAR mRNA and VEGF protein were observed in 61 (58.1%) cases, 70 (66.7%) cases and 67 (63.8%) cases, respectively. The uPA mRNA and uPAR mRNA positive expression rates in infiltrating-type cases (73.7%, 75.4%), stage III-IV (72.1%, 75.4%), vessel invasion (63.2%, 69.9%), lymphatic metastasis (67.1%, 74.4%) and distant metastasis (88.1%, 85.7%) were significantly higher than those of the expanding-type (χ² = 15.57, P = 0.001; χ² = 6.91, P = 0.046), stage I-II (χ² = 19.22, P = 0.001; χ² = 16.75, P = 0.001), non-vessel invasion (χ² = 11.92, P = 0.006; χ² = 14.15, P = 0.002), non-lymphatic metastasis (χ² = 28.41, P = 0.001; χ² = 22.5, P = 0.005) and non-distant metastasis (χ² = 12.32, P = 0.004; χ² = 17.42, P = 0.002; χ² = 11.25, P = 0.012; χ² = 18.12, P = 0.002).The VEGF positive expression rates in infiltrating-type cases (75.4%), stage III-IV (88.5%), vessel invasion (82.9%), lymphatic metastasis (84.3%) and distant metastasis (95.2%) were significantly higher than those of the expanding-type (χ² = 9.61, P = 0.021), stage I-II (χ² = 16.66, P = 0.001), non-vessel invasion (χ² = 29.38, P = 0.001), non-lymphatic metastasis (χ² = 18.68, P = 0.005), and non-distant metastasis (χ² = 22.72, P = 0.007; χ² = 21.62, P = 0.004). The mean MVD in the specimens positive for the uPA mRNA, uPAR mRNA and VEGF protein was markedly higher than those with negative expression groups. Moreover, a positive relation between MVD and uPA mRNA (rs = 0.199, P = 0.042), uPAR mRNA (rs = 0.278, P = 0.035), and VEGF (rs = 0.398, P = 0.048) expressions was observed. The mean survival time in cases with positive uPA mRNA, uPAR mRNA and VEGF protein expression or MVD value ≥ 54.9 was significantly shorter than those in cases with negative expression or MVD value < 54.9.

CONCLUSION: uPA and uPAR expressions are correlated with enhanced VEGF-induced tumor angiogenesis and may play a role in invasion and nodal metastasis of gastric carcinoma, thereby serving as prognostic markers of gastric cancer.

Expression of vascular endothelial growth factor in chronic alcoholic liver fibrosis in rats

AIM: To investigate the expression of vascular endothelial growth factor (VEGF) and its role in the pathogenesis and development of chronic alcoholic liver fibrosis in rats.

METHODS: Liver fibrosis models were established in 24 SD rats by intragastric administration (7 g/kg) of alcohol (56º, 560 mL/L) every morning, and 10 normal rats served as controls. The rats in model group were killed by exsanguination from femoral vein at 4, 12 and 24 wk. Pathological changes of liver tissues in rats were identified by Masson staining, and the expression of VEGF mRNA was detected by semiquantitative reverse transcription-polymerase chain reaction (RT-PCR).

RESULTS: VEGF mRNA expression was not detected in the control rats. The expression of VEGF mRNA in model rats was the highest at 4 wk, reaching 83.3% (5/6), which was significantly higher than that in the controls (P < 0.01). The positive rate of VEGF mRNA expression dropped to 18.2% (2/11) at 12 wk, and then rose up again to 57.1% (4/7) at 24 wk, which was markedly higher than that in the controls. The expression of VEGF mRNA was also notably different between 4 and 12 wk (P < 0.01), but not between 4 and 24 wk (P > 0.05). Fatty and vacuole-like degeneration, necrosis and production of collagen were observed in the model rats.

CONCLUSION: VEGF plays an important role in the pathogenesis and development of chronic alcoholic liver fibrosis.

Effect of Ezhu on expression of cyclooxygenase, vascular endothelial growth factor and prostaglandin E2 in human gastric cancer cell line SGC7901

AIM: To investigate the effect of Ezhu on the expression of cyclooxygenase-1 (COX-1), cyclooxygenase-2 (COX-2), vascular endothelial growth factor (VEGF) and prostaglandin E₂ (PGE₂) in human gastric cancer cell line SGC7901.

METHODS: The MTT method was used to observe the suppression of the human gastric cancer (SGC7901) cells treated with Ezhu. By drawing the suppression rate curves, we selected the appropriate Ezhu concentration at the 25% proliferation suppression rate as experimental concentration. Reverse transcription-polymerase chain reaction (RT-PCR) and Western blot were adopted, respectively, to examine the expression of COX gene and protein. Furthermore, ELISA method was used to detect the variation of the VEGF and PEG₂ expression in culture medium.

RESULTS: Ezhu definitely inhibited the proliferation of human gastric cancer cells in a concentration dependent manner. Electrophoresis of the RT-PCR products demonstrated the expression of COX-1 and COX-2 gene in the human gastric cancer cells. Gray scale analysis showed that both Ezhu and celecoxib inhibited the expression of COX-1 and COX-2 gene, and the inhibitory action of Ezhu was greater than celecoxib. However, Western blot clearly showed that a specific protein strip was observed in COX-1 group at the 70 kDa, while in COX-2 group at the 80 kDa. Gray scale analysis confirmed than both Ezhu and celecoxib had apparent suppression on COX-2 protein, but had no effect on COX-1. Moreover, the suppression function of Ezhu surpassed celecoxib. Ezhu and celecoxib obviously degraded the content of VEGF in gastric cancer cells. In comparison with those in the control group, the results are statistically significant (91.0 ± 18.2, 127.8 ± 12.1 ng/L vs 162.0 ± 15.1 ng/L, P < 0.01). The level of PGE₂ in the cells treated with celecoxib was lower than the control group with no statistical significance. Nevertheless, Ezhu decreased the level of PGE₂ significantly (67.5 ± 6.9 ng/L vs 78.7 ± 5.6 ng/L, P < 0.01).

CONCLUSION: Ezhu can inhibit COX-2 and its downstream expression of PGE₂, and down-regulates VEGF expression, so as to suppress the proliferation of gastric cancer cells.

Expression of CD44v6 and vascular endothelial growth factor in hepatocellular carcinoma after transcatheter hepatic arterial chemoembolization

AIM: To investigate the role of vascular endothelial growth factor (VEGF) and CD44v6 in the recurrence and metastasis of hepatocellular carcinoma (HCC) after transcatheter hepatic arterial chemoembolization (TACE).

METHODS: The expression of CD44v6 and VEGF in 29 HCC samples obtained from the patients underwent secondary hepatectomy after TACE was examined by immunohistochemical staining and morphometric analysis. HCC samples (n = 30) obtained from the patients without TACE were used as the control group.

RESULTS: The value of VEGF absorbance in the TACE group was 0.149 ± 0.021, significantly higher than that in the controls (0.134 ± 0.018, P < 0.05). The positive rate of CD44v6 expression was 82.8% and 66.7% in the TACE group and control group, respectively, without significant difference between them (P > 0.05). The numbers of CD44v6 positive cells were also not markedly different between the two groups (112.4 ± 22.3 vs 102.4 ± 21.2, P > 0.05).

CONCLUSION: VEGF may take part in the recurrence and metastasis of HCC after TACE, while CD44v6 may not.

Effects of meloxicam on vascular endothelial growth factor and angiopoietin-2 expression in colon carcinoma cell line HT-29

AIM: To investigate the effect of meloxicam, a nonsteroidal anti-inflammatory drug (NSAID), on the expression of vascular endothelial growth factor (VEGF) and angiopointin-2 (Ang-2) in colon carcinoma cell line HT-29.

METHODS: The cultured HT-29 cells were treated with different concentrations of meloxicam (100, 200, 400, 800 μmol/L) for different time. The proliferation of HT-29 cells was detected by Cell Counting Kit 8 (CCK8). Cell cycle was detected by flow cytometry. The levels of VEGF and Ang-2 protein in the supernatants were determined by enzyme-linked immunosorbent assay (ELISA) and the expression of VEGF and Ang-2 mRNA in HT-29 cells were examined by real-time quantitative reverse-transcription-polymerase chain reaction (RT-PCR).

RESULTS: Meloxicam inhibited the proliferation of HT-29 cells in a concentration- and time-dependent manner (P = 0.000→0.029; 0.000→0.043), and the proliferating activity was decreased with the increase of concentration and prolonging of action time. Meloxicam changed the cycles of HT-29 cells in a concentration-dependent manner, and the number of cells at G₀/G₁ phase was significantly increased (P = 0.000→0.015). The levels of VEGF and Ang-2 protein in supernatants were reduced gradually with the increase of concentration or action time (P = 0.000→0.018; 0.000→0.028). The expression of COX-2, VEGF and Ang-2 mRNA were also reduced with the increase of Meloxicam concentration (P = 0.000→0.025).

CONCLUSION: Meloxicam can reduce the expression of VEGF and Ang-2 at the levels of protein and mRNA in colon carcinoma cell line.

Role of p38MAPK signal transduction pathway in adhesion of hepatocellular cancinoma cell line HepG2 induced by vascular endothelial growth factor

AIM: To investigate the role of the p38MAPK signal transduction pathway in the metastasis and adhesion of hepatocellular carcinoma cell line HepG₂ induced by vascular endothelial growth factor (VEGF).

METHODS: Hepatocellular cancinoma cell line HepG₂ were or not pretreated with specific blocker (SB203580) of p38MAPK signal transduction pathway. ³H-TdR infiltration and the experiment of rat tail colloid were used to measure the effects of different concentrations of VEGF on the homotypic and hetertypic adhesion in HepG₂ cells. Flow cytometry was adopted to detect VEGF-induced expression of CD44v6 and by Boyden-Chamber assay was used to evaluate VEGF-induced metastasis of HepG₂ cells.

RESULTS: After 1 and 5 mg/L VEGF induction for 60 min, the values (dpm/min) of ³H-TdR infiltration in HepG₂ cells were 1 758.67 ± 289.46 and 1 380.03 ± 328.55; for 90 min, the values were 3 124.30 ± 2 262.14 and 2 245.60 ± 273.24, respectively. After 10 mg/L VEGF induction, the values were 1 232.32 ± 201.04, 2 337.50 ± 333.04, and 2 236.99 ± 237.07, respectively, which were dramatically lower than those in control group (P < 0.05 or 0.01). However, in the HepG₂ cells pretreated with SB203580, the values of ³H-TdR infiltration after 60, 90 and 120 min were 1 232.32 ± 201.04, 2 337.50 ± 333.04, and 2 236.99 ± 237.07, respectively, and the homotypic adhesion induced by VEGF were inhibited. After 5 and 10 mg/L induction for 60 min, the optical densities (A values) of the experiment of rat tail colloid were 0.263 ± 0.021 and 0.238 ± 0.034, respectively. After 1, 5, and 10 mg/L VEGF induction for 90 min, the A values were 0.269 ± 0.023, 0.373 ± 0.083, and 0.393 ± 0.081, respectively; for 120 min, the A values were 0.371 ± 0.061, 0.390 ± 0.074, and 0.433 ± 0.122, respectively, in HepG₂ cells, which were remarkably higher than those in control group (P < 0.05 or P < 0.01). However, in the HepG₂ cells pretreated with SB203580, the A values after 60, 90, and 120 min were 0.201 ± 0.035, 0.347 ± 0.112, and 0.479 ± 0.217, respectively, and the hetertypic adhesion induced by VEGF was restrained. After 5 mg/L VEGF induction for 2 h, the CD44v6 positive HepG₂ cells counted for a percentage of 32.6% ± 4.2%, but rate of positive cell decreased to 4.3% ± 0.54% when p38MAPK signal transduction pathway was blocked (P < 0.01).

CONCLUSION: VEGF can promote the hetertypic adhesion and decrease the homotypic adhesion of hepatocellular carcinoma HepG₂ cells by through p38MAPK signal transduction pathway, which play an important role in the invasion and metastasis of HepG₂ cells.

Effect of down-regulating vascular endothelial growth factor gene on proliferation of gastric cancer cell line SGC-7901

AIM: To study the effect of small interfering RNA (siRNA) on the gene expression of vascular endothelial growth factor (VEGF) as well as the proliferation of gastric cancer cell line SGC-7901.

METHODS: Two groups of siRNA were designed targeting VEGF mRNA and finally obtained by in vitro transcription. Then the obtained siRNA was transfected into cultured human gastric cancer cell line SGC-7901 by Lipofectamine. Hoechst33258 staining was used to observe the apoptotic bodies in the cells, and flow cytometry was used to detect the change of cell cycles. The level of VEGF mRNA expression was analyzed by reverse transcription polymerase chain reaction (RT-PCR) and the secretion of VEGF protein in the supernatant was examined by enzyme-linked immunosorbent assay (ELISA).

RESULTS: Both groups of VEGF-targeted siRNA inhibited the proliferation of SGC-7901 cells and induced cell apoptosis effectively and after transfection. The percentage of G₀/G₁ phase cells was significantly increased in siRNA₁- and siRNA₂-transfected cells in comparison with that in the control cells (75.04%, 76.52% vs 58.37%, P < 0.01), but the percentage of S phase cells was significantly decreased (17.82%, 16.73% vs 39.52%, P < 0.01). The level of VEGF mRNA expression was significantly inhibited in siRNA₁- and siRNA₂-transfected cells as compared with that in the controls (0.638 ± 0.078, 0.656 ± 0.085 vs 0.941 ± 0.046, P < 0.01), and the secretion of VEGF protein was also notably decreased in both siRNA-transfected cells (164.7 ± 22.7, 166.3 ± 26.6 vs 414.0 ± 61.5, P < 0.01).

CONCLUSION: VEGF-targeted siRNA can effectively inhibit the proliferation of human gastric cancer cell line SGC-7901.