Vascular Endothelial Growth Factor C Expression in Gastric Carcinoma and Its Relationship with Lymph Node Metastasis

Objective: To study the expression of vascular endothelial growth factor C (VEGF-C) in gastric carcinoma and its relationship with lymph node metastasis. Methods: The expression of VEGF-C mRNA in 5 gastric carcinoma cell lines was detected by reverse transcription-polymerase chain reaction (RT-PCR). Simultaneously, the expression of VEGF-C protein in gastric carcinoma tissues, which were obtained from 63 patients who underwent radical gastrectomy, was detected by immunohistochemistry. Results: Three of the 5 gastric carcinoma cell lines, MKN-45, SGC-7901 and AGS, expressed VEGF-C mRNA. VEGF-C protein was expressed in 52.4% (33/63) of patients. VEGF-C protein expression was more frequently found in tumors with lymph node metastasis than in those without (P<0.01). VEGF-C protein expression was also closely related to lymphatic invasion (P<0.01) and TNM stage (P<0.01). However, there was no significant correlation between VEGF-C expression and the age, gender, tumor size, tumor location, Lauren classification, depth of invasion, and vascular invasion. Conclusion: The expression of VEGF-C is closely related to lymph node metastasis of gastric carcinoma, and lymphangiogenesis might be a new target for treatment of gastric carcinoma.

Expression of vascular endothelial growth factor and its role in oncogenesis of human gastric carcinoma

AIM: To establish the role of vascular endothelial growth factor (VEGF) in the oncogenesis of human gastric carcinoma more directly. METHODS: The expression of VEGF and its receptor kinase-domain insert containing receptor (KDR) in human gastric cancer tissue were observed by immunohistochemical staining. VEGF levels were manipulated in human gastric cancer cell using eukaryotic expression constructs designed to express the complete VEGF(165) complimentary DNA in either the sense or antisense orientation. The biological changes of the cells were observed in which VEGF was up-regulated or down-regulated. RESULTS: VEGF-positive rate was 50%, and VEGF was mainly localized in the cytoplasm and membrane of the tumor cells, while KDR was mainly located in the membrane of vascular endothelial cells in gastric cancer tissues and peri-cancerous tissue. In 2 cases of 50 specimens, the gastric cancer cells expressed KDR, localized in both the cytoplasm and membrane. Introduction of VEGF(165) antisense into human gastric cancer cells (SGC-7901, immunofluorescence intensity, 31.6%)) resulted in a significant reduction in VEGF-specific messenger RNA and total and cell surface VEGF protein (immunofluorescence intensity, 8.9%) (P【0.05). Conversely, stable integration of VEGF(165) in the sense orientation resulted in an increase in cellular and cell surface VEGF (immunofluorescence intensity, 75.4%) (P【0.05). Lowered VEGF levels were associated with a marked decrease in the growth of nude mouse xenografted tumor (at 33 days postimplantation, tumor volume: 345.40 +/- 136.31 mm3)(P【0.05 vs control SGC-7901 group: 1534.40 +/- 362.88 mm3), whereas up-regulation of VEGF resulted in increased xenografted tumor size (at 33 days postimplantation, tumor volume: 2350.50 +/- 637.70 mm3) (P【0.05 vs control SGC-7901 group). CONCLUSION: This study provides direct evidence that VEGF plays an important role in the oncogenesis of human gastric cancer.

Serum vascular endothelial growth factor is a potential biomarker of metastatic recurrence after curative resection of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the most common malignancies in China. To date, surgery is still the best solution to it. However, metastatic recurrences after curative hepatic resections are very common. Tang et al have reported that recurrence rate within 5 years of curative hepatic resection is 61.5% [1]. As curative hepatic resection has a high tendency for metastatic recurrence, therapeutic interventions such as transarterial embolization and antiangiogenesis have been tried to further improve prognosis of HCC patients. Therefore, establishing a dependable, sensitive, easy, and economical method to predict metastatic recurrence following curative hepatic resection is of clinical urgency.

Quantitative analysis of vascular endothelial growth factor, microvascular density and their clinicopathologic features in human hepatocellular carcinoma

BACKGROUND: Angiogenesis is known to be essential to the survival, growth, invasion, and metastasis of tumor cells. Vascular endothelial growth factor (VEGF) are an important angiogenic factor regulating tumor angiogenesis, but its significance and tumor pathologic features are un- clear in hepatocellular carcinoma (HCC). In the present study, we analyzed expression of tissue VEGF, alteration of microvascular density (MVD) in microvessel angiogenesis, development and metastasis of HCC, and level of serum VEGF in differential diagnosis of benign and malignant liv- er diseases. METHODS: Tumor specimens were prospectively collected from HCC patients undergoing resection. Total RNAs were extracted and the expression levels were detected from different parts of HCC tissues. The cellular distributions of VEGF and MVD of liver tumors and their paracancerous and distal cancerous tissues were investigated by streptavi- din peroxidase (S-P) immunohistochemistry, respectively. The VEGF levels of circulating blood and hepatoma tissues were measured by enzyme-linked immunosorbent assay. RESULTS: The incidence of VEGF expression was 63.9% in HCCs (23/36 cases), 78.3% in non-encapsulated HCCs (18/23), and 90.9% in HCCs with extrahepatic metastasis (10/11), respectively. The VEGF expression was tightly correlated with MVD (P <0.01). The MVD in HCC with metastasis, low differentiation or non-encapsulation was significantly higher than that in HCC with intact capsule, high differentiation, or no metastasis. No significant diffe- rence was found between VEGF, MVD, tumor size, and hepatitis virus infection. The level of total RNA in HCC tis- sues was significantly lower but the VEGF level significantly higher than those in paracancerous or distal cancerous ones (P<0.01). The abnormal expression levels of VEGF in sera of HCC patients were directly correlated with the me- tastasis and recurrence of tumors. CONCLUSION: The high expression of VEGF and abnor- mality of tissue MVD are useful predictors for vascular inva- sion and metastasis of liver tumors.

Impact of Serum Vascular Endothelial Growth Factor on Prognosis in Patients with Unresectable Hepatocellular Carcinoma after Transarterial Chemoembolization

Objective： To investigate the expression level with unresectable hepatocellular carcinoma （HCC） and to assess the impact of serum VEGF as chemoembolization （TACE） treatments. of serum vascular endothelial growth factor （VEGF） in patients and its relationship with the c a predictive factor for HCC nicopathological characteristics, prognosis during transarterial Methods： Serum VEGF levels were measured using enzyme-linked immunosorbent assay （ELISA） in 60 random patients who underwent TACE or transarterial infusion （TAI） for unresectable HCC between May and September 2008 and 12 healthy volunteers were also involved in this study to serve as control. All patients＇ clinicopathological features were retrospectively analyzed. Serum VEGF levels were correlated with clinicopathological features of the HCC patients. The patients＇ survival rates were analyzed with Kaplan-Meier survival curves and compared by the log-rank test. The prognostic significance of serum VEGF levels and factors related to survival rate were evaluated by univariate and multivariate analysis. Results： The median serum VEGF level in the HCC patients was 285 pg/ml （range 14-1,207 pg/ml）, significantly higher than that of healthy controls （P=0.021）. The serum VEGF levels were significantly correlated with platelet counts （r=0.396, P=0.002） but not other clinicopathological features. Patients with serum VEGF level 〉285 pg/ml had worse overall survival compared with those with serum VEGF level 〈285 pg/ml （P=0.002）. By multivariate analysis, the serum VEGF level was a significant prognostic factor. Conclusion： High serum VEGF levels may predict poor prognosis of HCC after TACE. This study highlights the importance of tumor biomarker as a prognostic predictor in TACE therapy for HCC, which has an intrinsic problem of unavailability of histopathological prognostic features.

Association between vascular endothelial growth factor and metastasis after transcatheter arterial chemoembolization in patients with hepatocellular carcinoma

BACKGROUND: Hypoxia up-regulates vascular endothelialgrowth factor (VEGF) and stimulates the growth of hepa-tocellular carcinoma (HCC) cells. This study was designedto investigate the association between changes in plasmaVEGF levels after transcatheter arterial chemoembolization(TACE) and HCC progression, especially in relation tometastasis.METHODS: Plasma VEGF levels were measured by quati-tative sandwich enzyme-linked immunosorbent assay(ELISA R&D system). Plasma VEGF levels were measuredbefore, 3 days and 4 weeks after TACE in 30 patients withHCC. The development of metastasis was evaluated at theend of the third month after TACE.RESULTS: The plasma VEGF levels of the 30 patients withHCC were 154.47±90.17 pg/ml. The total plasma VEGFlevels after TACE increased compared with their basal levels(P<0.05), and the plasma VEGF levels had a tendency toincrease in patients with heterogenous uptake of iodizdoiland portal vein thrombosis. Follow-up for six monthsshowed metastatic foci in 20 patients (74%) with increasedplasma VEGF, but none of the patients with decreased plas-ma VEGF developed metastasis.CONCLUSION: Increased plasma VEGF expression is asso-ciated with the development of metastasis in HCC after TA-CE.

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.

Serum Vascular Endothelial Growth Factor-C and Vascular Endothelial Growth Factor Level in Patients with Colorectal Carcinoma and Clinical Significance

Circulating vascular endothelial growth factor-C （VEGF-C） and vascular endothelial growth factor （VEGF） levels in patients with colorectal carcinoma were determined in order to assess their clinical significance as a diagnostic tool for monitoring lymph node metastasis. In 66 patients with colorectal carcinoma and 30 healthy controls, circulating VEGF-C and VEGF levels were assessed by using enzyme-linked immunosorbent assay （ELISA）. Serum VEGF-C and VEGF levels were higher in patients with colorectal carcinoma than in healthy controls. Patients with lymph node metastasis had higher serum VEGF-C and VEGF levels than those without lymph node metastasis. The levels of VEGF-C and VEGF were higher in the invasion group than in the non-invasion group. Serum VEGF-C levels reached a sensitivity of 81% and a specificity of 76 % with a cutoff value of 1438.0 pg/mL, whereas VEGF levels reached 72 % sensitivity and 74 % specificity at 240.2 pg/ mL. If 66 patients were divided into 4 groups according to the combined determination of VEGF-C and VEGF levels, the positive predictive value was 85.3 %, the negative predictive value was 94.6 %, and accuracy was 93.7 %. It was suggested that circulating VEGF-C levels might provide additional information for distinguishing the absence from presence of lymph node metastasis in patients with colorectal carcinoma. The combined determination of VEGF-C and VEGF levels could be used as an important index for preoperatively clinical stage of colorectal carcinoma.

Expression of Livin and vascular endothelial growth factor in different clinical stages of human esophageal carcinoma

AIM： To investigate the role of Livin and vascular endothelial growth factor （VEGF） in human esophageal carcinoma, and analyze its relationship to clinical stages.METHODS： Expression of Livin in fresh esophageal cancer tissues was detected by immunohistochemistry （IHC）, Western blotting and reverse transcriptasepolyrnerase chain reaction （RT-PCR）, and VEGF by Western blotting and RT-PCR. All statistical analyses were performed by SPSS version 11.0. RESULTS： Livin positivity was also significantly correlated with tumor stages, increasing with tumor progression. Expression of Livin and VEGF increased with the process of esophageal carcinoma. In the fourth clinical stage, expression of Livin and VEGF was the most significant. Expression of Livin was positively correlated with VEGF. CONCLUSION： Over-expression of Livin and VEGF contributes to the pathogenesis of esophageal carcinoma.

Expression of hypoxia-inducible factor la and vascular endothelial growth factor in hepatocellular carcinoma: Impact on neovascularization and survival

AIM: To study the expression of hypoxia-inducible factor 1α(HIF-1α) and vascular endothelial growth factor (VEGF) in hepatocellular carcinoma (HCC) and the impact on neovascularization and survival. METHODS: Expressions of HIF-1α, VEGF and microvessel density (MVD) are studied through immunohistochemistry in 36 cases of HCC and the corresponding paraneoplastic tissue and 6 cases of normal liver tissue. The relationship of the expressions of HIF-1α and VEGF with the clinicopathological data and survival are analyzed. RESULTS: The positive rate of VEGF in HCC was 32/36, which is significantly higher than that in paraneoplastic tissue and normal liver tissue (P<0.05). The expression of HIF-1aaaaaa in HCC tissue is 24/36, also higher than that in paraneoplastic tissue and normal liver tissue (P<0.05). The expression of VEGF and HIF-1α in HCC with microscopic venous invasion is significantly higher than that in HCC without microscopic venous invasion (P<0.05). Spearman correlation analysis does not only show the expression of HIF-1α as correlated with the expression of VEGF (rs = 0.459, P<0.01), but it also shows the expression of HIF-1α and VEGF as correlated with MVD (rs=0.412 and 0.336, respectively, P<0.05). The differences of the survival rates among VEGF positive group and VEGF negative group are significant (P<0.05), whereas the differences of the survival rates among the HIF-1α negative group and positive group are not significant (P>0.05). CONCLUSION: HIF-1α plays important roles in neovascularization in HCC possibly through regulation of VEGF transcription.

Nerve Growth Factor and Vascular Endothelial Growth Factor: Retrospective Analysis of 63 Patients with Salivary Adenoid Cystic Carcinoma

Aim To detect the expression of nerve growth factor （NGF） and vascular endothelial growth factor （VEGF） in salivary adenoid cystic carcinoma （SACC） tissues, as well as to determine the correlation between growth factor expression and prognosis in SACC. Methodology Medical records of 63 patients surgically treated for SACC between January 1988 and October 2005 were reviewed. Immunohistochemistry was performed to examine the expression of NGF and VEGF in tumor tissues. Kaplan-Meier analysis and Cox＇s proportional hazard regression model were applied to assess predictors of survival. Results NGF and VEGF were overexpressed in SACC tissues, compared with those in normal salivary tissues （P〈0.05）, and the staining intensity of these two factors was stronger in groups of solid subtype, advanced TNM stage, perineural invasion and recurrence. Patients with high- expression of NGF and VEGF, solid subtype, advanced stage, perineural invasion, recurrence and extended resection alone had worse survival rates （P〈0.05）. Conclusion NGF and VEGF are expressed increasingly in the tissues of SACC cases with invasion and metastasis. NGF expression and VEGF expression are independent prognosis factors for survival.

Effects of endostatin on expression of vascular endothelial growth factor and its receptors and neovascularization in colonic carcinoma implanted in nude mice

AIM:To investigate the antiangiogenic effects of endostatin on colonic carcinoma cell line implanted in nude mice and its mechanism. METHODS:Nude mice underwent subcutaneous injection with LS-174t colonic carcinoma cell line to generate carcinoma and were randomly separated into two groups.Mice received injection of vehicle or endostatin every day for two weeks. After the tumor was harvested,the tumor volumes were determined,and the expressions of CD34,VEGF and FIk-1 were examined by immunohistochemical method. RESULTS:Tumor volume was significantly inhibited in the endostatin group(84.17%)and tumor weight was significantly inhibited in the endostatin group(0.197±0.049) compared to the control group(1.198±0.105)(F=22.56, P=0.001),microvessel density(MVD)was significantly decreased in the treated group(31.857±3.515)compared to the control group(100.143±4.290)(F=151.62,P<0.001). Furthermore,the expression of FIk-1 was significantly inhibited in the treated group(34.29%) ompared to the control group(8.57%)(X^2=13.745,P=0.001).However no significant decrease was observed in the expression of vascular endothelial growth factor(VEGF)between these two groups(X^2=0.119,P=0.730). CONCLUSION:Endostatin can inhibit tumor growth and angiogenesis by blocking Vegf/FIk-1 pathway.This experiment provides the theory basis for developing a new anti-carcinoma drug through studying the properties of anti-angiogenesis inhibitors.

Cyclooxygenase-2 promotes angiogenesis by increasing vascular endothelial growth factor and predicts prognosis in gallbladder carcinoma

AIM: To investigate the relationships between the expression of cyclooxygenase-2 (COX-2), vascular endothelial growth factor (VEGF) and the degree of vascularization, clinicopathologic feature, survival time of patients with gallbladder carcinomas. METHODS: Sixty-four gallbladder carcinoma specimens were evaluated for COX-2, VEGF expression by immunohi stochemical methods. Microvessel counts (MVC) were determined using CD34. The relationships between COX-2, VEGF expression, CD34-stained MVC, clinicopathologic features and survival time were analyzed. The correlations between COX-2 and VEGF expression, CD34-stained MVC were also investigated. RESULTS: COX-2, VEGF immunoreactivity were observed in 71.9% (46/64) and 54.7% (35/64) specimens, respectively. The average MVC in 64 cases of gallbladder carcinoma was 57±14 per high power vision field. The status of MVC was closely correlated with Nevin staging, tumor differentiation and lymph node metastasis (P<0.01, 0.002, and 0.003, 0.000, respectively). Increased VEGF expression was significantly correlated with tumor differentiation (poorly and moderately>well differentiated, P<0.05, P = 0.016). Clinical stages had no relation with the expression of VEGF (P>0.05, P = 0.612). There was a positive correlation between COX-2 expression and clinical stages. The positive rate of COX-2 was higher in cases of Nevin stages S4-S5 (81.8%) than in those of Nevin stages S1-S3 (50.0%) with a statistical significance (P0.01, P = 0.009). The expression of COX-2 did not vary with differentiation (P>0.05, P= 0.067). Statistically significant differences were also observed according to lymph node metastasis, COX-2 expression and VEGF expression (P<0.01,0.000, and 0.001, respectively). There was no relation between VEGF, COX-2 expression, MVC and the age and sex of patients. MVC and VEGF positive rate in the COX-2 positive gallbladder carcinoma tissue was higher than that in the COX-2 negative tissue (P<0.05, 0.000, and 0.032, respectively). Patients with VEGF, COX-2 positive tumors had a significantly shorter survival time than those with negative tumors (P<0.05,0.004, 0.01, respectively). CONCLUSION: Augmented tumor neovascularization induced by VEGF may be one of the several effects of COX-2 responsible for poor prognosis of human gallbladder carcinoma. COX-2 inhibitor, either in combination therapy with other agents, or for chemoprevention, may be effective via suppression of angiogenesis in this fatal disease.

Expression of Vascular Endothelial Growth Factor C and Its Correlation with Lymph Node Metastasis in Colorectal Carcinoma

Summary: To study the expression of vascular endothelial growth factor C (VEGF-C) in colorectal carcinoma and its relationship with lymph node metastasis, the expression of VEGF-C protein in colorectal carcinoma tissues obtained from 94 patients who underwent radical resection was immunohistochemically detected. Meanwhile, the expression of VEGF-C mRNA in 4 colorectal carcinoma cell lines was examined by reverse transcription polymerase chain reaction (RT-PCR).VEGF-C protein was found to be expressed in 53.2 % of patients. The expression was more frequently detected in tumors with lymph node metastasis than in those without metastasis (P<0.01), and there was significant correlation between its expression and lymphatic invasion, TNM stage (P<0.01). However, no significant correlation was found between its expression and the age, gender, tumor location, depth of invasion and vascular invasion. 2 of the 4 colorectal carcinoma cell lines, including LoVo and LoVo-5FU, expressed VEGF-C mRNA. The expression of VEGF-C is closely related to lymph node metastasis, and it might take part in the tumor lymphangiogenesis.

Inhibitory effect of antisense vascular endothelial growth factor RNA on the profile of hepatocellular carcinoma cell line in vitro and in vivo

AIM： To evaluate the effect of antisense vascular endothelial growth factor （VEGF） RNA （PCMV-FGEV） transfection on the profile of hepatocellular carcinoma （HCC） SMMC-7721 cells in vitro and in vivo.METHODS： SMMC-7721 cells were transfected with PCMV-FGEV antisense, PCMV-VEGF sense and empty vector plasmid encapsulated by lipofectamine as antisense group, sense group and control group respectively. The positive cell clones were selected with G418. The stable transfection and expression of VEGF in the cells were determined by RT-PCR and immunohistochemistry. Cell proliferation was observed by Mnassay. FACS analysis was used to determine the effect of PCMV-FGEV transfection on cell apoptosis. The growth of transfected cells in vivo was also observed in nude mice.RESULTS： VEGF expression was reduced in SMMC-7721 transfected with PCMV-FGEV, which was confirmed by RT-PCR and immunohistochemistry. No effect of PCMV- FGEV transfection was found on cell proliferation and cell apoptosis of SMMC-7721 in vitro. The growth of cells transfected with PCMV-FGEV was slow in nude mice and accompanied with obvious apoptosis. The latent time of tumors in the antisense group was 25.0 ：l： 1.8 d, which was longer than that in sense and control groups （F= 19.455, P〈 0.01）. The average tumor weight in antisense group （0.96 g±0.28 g） was the smallest among the three groups （F= 21.501, P〈 0.01）.CONCLUSION： The expression of VEGF can be inhibited by antisense PCMV-FGEV. Antisense PCMV-FGEV has no effect on cell proliferation and apoptosis of SMMC-7721 in vitro but can inhibit tumor growth and induce cell apoptosis in vivo.

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 SC/D 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 reo ceived 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 evaluo ated histologically for metastasis under microscope. Intratumoral microvessel density （MVD） and VEGF expression were evaluated immuohistochemically. VEGF mRNA expression in gastric tissue of SC/D 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 hepa- rin 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.

Inhibitory effect of interferon-α-2b on expression of cyclooxygenase-2 and vascular endothelial growth factor in human hepatocellular carcinoma inoculated in nude mice

AIM： To evaluate the effects of interferon-α-2b （IFN- α-2b） on expression of cyclooxygenase-2 （COX-2） and vascular endothelial growth factor （VEGF） in human hepatocellular carcinoma （HCC） inoculated in nude mice and to study the underlying mechanism of IFN-α- 2b against HCC growth. METHODS： Thirb/-two nude mice bearing human HCC were randomly divided into four groups （n = 8）. On the 10th day after implantation of HCC cells, the mice in test groups （groups A, B and C） received IFN-α- 2b at a serial dose （10000 IU for group A, 20000 IU for group B, 40000 IU for group C sc daily） for 35 d. The mice in control group received normal saline （NS）. The growth conditions of transplanted tumors were observed. Both genes and proteins of COX-2 and VEGF were detected by RT-PCR and Western blot. Apoptosis of tumor cells in nude mice was detected by TUNEL assay after treatment with IFN-α-2b. RESULTS： Tumors were significantly smaller and had a lower weight in the IFN-α-2b treatment groups than those in the control group （P 〈 0.01）, and the tumor growth inhibition rate in groups A, B and C was 27.78%, 65.22% and 49.64%, respectively. The expression levels of both genes and proteins of COX-2 and VEGF were much lower in the IFN-α-2b treatment groups than in the control group （P 〈 0.01）. The apoptosis index （AI） of tumor cells in the IFN-α-2b treatment groups was markedly higher than that in the control group （P 〈 0.01）. Group B had a higher inhibition rate of tumor growth, a lower expression level of COX-2 and VEGF and a higher AI than groups A and C （P 〈 0.05）, but there was no significant difference between groups A and C. CONCLUSION： The inhibitory effects of IFN-α-2b on implanted tumor growth and apoptosis may be associated with the down-regulation of COX-2 and VEGF expression. There is a dose-effect relationship. The medium dose of IFN-α-2b for inhibiting tumor growth is 20 000 IU/d.

Establishment of a Sandwich ELISA Method for Detection of Vascular Endothelial Growth Factor in Serum Samples of Hepatocellular Carcinoma Patients

Objective To establish a sandwich ELISA method for detecting vascular endothelial growth factor （VEGF） in sera of population and the patients with hepatocellular carcinoma （HCC）. Methods Full length and two truncated human VEGF cDNA sequences were amplified from a commercial plasmid pBLAST49-hVEGF by PCR and inserted into the prokaryotic-expression plasmid pET-32a or pGEX-2T. Various VEGF proteins were expressed and purified from E. coli in His-Trx or GST fusion forms. The specific VEGF antibodies were elicited in experimental rabbits and mice by immunization of the full length VEGF fusion protein His-Trx-VEGF1-165. After purification of antibodies with chromatograph of Protein G, a sandwich ELISA technique was established. Serum VEGF levels were evaluated in 229 adults and 291 HCC patients. Results SDS-PAGE displayed that the molecular weights of the expressed full length （His-Trx-VEGF1-165）, N-terminal （His-Trx-VEGF1-100） and C-terminal （GST-VEGF100-165） human VEGF fusion proteins were about 38KD, 31KD, and 33KD, respectively. Western blots confirmed that the prepared antisera were able to recognize both prokaryoticly and eukaryoticly expressed recombinant VEGF proteins. Assays of serially diluted His-Trx-VEGF1-100 by the established sandwich ELISA method showed that the linear range of the standard curve was 0.625-320 ng/mL, with the squared correlation coefficient R^2=0.991. Screening of a serum panel containing 291 serum samples of HCC patients and 229 health adults revealed that the average VEGF level in HCC patients was higher than that in healthy controls, with a statically significant difference. Conclusion The established sandwich ELISA reflects the level of serum VEGF and provide scientific basis for screening metastasis and recurrence of HCC using serum VEGF as an index.

Expression of Vascular Endothelial Growth Factor in Hepatocellular Carcinoma and Its Relationship to Tumor Growth and Metastasis

To understand the relationship between the expression of vasCular endothelial growth factor (VEGF) and the growth, metastasis of hepatocellular car cinoma (HCC), immunohistochemistry and Northern blot were used to investigate VEGF protein and mRNA in 21 cases of HCC with and without rnetastasis.VEGF protein was found in 8 of 9 cases with metastasis, whereas only in 4 of 12 cases without rnetastasis. The Positive rate of the former was significantly higher than that in the latter. VEGF mRNA was detectable in both carcinoma and its surrounding liver tissues, but its level in the former was 2 - 3 times higher than that in the latter. In carcinoma with metastasis, the mRNA level was 5-6 times higher than that without metastasis. It is concluded that VEGF Is closely related to the growth of HCC as well as its metastasis and it might be a useful indicator for the metastatic potential of HCC.

Treatment of metastatic colorectal carcinomas by systemic inhibition of vascular endothelial growth factor signaling in mice

AIM： Tumor angiogenesis has been shown to be promoted by vascular endothelial growth factor （VEGF） via stimulating endothelial cell proliferation, migration, and survival. Blockade of VEGF signaling by different means has been demonstrated to result in reduced tumor growth and suppression of tumor angiogenesis in distinct tumor entities. Here, we tested a recombinant adenovirus, AdsFItl-3, that encodes an antagonistically acting fragment of the VEGF receptor 1 （Fit-l）, for systemic antitumor effects in pre-established subcutaneous CRC tumors in mice.METHODS： Murine colorectal carcinoma cells （CT26） were inoculated subcutaneously into Balb/c mice for in vivo studies. Tumor size and survival were determined. 293 cell line was used for propagation of the adenoviral vectors. Human lung cancer line A549 and human umbilical vein endothelial cells were transfected for in vitro experiments.RESULTS： Infection of tumor cells with AdsFlt1-3 resulted in protein secretion into cell supernatant, demonstrating correct vector function. As expected, the secreted sFlt1-3 protein had no direct effect on CT26 tumor cell proliferation in vitro, but endothelial cell function was inhibited by about 46% as compared to the AdLacZ control in a tube formation assay. When AdsFlt1-3 （5×10^9 PFU/animal） was applied to tumor bearing mice, we found a tumor inhibition by 72% at d 12 after treatment initiation, in spite of these antitumoral effects, the survival time was not improved. According to reduced intratumoral microvessel density in AdsFlt1-3-treated mice, the antitumor mechanism can be attributed to angiostatic vector effects. We did not detect increased systemic VEGF levels after AdsFlt1-3 treatment and liver toxicity was low as judged by serum alanine aminotransferase determination.CONCLUSION： In this study we confirmed the value of a systemic administration of AdsFItl-3 to block VEGF signaling as antitumor therapy in an experimental metastatic colorectal carcinoma model in mice.