肝癌组织血管内皮生长因子表达水平的免疫组化研究

目的　旨在研究血管内皮生长因子 (VEGF)与肝癌微血管形成、生长和转移诸方面的关系。方法　对临床 3 6例肝癌术后癌组织 ,以免疫组织化学法研究VEGF在肿瘤组织的胞内分布及其表达 ;并以ELISA法测定癌灶、癌旁及远癌组织中的VEGF蛋白的表达水平。结果　癌组织中VEGF阳性表达率为 63 .9% ;无包膜或包膜不完整组VEGF阳性表达率与有包膜组存在显著差异 ;肝癌伴有远处转移组VEGF阳性表达水平显著高于无转移组 (P <0 .0 1) ,癌灶组织中VEGF的表达水平明显高于癌旁、远癌组织(P <0 .0 1)。结论资料提示VEGF在肝癌组织中高度表达 ,它在HCC的血管形成、肿瘤发展和转移过程中起重要作用 ,提示癌组织中VEGF过度表达是反映肿瘤侵袭生长及转移潜能的有效指标     

Clinicopathological features of hepatocellular carcinoma evaluated by vascular endothelial growth factor expression

AIM: To evaluate the significance of the expression of vascular endothelial growth factor (VEGF), its correlation with clinicopathological variables were studied in the tissue of hepatocellular carcinoma (HCC) and surrounding liver. METHODS: In 56 samples (tumor and non-tumor liver tissue) collected from 28 patients, VEGF expression was examined by immunohistochemistry and western blot analysis. RESULTS: The value of VEGF expression by western blotting was correlated with immunohistochemical staining grade. In tumor tissue, the value of VEGF expression correlated with tumor size (P = 0.034), á-fetoprotein (P = 0.036) and protein induced by vitamin K absence-II by simple regression, and histological grade (P = 0.0132) by the unpaired t-test. The level of VEGF expression in non-tumor liver was found to correlate with the value of serum albumin (P = 0.008), cholinesterase (P = 0.012) and prothrombin activity (P = 0.046). The frequency of simple nodular type in gross appearance decreased in cases with high tumor/non-tumor (T/N) ratio (P = 0.022), and the degree of portal vein invasion progressed with an increase in the T/N ratio (P = 0.008). The T/N ratio was significantly higher in early recurrence cases (P = 0.0081). CONCLUSION: This study on the expression of VEGF might be useful to estimate the liver condition and the clinicopathological features of HCC.     

High serum levels of vascular endothelial growth factor in patients with human hepatocellular carcinoma

Vascular endothelial growth factor (VEGF) is intimately involved in neovascularization. In addition, it is know that in human hepatocellular carcinoma (HCC), angiogenesis is indispensable for tumor growth. In this study, we measured the serum VEGF levels of patients with HCC and studies the relationship between the serum VEGF level and maximum tumor diameter as well as that between the serum VEGF level and the serum α-fetoprotein (AFP) level. Mean serum VEGF level were 5.33 ± 0.77, 3.97 ± 0.68, 2.64 ± 0.78, and 2.57 ± 0.97 ng/ml for patients with HCC, chronic hepatitis (CH), or liver cirrhosis (LC) and normal controls (NC), respectively, with that of the HCC patients being significantly (P < 0.05) higher than that of the LC patient or NC. In addition, the serum VEGF level was significantly (r = 0.53, P < 0.05) correlated with the maximum tumor diameter in the HCC patients, and the sera of the patients with hypervascular HCC showed a significantly (P < 0.01) higher VEGF titer than the sera of the patients with isovascular or hypovascular HCC. However, there was no significant correlation between serum VEGF level and serum AFP level. These findings suggest that VEGF may play an important role, apart from that in AFP production, in the development of HCC.     

Expression of vascular endothelial growth factor-C in human hepatocellular carcinoma

Background/Aims: Vascular endothelial growth factor‐C (VEGF‐C) is thought to be an important factor in tumor angiogenesis/lymphangiogenesis, but its role in hepatocellular carcinoma (HCC) has not yet been fully investigated. Methods: We immunohistochemically examined VEGF‐C expression in surgically resected tissues of 90 HCC. Results: In the 78 HCC with a single histological grade, VEGF‐C expression was significantly stronger in poorly differentiated HCC than in well‐ (P = 0.003) or moderately differentiated HCC (P = 0.0002). A ‘nodule‐in‐nodule’ case presented VEGF‐A expression in the well‐differentiated component and VEGF‐C expression in the moderately–poorly differentiated component. According to nodular diameter, VEGF‐C expression was significantly higher in nodules of 3.0 cm or larger (P = 0.0263). Extrahepatic metastases seen in seven cases expressed VEGF‐C. In 20 of the 28 cases who were able to be followed up, the frequency of intrahepatic recurrence tended to be higher and extrahepatic metastasis was significantly higher in the cases who had VEGF‐C expression in the tumor casts of the intrahepatic portal/hepatic vein branches than other cases without the expression (P = 0.0139). Disease‐free survival time tended to be shorter in cases with VEGF‐C expression in tumor casts of the portal/hepatic vein than in those without VEGF‐C expression (P = 0.053; log–rank test). Conclusions: VEGF‐C expression is related to the progression of HCC, and VEGF‐C expression in tumor casts of the intrahepatic portal/hepatic vein is considered to be a factor indicating recurrence/metastasis sites.     

Expression of vascular endothelial growth factor in surgical specimens of hepatocellular carcinoma

Purpose: Vascular endothelial growth factor (VEGF) has been reported to play an important role in angiogenesis in hepatocellular carcinoma (HCC). However, there is great variation in reports on the distribution of VEGF expression, especially in non-carcinoma liver cells. Furthermore, some reports have mentioned that endothelial cells were positive for VEGF antibody but have not evaluated its significance. In this study, we focused our attention to these problems and try to solve them. We also analyzed the factors influencing VEGF expression and evaluated the prognostic potential of VEGF protein in HCC. Methods: We examined the VEGF expression in specimens surgically removed from 46 HCC patients and 3 patients with liver cancer metastatic from the colon, and in 4 specimens of liver tissue with benign disease, by immunohistochemical methods. Results/conclusions: VEGF was expressed in HCC cells and hepatocytes and on vascular endothelial cells. Our finding that about seven times more endothelial cells were positive for VEGF antibody in carcinoma areas than in non-carcinoma areas (P < 0.001) suggests that VEGF is a very important angiogenesis factor for HCC growth. VEGF expression in HCC cells and non-carcinoma liver cells and on endothelial cells did not closely correlate with the disease recurrence rate (P > 0.05), suggesting that VEGF expression may not be useful as an individual factor for estimating the prognosis of HCC. A statistical analysis of the relationships between VEGF expression and clinicopathological variables revealed the following: preoperative transcatheter arterial embolization enhanced VEGF expression in both HCC cells and non-carcinoma liver cells. The histological grade of HCC and the level of alanine aminotransferase was related to VEGF expression in non-carcinoma liver cells and on endothelial cells in HCC areas. Tumor size and the histological status of the accompanying chronic hepatitis also influenced the VEGF expression on endothelial cells. Our findings concerning not only HCC but also the surrounding liver and endothelial cells may provide useful information for further research on the role of VEGF expression in HCC patients. Received: 29 July 1999 / Accepted: 11 October 1999     

Synergistic effect of basic fibroblast growth factor and vascular endothelial growth factor in murine hepatocellular carcinoma

The growth of any solid tumor depends on angiogenesis. Among the known angiogenic factors, basic fibroblast growth factor (bFGF) and vascular endothelial growth factor (VEGF), are potent and representative factors involved in tumor development. It has been reported that bFGF and VEGF showed a synergistic effect in both in vitro and in vivo angiogenesis. However, the interaction of these factors on tumor development and angiogenesis, including hepatocellular carcinoma (HCC), has not yet been elucidated. In this study, we examined the combined effect of bFGF and VEGF overexpression by means of a combination of a retroviral tetracycline (tet)-regulated (Retro-Tet) gene expression system, which can manipulate the gene expression in vivo by providing tet in the drinking water, and a conventional plasmid gene expression system. In an allograft study, bFGF and VEGF overexpression synergistically increased tumor growth and angiogenesis in the murine HCC cells. This synergistic effect also was found in established tumors. VEGF messenger RNA (mRNA) expression in the tumor was increased 3.1-fold by bFGF-overexpression, and the bFGF-induced tumor development was significantly attenuated by treatment with KDR/Flk-1 neutralizing monoclonal antibody. In conclusion, these results suggest that bFGF synergistically augments VEGF-mediated HCC development and angiogenesis at least partly by induction of VEGF through KDR/Flk-1.     

Prognostic implication of serum vascular endothelial growth factor in advanced hepatocellular carcinoma staging

Background. Staging systems have considerable impact on hepatocellular carcinoma (HCC) treatment approaches and outcomes. There is an unmet need to improve their stratification ability. We have evaluated four commonly used staging systems and assessed whether angiogenic biomarker vascular endothelial growth factor (VEGF) could improve their prognostic stratification.Material and methods. Four staging systems; Okuda, Cancer of the Liver Italian Program (CLIP), Barcelona Clinic Liver Cancer (BCLC), and Child-Pugh were evaluated in 78 HCC patients; their stratification abilities were detected by Kaplan-Meier curves and log-rank test; their accuracies of predicting survival were compared with the concordance index. Serum VEGF levels were measured using ELISA method. Recursive partitioning was used to determine the optimal VEGF cutoff. The prognostic significance of VEGF cutoff and other parameters were analyzed using univariate and multivariate models.Results. None of the staging systems demonstrated better discriminatory ability in predicting survival. The four staging systems did not reveal significant differences in probability of survival across their intermediate-advanced stages. Optimal cutoff identified for VEGF was 445 pg/mL. In advanced HCC, VEGF level (p = 0.004) and in early HCC, bilirubin level (p = 0.009) were identified as the independent prognostic factors. Survival comparison with high and low VEGF levels was significant for advanced HCC, while insignificant for early disease.Conclusion. Staging systems with conventional parameters did not provide good prognostic stratification for survival in advanced HCC population. Serum VEGF level was an independent predictor of survival in advanced HCC, and provided more survival homogeneity within the advanced stages of conventional staging systems.     

Expression of platelet-derived endothelial cell growth factor and vascular endothelial growth factor in hepatocellular carcinoma and portal vein tumor thrombus

Purpose: Both platelet-derived endothelial cell growth factor (PD-ECGF) and vascular endothelial growth factor (VEGF) are known to promote the development of new blood vessels, which are fundamental to tumor growth and metastasis. We aimed at evaluating the gene expression of PD-ECGF and VEGF in hepatocellular carcinoma (HCC) and portal vein tumor thrombus (PVTT). Patients and methods: Surgical specimens (28 HCC, 28 nontumorous liver tissues and 18 PVTT) were studied by Northern blot analysis. The levels of PD-ECGF mRNA and VEGF mRNA expression were measured by densitometric scanning of the autoradiographs, and they were normalized to the level of expression of an internal control (glyceraldehyde-phosphate dehydrogenase) mRNA. Results: The expression rates of PD-ECGF mRNA in PVTT, HCC and nontumorous liver tissues were 77.8% (14/18), 67.9% (19/28) and 35.7% (10/28), being 88.9% (16/18), 75.0% (21/28) and 17.9% (5/28) respectively for VEGF mRNA. The expressions of PD-ECGF mRNA and VEGF mRNA were higher in HCC with PVTT than when PVTT was absent (P < 0.05). The PVTT was more often seen in patients with positive expression of both PD-ECGF mRNA and VEGF mRNA in HCC than in patients who were positive for only one of these factors or negative for both (P < 0.05). Conclusion: Both PD-ECGF and VEGF correlated well with the formation of PVTT of HCC. Received: 20 June 1999 / Accepted: 20 July 1999     

Involvement of the vascular endothelial growth factor receptor-1 in murine hepatocellular carcinoma development

BACKGROUND/AIMS: The role of the vascular endothelial growth factor receptor-1 (VEGFR-1) in hepatocellular carcinoma (HCC) development has not been elucidated yet. The aim of this study was to examine the role of VEGFR-1 in VEGF-mediated HCC development and angiogenesis as compared to that of VEGFR-2. METHODS: We examined the effects of VEGFR-1, and VEGFR-2 neutralizing monoclonal antibodies (R-1mAb and R-2mAb, respectively) on VEGF-mediated HCC development both in an allograft and orthotopic models. RESULTS: In the allograft model, both R-1mAb and R-2mAb significantly attenuated the VEGF-mediated tumor development in a dose dependent manner with associated reduction of angiogenesis in the tumor. The inhibitory effect of R-2mAb was more potent than that of R-1mAb, and the combination treatment with both mAbs almost completely attenuated VEGF-mediated HCC development. Immunohistochemical analysis revealed that apoptosis increased markedly in the tumor. Furthermore, these inhibitory effects with both mAbs were achieved even on established tumors and orthotopic transplantation. CONCLUSIONS: In addition to VEGFR-2, VEGFR-1 also lies on the signal transduction pathway by which VEGF augments HCC development and angiogenesis not only at the initial stage but also in the established tumor.     

Association between vascular endothelial growth factor gene polymorphisms and survival in hepatocellular carcinoma patients

Vascular endothelial growth factor (VEGF) plays an important role in angiogenesis and progression of tumor, including hepatocellular carcinoma (HCC), and elevated VEGF levels in serum and tissues have been known to be related with poor prognosis in patients with HCC. However, the effect of such polymorphisms of the VEGF gene on HCC prognosis has not been elucidated. In the present study, we investigated the association between VEGF gene polymorphisms and HCC patient prognosis. The study involved 416 HCC patients treated at the National Cancer Center Korea from November 2000 to December 2005. The median patient age was 57 years, and 328 patients (78.8%) were men. A total of 19 polymorphisms were analyzed, and the hazard ratios (HRs) for genotypes and haplotypes were determined in terms of risk for overall survival using Cox proportional hazard regression analysis. Of the 19 alleles, 7 showed no heterozygous allele. PHASE analysis identified a total of 36 haplotypes. The -2578 to -1498 region of the VEGF gene showed a strong linkage disequilibrium (correlation coefficient, r(2) = 0.91; Lewontin's D', D' = 0.982). The adjusted HRs were 0.67 [95% confidence interval (CI), 0.46 to 0.99] for -634CC genotype carriers and 0.57 (95% CI, 0.36 to 0.92) for homozygous haplotype 1 (Ht1: CCGAGCCC at -2578/-1203/-1190/-1179/-1154/-634/-7/+936) carriers compared with noncarriers. CONCLUSION: These findings suggest that VEGF polymorphisms may be significant prognostic indicators for HCC patients.     

Expression of plasma vascular endothelial growth factor in patients with hepatocellular carcinoma and effect of transcatheter arterial chemoembolization therapy on plasma vascular endothelial growth factor level

AIM: To investigate the expression level of plasma vascular endothelial growth factor (P-VEGF) in patients with hepatocellular carcinoma (HCC) and its relationship with the clinicopathologic characteristics, and to examine the changes of P-VEGF in the course of transcatheter arterial chemoembolization (TACE). METHODS: Peripheral blood samples were taken from 45 HCC patients before and 1, 3, 7 d, and 1 mo after TACE. Plasma VEGF level was measured with the quantitative sandwich enzyme-linked immunosorbent assay (ELISA). Twenty patients with benign liver lesions and 17 healthy control subjects were also included in this study. RESULTS: Plasma VEGF levels in HCC patients were significantly elevated as compared to those in patients with benign liver lesions (P = 0.006) and in the normal controls (P = 0.003). Significant differences were observed when P-VEGF was categorized by tumor size (P = 0.006), portal vein thrombosis (P = 0.011), distant metastasis (P = 0.017), arterial-portal vein shunting (P = 0.026), and International Union Against Cancer (UICC) TNM stage (P = 0.044). There was no correlation between plasma level of VEGF and the level of alpha fetoprotein (alpha-FP) (r = 0.068, P = 0.658) and weakly correlated with the number of platelets (r = 0.312, P = 0.038). P-VEGF levels increased significantly and reached the peak value on the first day after TACE, and then decreased gradually. The change rate of P-VEGF concentration (one month post-TACE/pre-TACEX100%) was correlated with the retention rate of lipiodol oil (r s = 0.494, P = 0.001) and the tumor volume change (r s = 0.340, P = 0.034). The patients who achieved a partial or complete response to TACE therapy showed significantly less pre-treatment P-VEGF than those nonresponders (P = 0.025). A high pre-therapeutic P-VEGF level was associated with poor response to treatment (P = 0.018). CONCLUSION: A high pre-treatment P-VEGF level is a useful marker for tumor progression, especially for vascular invasion. TACE increases the level of P-VEGF only temporarily which may be associated with tumor ischemia. P-VEGF may be useful in predicting treatment response, monitoring disease course after TACE and judging the effect of different TACE regimens.     

肝癌化疗栓塞术后残癌组织微血管密度及血管内皮细胞生长因子表达的研究

目的 研究肝癌经导管动脉内化疗栓塞(transcatheter arterial chemoembolization,TACE)术后残癌组织微血管密度(microvessel density,MVD)、血管内皮细胞生长因子(vascular endothelial growth factor,VEGF)和成纤维细胞生长因子(basic fibroblast growth factor,BFGF)的表达变化。方法 对40例原发性肝癌患者的手术切除标本作免疫组织化学染色,检测肿瘤组织的MVD和肿瘤细胞VEGF、BFGF的表达。40例患者中20例术前接受l~7次不等的TACE治疗(TACE组),另20例为直接手术患者,术前未进行任何其它治疗(直接手术组)。结果TACE组平均MVD为130.51±75.5,直接手术组为152.35±58.80,两组差异无显著性(t=－1.021．P=0.341)。VEGF平均染色强度TACE组为645.60±543.27,直接手术组为158.28±188.48,前者强于后者(t=281,P＜0.001)。BFGF阳性率TACE组和直接手术组分别为35%和40%,差别无显著性(x~2=0.107,P=0.744)。结论TACE术后残癌组织只有丰富的肿瘤血供,残存肿瘤细胞VEGF表达增强,可能在TACE术后肿瘤血供的重建中起重要作用。     

Dual role of vascular endothelial growth factor in experimental obliterative bronchiolitis

Obliterative bronchiolitis (OB) is the major limitation for long-term survival of lung allograft recipients. We investigated the role of vascular endothelial growth factor (VEGF) in the development of OB in rat tracheal allografts. In nonimmunosuppressed allografts, VEGF mRNA and protein expression vanished in the epithelium and increased in smooth muscle cells and mononuclear inflammatory cells with progressive loss of epithelium and airway occlusion compared with syngeneic grafts. Intragraft VEGF overexpression by adenoviral transfer of a mouse VEGF(164) gene increased early epithelial cell proliferation and regeneration but increased microvascular remodeling and lymphangiogenesis and luminal occlusion by more than 50% compared with AdlacZ-treated allografts. Although VEGF receptor inhibition decreased early epithelial regeneration in noninfected allografts, it reduced microvascular remodeling, lymphangiogenesis, intragraft traffic of CD4(+) and CD8(+) T cells, and the degree of luminal occlusion. Simultaneous VEGF gene transfer and platelet-derived growth factor receptor inhibition with imatinib preserved respiratory epithelium and totally prevented luminal occlusion. In conclusion, our findings indicate that VEGF has a dual role in transplant OB. Our results suggest that VEGF may protect epithelial integrity. On the other hand, VEGF may enhance luminal occlusion by increasing the recruitment of mononuclear inflammatory cells with platelet-derived growth factor acting as a final effector molecule in this process.