Tumor angiogenesis and its clinical significance in pediatric malignant liver tumor

AIM: To investigate the expression of vascular endothelial growth factor (VEGF) and microvascular density (MVD) count in pediatric malignant liver tumor and their clinical significances. METHODS: Fourteen children with malignant liver tumors including seven hepatocellular carcinomas (HCCs), five hepatoblastomas, one malignant mesenchymoma and one rhabdomyosarcoma were studied. Twelve adult HCC samples served as control group. All samples were examined with streptavidin-biotin peroxidase (SP) immunohistochemical staining for VEGF expression and MVD count. RESULTS: VEGF positive expression in all pediatric malignant liver tumors was significantly higher than that in adult HCC (0.4971±0.14 vs0.4027±0.03, P<0.05). VEGF expression in pediatric HCC group was also markedly higher than that in adult HCC group (0.5665±0.10 vs0.4027±0.03, P<0.01) and pediatric non-HCC group (0.5665±0.10 vs 0.4276±0.15, P<0.05). The mean value of MVD in pediatric malignant liver tumors was significantly higher than that in adult HCC (33.66±12.24 vs 26.52±4.38, P<0.05). Furthermore, MVD in pediatric HCC group was significantly higher compared to that in adult HCC group (36.94±9.28 vs 26.52±4.38, P<0.05), but there was no significant difference compared to the pediatric non-HCC group (36.94±9.28 vs 30.37±14.61, P>0.05). All 7 children in HCC group died within 2 years, whereas the prognosis in pediatric non-HCC group was better, in which two patients survived more than 5 years. CONCLUSION: Children with malignant liver tumors, especially with HCC, may have extensive angiogenesis that induces a rapid tumor growth and leads to a poor prognosis.     

Decreased ratio of circulatory vascular endothelial growth factor to endostatin in patients with systemic sclerosis--association with pulmonary involvement

OBJECTIVE: Vascular endothelial growth factor (VEGF) and endostatin appear to be involved in development of systemic sclerosis (SSc). We undertook this study to determine ratios of serum concentrations of VEGF to endostatin in SSc patients, healthy controls, assessments between cytokines, and lung-diffusing capacity (DLCO) as lung injury measurements related to interstitial lung disease (ILD). MATERIALS AND METHODS: Serum VEGF and endostatin levels were measured with ELISA in 28 SSc patients (16 with lcSSc) and 20-matched healthy volunteers, evaluating correlation and balance. DLCO was corrected for hemoglobin, alveolar volume, and determined with a single breath technique. RESULTS: SSc serum concentrations (median; range) of endostatin were higher than controls (107.2; 13.6-261.2 vs. 77.8; 18.0-110.4 ng/ml, p < 0.05); VEGF levels did not differ (151.2; 4.5-836.4 vs. 286.4; 23.7-708.5 pg/ml, p < 0.05). Ratios of VEGF to endostatin were 2.6 and 3.6 times lower (p < 0.05) in SSc and dcSSc in comparison to healthy subjects. There were significant negative correlations between VEGF, endostatin in SSc (r = -0.51), and controls (r = -0.57). SSc with ILD (n = 20) had similar concentrations of VEGF, endostatin, and ratios of VEGF to endostatin compared to SSc alone. No correlations were seen between DLCO, VEGF, endostatin and their ratios in the whole SSc group. Negative correlations were noted between DLCO and VEGF (r = -0.82), with DLCO and the ratio of VEGF to endostatin (-0.62) in lcSSc with ILD (n = 10). CONCLUSION: Decreased ratios of VEGF to endostatin may reflect imbalances between serum angiogenic, and anti-angiogenic activity in SSc, explaining impaired neoangiogenesis.     

Serum endostatin levels are elevated and correlate with serum vascular endothelial growth factor levels in patients with pituitary adenomas

Endostatin, a cleaved fragment of collagen XVIII, is a potent endogenous angiogenesis inhibitor. Elevated serum endostatin levels have been recently reported in patients with various types of neoplasms. The purpose of our study was to evaluate serum concentrations of endostatin in patients harbouring various pituitary adenoma types and to examine the relationship of serum endostatin levels to circulating vascular endothelial growth factor (VEGF) levels. Preoperative serum endostatin and VEGF concentrations were measured using competitive enzyme immunoassays in 71 patients with pituitary adenomas (20 somatotropinomas, 3 corticotropinomas, 6 prolactinomas and 42 clinically nonfunctioning pituitary adenomas – CNFPAs) and compared with levels from age-matched controls. In 35 patients postoperative immunohistochemical investigations were performed. Serum endostatin concentrations were significantly higher in all pituitary adenoma types, except for prolactinomas (somatotropinomas: 124 ± 16; p < 0.02, corticotropinomas: 157 ± 42; p < 0.02, prolactinomas: 141 ± 37; p > 0.05, CNFPAs: 169 ± 11 ng/ml; p < 0.000005 vs 73 ± 10 ng/ml in controls). There was a significant positive correlation between endostatin and VEGF serum levels in patients with pituitary adenomas (r = +0.322; p = 0.006). In the control group a significant negative correlation xbetween circulating endostatin and VEGF was found (r = −0.653; p = 0.00975). The simultaneous elevation of endostatin and VEGF may attenuate the pro-angiogenic action of VEGF and be responsible for rather weak neovascularization of pituitary adenomas. Prospective studies are required to assess the usefulness of circulating endostatin and VEGF as markers of progression or recurrence of pituitary tumors.     

Recurrence or metastasis of HCC:predictors, early detection and experimental antiangiogenic therapy

AIM To investigate the predictors for recurrence or metastasis of HCC, and to evaluate the effect of antiangiogenic therapy on the growth of transplantable human HCC in nude mice. METHODS RT-PCR was used to measure the expression of matrix metalloproteinase-9 (MMP-9) and vascular endothelial growth factor (VEGF) in 56 pairs of nontumorous liver and tumor samples. Sixty blood samples from human HCC were examined by nested RT-PCR to find out AFP mRNA. Recombinant human endostatin and polyclonal antibody against VEGF were administered to treat human HCC transplanted in nude mice. RESULTS Thirty of 56 HCC samples showed stronger expression of MMP-9 in tumorous tissues than in nontumorous tissues. Fifteen of the 26 patients with relative expression level of MMP-9 more than 0.34 developed tumor recurrence or metastasis, whereas only 7 of 30 patients with relative expression level less than 0.34 developed tumor recurrence (P＜0.05).There was no significant difference in the relative expression level of VEGF between patients with postoperative recurrence or metastasis and those without recurrence. AFP mRNA was detectable in 53.3% of patients with HCC. The sensitivity and specificity of AFP mRNA as a marker to detect hematogenous dissemination of HCC cells was 81.8% and 84.4%, respectively. Recombinant human endostatin and polyclonal antibody against VEGF inhibited the growth of transplantable HCC in nude mice by 52.2% and 45.7%, respectively.CONCLUSION MMP-9 expression in HCC correlates with the postoperative recurrence or metastasis of HCC. Patients with high level of MMP-9 expression in HCC are susceptible to metastasis. AFP mRNA could serve as an indicator of hematogenous spreading of HCC cells in circulation and a predictor of recurrence or metastasis of HCC. Antiangiogenesis may be an adjuvant therapy for HCC.     

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     

Correlations between Serum Levels of Vascular Endothelial Growth Factor and Endostatin with Clinical Pathological Characteristics of Patients with Gastrointestinal Cancers

Background/Aims: To study the relationship between serum levels of vascular endothelial growth factor (VEGF), endostatin and pathological characteristics of patients with gastrointestinal cancers. Methodology: Serum VEGF and endostatin levels were measured by enzyme-linked immunoassay in 60 patients with gastric carcinoma, 55 with hepatocellular carcinoma and 58 with colorectal carcinoma before and after surgical resection. Results: The preoperative levels of VEGF and endostatin in patients with gastrointestinal cancers were significantly higher than those in control groups respectively. They were closely related to the grades of cell differentiation, size of primary tumors, depth of invasion, metastasis and pathological stage, but not to tumor site and gender. The postoperative VEGF levels were significantly lower than those of preoperation, while postoperative endostatin levels were significantly higher than those of preoperation. Conclusions: Preoperative serum VEGF and endostatin levels may be used for evaluating the biological behavior, invasion and metastasis of gastric, hepatocellular and colorectal carcinoma. Elevated serum endostatin levels were found in the patients with gastric cancer, HCC and colorectal cancer after surgery. Gastrointestinal tumor itself may be not the main source of endostatin.     

胃癌患者VEGF和Endostatin的表达及其与临床病理特征的关系

目的探讨胃癌患者手术前后血清血管内皮生长因子（VEGF）和Endostatin的动态变化规律及其与临床病理特征的关系。方法采用ELISA法检测胃癌患者（胃癌组）术前及术后2周血清VEGF和Endostatin水平,并与慢性胃炎患者（胃炎组）和健康对照者（对照组）进行比较。结果①胃癌组术前血清VEGF、Endostatin水平均显著高于胃炎组及对照组（P均〈0．01）。②胃癌组术前血清VEGF、Endostatin水平与细胞分化程度、肿瘤大小、浸润深度、淋巴结转移、远处转移及临床分期密切相关（P均〈0．05）,与性别、肿瘤部位等因素无关（P〉0．05）。③胃癌组术后2周血清VEGF水平较术前显著下降,而血清Endostatin水平较术前升高（P均〈0．01）。结论血清VEGF和Endostatin水平是评价胃癌恶性行为、预测浸润和转移程度的有效指标。     

慢性乙肝病毒感染者血清血管内皮生长因子的研究

目的:检测慢性乙型肝炎病毒感染患者血清中血管内皮生长因子(VEGF)的水平,探讨其临床意义.方法:采用双抗体夹心ELISA法对50例肝细胞癌、40例乙型肝炎肝硬化、36例乙型肝炎肝纤维化、40例慢性乙型肝炎患者血清中VEGF进行检测,并以43例健康者作为对照.同时采用全自动生化分析仪检测所有人员的肝功能常规指标.结果:慢性乙型肝炎、肝纤维化、肝硬化、肝细胞癌组患者血清VEGF浓度明显高于正常对照组(P＜0.01,P＜0.05,P＜0.05,P＜0.05),同时四组患者之间比较,差异均有统计学意义(P＜0.05).四组患者血清VEGF水平与肝功能指标AST、ALT无相关性,与GGT成正相关(r=0.337,P＜0.05).结论:VEGF与慢性乙型肝炎病毒感染者病情密切相关,可作为病情发展动态监测的指标.VEGF与GGT联合检测,可显著提高肝细胞癌的检出率.     

Levels of angiogenic proteins in plasma and platelets are not different between patients with hepatitis B/C-related cirrhosis and patients with cirrhosis and hepatocellular carcinoma

Increasing evidence suggests that levels of angiogenic proteins within blood platelets change at the earliest stages of cancer development and may thus provide a promising diagnostic and prognostic tool. Patients with cirrhosis have increased risk of developing hepatocellular carcinoma (HCC). We aimed to study whether development of HCC in hepatitis-related cirrhosis results in changes in platelet levels of angiogenic proteins. We studied the intraplatelet levels of vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), platelet-derived growth factor (PDGF), hepatocyte growth factor (HGF), endostatin, platelet factor 4 (PF4) and thrombospondin type 1 (TSP-1) in 38 consecutive patients with hepatitis B- or C-related liver cirrhosis with or without HCC in addition to plasma levels of the same proteins. Twenty healthy volunteers were included to establish reference values for the various tests. Intraplatelet levels of VEGF, bFGF, HGF and endostatin were significantly higher in patients compared to controls. Intraplatelet levels of PDGF, PF4 and TSP-1 were comparable between patients and controls. Plasma levels of VEGF, bFGF and endostatin were comparable between patients and controls. Plasma levels of PDGF, PF4 and TSP-1 were decreased in patients, but this difference disappeared when levels were corrected for platelet count. Intraplatelet and plasma levels of all proteins assessed were comparable between patients with and without HCC. In conclusion, the intraplatelet levels of some angiogenic proteins are elevated in cirrhosis, but do not discriminate between patients with and without HCC. Thus, intraplatelet levels of angiogenic proteins do not seem useful as diagnostic or prognostic biomarker of HCC in cirrhotic patients.     

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.     

长期吸烟老年人检测血清血管内皮生长因子和内皮抑素对肺癌早期诊断的临床意义

目的 探讨长期吸烟老年人血清血管内皮生长因子(vascular endothelial growth factor,VEGF)和内皮抑素(endostatin)水平的变化及其临床意义.方法 测定52例长期吸烟老年人血清VEGF和endostatin水平,其中伴肺癌组32例,不伴肺癌组20例,20例不吸烟健康老年人为正常对照组.结果 (1)伴肺癌组血清VEGF水平明显高于不伴肺癌组(t=13.681,P＜0.01)和对照组(t=9.372,P＜0.01).不伴肺癌组高于对照组(t=5.250,P＜0.05);(2)伴肺癌组血清endostatin水平明显高于对照组(t=5.332,P＜0.01),但与不伴肺癌组比较,差异无统计学意义(t=0.814,P＞0.05).不伴肺癌组与对照组比较,差异有统计学意义(t=3.700,P＜0.05);(3)伴肺癌组血清endostatin/VEGF比值明显低于不伴肺癌组(t=6.270,P＜0.01)和对照组(t=7.138,P＜0.01),但不伴肺癌组与对照组比较,差异无统计学意义(t=1.022,P＞0.05).结论 长期吸烟老年人应定期检测血清VEGF、endostatin水平及endostatin/VEGF比值,endostatin/VEGF比值可能是长期吸烟老年人早期诊断肺癌的指标之一.

Abstract：

Objective To explore the changes and clinical significances of serum vascular endothelial growth factor (VEGF) and endostatin concentrations for early detection of lung cancer in elderly long-term smokers. Methods Serum VEGF and endostatin concentrations were determined in 52 elderly long-term smokers and 20 elderly non-smokers by enzyme linked immunoabsent assay (ELISA) or competitive enzyme immunoassay. The 52 elderly long-term smokers were divided into lung cancer group (n = 32) and non-lung cancer group (n = 20). Results The concentration of serum VEGF was markedly higher in lung cancer group [(15. 7±8. 0) ng/L] than in non-lung cancer group and normal control group (t= 13. 681, t= 9. 372, respectively, both P＜0. 01). And the level of serum VEGF was significantly higher in non-lung cancer group than in normal control group (t=5. 250, P＜0. 05). The level of serum endostatin was significantly higher in elderly long-term smokers with or without lung cancer than in normal control group (t=5. 332, t=3. 700, respectively, P＜0. 01 and P＜0.05). But there was no statistic difference between non-lung cancer group and lung cancer group (t = 0. 814, P＞ 0.05 ). Notably, the endostatin/VEGF ratio was lower in lung cancer group than in non-lung cancer group and normal control group (t= 6. 270, t= 7. 138, respectively, both P＜0.01), while there was no significant difference between non-lung cancer group and normal control group (t= 1. 022, P＞0.05). Conclusions These findings suggest that the periodic detection of serum VEGF and endostatin and endostatin/VEGF ratio, especially endostatin/VEGF ratio, is of clinical importance and can be used as an early diagnostic marker of lung cancer in elderly long-term smokers.     

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     

Decreased level of vascular endothelial growth factor in bronchoalveolar lavage fluid of normal smokers and patients with pulmonary fibrosis

Vascular endothelial growth factor (VEGF) plays multifunctional roles in both the development of vasculature and the maintenance of vascular function. A decrease in VEGF reduces angiogenesis and induces apoptosis of vascular endothelial cells. Inhibition of the VEGF receptor causes endothelial cell apoptosis and emphysema. We postulated that VEGF concentrations might be reduced in patients with chronic lung diseases. The level of VEGF was evaluated by enzyme-liked immunosorbent assay in bronchoalveolar lavage fluid (BALF) from normal smokers, nonsmoking volunteers, idiopathic pulmonary fibrosis, pulmonary fibrosis associated with a connective tissue disease, and sarcoidosis. The isoforms of VEGF in BALF were determined by high-performance liquid chromatography. VEGF in nonsmoking volunteers was detectable at a high concentration. In contrast, VEGF in most of the normal smokers was below the detectable limit. The VEGF found in nonsmoking volunteers BALF was VEGF165. VEGF was significantly decreased in idiopathic pulmonary fibrosis, pulmonary fibrosis associated with a connective tissue disease, and sarcoidosis compared with nonsmoking volunteers. The smoking patients showed a further decrease in VEGF. These data suggest that the decrease in VEGF in smokers and patients with chronic lung diseases may reduce angiogenesis and induce apoptosis of vascular endothelial cells.     

Circulating angiogenesis inhibitor endostatin and positive endothelial growth regulators in patients with systemic lupus erythematosus

Serum concentrations of three angiogenic cytokines: vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), interleukin-18 (IL-18) and antiangiogenic factor endostatin in the serum of 52 patients with systemic lupus erythematosus (SLE) and 20 healthy subjects were investigated. The possible association between serum levels of these proteins and SLE activity as well as correlation between the concentrations of angiogenic cytokines and the level of endostatin was also analyzed. VEGF and IL-18 were detectable in all SLE patients and healthy control group. bFGF was measurable in 71.2% of patients with SLE and 65% of healthy persons. Endostatin was detectable in 94.2% of SLE patients and 95% of normal subjects. The serum levels of endostatin and bFGF were not significantly different in SLE and healthy control (P > 0.05). The median concentration of VEGF was higher in active SLE (238.4 pg/ml) than in inactive disease (118.1 pg/ml, P < 0.05) or in control group (133.5 pg/ml, P < 0.04). The median serum level of IL-18 was higher in the SLE patients (595.2 pg/ml) than in the control group (252.7 pg/ml) (P < 0.001). The correlations between the levels of angiogenic cytokines and endostatin with clinical features, laboratory abnormalities and also with the type of treatment were analysed. We found a positive correlation between VEGF serum concentration and SLE activity according to SLAM score (p = 0.275, P < 0.05). The significant positive correlation was also found between IL-18 and endostatin (p = 0.289, P < 0.04). In contrast, the correlation between bFGF and endostatin was significantly negative (p = - 0.299, P < 0.04). In conclusion, serum levels of the angiogenic and antiangiogenic factors may play an important role in SLE pathogenesis.