儿童急性白血病骨髓细胞中血管内皮生长因子及其受体的表达

  目的 探讨血管内皮生长因子（VEGF）及其受体（VEGFR）在儿童急性白血病（AL）患者骨髓中的表达,分析其在化疗前后的变化。方法 采用免疫组化S-P法检测53例AL患儿治疗前后以及对照组骨髓中VEGF／VEGFR（包括Flt-1和KDR两种）变化,分析其与临床特征的关系。结果 VEGF,Flt-1,KDR在AL患儿骨髓中表达水平高于对照组。VEGF,Flt-1,KDR的表达于化疗达完全缓解（CR）后下调;化疗后未获得CR患儿VEGF,Flt-1,KDR的表达在化疗前后差异无统计学意义。骨髓中VEGF,Flt-1,KDR的表达水平在不同年龄、性别、有无髓外浸润间差异无统计学意义。结论 VEGF,Flt-1,KDR在儿童AL中呈高表达,化疗后表达明显降低,说明VEGF可能作为评价儿童AL化疗反应的指标。     

血管内皮细胞生长因子影响难治性急性髓系白血病发生发展的作用研究

背景和目的:难治性白血病的发生发展机制非常复杂,近年来发现白血病患者骨髓过度表达血管内皮细胞生长因子(vascularendothelialgrowthfactor,VEGF),但VEGF如何影响难治性白血病尚未明确。本研究探讨高表达VEGF对人急性髓系白血病细胞株HL-60增殖及三尖杉酯碱诱导HL-60细胞凋亡影响;观察难治性急性髓系白血病(acutemyeloidleukemia,AML)中VEGF蛋白表达与疾病发展的相关性。方法:采用脂质体转染VEGF165cDNA入HL-60细胞,通过RT-PCR及ELISA方法鉴定转染克隆HL-60/VEGF165细胞中VEGFmRNA及蛋白的表达,MTT法、集落形成实验比较HL-60/VEGF165及转染pcDNA3.1-neo空载体的HL-60/neo细胞增殖活性,流式细胞仪观察三尖杉酯碱诱导的细胞凋亡。用ELISA法检测难治性与非难治性AML患者血浆中VEGF蛋白浓度。结果:HL-60/VEGF165细胞培养上清中VEGF蛋白浓度为(399.07±12.45)ng/L,高于HL-60/neo细胞(184.45±10.53)ng/L(P<0.01)。HL-60/VEGF165细胞与HL-60/neo细胞相比生长速度明显加快,集落形成能力明显增加,集落数分别为(157.00±17.00)/500细胞和(110.00±12.90)/500细胞(P<0.05);而细胞凋亡率减少,分别为(3.18±0.33)%和(6.61±0.50)%,三尖杉酯碱诱导HL-60/VEGF165细胞凋亡率低于HL-60/neo细胞。难治性AML患者血浆中VE     

Increased expression of vascular endothelial growth factor (VEGF) in bone marrow of patients with myeloproliferative disorders (MPD)

Angiogenesis is a multistep process of the development of capillaries from established blood vessels. Angiogenesis probably plays a significant role in the development and progression of hematopoietic malignancies. Higher microvascular density and increased serum levels of proangiogenic factors such as vascular endothelial growth factor (VEGF) or basic fibroblasts growth factor (bFGF) have been reported in acute and chronic leukemias, myeloproliferative and myelodysplastic disorders, multiple myeloma and lymphomas. The microvessel density of bone marrow stroma in myeloproliferative disorders is increased and VEGF is considered as the most potent endothelial cell activator. The purpose of this study was to examine the expression of VEGF in bone marrow of patients with MPD. 60 paraffinembedded bone marrow core biopsy specimens from newly diagnosed patients with MPD were evaluated. In addition 10 bone marrow core biopsy specimens from adult patients without evidence of malignancy were used as controls. Bone marrow sections were stained immunohistochemically for VEGF (PharMingen, USA). Obtained data show that MPD are associated with an increased expression of VEGF in the bone marrow. This observation support previous studies suggesting that angiogenesis may play a role in the pathophysiology of myeloproliferative disorders. Clinical significance of this phenomenon needs further investigation however thus provides rationale for use of angiogenesis inhibitors in MPD therapy.     

前列腺癌细胞株VEGF及其受体KDR,bFGF及其受体FGFR2的表达及意义

目的:探讨人前列腺癌细胞株血管内皮细胞生长因子(VEGF)及其受体(KDR),碱性成纤维细胞生长因子(bFGF)及其受体(FGFR2)的表达,进一步阐明前列腺癌细胞中VEGF和bFGF的自分泌机制。方法:以小鼠成纤维细胞系L929作为对照,选取三种前列腺癌细胞株(PC3、LNcap和DU145),采用免疫组化染色、RT-PCR及Westernblot,检测VEGF及其受体KDR,bFGF及其受体FGFR2的表达。结果:三种前列腺癌细胞株(PC3、LNcap和DU145)中均有VEGF、KDR及bFGF、FGFR2的表达,但表达水平略有差别。结论:在前列腺癌的血管形成中可能存在VEGF和bFGF的自分泌机制。     

Expression of VEGF-C and its receptor VEGFR-3 in the bone marrow of patients with acute myeloid leukaemia

Vascular endothelial growth factor-C (VEGF-C) has been shown to promote survival and resistance to chemotherapy of AML-cells in vitro. We investigated the expression of VEGF-C/VEGFR-3 in the bone marrow and pretherapeutic plasma levels of VEGF-C in patients with newly diagnosed AML. Expression of VEGF-C/VEGFR-3 was significantly higher in AML patients than in controls, while circulating levels did not differ. However, VEGF-C/VEGFR-3 expression was not able to predict clinical outcome. In conclusion, AML is associated with an increased expression of VEGF-C/VEGFR-3. Although expression levels display no prognostic significance in our study, strategies targeting the VEGF-C/VEGFR-3-pathway might be a promising treatment approach.     

成人急性白血病患者细胞血管内皮生长因子及其受体FLT-1、KDR的表达

目的　探讨成人急性白血病 (AL )患者细胞血管内皮生长因子 (VEGF)及其受体 FL T- 1(fm s- like tyro-sine kinase)、KDR(kinase- dom ain insert containing receptor)的表达。方法　采用 RT- PCR方法检测骨髓单个核细胞 (BM MNCs) VEGF及其受体 FL T- 1、KDR m RNA的表达水平。结果　 (1)初发未治患者、骨髓缓解患者 (BMR)和正常对照者 BM MNCs VEGF m RNA阳性表达例数的差异无显著性 (P>0 .0 5 ) ,而 BM MNCs VEGF/β- actin相对表达量 ,在初发未治组显著高于 BMR组和正常对照组 (P值均 <0 .0 1) ,后两组之间的差异无显著性 (P>0 .0 5 ) ;AML组高于 AL L患者 (P<0 .0 5 )。 (2 )初发未治患者 BM MNCs FL T- 1、KDR m RNA阳性表达例数较 BMR及正常对照者高 (P值均 <0 .0 5 ) ,后两组之间的差异无显著性 (P>0 .0 5 ) ;AML组 BM MNCs KDR m RNA阳性表达例数高于 AL L组 (P<0 .0 5 ) ;应用 FL T- 1/β- actin、KDR/β- actin相对表达量分析与上述结果一致。 (3) BM MNCsVEGF的相对表达量与其受体 FL T- 1和 KDR的相对表达量呈相关性 (P值均 <0 .0 5 )。结论　 AL细胞 VEGF、FL T- 1和 KDR m RNA呈过表达 ;VEGF和 KDR m RNA表达强度 ,在 AML明显高于 AL L。应用半定量方法更能反映患者细胞 VEGF m RNA表达     

Expression of vascular endothelial growth factor (VEGF)-D and its receptor, VEGF receptor 3, as a prognostic factor in endometrial carcinoma.

PURPOSE: To evaluate the prognostic value of vascular endothelial growth factor (VEGF)-D and VEGF receptor (VEGFR)-3 in endometrial carcinoma. EXPERIMENTAL DESIGN: We assessed the levels of immunoreactivity for VEGF-D and VEGFR-3 in 71 endometrial carcinomas, 14 complex atypical endometrial hyperplasias, and 16 normal endometria by immunohistochemistry. RESULTS: VEGF-D was stained in both tumor cells and adjacent stromal cells. VEGFR-3 was stained in both tumor cells and adjacent endothelial cells. Immunoreactivity for VEGF-D in tumor cells and adjacent stromal cells became significantly stronger as lesions progressed from normal endometrium to advanced carcinoma. Similarly, immunoreactivity for VEGFR-3 in tumor cells and adjacent endothelial cells was significantly greater as lesions progressed from normal endometrium to advanced carcinoma. A strong correlation was found between high levels of VEGF-D immunoreactivity in carcinoma cells and VEGFR-3 in both carcinoma cells and adjacent endothelial cells. Similarly, high levels of VEGF-D immunoreactivity in stromal cells were significantly correlated with those of VEGFR-3 in both carcinoma cells and endothelial cells. High levels of VEGF-D in carcinoma cells and stromal cells, as well as those of VEGFR-3 in carcinoma cells and endothelial cells, were significantly related to myometrial invasion and lymph node metastasis. A strong correlation was found between poor survival and high levels of VEGF-D in both carcinoma cells and stromal cells and between poor survival and high levels of VEGFR-3 in carcinoma cells. Moreover, the high levels of VEGF-D in stromal cells and VEGFR-3 in carcinoma cells were independent prognostic factors in endometrial carcinoma. CONCLUSIONS: The presence of VEGF-D and VEGFR-3 in endometrial carcinoma may predict myometrial invasion and lymph node metastasis and may prospectively identify patients who are at increased risk for poor outcome. In addition, VEGF-D and VEGFR-3 may be promising targets for new therapeutic strategies in endometrial carcinoma.     

VEGF及其受体KDR在胃癌组织新生血管中的作用

目的探讨血管内皮生长因子VEGF及其受体KDR在胃癌新生血管形成中的作用.方法应用免疫组织化学技术,检测60例胃癌组织VEGF及KDR蛋白表达和以CD105标记的微血管密度,分析VEGF、KDR和MVD及其与肿瘤大小、肿瘤分化、浸润深度、淋巴结转移、组织学分级和预后关系.结果VEGF及KDR阳性者MVD值显著高于阴性者(t=3.85,t=3.76,P＜0.01).VEGF、KDR表达和MVD与胃癌浸润深度(x2=8.31,P＜0.01;x2=5.05,P＜0.05;t=2.24,P＜0.05)、淋巴结转移(x2=10.62,P＜0.01;x2=5.66,P＜0.05;t=5.19,P＜0.05)、组织学分级(x2=11.05,P＜0.01;x2=8.21,P＜0.01;t=2.11,P＜0.05)密切相关.VEGF及KDR表达阳性或高MVD的胃癌患者5年生存率较低(x2=5.18,P＜0.05;x2=8.94,P＜0.01;t=3.51,P＜0.01).结论VEGF及KDR与胃癌新生血管生成密切相关,对胃癌的生长和浸润转移有促进作用,VEGF及KDR和以CD105标记的MVD可作为反映胃癌生物学行为的客观指标.     

Selective inhibition of vascular endothelial growth factor (VEGF) receptor 2 (KDR/Flk-1) activity by a monoclonal anti-VEGF antibody blocks tumor growth in mice

Vascular endothelial growth factor (VEGF) is a multifunctional angiogenic growth factor that is a primary stimulant of the development and maintenance of a vascular network in embryogenesis and the vascularization of solid tumors. At the present time there are two well-characterized receptors for VEGF that are selectively expressed on endothelium. VEGF receptor 2 [VEGFR2 (KDR/Flk-1)] mediates endothelial cell mitogenesis and permeability increases, whereas the role of VEGF receptor 1 [VEGFR1 (Flt-1)] has not been clearly defined. In the present study, a monoclonal antibody, 2C3, is shown to block the interaction of VEGF with VEGFR2 but not with VEGFR1 through ELISA, receptor binding assays, and receptor activation assays. 2C3 blocks the VEGF-induced vascular permeability increase in guinea pig skin. 2C3 has potent antitumor activity, inhibiting the growth of newly injected and established human tumor xenografts in mice. These findings demonstrate the usefulness of 2C3 in dissecting the pathways that are activated by VEGF in cells that express both VEGFR1 and VEGFR2, as well as highlighting the dominant role of VEGFR2 in mediating VEGF-induced vascular permeability increase and tumor angiogenesis.     

Overexpression of vascular endothelial growth factor 165 (VEGF165) protects cardiomyocytes against doxorubicin-induced apoptosis

Doxorubicin (Dox) has been employed in cancer chemotherapy for a few decades. However its clinical application became restricted because of dose-dependent cardiomyopathy. Recent studies suggest that Dox-induced cardiomyocyte apoptosis is a primary cause of cardiac damage. Vascular endothelial growth factor (VEGF) is a major factor for endothelial cell survival and angiogenesis. We have previously shown that VEGF165 significantly attenuates oxidative stress-induced cardiomyocytes apoptosis. We hypothesized that VEGF165 will protect the cardiomyocytes from Dox-induced apoptosis. to evaluate our hypothesis, we transfected cardiomyocytes H9c2 with adenovirus expressing VEGF165 24 hours before the cells were challenged with Dox at a concentration of 2 μm. Cardiomyocyte apoptosis was evaluated by Annexin V-FITC staining and by Western blot detection of cleaved caspase-3. The hypothesis was confirmed, and the protective mechanisms involve the inhibition of death receptor-mediated apoptosis and up-regulation of the prosurvival Akt/Nf-κb/bcl-2 signaling pathway.     

Use of soluble recombinant decoy receptor vascular endothelial growth factor trap (VEGF Trap) to inhibit vascular endothelial growth factor activity

Primary tumors and metastases require blood vessel formation to support their continued growth and eventual metastasis. They use existing vasculature during initial growth but eventually must orchestrate the development and maintenance of new vessels--a process termed angiogenesis--to grow beyond a small size and spread. Angiogenesis is regulated by a number of soluble factors, the relative proportions of which can exacerbate or inhibit the process. Vascular endothelial growth factor (VEGF) is a potent stimulator of angiogenesis, produced by the majority of human solid tumors. Inhibitors of VEGF might have an impact on the growth and metastasis of these cancers. The relevance of this strategy to the treatment of colorectal cancer was first successfully demonstrated in human clinical trials using a monoclonal antibody against VEGF. A potent antiangiogenic soluble recombinant decoy, VEGF Trap is a protein constructed from VEGF receptor-binding domains linked to an immunoglobulin G(1) constant region. It possesses an affinity for VEGF that is significantly higher than that of the monoclonal antibody. VEGF Trap has demonstrated marked efficacy in halting angiogenesis and shrinking tumors in preclinical animal models and is currently being studied in phase I clinical trials in humans with advanced solid malignancies.     

Axitinib—a selective inhibitor of the vascular endothelial growth factor (VEGF) receptor

An improved understanding of the molecular biology involved in many solid tumors has led to the development of novel targeted agents. Axitinib is a potent and selective inhibitor of vascular endothelial growth factor (VEGF) receptor tyrosine kinases 1, 2, and 3. This review presents preclinical and clinical data available for axitinib, including findings from key phase II clinical trials in a wide variety of tumors including melanomas and renal, pancreatic, thyroid, breast, lung, and colorectal carcinomas. The differences between axitinib and other VEGFR inhibitors are explored and details of the possible use of blood pressure elevation and erythropoietin blood levels as predictive markers of VEGF/VEGFR pathway inhibition are outlined. Ongoing Phase III studies in pancreatic and metastatic renal cell carcinoma should help to determine the optimum utilization of these agents at the appropriate stage of disease.     

Soluble vascular endothelial growth factor receptor 1, and not receptor 2, is an independent prognostic factor in acute myeloid leukemia and myelodysplastic syndromes

BACKGROUND: Vascular endothelial growth factor (VEGF) and its receptors (VEGFRs) are major regulators of angiogenesis, which plays a key role in the growth and dissemination of solid tumors and hematologic neoplasms. METHODS: The authors measured the plasma concentrations of soluble VEGFR1 (sVEGFR1) and sVEGFR2 in 133 patients with acute myeloid leukemia (AML) and in 80 patients with myelodysplastic syndromes (MDS) at the time of initial presentation and compared clinical behaviors. RESULTS: A reverse correlation was observed between plasma sVEGFR1 levels and the rate of complete remission (CR) in patients with AML, but not in patients with MDS. In contrast, increased plasma levels of sVEGFR2 were correlated with a lower CR rate in patients with MDS, but not in patients with AML. Cox regression model analysis demonstrated that plasma levels of sVEGFR1, but not sVEGFR2, were independent prognostic factors in both patients with AML and patients with MDS. CONCLUSIONS: The findings suggest that different mechanisms are involved in the pathophysiology of AML and MDS. The concentration of sVEGFR1 and sVEGFR2 in plasma should be considered a significant factor in guiding antiangiogenic therapy for AML and MDS. They may play a role in the pharmacodynamics of therapeutic agents that are supposed to bind directly to these receptors.     

The vascular endothelial growth factor receptor (VEGFR-1) supports growth and survival of human breast carcinoma

Vascular endothelial growth factor receptor 1 (VEGFR-1) is present on endothelial cells and subsets of human tumor cells, raising the hypothesis that angiogenic factors may promote tumor growth both by inducing angiogenesis and directly signaling through activation of VEGFR-1 on tumor cells. Here, we report that VEGFR-1 is expressed on a panel of 16 human breast tumor cell lines, and the vasculature and the tumor cell compartment of a subset of breast carcinoma lesions, and that selective signaling through VEGFR-1 on breast cancer cells supports tumor growth through downstream activation of the p44/42 mitogen-activated protein kinase (MAPK) or Akt pathways. Ligand-stimulated proliferation of breast tumor cells was inhibited by specific blockade with an anti-VEGFR-1 neutralizing monoclonal antibody. Treatment with anti-VEGFR-1 mAb significantly suppressed the growth of DU4475, MCF-7, BT-474 and MDA-MB-231 breast xenografts in athymic mice. Histological examination of anti-VEGFR-1 mAb treated tumor xenografts showed a significant reduction of activation of the p44/42 MAPK or Akt pathways in tumor cells resulting in an increase in tumor cell apoptosis. Importantly, cotreatment with mAbs targeting human VEGFR-1 on tumor cells and murine VEGFR-1 on vasculature led to more potent growth inhibition of breast tumor xenografts. The results suggest that VEGF receptors may not only modulate angiogenesis, but also directly influence the growth of VEGF receptor expressing tumors.     

Plasma vascular endothelial growth factor levels have prognostic significance in patients with acute myeloid leukemia but not in patients with myelodysplastic syndromes

BACKGROUND: Vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) are positive regulators of angiogenesis. Increased levels in urine, serum, plasma, or malignant tissue have been associated with an adverse prognosis in patients with solid tumors. METHODS: The authors used an enzyme-linked immunosorbent assay to measure VEGF and bFGF levels in plasma samples from 99 patients with previously untreated myelodysplastic syndromes (MDS) (n = 41 patients; 42%) or acute myeloid leukemia (AML) (n = 58 patients; 58%) and compared the results with the results from a group of normal control participants. RESULTS: Increased expression levels of VEGF and bFGF were found in the plasma from patients with AML and MDS (P < 0.01) compared with the levels found in the control group. Plasma levels of VEGF in patients with AML or MDS were similar (median, 30.63 pg/mL and 34.41 pg/mL, respectively). There was no significant difference in bFGF levels between patients with AML and patients with MDS (median, 6.38 pg/mL and 6.98 pg/mL, respectively). Elevated levels of VEGF were associated with reduced survival (P = 0.02) in patients with AML as well as lower complete remission (CR) rates (P = 0.004). Elevated VEGF levels were not associated with reduced remission duration (CRD) in patients with AML. There was no correlation between VEGF levels and survival, CRD, or CR rates in patients with MDS. There was no correlation between bFGF levels and CR rates or survival in patients with either AML or MDS. CONCLUSIONS: Plasma VEGF levels have prognostic significance in patients with AML. The lack of clinical relevance of VEGF levels in patients with MDS suggests some biologic difference between AML and MDS.     

Concentration of vascular endothelial growth factor (VEGF) in the serum of patients with suspected ovarian cancer.

As a promoter of angiogenesis, vascular endothelial growth factor (VEGF) is believed to play a pivotal role in tumour growth and metastasis. The aim of this study was to determine the value of preoperative serum VEGF levels in the early diagnosis of ovarian cancer and in the differential diagnosis of adnexal masses. We examined preoperative serum VEGF levels in healthy women (n = 131), patients with benign ovarian cysts (n = 81) and in ovarian cancer patients (n = 44) by using an ELISA (R&D Systems, Minneapolis, MN, USA). A logistic regression model was carried out to determine the influence of VEGF and CA 125 on the probability of malignancy. VEGF revealed a significant influence on the odds of presenting with malignancy vs healthy women (P = 0.001). At 363.7 pg ml(-1), VEGF achieved a sensitivity of 54% and a specificity of 77%. With respect to the differentiation between benign cysts and ovarian cancer, CA 125 (P < 0.0001) but not VEGF (P = 0.229) predicts the presence of malignancy in a multivariate model. In conclusion, VEGF does not appear to be a useful tool in the early diagnosis of ovarian cancer or for indicating the absence or presence of malignancy in patients with an adnexal mass.     

Down-regulation of cellular vascular endothelial growth factor levels induces differentiation of leukemic cells to functional leukemic-dendritic cells in acute myeloid leukemia

We examined the effect of cellular vascular endothelial growth factor (VEGF) levels on the generation of leukemic dendritic cells (DCs). Leukemic DCs were successfully generated in vitro from bone marrow cells of 16 of 21 acute myeloid leukemia (AML) patients, and the cellular VEGF concentrations in the leukemic cells and the neutralization of VEGF with anti-VEGF antibody were determined. AML cells that failed to generate leukemic DCs showed significantly higher cellular VEGF levels compared with generated leukemic DCs, and down-regulation of cellular VEGF levels induced the generation of leukemic DCs from AML cells. Inhibition of cellular VEGF levels increased interleukin (IL)-12 production and the allostimulatory capacity of leukemic DCs. These results suggest that the generation of leukemic DCs from AML cells is inversely related to the VEGF production of the cells and that the down-regulation of cellular VEGF levels can induce potential differentiation of leukemic cells to functional leukemic DCs in patients with AML.     

Expressions of vascular endothelial growth factor (VEGF) and its mRNA in uterine endometrial cancers.

To know the potential of growth, invasion and metastasis of uterine endometrial cancer associated with neovascularization, the expressions of VEGF and its mRNA, especially their subtypes, in uterine endometrial cancers and normal uterine endometria as controls were determined by Western blot analyses with a sandwich enzyme immunoassay and RT-PCR-Southern blot analysis, respectively, and the relation between their expressions and histological grades, grades of myometrial invasion and clinical stages of uterine endometrial cancers was analyzed. The levels of VEGF (VEGF165 and VEGF121) protein and mRNA were in a wide range and higher in normal uterine endometria than in the malignant counterparts. The levels of VEGF protein were higher in order of histopathological differentiation (normal uterine endometrium > well-differentiated (G1) > moderately differentiated (G2) and poorly differentiated (G3)) and those of VEGF protein and VEGF121 mRNA were lower in order of the advance of clinical stages (normal uterine endometrium > stage I > stage II > stages III and IV). There was, however, no significant difference in their levels among uterine endometrial cancers classified according to grades of myometrial invasion. This suggests that VEGF is downregulated during uterine endometrial cancer progression with dedifferentiation. Namely, VEGF in some endometrial cancers might contribute to the early process of advancing of malignancy via angiogenic activity.