VEGF和 bFGF在浅表膀胱移行细胞癌中的表达及意义

背景与目的：血管内皮生长因子（vascular endothelial growth factor,VEGF)和碱性成纤维细胞生长因子（basic fibroblast growth factior,bFGF)都能促进血管内皮细胞分裂和诱导血管形成,是肿瘤的生长,浸润,和转移过程中非常重要的物质,但它们在单发性和多发性浅表膀胱移行细胞癌中表达的差异则未见报道,本研究主要是探讨VEGF和bFGF在浅表膀胱移行细胞癌中的表达及意义。方法：采用免疫组化法对60例浅表膀胱移行细胞癌组织及10例正常膀胱组织进行VEGF和bFGF的检测,观察单发性和多发性浅表膀胱移行细胞癌组织中VEGF和bFGF表达的关系。结果：多发性浅表膀胱移行细胞癌的VEGF阳性率为55.6%,bFGF阳性率为50.0%,以及VEGF和bFGF共同表达阳性率为50.0%。均明显高于单发者的水平,而高水平表达的多发性肿瘤患者的术后复发率61.1%也明显高于单发组的复发率（单发组的复发率16.7%)。结论：VEGF和bFGF表达水平的高低与浅表膀胱移行细胞癌的生物学行为有关。     

MMP-7 (matrilysin) expression in human brain tumors

Matrix metalloproteinases (MMP) which degrades protein components of the extra-cellular matrix and basement membrane seems to be largely involved in cancer invasiveness. MMP proteolitic activity essentially comes from stromal cells but matrilysin (MMP-7) is produced by the tumor itself. Thus, MMP-7 is investigated to address the particular invasive behavior of human glioma. Both MMP-7 mRNA and protein were clearly identified in human glioma. MMP-7 mRNA expression was highly variable within our glioma population. When analyzing MMP-7 mRNA expression in different primary brain tumors, we found highly variable levels of expression not related to their invasive behavior. In successive biopsies obtained in the same patients with glioblastoma, MMP-7 mRNA was quantified and appeared variable, but intra-individual variations were lower than inter-individual differences. With a xenograft model of U87 human tumors in RAG2/gamma(c) immune-deficient mice, the strict tumor origin of MMP-7 was shown. Additionally, MMP-7 expression by U87 cells which is low in culture was stimulated by these cells while forming tumors and the level of expression was higher when the tumor cells were implanted within the brain. These data provide some consistent information about cross-talk occurring between the tumor and the surrounding stroma to regulate MMP-7 expression.     

P-glycoprotein expression in brain tumors

Summary Overexpression of P-glycoprotein (P-gp) in cancer cells can result in resistance to several chemotherapy agents (multidrug resistance) including doxorubicin and vincristine. The drugs to which resistance develops also penetrate the blood brain barrier poorly. P-gp expression in brain capillary endothelial cells suggests that P-gp may restrict drug entry into brain tumors and thus be another mechanism of drug resistance. To seek evidence for either of these roles in the drug resistance of brain tumors, we examined the location of expression of P-gp in 49 brain tumors, using an anti-P-gp mouse monoclonal antibody and immunohistochemistry. P-gp expression was observed in tumor cells of two glioblastomas and a meningeal sarcoma but not in low-grade primary or metastatic tumors. In low-grade primary tumors, P-gp was present in all vascular endothelial cells. In the vascular endothelial cells of anaplastic primary brain tumors and brain metastases, P-gp expression was heterogeneous or absent. These findings are consistent with a role for P-gp in the resistance of some brain tumors to chemotherapy agents.     

The relationship between peritumoral brain edema and the expression of vascular endothelial growth factor and its receptors in intracranial meningiomas

We examined the radiological and histological features of, and the influences of the expression of VEGF and its two major receptors, Flt-1 and Flk-1, on the development of peritumoral brain edema (PTBE) in patients with intracranial meningiomas. The expressions of VEGF and VEGF receptors in the immunohistochemical study were analyzed in relation to several factors, including tumor size, location, vascularity, and blood supply, as seen on digital subtraction angiographic studies. The edema volume (P = 0.0003) and edema index (P < 0.0001) had a significantly positive relation to VEGF expression. The positivity of Flt-1 and Flk-1 was mainly observed in tumor vessels; 44 cases (37.2%) were positive for the Flt-1 antibody and 37 cases (31.4%) for the Flk-1 antibody. The mean value of the edema index of the positive-Flt-1 group (5.220 ± 11.586) was significantly higher than that of the negative-Flt-1 group (1.782 ± 2.559) (P < 0.0001). The mean value of the edema index of the positive-Flk-1 group (3.925 ± 5.870) was slightly higher than that of the negative-Flk-1 group (2.671 ± 8.136) (P < 0.0001). Our data suggest that the expressions of VEGF and VEGF receptors positively relate to each other and to the formation of PTBE in patients with meningiomas.     

A placenta growth factor 2 variant acts as dominant negative of vascular endothelial growth factor A by heterodimerization mechanism

Angiogenesis is one of the crucial events for cancer development and growth and vascular endothelial growth factor (VEGF) family plays an essential role in this biological phenomenon. The members of VEGF family mainly involved in angiogenesis are VEGF-A, VEGF-B and placental growth factor (PlGF), which exert their activity through the binding and activation of two VEGF receptors, VEGFR-1 and VEGFR-2. Human VEGF-A and PlGF are expressed in different isoforms and have the peculiarity to form heterodimer if co-expressed in the same cell. The difference of two main human PlGF isoforms, PlGF1 and PlGF2, consist in the exclusive ability of PlGF2 to bind heparin and Neuropilin receptors. As previously reported for PlGF1 isoform, we have generated a PlGF2 variant named PlGF2 -DE, in which the residues D(72) and E(73) were substituted with alanine, that is unable to bind and activate VEGFR-1 but is still able to heterodimerize with VEGF. Here we report that overexpression in VEGF-A producing human tumor cell line derived from ovarian carcinoma (A2780) of PlGF2-DE variant by stable transfection, significantly reduces the production of VEGF-A homodimer via heterodimerization, determining a strong inhibition of xenograft tumor growth and associated neoangiogenesis, as well as significant reduction of monocyte-macrophage infiltration. Conversely, the overexpression of PlGF2wt, also reducing the VEGF-A homodimer production comparably to PlGF2-DE variant through the generation of VEGF-A/PlGF2 heterodimer, does not inhibit tumor growth and vessel density compared to control, but induces increase of monocyte-macrophage infiltration. Interestingly the comparison of PlGF2wt with PlGF1wt overexpression evidences a significant reduction of monocyte-macrophages recruitment as unique difference among the activity of the two PlGFwt isoforms. Therefore, the 'less soluble' PlGF2 shows a limited potential in monocyte-macrophages recruitment. In conclusion data here reported demonstrate that PlGF-DE variant acts as 'dominant negative' of VEGF-A independently from the PlGF isoform utilized, that the expression of active PlGF2 homodimer and VEGF-A/PlGF2 heterodimer is sufficient to rescue pro-angiogenic activity lost for reduction of VEGF-A due to heterodimerization mechanism, and that PlGF2 shows lower activity into recruitment of monocyte-macrophage cells compared to PlGF1 isoform.     

阻癌胃泰对大鼠胃癌癌前病变VEGF表达的影响

目的:探讨益气活血中药阻癌胃泰对大鼠胃癌癌前病变血管内皮生长因子(VEGF)mRNA表达水平的影响.方法:MNNG及胃窦部内置弹簧联合诱发胃癌癌前病变模型.将大鼠随机分为4组,分别为造模对照组、阻癌胃泰治疗组、维酶素治疗组和正常组.取大鼠胃窦部组织送检作病理检测,采用反转录PCR( RT-PCR)技术对各组大鼠的血管内皮生长因子mRNA含量进行测定,用RNA指数(RI)表示.结果:造模大鼠血管内皮生长因子mRNA的RI指数升高,经药物治疗后RI指数下降.阻癌胃泰组与对照组和维酶素组比较均有显著差异(P<0.05),中药组与正常组比较无显著性差异(P>0.05).维酶素组与对照组比较无显著性差异(P>0.05).结论:阻癌胃泰影响胃癌前病变血管内皮生长因子mRNA的表达,可能是其治疗作用的分子机制之一.     

Vascular endothelial growth factor expression correlates with matrix metalloproteinases MT1-MMP,MMP-2 and MMP-9 in human glioblastomas

Vascular endothelial growth factor (VEGF) is the major endothelial mitogen in central nervous system neoplasms and it is expressed in 64-95% of glioblastomas (GBMs). Tumour cells are the main source of VEGF in GBMs whereas VEGF receptors (VEGFR-1, its soluble form sVEGFR-1, VEGFR-2 and neuropilin-1) are expressed predominantly by endothelial cells. Infiltrating tumour cells and newly-formed capillaries progress through the extracellular matrix by local proteolysis involving matrix metalloproteinases (MMPs). Recent studies have shown that VEGF expression and bioavailability can be modulated by MMPs. We reported previously that the expression of MT1-MMP in human breast cancer cells was associated with an enhanced VEGF expression. We used quantitative RT-PCR, Western blot, gelatin zymography and immunohistochemistry to study the expression of VEGF, VEGFR-1, VEGFR-2, sVEGFR-1, neuropilin-1, MT1-MMP, MMP-2, MMP-9 and TIMP-2 in 20 human GBMs and 5 normal brains. The expression of these MMPs was markedly increased in most GBMs with excellent correlation between mRNA and protein levels; activated forms of MMP-2 and MMP-9 were present in 8/18 and 7/18 of GBMs. A majority of GBMs (17/20) also expressed high levels of VEGF, as previously reported, with strong correlation between VEGF and MT1-MMP gene expression levels, and double immunostaining showed that VEGF and MT1-MMP peptides co-localize in tumour and endothelial cells. Our results suggest that the interplay between metalloproteinases and VEGF previously described in experimental tumours may also be operative in human GBMs. Because of its dual ability to activate MMP-2 and to up-regulate VEGF, MT1-MMP might be of central importance in the growth of GBMs and represent an interesting target for anti-cancer treatments.     

Correlations of oral tongue cancer invasion with matrix metalloproteinases (MMPs) and vascular endothelial growth factor (VEGF) expression

BACKGROUND AND OBJECTIVES: In oral tongue cancer, the degree of tumor invasion has a significant effect on the prognosis. We hypothesized that the destruction of extracellular matrix and neovascularization are related to tumor infiltration mechanism. By studying the tissues of early stage oral tongue cancer patients, we are intending to clarify the invasion-related factors. MATERIALS AND METHODS: To demonstrate the invasion process in early T-stage oral tongue cancer, the expressions of extracellular matrix destruction-related molecules (MMP-2, MMP-9) and neovascularization-related molecule (VEGF) were observed by immunohistochemical study. Also, staining of CD31 was done for quantification of neovascularization. We analyzed relationship between expression of each substances and tumor invasion depth, tumor free survival rates, and cervical lymph node metastasis rate. RESULTS: The expression rates of MMP-2, MMP-9, VEGF in 38 early oral cancer patients were 52.6%, 78.9%, and 52.6%, respectively. Significant correlation was found between the VEGF expression and microvessel density showed by CD31 immunohistochemical staining (P < 0.001). VEGF expressions were significantly related with tumor invasion depth (P = 0.002). The tumor-free survival rate of those patients with VEGF-positive tumors was significantly poorer than in those with VEGF-negative tumors (P = 0.019). CONCLUSIONS: These results indicate that VEGF is a useful marker for predicting the tumor invasion in patients with early tongue cancer.     

Cisplatin,ara-C and etoposide (PAE) in the treatment of recurrent childhood brain tumors

Sixteen patients with recurrent childhood brain tumors were treated with intravenous cisplatin, cytosine arabinoside and etoposide (PAE), daily for three days every three to four weeks. Objective responses were observed in 6 of 15 evaluable patients and an additional six patients had stable disease for > 6 months. The tumor-specific response rate for astrocytoma/glioma was 3 of 7 and for medulloblastoma was 2 of 4. The mean progression-free interval was 11.0 months and the hazard rate for progression was 0.085 per patient-month of observation. The most common toxicities were neutropenia and thrombocytopenia. Clinically significant ototoxicity wasidentified in 7 patients. The activity of PAE chemotherapy for recurrent childhood brain tumors warrants further investigation.     

肺癌患者血浆中血管内皮生长因子与碱性纤维母细胞生长因子表达

目的　研究血管内皮生长因子 (VEGF)与碱性纤维母细胞生长因子 (bFGF)在肺癌患者血浆中表达水平。方法　采用定量免疫酶标 (ELISA)方法 ,检测 92例肺癌患者及肺部良性疾病血浆中VEGF与bFGF的含量。结果　 84例肺癌与 7例肺部良性疾病血浆中VEGF含量分别为 2 0 1.5± 183.0pg/ml,10 2 .5± 6 2 .5pg/ml,两者差异有显著性 (P <0 .0 5 ) ;其中 4 4例腺癌和 7例小细胞癌的VEGF含量分别为 2 0 2 .3± 177.0pg/ml、381.4± 314 .3pg/ml,与其肺部良性疾病比较 ,差异均有显著性 (分别为P <0 .0 5、P <0 .0 0 1)。在 5 6例肺癌与 4例肺部良性疾病血浆中bFGF含量分别为 4 5 .4± 2 3.9pg/ml,5 0 .4± 2 7.2pg/ml,两者差异无显著性。结论　在肺癌患者血浆中VEGF的含量明显高于肺部良性疾病的含量 ,其中腺癌和小细胞肺癌差异有显著性。而肺癌与肺部良性疾病无明显差异     

晚期恶性肿瘤血清VEGF含量测定的临床意义

目的：探讨血清血管内皮生长因子（VEGF）浓度在晚期恶性肿瘤中的临床意义。方法：应用酶联免疫吸附试验（ELISA）测定40例晚期恶性肿瘤（非小细胞肺癌、鼻咽癌、食管癌）患者血清的VEGF浓度,10名健康成人作为对照。结果：40例晚期恶性肿瘤患者血清VEGF浓度为（477．07±374．10）pg／ml,显著高于健康成人（139．09±133．41）pg／ml,差异有统计学意义（P=0．016）,其中治疗前血清VEGF浓度在非小细胞肺癌为（518．53±378．99）pg／ml,食管癌为（399．21±393．69）pg／ml,鼻咽癌为（500．68±348．48）pg／ml,与健康成人比较差异有统计学意义（P值分别为0．011、0．044和0．019）。化疗有效患者的血清VEGF浓度（400．41±332．84）pg／ml显著低于化疗前浓度（777．10±666．01）pg／ml,差异有统计学意义（P=0．034）。结论：血清VEGF可作为晚期恶性肿瘤监测病情、判断放疗和预后一个有用的指标。     

Development of the tumor vascular bed in response to hypoxia-induced VEGF-A differs from that in tumors with constitutive VEGF-A expression

Tumors arise initially as avascular masses in which central hypoxia induces expression of vascular endothelial growth factor-A (VEGF-A) and subsequently tumor vascularization. However, VEGF-A can also be constitutively expressed as a result of genetic events. VEGF-A is alternatively spliced to yield at least 6 different isoforms. Of these, VEGF-A(121) is freely diffusible whereas basically charged domains in the larger isoforms confer affinity for cell surface or extracellular matrix components. We previously reported that in a mouse brain metastasis model of human melanoma, VEGF-A(121) induced a qualitatively different tumor vascular phenotype than VEGF-A(165) and VEGF-A(189): in contrast to the latter ones, and VEGF-A(121) did not induce a neovascular bed but rather led to leakage and dilatation of preexistent brain vessels. Here, we correlate vascular phenotypes with spatial VEGF-A expression profiles in clinical brain tumors (low grade gliomas; n = 6, melanoma metastases; n = 4, adenocarcinoma metastases; n = 4, glioblastoma multiforme; n = 3, sarcoma metastasis; n = 1, renal cell carcinoma metastasis; n = 1). We show that tumors that constitutively express VEGF-A present with different vascular beds than tumors in which VEGF-A is expressed as a response to central hypoxia. This phenotypic difference is consistent with a model where in tumors with constitutive VEGF-A expression, all isoforms exert their effects on vasculature, resulting in a classical angiogenic phenotype. In tumors where only central parts express hypoxia-induced VEGF-A, the larger angiogenic isoforms are retained by extracellular matrix, leaving only freely diffusible VEGF-A(121) to exert its dilatation effects on distant vessels.     

A quantitative analysis of the reduction in oxygen levels required to induce up-regulation of vascular endothelial growth factor (VEGF) mRNA in cervical cancer cell lines.

The presence of hypoxia (low oxygen concentrations) in solid tumours correlates with poor prognosis, increased metastasis, and resistance to radiotherapy and some forms of chemotherapy. Malignant cells produce an angiogenesis factor, vascular endothelial growth factor (VEGF), which may increase metastatic ability and is up-regulated in the presence of hypoxia. Clinical data for cancers of the cervix and head and neck relate oxygen levels in the tumour to treatment outcome. This suggests the possibility that the presence of VEGF mRNA might be used as a marker for relevant levels of hypoxia. Suspension cultures of three human cervical cancer cell lines, SiHa, ME-180 and HeLa, were used to investigate up-regulation of VEGF mRNA levels following exposure to precisely defined oxygen concentrations for 2 or 4 h. An oxygen sensor was used to confirm the actual levels of dissolved oxygen present. The oxygen concentrations which caused half-maximal upregulation (the Km value) of VEGF mRNA level in the three cell lines were similar except for one instance (Km at 4 h: SiHa 27.0 +/- 5.7 microM, ME-180 16.8 +/- 3.3 microM, HeLa 13.0 +/- 1.8 microM, SiHa and HeLa P = 0.01). The Km values for the HeLa cell line as measured at 2 h (24.9 +/- 0.8 microM) and 4 h (13.0 +/- 1.8 microM) were significantly different (P < 0.0001). VEGF mRNA half-lives measured in air were consistent with values in the literature (SiHa 59.8 +/- 5.8 min, ME-180 44.4 +/- 7.2 min, HeLa 44.5 +/- 6.3 min). Differences in oxygen consumption at low oxygen concentrations were noted between the different cell lines. Stirring in suspension culture was found to induce VEGF mRNA in SiHa cells. The presence of VEGF mRNA may be a marker for radiobiologic hypoxia.     

高表达P73基因抑制肺腺癌细胞VEGF、bFGF mRNA表达

目的　观察高表达的p73基因对肺腺癌细胞生长曲线以及血管内皮生长因子 (VEGF)、碱性成纤维细胞生长因子 (bFGF)mRNA表达水平的影响 ,探讨高表达 p73基因在肺腺癌血管生成中的作用。 方法　将 p73α、p73 β以脂质体法转染A5 49细胞、H12 99细胞 ,采用细胞计数法绘制转染前后两种细胞生长曲线 ,RT PCR法半定量分析转染前后两种细胞中VEGF、bFGFmRNA的表达水平的变化。结果　转染p73基因后 ,A5 49细胞、H12 99细胞生长受到抑制 ,VEGF、bFGFmRNA表达水平下降 ,较未转染 p73基因的细胞有显著性差异 (P <0 .0 5 ) ,其中 p73 β对VEGFmRNA表达的抑制作用更为显著 (P <0 .0 1)。 结论　高表达的 p73基因能够抑制肺腺癌细胞生长 ,降低肺腺癌细胞中VEGF、bFGFmRNA表达水平 ,提示高表达的 p73基因可能参与调控人肺腺癌VEGF和bFGF基因表达 ,从而起到一个抑癌基因的作用     

Elevated expression of vascular endothelial growth factor correlates with increased angiogenesis and decreased progression-free survival among patients with low-grade neuroendocrine tumors

BACKGROUND: Vascular endothelial growth factor (VEGF) is a critical proangiogenic factor in solid tumors. However, its expression and role in human neuroendocrine tumor development and progression remains unclear. METHODS: Using immunohistochemistry, VEGF and Sp1 expression patterns were investigated in 50 cases of human gastrointestinal neuroendocrine tumor having various clinicopathologic characteristics. RESULTS: It was found that strong VEGF expression was detected in tumor cells, whereas no or very weak VEGF expression was detected in stromal cells surrounding or within the tumors. The levels of VEGF expression directly correlated with the expression levels of Sp1 and microvessel density. Strong, weak, and negative VEGF expression was observed in 32%, 54%, and 14% of cases, respectively. Compared with the group with negative VEGF expression, VEGF (weak/strong) expression was associated with metastasis (14% versus 58%; P = .03). The median progression-free survival (PFS) durations of patients with strong and weak VEGF expression were 29 months and 81 months, respectively. With a median follow-up duration of 50 months, the median PFS duration for the group with negative VEGF expression has not been reached. Compared with the log-rank test, VEGF expression was associated with poor PFS (P = .02). Using in vitro and in vivo models, human carcinoid cell lines were treated with bevacizumab, a monoclonal antibody targeting VEGF. Bevacizumab did not inhibit the growth of carcinoid cells in vitro but significantly reduced tumor angiogenesis and impaired tumor growth in animals. CONCLUSIONS: The data suggest that overexpression of VEGF promotes the growth of human neuroendocrine tumors in part through up-regulation of angiogenesis.     

Survivin promotes glioma angiogenesis through vascular endothelial growth factor and basic fibroblast growth factor in vitro and in vivo

Survivin is involved in multiple signaling mechanisms in tumor maintenance, and accumulated studies elucidate that knockdown of survivin in endothelial cells could inhibit angiogenesis; however, the role of survivin in tumor cells to regulate tumor-derived angiogenesis remains largely unclear. In the present study 80 cases of brain glioma were chosen and protein expressions of survivin, vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), and platelet-derived growth factor (PDGF) in glioma cells were investigated by immunohistochemistry (IHC). Human umbilical vein endothelial cells (HUVEC) were cocultured with human glioma U251 wild-type cells, U251 cells survivin silenced, SHG44 wild-type cells, and SHG44 survivin-overexpressing cells, respectively. The proliferation and migration of HUVEC were evaluated by MTT assay and transwell chamber assay. The microvessels density (MVD) marked by CD31 expression in vascular endothelial cells in glioma xenografts in nude mice was detected by IHC. VEGF, bFGF, and PDGF in the aforementioned cells were detected by quantitive PCR (qPCR), Western blot, ELISA, and IHC in vitro and in vivo. The results showed that VEGF immunoreactivity score (IRS), bFGF IRS, and PDGF IRS were all positively correlated with survivin IRS in gliomas, respectively (P < 0.01). Survivin in human glioma cells could significantly promote the proliferation and migration of HUVEC and increase MVD, which could be contributed to survivin-dependent burst of VEGF and bFGF expression, followed by increase of tumor growth and proliferation. In summary, survivin, through upregulation of VEGF and bFGF, plays an essential role during glioma angiogenesis.     

晚期恶性肿瘤血清VEGF含量测定的临床意义

Objective: To elucidate the clinical significance of serum vascular endothelial growth factor (VEGF) level in patients with advanced cancer. Methods: Enzyme linked immunosorbent assay (ELISA) was used to determine the serum VEGF concentration in 40 patients with advanced cancer [non-small cell lung cancer (NSCLC), esophageal cancer (EC) and nasopharyngeal carcinoma (NPC)] before and after chemotherapy and 10 healthy volunteers as control group. Results: The serum VEGF concentrations in 40 cases of advanced cancer patients were significantly higher than those of 10 healthy control cases [(477.07 ± 374.10 ) pg/mL vs (139.09 ± 133.41 ) pg/mL; P = 0.016]. The serum VEGF concentrations in patients with NSCLC, EC and NPC were (518.53 ± 378.99) pg/mL, (399.21 ± 393.69) pg/mL and (500.68 ± 348.48) pg/mL, respectively. The differences were all statistically significant as compared with healthy control group (P values were 0.011,0.044 and 0.019, respectively). The serum VEGF concentrations of the patients in response to chemotherapy was significantly lower than those of the same patients before they undergoing chemotherapy [(400.41 332.84) pg/mL vs (777.10 ± 666.01) pg/mL; P = 0.034]. Conclusion: The serum VEGF level might be a novel and promising tumor marker of advanced malignancies and a predictor of disease progression, prognosis and therapeutic efficacy.