Expression of vascular endothelial growth factor protein in human renal cell carcinoma

OBJECTIVE: To evaluate the effect of vascular endothelial growth factor (VEGF, one of the most important angiogenetic factors) in renal cell carcinoma (RCC) by analysing many RCCs for the expression of immunohistochemical (IHC) VEGF-staining related to clinicopathological findings and survival. PATIENTS AND METHODS: VEGF immunostaining was examined with the tissue microarray (TMA) method on tumour samples from 229 patients and validated in 71 by ordinary tissue sections (TS). IHC VEGF expression was quantified by estimating the volume density and staining intensity on a three-grade scale. RESULTS: In most RCCs there was VEGF staining in the cell cytoplasm and membrane. In cell membranes the VEGF expression declined with storage time. IHC VEGF expression analysed by TMA and TS gave corresponding results. There was no difference in VEGF expression among conventional, papillary and chromophobe RCCs. There were significant correlations between VEGF expression and tumour size and stage. In univariate analysis VEGF expression correlated with survival, especially in conventional RCCs; this prognostic information was lost in multivariate analysis. The VEGF staining intensity correlated only with VEGF expression but not with any clinicopathological factors. CONCLUSIONS: VEGF protein was present in most RCC cells. There was no difference in VEGF expression among the different RCC types. The correlation between VEGF expression and tumour stage and with prognosis indicates the significance of VEGF within tumour growth and progression in RCC.     

肾细胞癌中血管内皮生长因子的表达

目的 探讨肾癌组织中血管内皮生长因子的表达及其与肾癌生物学行为的关系。方法 应用单克隆鼠抗-VEGF抗体通过免疫组化SP法研究肾癌中血管内皮生长因子的表达。结果 60例肾癌组织中35例(58.3％)血管内皮生长因子阳性。血表达与组织学分级(P<0.05)和TNM分期(P<0.05)均明显相关。 结论 血管内皮生长因子表达对肾癌生物学行为有重要影响,设法抑制血管内皮生长因子有望成为肾癌治疗的另一有效方法。     

同侧肾脏同时发生透明细胞型与乳头状肾细胞癌

目的探讨同侧肾脏发病并且相对独立的透明细胞型和肾乳头状细胞癌的临床病理特点及免疫表型,提高对该肿瘤的认识和诊断水平。方法本研究回顾了2例病理诊断为透明细胞型合并肾乳头状细胞癌的临床资料,通过光镜和免疫组织化学染色,针对肾细胞癌相关蛋白标志物[包括 Vimentin、CD10、CK（AE1/AE3）、CK7、CK8/18、PAX2、PAX8、CAⅨ、AMACR]进行了观察和分析。结果2例患者为男性,年龄分别为70、63岁。2例患者的两处独立肿瘤均位于左侧肾脏,镜下观察均可见两处独立肿瘤,肿瘤间隔有正常肾脏组织,分别为乳头状肾细胞癌及透明细胞型肾细胞癌,且免疫组化显示2例患者肿瘤的表型一致。结论单侧肾脏肾透明细胞癌合并肾乳头状细胞癌是一种少见的临床现象,这种现象的存在以及类似的免疫组化表型提示透明细胞型肾细胞癌和乳头状肾细胞癌在发生过程中可能存在着内部的联系。     

肾细胞癌VEGF表达和MVD检测的临床意义

目的 探讨肾细胞癌（RCC）组织中血管内皮细胞生长因子（VEGF）的表达与肿瘤间质微血管密度（MVD）检测的临床意义。方法 采用免疫组化方法对65例肾细胞癌（RCC）及10例正常肾组织进行VEGF单克隆抗体及CD34单克隆抗体染色，观察RCC的VEGF表达与MVD之间的相关性。结果 VEGF的表达与肿瘤间质微血管密度之间存在正相关性，二者均与RCC的病理分级、临床分期及远处转移显著相关（P〈0.05，P〈O．001）。结论 VEGF与MVD可客观准确反映RCC的生物学行为，上述二项指标可作为评估RCC恶性程度、转移及预后的重要指标。     

Down-regulation of HLA class I antigen is an independent prognostic factor for clear cell renal cell carcinoma

PURPOSE: We determined the prognostic impact of human leukocyte antigen class I on the survival of patients with clear cell renal cell carcinoma. MATERIALS AND METHODS: Immunohistochemical staining for HLA class I was performed on specimens from 45 patients with clear cell renal cell carcinoma. We performed univariate and multivariate analyses of various factors affecting cause specific survival including HLA class I, Fuhrman grade, TNM stage and tumor size. Furthermore, we compared the survival of patients with HLA class I positive renal cell carcinoma to that of those with down-regulated HLA class I using the Kaplan-Meier method and log rank test. RESULTS: HLA class I was immunohistochemically down-regulated in 17 (37.8%) clear cell renal cell carcinomas. The down-regulation had no correlation with other clinicopathological parameters such as tumor size, perirenal fat invasion, tumor thrombus, TNM stage or nuclear grade. Univariate and multivariate analyses revealed that HLA class I expression, tumor grade and TNM stage were significant factors influencing the disease specific survival of patients with renal cell carcinoma. Patients with HLA class I positive renal cell carcinoma had longer recurrence-free survival than those with down-regulated expression at 5-year followup (95.5% and 61.1%, respectively). CONCLUSIONS: Our data demonstrate that down-regulation of HLA class I on tumor cells is an independent prognostic factor for clear cell renal cell carcinoma. This finding suggests that HLA class I restricted cytotoxic T lymphocytes have an important role in the suppression of renal cell carcinoma.     

The lymphatic system and its specific growth factor vascular endothelial growth factor C in kidney tissue and in renal cell carcinoma

OBJECTIVE

To determine the role of vascular endothelial growth factor C (VEGF‐C) and the quantitative extent of the lymphatic system in renal cell carcinoma (RCC) to analyse a possible correlation with the metastatic spread of cancer cells.

PATIENTS AND METHODS

In all, 44 patients with clear cell RCC and 12 with papillary or chromophobe RCC were included in an immunohistochemical study. The lymphatic vessel density (LVD) was assessed in the tumour body, the tumour capsule and the tumour‐free adherent renal tissue. The expression of VEGF‐C was semiquantitatively assessed by the percentage of positive epithelial and cancer cells. Data were analysed for any correlation with the clinicopathological variables.

RESULTS

The clear and papillary cell RCC contained no lymphatic vessels (0.2, sd 0.8). Chromophobe RCC specimens showed scattered obliterated vessels (0.0–7.7). Several lymphatic vessels were found in the normal renal tissue, mainly associated with blood vessels (2.9, sd 1.9). The highest mean (sd ) LVD was in the tumour capsule, of 6.9 (3.4). There was no statistical correlation between the LVD and VEGF‐C. In clear cell RCC the expression of VEGF‐C was correlated with the size of the tumour (P = 0.042).

CONCLUSIONS

RCC does not promote the growth of its own lymphatic vessels. The role of a high LVD in the tumour capsule needs to be determined. The VEGF‐C staining pattern in normal kidney tissue hints at functions other than lymphangiogenesis.     

Clinical response to therapy targeted at vascular endothelial growth factor in metastatic renal cell carcinoma: impact of patient characteristics and Von Hippel-Lindau gene status

OBJECTIVE: To describe the relationship among patient characteristics, Von Hippel-Lindau (VHL) gene status and clinical outcome in metastatic renal cell carcinoma (RCC) in patients receiving vascular endothelial growth factor (VEGF)-targeted therapy. PATIENTS AND METHODS: All patients with metastatic RCC who received therapy with interferon-alpha plus bevacizumab, SU11248 or AG013736 at the authors' institution were considered. Clinical features were collected and activation status of the VHL gene (VHL) was determined from baseline paraffin-embedded tumour samples. Tumour response, time to tumour progression (TTP) and overall survival were recorded. RESULTS: Forty-three patients were evaluable for determination of VHL status and clinical response. There was an objective response in 18 patients (43%; 95% confidence interval 28-59%). The median TTP for the entire cohort was 8.1 months. There was an improved clinical outcome in patients with the following clinical features: male gender, lack of hepatic metastases, no previous radiation therapy and higher baseline haemoglobin level. Twenty-six patients (60%) had evidence of VHL mutation or promoter methylation; such patients had an objective response rate of 48%, vs 35% in patients with no VHL mutation or methylation. Patients with VHL methylation or a mutation predicted to truncate or shift the VHL reading frame had a median TTP of 13.3 months, vs 7.4 months in patients with none of these features (P = 0.06). CONCLUSION: VEGF-targeted therapy is active in metastatic RCC and the response can be associated with certain clinical features. The TTP with VEGF-targeted therapy might be prolonged in patients with VHL methylation or mutations that truncate or shift the VHL reading frame. Further investigation of VHL pathway components is needed to understand the biology of the response to VEGF-targeted agents in metastatic RCC.     

肌动蛋白交联蛋白与血管内皮生长因子在肾细胞癌中的表达及其相关性

目的 探讨肌动蛋白交联蛋白(Fascin)与血管内皮生长因子(VEGF)在肾细胞癌组织的表达及与其生物学行为的关系.方法 采用免疫组织化学SP法检测Fascin与VEGF在92例肾细胞癌组织及20例正常肾脏组织中的表达.结果 Fascin及VEGF在肾细胞癌组织中的表达阳性率明显高于正常肾组织(P＜0.05);肾细胞癌组织中两种蛋白的表达与肿瘤组织学分级和临床分期均呈正相关(P＜0.05);与年龄、性别及肿瘤病理类型无明显相关(P＞0.05).且Fascin和VEGF的表达之间呈正相关(P＜0.05).结论 Fascin与VEGF可作为反映肾细胞癌生物学行为的参考指标.

Abstract：

Objective To investigate the expression of Fascin and vascular endothelial growth factor (VEGF) in renal cell carcinoma (RCC) and the correlation with the biological behaviors. Methods The immunohistochemistry staining method was used to detect the expression of Fascin and VEGF in 92 cases of RCC and 20 cases of normal renal tissues as controls. Results The expression of Fascin in carcinoma tissue was significantly higher than that in normal tissues ( P ＜ 0. 05 ). Positive expression of Fascin and VEGF in renal cell carcinoma tissue was correlated with tumor grade ( P ＜ 0. 05 ) and clinical stage (P ＜0. 05 ) , but not with age, gender and different histological categories (P ＞ 0. 05 ). There was also a positive correlation between Fascin and VEGF (P ＜ 0. 05 ). Conclusion Fascin and VEGF are objective markers to estimate the behaviors of renal cell carcinoma.     

Prognostic value of the expression of Ki-67, CD44 and vascular endothelial growth factor, and microvessel invasion, in renal cell carcinoma

OBJECTIVE: To determine if use of cell proliferation, cell adhesion, level of angiogenesis-related factors and presence of microscopic vascular invasion (MVI) could better predict the biological behaviour of renal cell carcinoma (RCC), which has a widely variable clinical outcome despite the use of conventional prognostic factors (staging and grading). MATERIALS AND METHODS: The expression of Ki-67, CD44H and vascular endothelial growth factor (VEGF) were assessed immunohistochemically in formalin-fixed, paraffin-embedded tissues from 48 RCCs, using a Ki-67 labelling index (LI), CD44 LI and level of VEGF expression, respectively. In addition all the pathological slides were reviewed retrospectively for the presence and absence of MVI. The prognostic value of all the variables assessed was then evaluated, and correlated with the usual prognostic variables and cancer-specific survival. RESULTS: Univariate analysis of cancer-specific survival showed that tumour stage (P < 0.001), tumour size (P = 0.005), metastasis, MVI, Ki-67 LI, CD44H LI and VEGF expression (all P < 0.001) were predictors of tumour-related death. There was a statistical correlation between CD44H LI and each of Ki-67 LI (r = 0.61), expression level of VEGF (r = 0.72) and presence of MVI (r = 0.71). Independent predictors of cancer-specific survival in a multivariate analysis were: in all patients with RCC, the MVI (P = 0.003) and VEGF expression (P = 0.01); in those with no metastases, MVI (P = 0.01); in patients with no MVI, VEGF (P = 0.04); and in patients with MVI, Ki-67 LI (P = 0.003). No independent predictor was identified in patient with metastases. CONCLUSION: This study suggests that cell proliferation, cell adhesion, the level of VEGF expression and the presence of MVI represent a complex tumour-host interaction that may favour the progression of RCC. Cell proliferation, CD44H and VEGF expression appear to be powerful markers for identifying patients with an adverse prognosis.     

肾细胞癌血管内皮生长因子及微血管密度的免疫组化研究

目的　探讨血管内皮生长因子（VEGF）和微血管生成与肾癌发展的关系。　方法　应用免疫组化技术检测46例肿瘤组织中的VEGF。　结果　46例肿瘤组织中VEGF阳性表达28例 (60.8%)、微血管密度（MVD）为63.64±33.20,均显著高于正常组织。VEGF、MVD与肿瘤的组织类型无关（P＞0.05),与肿瘤的组织学分级有关（P＜0.05);VEGF阳性组MVD明显高于阴性组(P＜0.05);有淋巴结转移组VEGF、MVD均高于无淋巴结转移组(P＜0.05);VEGF阳性组术后5年复发转移率明显高于阴性组（P＜0.01)。　结论　VEGF与肾癌的血管生成有关,VEGF和MVD可作为反映肾细胞癌生物学行为的指标之一。     

Tumor VEGF expression correlates with tumor stage and identifies prognostically different groups in patients with clear cell renal cell carcinoma

ObjectivesVascular endothelial growth factor (VEGF) is a potent inducer of tumor angiogenesis and represents the key element in the pathogenesis of clear cell renal cell carcinoma (ccRCC). The aim of this study was to investigate the use of tumor VEGF expression as a parameter to identify tumor stage and prognostically different patient groups.Methods and materialsWe retrospectively collected clinical data of 137 patients treated with partial or radical nephrectomy at our institutions for organ-confined, locally advanced, and metastatic ccRCCs between 1984 and 2013. Tumor cell VEGF immunohistochemical expression was compared with pathological and clinical features including age, sex, tumor stage, and Fuhrman grade. Comparison of VEGF expression levels between tumor stages was performed via Kruskal-Wallis nonparametric test. Survival analysis was conducted via Kaplan-Meier product-limit method, and Mantel-Haenszel log-rank test was employed to compare survival among groups.ResultsMedian age at diagnosis was 61 years (range: 33–85 y). Tumor stage was pT1N0M0 in 67 patients (49%), pT2N0M0 in 5 (4%), and pT3N0M0 in 25 (18%), while 40 patients (29%) had metastatic tumors at diagnosis. Fuhrman nuclear grade was G1 in 22 patients (16%), G2 in 60 (44%), G3 in 33 (24%), G4 in 13 patients (9%), and unknown in 9 patients. Tumor VEGF was differentially expressed among different stages (P<0.001) and in low (G1–2) and high (G3–4) Fuhrman grade tumors (P<0.001). No significant differences were found when stratifying by sex (P = 0.06) or age (P = 0.29). Median overall survival (OS) from partial or radical nephrectomy was 161 months (range: 1–366). We observed a significantly longer OS in patients with low (<25%) vs. high (>25%) VEGF expression levels (median OS 206 vs. 65 mo, P<0.001).ConclusionsOur data show that tumor cell VEGF expression is significantly associated with tumor stage and Fuhrman grade and is able to predict patient outcome, suggesting a potential use of this parameter in identifying prognostically different patients with ccRCC.     

Effects of combined valproic acid and the epidermal growth factor/vascular endothelial growth factor receptor tyrosine kinase inhibitor AEE788 on renal cell carcinoma cell lines in vitro

OBJECTIVE

To evaluate adhesion and growth inhibiting effects of the multiple receptor tyrosine kinase inhibitor AEE788 and the histone deacetylase (HDAC) inhibitor valproic acid (VPA) on renal cell carcinoma (RCC) cells.

MATERIALS AND METHODS

Caki‐1 cells were treated with AEE788 and VPA, either alone or in combination, to investigate RCC cell adhesion to vascular endothelial cells or to immobilized extracellular matrix proteins. Tumour cell proliferation was examined by MTT dye reduction assay. Effects of drug treatment on cell signalling pathways were determined by Western blotting. The expression levels of integrin α and β subtypes were evaluated by flow cytometry (surface expression) and Western blotting (intracellular protein expression).

RESULTS

RCC cell treatment with AEE788 and VPA in combination resulted in a stronger inhibition of tumour cell proliferation than that caused by either drug alone. There were also additive effects of the combined treatment on tumour cell adhesion to endothelial cells and to immobilized laminin (but not to immobilized fibronectin and collagen). AEE788 alone or combined with VPA reduced Akt expression and histone H3 acetylation. Both compounds altered integrin α and β subtype expression, in particular α1, α3 and β4, and blocked integrin‐dependent integrin‐linked kinase and focal‐adhesion kinase (total and phosphorylated) signalling.

CONCLUSIONS

Both AEE788 and VPA profoundly block the interaction of RCC cells with endothelium and extracellular matrix and reduce tumour growth in vitro. Therefore, this combined regimen warrants further preclinical and possible clinical study for treating advanced RCC.     

Angiogenesis in renal cell carcinoma: Evaluation of microvessel density, vascular endothelial growth factor and matrix metalloproteinases

BACKGROUND: Angiogenesis, the growth of new blood vessels, has a critical role in tumor growth and metastasis. The purpose of this study was to investigate the involvement of angiogenesis and angiogenic factors in the pathogenesis of renal cell carcinoma (RCC). METHODS: Formalin-fixed and paraffin-embedded tissue blocks from 70 patients with RCC were studied. The situations of tumor angiogenesis were evaluated by assessing microvessel density (MVD) through CD31 immunostaining. The expression of vascular endothelial growth factor (VEGF), matrix metalloproteinase-2 (MMP-2) and metalloproteinase-9 (MMP-9) was detected immunohistochemically. RESULTS: The value of MVD ranged from 12.0 to 93.0 with a median of 39.91 in RCC. Of the 70 RCCs, the expression of VEGF was detected in 52 (74.3%), MMP-2 in 29 (41.4%) and MMP-9 in 19 (27.1%) cases. Statistical analysis revealed significant associations of the tumor stage with MVD, and the expression of VEGF and MMP-2 in RCC. Additionally, MVD was closely related to the expression of VEGF but was not related to the expression of MMP-2 and MMP-9 in RCC. CONCLUSION: The degree of angiogenesis may be closely related to the tumor progression of RCC. The expression of VEGF may be responsible for angiogenesis in RCC, and both VEGF and MMP-2 expression may function as tumor associated angiogenic factors in RCC.     

血管内皮生长因子在终末期肾细胞癌中的表达及其意义

目的 检测终末期肾细胞癌动物模型血管内皮生长因子(VEGF)血浆水平,探讨肾细胞癌侵袭力标记物的相关性.方法 以人肾癌细胞grc-1经皮下植入裸鼠的背部建立终末期细胞癌模型,对实验裸鼠血浆VEGF水平检测,并进行统计学分析.结果 在肿瘤植入度为(4500±2340)ng/L,而对照组裸鼠血浆VEGF浓度几乎未发现变化.结论 VEGF表达强度与肾癌细胞的侵袭能力呈正相关,血浆VEGF浓度越高,肾癌细胞的侵袭能力越强.