Hypoxia-inducible factor 1 alpha expression correlates with angiogenesis and unfavorable prognosis in bladder cancer

INTRODUCTION AND OBJECTIVES: Hypoxia-inducible factor 1 alpha (HIF-1 alpha) is a critical regulatory protein of cellular response to hypoxia and is closely related to the triggering of the angiogenic process. We examined the relationship between hypoxia and angiogenesis, as well as their prognostic impact in patients with urothelial bladder cancer. METHODS: The immunohistochemical expression of HIF-1 alpha was evaluated in 93 formalin-fixed paraffin-embedded primary transitional cell carcinoma tissue samples. HIF-1 alpha was recognized through nuclear staining of positive cells. The angiogenic profile was individually assessed immunohistochemically using a monoclonal antibody to vascular endothelial growth factor (VEGF) and microvessel density (MVD) was calculated with immunohistochemical staining of the adhesion molecule CD31 of the endothelial cells. RESULTS: A significant positive association between HIF-1 alpha immunoreactivity and histological grade (p=0.009) was found. VEGF and MVD were closely related to tumor grade (p=0.06 and p<0.001) and clinical stage (p=0.04 and p<0.01, respectively). HIF-1 alpha was significantly correlated with VEGF expression (p=0.01) and MVD (p<0.001). Patients characterized by HIF-1 alpha overexpression had significantly worse overall (p=0.009) and disease-free survival (p=0.03). When HIF-1 alpha, histologic grade and stage were included in multivariate Cox regression analysis, HIF-1 alpha emerged as an independent prognostic factor (p=0.02) along with grade and stage, but lost its independent prognostic value after the inclusion of angiogenic factors in the multivariate model. In the subgroup of patients with T1 disease, HIF-1 alpha emerged as a significant negative predictor of the time to first recurrence. CONCLUSIONS: HIF-1 alpha and angiogenesis markers may play an important predictive and prognostic role in patients with bladder cancer. HIF-1 alpha may be of biologic and clinical value as its overexpression is related to up-regulation of VEGF, the stimulation of angiogenesis and worse prognosis.     

高压氧对精索静脉曲张大鼠生精细胞凋亡及其基因缺氧诱导因子-α、bcl-2及bax表达的影响

目的 观察高压氧(HBO)对精索静脉曲张(VC)SD大鼠生精细胞凋亡的影响,探讨精索静脉曲张导致男性不育的机制.方法 50只青春期雄性SD大鼠,随机抽出10只作为假手术对照组(A).A组只游离左肾静脉不予结扎,其余40只部分结扎左肾静脉建立VC模型,8周后,将建立了VC模型的40只随机分为VC模型组(B)和HBO干预的VC模型组(C),C组用HBO对VC模型进行干预.实验结束后各组大鼠切取双侧睾丸,采用原位末端标记法(TUNEL)检测大鼠睾丸生精细胞凋亡,免疫组织化学检测低氧诱导因子(HIF)-α、bcl-2及bax的基因表达.结果 B组较A组生精细胞凋亡数明显增多,HIF-α、bax表达增强(P＜0.01),bcl-2表达减弱(P＜0.01),bcl-2/bax比值降低;C组大鼠较B组生精细胞凋亡数减少(P＜0.01),HIF-α表达减弱(P＜0.01)、bcl-2/bax比值上升,而与A组比较差异无统计学意义.结论 VC大鼠生精细胞凋亡率增加,HIF-α表达增强、bcl-2和bax基因表达失调为其凋亡机制之一;高压氧可能通过HIF-α、bcl-2和bax基因调控途径调节生精细胞凋亡,从而改善VC所致的生精功能障碍.     

血管瘤中缺氧诱导因子-1α的表达和血管生成的研究

目的　探讨缺氧诱导因子- 1α(HIF-1α)在血管瘤中的表达以及其和血管内皮细胞生长因子 (VEGF)、新生微血管密度 (MVD)的关系。方法　采用免疫组化SP法检测 2 8例婴幼儿血管瘤中HIF 1α、VEGF的蛋白表达和MVD。结果　 2 8例血管瘤中HIF-1α、VEGF的蛋白表达阳性率分别是6 4 % ,71.4 %。其中增生期和消退期HIF 1α阳性率分别为 87.5 %、33.3% (P <0.0 1) ,VEGF阳性率分别为 93.7%、4 1.7% (P <0.0 1) ;MVD分别为 73 4± 14 6 3、30 2± 9 1(P <0.0 1)。HIF 1α蛋白表达与VEGF成正相关 (P <0.0 1) ,HIF 1α和VEGF与MVD都成正相关 (P <0.0 1)。结论　血管瘤增生期血管内皮细胞存在着特殊的缺氧微环境 ,并通过HIF-1α表达水平提高调节VEGF等血管生成相关因子表达水平升高 ,促进了新生微血管生成     

胃癌组织缺氧诱导因子-1α与胰岛素样生长因子-Ⅱ表达对肿瘤血管生成的影响及预后评估

目的探讨胃癌组织中缺氧诱导因子-1α（HIF-1α）及胰岛素样生长因子-Ⅱ（IGF—Ⅱ）mRNA的表达水平及其与血管生成和预后的关系。方法采用原位杂交检测118例胃癌组织中HIF-1αmRNA和IGF—ⅡmRNA的表达情况,用免疫组化SP法标记CD34单克隆抗体,计算肿瘤微血管密度（MVD）。结果HIF—1αmRNA和IGF—ⅡmRNA在胃癌组织中的阳性表达率分别为49．2％和47．4％。且与胃癌临床侵袭转移病理指标均相关。HIF-1αmRNA和IGF-ⅡmRNA阳性表达者的MVD值,均高于阴性表达者;HIF-1αmRNA和IGF-ⅡmRNA表达呈正相关,MVD分别与HIF-1αmRNA和IGF—ⅡmRNA的表达水平呈正相关。HIF—1αmRNA和IGF—ⅡmRNA表达阳性及MVD值≥41．5个／0．72mm^2的患者的平均生存时间及5年生存率均低于表达阴性及MVD值〈41．5个／0．72mm^2者。结论HIF-1α与IGF—Ⅱ对胃癌的浸润转移,特别是对肿瘤血管形成具有重要作用,可作为预测患者预后和指导治疗的新途径。     

经导管动脉化疗栓塞术后肝细胞癌残癌组织HIF-1α、VEGF及CD34的表达水平

目的探讨缺氧诱导因子-1α（HIF-1α）在经导管动脉化疗栓塞术（TACE）后肝细胞癌（HCC）残癌组织中的表达及其与肿瘤新生血管的相关性。方法取TACE后手术切除的HCC组织标本24份（TACE组）和未经任何治疗直接手术切除的HCC组织标本30份（单纯手术组）。采用免疫组化SP法,检测残癌组织HIF-1α、血管内皮生长因子（VEGF）表达水平和微血管密度[MVD（CD34标记）]。结果 HIF-1α和VEGF在TACE组阳性表达率分别为95.83%、91.67%,显著高于单纯手术组（66.67%、63.33%,P=0.008、0.016）;TACE组残癌组织中MVD值显著高于单纯手术组（P〈0.001）。TACE组残癌组织中HIF-1α与VEGF表达呈正相关（r=0.546,P=0.006）;HIF-1α、VEGF表达与MVD值变化呈正相关（r=0.512,P=0.010;r=0.793,P〈0.001）。结论 TACE后能明显上调HIF-1α的表达,HIF-1α/VEGF通路在血管新生过程中起重要作用,可能是HCC经TACE后残癌复发、转移的原因之一。     

低氧诱导因子1α及血管内皮生长因子在前列腺癌中的表达及意义

目的:观察低氧诱导因子1α(H IF-1α)及血管内皮生长因子(VEGF)在前列腺癌(PCa)中的表达及意义。方法:32例PCa患者,根据G leason评分,将≥7分者设为高G leason评分组(n=12),<7分者为低G leason评分组(n=20)。良性前列腺增生(BPH)16例,BPH伴高级别前列腺上皮内瘤(PIN)15例,正常前列腺组织(NP)12例。采用免疫组化染色CD34观察各组组织中微血管密度(MVD)及H IF-1α、VEGF的表达情况。结果:PCa、PIN中H IF-1α阳性表达率分别为62.5%、60.0%,较BPH(6.3%)及NP(0)高,差异有统计学意义(P<0.05)。PCa、PIN中VEGF阳性表达率分别为78.1%、73.3%,较BPH(18.7%)及NP(8.3%)高,差异亦有统计学意义(P<0.05)。PCa的MVD为66.9±18.0,明显高于BPH(28.3±6.9)及NP(15.3±2.9)(P<0.05)。高G leason评分组H IF-1α、VEGF阳性率及MVD值均高于低G leason评分组,差异均有显著性(P<0.05)。结论:H IF-1α及VEGF过表达是PCa形成的早期事件,与PCa密切相关。     

精索静脉曲张大鼠睾丸低氧与生精细胞凋亡的研究

目的 观察实验精静索静咏曲张(varicocele,VC)大鼠睾丸低氧诱导因子1α(HIF-1α)的表达与睾丸生精细胞凋亡的关系,探讨VC导致不育的病理生理机制.方法 40只大鼠,随机分为3组.建立模型49d后,取其左侧睾丸组织,检测睾丸组织的HIF-1α的表达和生精细胞的凋亡率.结果 westernblot和免疫组化检测的实验组睾丸HIF-1α的表达(2.529±1847,78.57%)显著高于对照组(0.308±0.165,14.29%)和假手术组(0.309±0.164,0.00%)(P<0.05),差异均具统计学意义;实验组睾丸细胞凋亡指数(20.79±5.70)显著低于对照组(0.6±1.4)和假手术组(0.36±0.71)(P<0.001),差异均具统计学意义;实验组睾丸HIF-1α的表达与其细胞凋亡指数呈正相关(r=0.844,P=0.017).结论 VC可引起睾丸低氧,而低氧可以通过诱导生精细胞凋亡来引起睾丸功能的改变.同时,HIF-1α是一种预测生精细胞凋亡程度的有用指标.     

Ang2,HIF-1α及VEGF对肝癌血管形成的影响

摘要：目的:探讨促血管生成素2（Ang2）、缺氧诱导因子1α（HIF-1α）及血管内皮生长因子（VEGF）与肝细胞癌血管形成的关系。方法:检测52例肝癌组织中Ang2，HIF-1α及VEGF mRNA及蛋白的表达，对共表达的肝癌组织进行微血管计数。结果:RT-PCR 显示,52例肝癌组织中有38例共表达Ang2mRNA，HIF-1αmRNA 和VEGF mRNA，且两两之间呈明显正相关(分别为r=0.783，P<0.01；r=0.427，P<0.05；r=0.433，P<0.05)；免疫组化发现,52例肝癌组织36例共表达Ang2，HIF-1α和VEGF蛋白。共表达Ang2 mRNA，HIF-αmRNA 和VEGF蛋白的38例肝癌组织中,平均微血管数［(45.4±8.90) 个/HP］,明显高于非共表达组［(13.6±3.30)个/HP］（P<0.05)。结论:Ang2，HIF-1α和VEGF与肝癌的新生血管形成有关；肿瘤组织缺氧可能是其始动因素。     

Expression of hypoxia-inducible angiogenic proteins (hypoxia-inducible factor-1alpha, vascular endothelial growth factor, and E26 transformation-specific-1) and plaque hemorrhage in human carotid atherosclerosis

OBJECT: Plaque hemorrhage in carotid atherosclerosis promotes plaque progression, resulting in cerebrovascular disease. Hypoxia inducible factor-1alpha (HIF-1alpha) induces angiogenesis via the expression of vascular endothelial growth factor (VEGF) and E26 transformation-specific-1 (Ets-1). The authors investigated human carotid plaques to determine whether these hypoxia-inducible angiogenic proteins play a major role in intraplaque angiogenesis and hemorrhage. METHODS: The expression of HIF-1alpha, VEGF, and Ets-1 was analyzed using immunohistochemistry and Western blotting in 29 human carotid plaques obtained at carotid endarterectomy. The authors investigated the relationship between plaque characteristics and clinical symptoms. RESULTS: A higher incidence of plaque hemorrhage was observed in plaques associated with symptoms than in those without symptoms (p = 0.03). Hypoxia-inducible factor-1alpha, VEGF, and Ets-1 coexisted in the deep layer of plaque, where angiogenesis was remarkably developed; the expression levels of HIF-1alpha, VEGF, and Ets-1 were significantly enhanced in the main lesion of the plaque (p < 0.01). Symptomatic plaques showed higher expression of VEGF (p = 0.04) than asymptomatic plaques. Plaques with hemorrhage showed a higher incidence of plaque ulcer (p = 0.001) and higher expression of Ets-1 (p = 0.03) than those without hemorrhage. Moreover, significantly increased expressions of VEGF (p = 0.01) and Ets-1 (p = 0.006) were observed in plaques with not only hemorrhages but also ulcers and severe stenosis. CONCLUSIONS: The findings in this study suggest that hypoxia-inducible angiogenic proteins in human carotid atherosclerosis promote intraplaque angiogenesis, which can induce plaque hemorrhage and progression.     

Expression of hypoxia-inducible factor-1alpha and its relationship to tumour angiogenesis and cell proliferation in cartilage tumours

We investigated the use of hypoxia-inducible factor (HIF) proteins as prognostic markers in chondrosarcoma and the relationship of HIF to the biological characteristics of cartilage tumours. The expression of HIF-1alpha, HIF-2alpha, proliferating cell nuclear antigen (PCNA) and microvessel density (MVD) were measured immunohistochemically in 29 specimens of cartilage tumour. There was no HIF-1alpha and HIF-2alpha staining in any of the nine benign cartilage tumours. In 20 specimens of chondrosarcoma, the rate of HIF-1alpha and HIF-2alpha expression was 40% and 25%, respectively. The tumour size (> or = 8 cm), histological grade (grade 2 and grade 3) surgical margin (marginal and intralesional) and HIF-1alpha expression (positive) correlated significantly with a shorter disease-free survival. There was a significant association between HIF-1alpha and the MVD and a strong trend towards a correlation between HIF-1alpha and the PCNA index or histological grade. Our findings suggest that HIF-1alpha protein may be a useful objective marker in the assessment of the prognosis in chondrosarcoma, since it plays an important role in tumour angiogenesis and cell proliferation.     

反义HIF-1α基因治疗人肝癌裸鼠移植瘤的实验研究

摘要：目的:探讨反义HIF-1α基因对人肝癌裸鼠皮下移植瘤的影响及其相关机制。方法:使用人原发性肝癌细胞株SMMC-7721建立人肝癌裸鼠皮下移植瘤动物模型。待肿瘤生长至直径约0.4cm时，将荷瘤裸鼠随机分为3组，分别注射生理盐水、质粒PcDNA3和HIF-1α/PcDNA3B，质粒用脂质体DOTAP介导转染细胞。观察各组动物的肿瘤生长曲线；取肿瘤标本作免疫组织化学检查（SABC法）及蛋白质印迹检查，检测各组肿瘤的VEGF和HIF-1α表达及微血管密度（MVD）和细胞凋亡。结果:HIF-1α/PcDNA3B治疗组各时点的肿瘤体积，以及肿瘤组织中HIF-1α蛋白、MVD，VEGF表达均低于对照组，而细胞凋亡指数高于对照组，差异均有显著性（P＜0.05）。结论:通过阻断癌细胞的缺氧适应途径，反义HIF-1α基因治疗肝癌有抑制肿瘤生长、抑制肿瘤血管生成及诱导细胞凋亡的作用。     

缺氧诱导因子-1α在大鼠门静脉高压胃病中的作用研究

摘要：目的:通过检测缺氧诱导因子-1α(HIF-1α)在门静脉高压胃病（PHG）大鼠胃壁中的表达，探讨其对PHG病变所起的作用。方法:通过门静脉部分缩窄方法制备PHG大鼠模型，并设立假手术组（SO）作为对照，免疫组化法检测HIF-1α和血管内皮生长因子(VEGF)及CD34在大鼠胃壁组织中的表达，并对CD34阳性血管进行微血管密度 (MVD) 计数。结果:HIF-1α，VEGF和CD34在PHG组大鼠胃壁中的表达均明显高于SO组（P<0.01）。结论:HIF-1α的过度表达可能在PHG发病机制中起重要作用。     

大鼠退变椎间盘中环氧化酶-2、缺氧诱导因子-1α的表达及其与血管生成的关系

目的探讨环氧化酶-2(COX-2)与缺氧诱导因子-1α(HIF-1α)在退变的大鼠椎间盘的表达相关性,以及它们与椎间盘内新生毛细血管生成的相关性。方法选取3个月龄的大白鼠20只,随机分为实验组与对照组。将实验组10只大鼠手术切除腰1-骶1棘突、关节突,棘上、棘间韧带,切断双侧竖棘肌,然后缝合切口。对照组不行手术。12周后,处死所有大鼠,立即取L4-5椎间盘。通过免疫组化方法检测两组实验动物椎间盘中COX-2、HIF-1α表达情况及微血管的密度(MVD)。并通过统计分析描述COX-2与HIF-1α之间的关系及它们分别与椎间盘微血管密度(MVD)之间的关系。结果实验组的髓核中HIF-1α、COX-2阳性细胞率明显增高,在对照组的髓核组织中极少出现阳性细胞。此外,实验组椎间盘中的微血管密度明显增加。用直线相关分析表明,实验组动物椎间盘髓核组织内HIF-1α、COX-2之间呈显著正相关关系(P<0.05,r=0.678)。经多元线性回归分析实验组椎间盘髓核组织中MVD值与HIF-1α的表达之间和MVD与COX-2的表达之间具有相关性(P均<0.05)。结论 1.大鼠椎间盘退变过程中HIF-1α、COX-2的表达有相互促进作用;2.退变椎间盘的MVD值与HIF-1α及COX-2的高表达具有相关关系。     

超声微泡联合Ad-EGFP/HIF-1α介导EPCs移植治疗大鼠心肌梗死

目的探讨超声微泡联合Ad-EGFP/HIF-1α介导内皮祖细胞（EPCs）移植治疗大鼠心肌梗死的可行性。方法将Ad-EGFP/HIF-1α转染EPCs。将30只SD大鼠建立心肌梗死模型后随机分为5组：空白对照组（C组）、超声＋微泡组（US＋MB组）、单纯EPCs组、超声＋EPCs组（US＋EPCs组）及超声＋微泡＋EPCs组（US＋MB＋EPCs组）。EPCs移植后4周,用超声心动图检测大鼠左心室收缩功能,免疫组织化学（I HC）染色法检测CD34的表达及微血管密度（MVD）,Western blot检测VEGF蛋白的表达。结果 US＋MB＋EPCs组射血分数、短轴缩短率高于其他各组（P〈0.05）,MVD计数高于其他各组（P〈0.05）且VEGF蛋白表达水平最高（P〈0.05）。结论超声微泡联合Ad-EGFP/HIF-1α介导EPCs移植可通过促进VEGF的高效表达、刺激心肌梗死周边区血管生成等途径改善心肌梗死大鼠的心功能。     

重组人内皮抑素对尿毒症腹膜透析大鼠腹膜新生血管形成的影响

目的 研究重组人内皮抑素对尿毒症腹膜透析（PD）大鼠腹膜新生血管形成的影响。 方法 40只雄性SD大鼠,按随机数字表法分为正常对照组、肾衰竭非透析组、4.25%PD组、重组人内皮抑素10 mg/kg PD组、重组人内皮抑素40 mg/kg PD组,每组8只。对PD组规律PD 28 d。重组人内皮抑素干预组在行规律PD期间,隔天1次皮下注射重组人内皮抑素,至透析第28天结束。28 d后取各组大鼠新鲜腹膜组织,RT-PCR法检测腹膜组织血管内皮生长因子（VEGF）、碱性成纤维细胞生长因子（bFGF） mRNA表达;免疫组化染色检测VEGF、bFGF蛋白表达。CD34染色观察腹膜组织毛细血管密度（MVD）。 结果 各组大鼠腹膜组织均表达VEGF和bFGF,肾衰竭非透析组、4.25%PD组VEGF及bFGF mRNA、蛋白表达均显著高于正常对照组（均P < 0.05）;重组人内皮抑素10 mg/kg PD组、40 mg/kg PD组VEGF及bFGF mRNA、蛋白表达均显著低于4.25%PD组（均P < 0.05）。肾衰竭非透析组、4.25%PD组腹膜组织MVD均显著高于正常对照组（均P < 0.05）;重组人内皮抑素10 mg/kg、40 mg/kg PD组腹膜组织MVD均显著低于正常对照组（均P < 0.05）。 结论 重组人内皮抑素可以有效抑制PD大鼠腹膜新生血管的形成,下调VEGF、bFGF mRNA及蛋白表达可能是其抑制腹膜新生血管形成的机制之一。     

PTEN和VEGF的表达与膀胱癌血管生成关系的研究

目的研究膀胱癌组织中抑癌基因PTEN和血管内皮生长因子（VEGF）的表达与膀胱癌血管生成的关系。方法应用免疫组织化学S-P法检测62例膀胱癌组织和18例慢性膀胱炎组织（对照组）中PTEN和VEGF的表达，同时分析不同PTEN和VEGF表达状态下，膀胱癌组织微血管密度（MVD）的变化。结果膀胱癌组和对照组PTEN阳性率分别为53．2％（33／62）和100．0％（18／18），2组比较差异有统计学意义（P＜0．01）；膀胱癌组和对照组VEGF阳性率分别为62．9％（39／62）和27．8％（5／18），2组比较差异有统计学意义（P＜0．01）；PTEN和VEGF的表达呈负相关（r=-0．832，P＜0．01）。将膀胱癌分为4组，组A为PTEN阴性VEGF阳性（n=19），组B为PTEN阴性VEGF阴性（n=10），组C为PTEN阳性VEGF阳性（n=20），组D为PTEN阳性VEGF阴性（n=13）。4组平均MVD分别为41．53、31．40、26．55、25．15，组A显著高于其他3组（P＜0．05）。结论膀胱癌PTEN基因失活可能通过增加VEGF的表达来促进血管生成，导致肿瘤恶性进展。     

Effects of cyclooxygenase - 2 inhibitor on peritoneal function and angiogenesis in uremic peritoneal dialysis rats

Objective To investigate the effects of the cyclooxygenase-2 (COX-2) inhibitor (celecoxib) on angiogenesis and peritoneal function of uremic peritoneal dialysis rats. Methods Forty - eight male SD rats were selected, and they were randomly divided into five groups: normal control group(n=8), sham operation group(n=8), uremia group(5/6 nephrectomy, n=8), PD group [4.25% PD solution, 2 weeks PD model(n=8) and 4 weeks PD model(n=8)], PD + celecoxib intervention group[treated by celecoxib(20 mg/kg) via oral gavage, n=8].The peritoneum of uremic peritoneal dialysis rats was observed in different dialysis time from peritoneal structures, functions, peritoneal tissue capillary density (microvessel density, MVD) and COX-2, vascular endothelial growth factor (VEGF) expression level, and the impacts of celecoxib on uremic peritoneal dialysis rats peritoneal angiogenesis and peritoneal function were study. Results With the conduct of the peritoneal dialysis, peritoneal thickness increased, the inflammatory cells infiltrated, peritoneal equilibration test (PET) showed that ultrafiltration volume decreased significantly (P＜0.05), the amount of glucose transport rate rised significantly (P＜0.05), but the celecoxib could improve net ultrafiltration volume (P＜0.05), and reduce the glucose transport rate (P＜0.05). The peritoneal tissue MVD and COX - 2, VEGF expression were significantly increased in uremia group and PD group compared with that in the normal control group (all P＜0.05), were significantly lower in PD + Celecoxib intervention group than that in uremia group (P＜0.05). The correlation analysis showed that the level of COX-2 protein expression with MVD, VEGF protein expression was positively correlated (both P＜0.05), the level of VEGF protein expression and MVD was positively correlated (P＜0.05). Conclusions In vivo high glucose dialysate and uremia environmental can stimulate the COX-2 and VEGF expression raised, and the capillaries production increased in peritoneal tissue. Celecoxib can alleviate the change of peritoneal tissue morphology and function in long-term peritoneal dialysis rats. Celecoxib inhibits the peritoneal neovascularization of uremic peritoneal dialysis rats, possibly through inhibition of COX-2 expression to reduce the production of VEGF.     

Overexpression of vascular endothelial growth factor is responsible for the hematogenous recurrence of early-stage gastric carcinoma

Vascular endothelial growth factor (VEGF) is crucial for angiogenesis in various malignant tumors. However, it is still unclear whether VEGF is responsible for hematogenous metastasis after the curative resection of gastric carcinoma. In the present study, we evaluated the relevance of VEGF expression to the hematogenous recurrence of stage 1 or 2 primary gastric adenocarcinoma. Among 530 patients, 11 (2.1%) had hematogenous recurrence. Clinicopathological variables were compared between these 11 patients (group R) and 88 patients without intramucosal carcinoma who survived for more than 5 years (group S). Microvessel density (MVD) was assessed immunohistochemically along with VEGF protein expression in all patients from group R and 21 randomly selected patients from group S. There were significant differences in age, tumor size and VEGF expression in tumor tissue between the groups. Positive staining for VEGF protein was observed in all patients of group R, of whom 6 had strongly positive staining. On the other hand, 11 out of 21 patients in group S had positive staining and it was weak in all cases. Both the positive and strongly positive rate were significantly higher in group R than those in group S. There was no significant difference in MVD between the 2 groups (17.7 +/- 11.09/field in group R vs. 14.8 +/- 10. 27/field in group S) and no significant correlation between VEGF expression, MVD and venous invasion, though a weak correlation between the intensity of VEGF staining and MVD was observed (negative staining 12.1 +/- 10.51; weakly positive 16.67 +/- 10.41; strongly positive 19.7 +/- 9.97). Our results suggest that overexpression of VEGF, and not MVD or venous invasion, plays an important role in the hematogenous recurrence of curatively resected gastric carcinoma.