人脑胶质瘤血管内皮细胞生长因子受体表达的研究

目的　研究人脑胶质瘤血管内皮细胞生长因子受体 (Vascularendothelialgrowthfactorreceptors,VEGFR)的表达及意义 .方法　应用免疫组织化学技术 ,检测 5 2例手术切除的脑胶质细胞瘤组织中两种VEGFR(flt- 1和flk - 1)的表达 .结果　①胶质细胞瘤组织中有flt- 1和flk- 1的表达 ,主要表达于肿瘤血管内皮细胞 ,同时巨噬细胞的胞浆中也有表达 ;② 3组胶质细胞瘤中 ,VEGFR的表达率分别为 16 .0 %、5 8.8%、90 .0 % ,3组间有差异 (p <0 .0 5 ) ;③脑胶质细胞瘤中 ,flt- 1的表达与flk - 1的表达相关 (R =0 .993,p<0 .0 1) .结论　正常脑组织中无VEGFR表达 ,脑胶质细胞瘤中有VEGFR表达 ,主要表达于血管内皮细胞中 ,VEGF通过旁分泌途径刺激脑胶质细胞瘤的血管发生 ;VEGF的促血管发生作用既可通过血管内皮细胞的VEGFR直接产生 ,又可通过促进巨噬细胞的局灶浸润间接产生 ;VEGFR表达与脑胶质瘤恶性程度呈正相关     

血管内皮生长因子及其受体在大鼠附睾内精子上的表达

背景：血管内皮生长因子及其受体在男性生殖领域中占有重要地位,但其在生殖系统中表达的意义和调节机制仍不十分清楚。 目的：观察血管内皮生长因子及其受体类fms酪氨酸激酶在青春期大鼠附睾内精子上的表达定位情况。 方法：取10只青春期雄性SD大鼠双侧附睾,分离得到浓度为(30~40)×109 L-1的精子,涂片,免疫荧光法检测精子上血管内皮生长因子及其受体类fms酪氨酸激酶的表达定位情况。 结果与结论：免疫荧光结果显示,血管内皮生长因子及其受体类fms酪氨酸激酶阳性蛋白均定位于大鼠附睾精子头部的顶体、尾部的颈段、中段和主段,尾部末段和精子核未见阳性染色。提示,血管内皮生长因子及其受体类fms酪氨酸激酶可能参与了精子的成熟过程,与精子的运动能力、获能和顶体反应有关。      

血管内皮细胞生长因子受体结构与功能分析

血管内皮细胞生长因子受体(VEGFR)是VEGF特异性的受体,属于酪氨酸激酶亚家庭中的一个新成员,具有特征性的胞外区和酪氨酸激酶区,因其在刺激血管内皮细胞增殖、促进新生血管生成,特别是在促进肿瘤生长及转移中的作用,已越来越成为人们研究的热点。本文概括了3种VEGF受体在体内的不同分布,分析了不同VEGF受体在碱基序列及蛋白质功能结构域的异同,并介绍了可溶性VEGF受体功能差异,以及在肿瘤及与血管生成有关等疾病上的应用。     

胰岛素样生长因子-1在大鼠脑内的分布及禁食对其表达的影响

目的：观察大鼠脑内胰岛素样生长闪子-1（IGF-1）的分布,探讨禁食对大鼠脑IGF-1表达的影响。方法：大鼠分为对照组、禁食24h组和禁食72h组,SABC法免疫组织化学染色显示IGF-1免疫反应细胞。结果：IGF-1免疫反应细胞广泛分布于嗅球、大脑、小脑、下丘脑、中脑、延髓等部位。禁食组大鼠乳头体外侧核、嗅内皮质IGF-1表达水平减弱,海马下托和枕皮质IGF-1表达增强。禁食24h组和禁食72h组,脑内IGF-1表达无明显差异。结论：IGF-1在脑内广泛分布,禁食可改变某些脑区IGF-1的表达水平。     

人脑胶质瘤VEGF的表达和微血管检测及意义

目的探讨人脑胶质瘤中血管内皮细胞生长因子(VEGF)的表达与微血管数量(MVQ)和肿瘤良恶性程度的关系. 方法用免疫组织化学染色方法检测手术切除石蜡包埋的47例人脑胶质瘤(Ⅰ～Ⅱ级22例,Ⅲ级15例,Ⅳ级10 例)组织中的VEGF蛋白表达情况和MVQ数量,借助显微镜观察其阳性细胞数和阳性血管数; 另外,分别取脑外伤后开颅内减压术中切除的正常脑组织10例作为对照组. 结果①正常脑组织未检测到VEGF蛋白的表达,而MVQ数量少 ,表达强度弱;②各级别胶质瘤组织中均有VEGF和MVQ表达,主要表达于肿瘤细胞的胞浆和血管内皮细胞胞膜中;③3组胶质细胞瘤中VEGF的表达阳性率分别为22.2%、86.7%、90%、Ⅰ～Ⅱ级组与其它两组间差异有显著性意义(p<0.05;p<0.01),VEGF表达阳性组的MVQ平均值(46.8±12.4)明显高于阴性组MVQ值 (22.4±11.5)(p<0.01);④VEGF的表达与MVQ相关(r=0.75, p <0.001). 结论①VEGF在脑胶质瘤血管生成中起重要作用 ,能促进胶质瘤血管的形成;②VEGF和MVQ与胶质瘤良恶性程度明显相关,可作为脑胶质瘤病理诊断的补充指标;③VEGF可作为治疗脑胶质瘤的靶向,为胶质瘤的基因治疗提供指导方向.     

血管内皮细胞生长因子在人胎儿胃黏膜的表达

目的:探讨血管内皮细胞生长因子(VEGF)在不同胎龄的正常人胎儿胃黏膜的表达及其意义。方法:应用免疫组织化学SP法检测VEGF在20例12～34周人胎胃黏膜的表达。结果:VEGF在20例人胎胃黏膜上皮细胞和腺上皮细胞中均有表达,免疫反应产物分布于细胞质,胞核为阴性,在胃黏膜上皮细胞中的表达较腺上皮细胞弱。经与HE染色的邻片比较,腺上皮细胞中的免疫反应阳性细胞为壁细胞。随着胎儿的发育,胃腺内VEGF呈免疫反应阳性的壁细胞数目增多,免疫反应强度无明显变化。结论:VEGF在不同胎龄的人胎儿胃黏膜组织中均有表达,提示VEGF与人胎儿胃黏膜的生长发育有重要的调节作用。     

AKT和GSK3β在人脑胶质瘤中的表达

目的通过观察AKT和GSK3β蛋白在人脑胶质瘤中的表达变化,探讨AKT和GSK3β在脑胶质瘤发生中的关系及临床意义。方法应用免疫组织化学(IHC)SP法检测90例脑胶质瘤组织及15例正常脑组织中AKT和GSK3β蛋白的表达变化。结果正常脑组织与胶质瘤组织中AKT蛋白阳性率分别是30.00%与85.71%,两者差异有统计学意义(P0.05);AKT蛋白在低级别胶质瘤和高级别胶质瘤中的阳性率分别是65.71%与98.18%,两者之间差异有统计学意义(P0.05);GSK3β蛋白在低级别胶质瘤和高级别胶质瘤中的阳性率分别是48.57%与21.82%,两者之间差异有统计学意义(P0.05)。结论胶质瘤组织中AKT蛋白表达明显增加,且随着胶质瘤恶性程度的增加而增加,胶质瘤组织中GSK3β蛋白表达明显降低,且随着胶质瘤恶性程度的增加而降低,提示AKT和GSK3β蛋白在胶质瘤发生中相互作用。     

酪氨酸激酶受体RON在上皮性卵巢癌中的表达及其意义

目的:研究酪氨酸激酶受体 RON 在上皮性卵巢癌组织中的表达及其与临床病理学参数的关系.方法:采用逆转录聚合酶链反应和免疫组织化学方法分别检测 42 例上皮性卵巢癌新鲜组织 RON mRNA 及其对应 32 例石蜡组织中 RON蛋白的表达.结果:上皮性卵巢癌新鲜组织中 RON mRNA 阳性表达率为57.14%,对应的上皮性卵巢癌石蜡组织中 RON蛋白平均面密度值为(0.060 1±0.028 4),RON mRNA 和蛋白表达均与上皮性卵巢癌组织的临床分期、组织学分级及淋巴结转移有关.结论:RON 的过度表达与上皮性卵巢癌的进展、转移密切相关,检测 RON 的异常对判断肿瘤的临床进展及转移有一定的参考价值,RON 可能成为诊断治疗的新靶点.     

血管生成素-1激活tyrosine kinase/PDK增加血管内皮细胞[Mg2+]i

目的:探讨血管生成素-1(Ang-1)对人脐静脉内皮细胞(HUVECs)内游离镁离子浓度([Mg2 ]i)的调节机制.方法:我们采用荧光指示剂mag-fura-2,运用PTi阳离子测定系统动态测HUVECs的[Mg2 ]i.结果:Ang-l诱导的[Mg2 ]i增加与细胞外Mg2 浓度无关.Ang-1诱导的[Mg2 ]i增加与细胞内Ca2 浓度无关.经酪氨酸激酶阻断剂(tyrphostin A23和genistein),磷脂酰3激酶阻断剂(wortmannin和LY294002)预处理,均显著阻断Ang-1诱导的[Mg2 ]i增加.但经活化丝裂原激活激酶阻断剂(SB202190和PD98059)预处理,不能阻断Ang-1诱导的[Mg2 ].增加.结论:Ang-1通过酪氨酸激酶/磷脂酰3激酶信号传递途径使细胞内的Mg2 库释放Mg2 ,从而增加HUVECs的[Mg2 ]i.     

受体酪氨酸激酶EphA7在乳腺癌中的表达及其临床意义

目的观察受体酪氨酸激酶EphA7在乳腺癌和正常乳腺组织中的表达,探讨EphA7蛋白表达的临床意义。方法应用免疫组化En Vision法染色检测乳腺正常细胞系、乳腺癌肿瘤细胞系和150例浸润性导管癌组织中EphA7的表达,分析其表达与临床病理特征的相关性。结果 EphA7蛋白在乳腺癌细胞系和浸润性导管癌中表达丢失,其表达水平与患者年龄(r_s=-0.157,P=0.055)、肿瘤分级(r_s=-0.331,P0.001)呈负相关;与淋巴结转移(r_s=0.245,P=0.002)、TNM分期(r_s=0.217,P=0.008)、HER-2表达(r_s=0.179,P=0.028)呈正相关。结论 EphA7在多数乳腺癌细胞中表达丢失,可能在乳腺癌发生和转移中发挥重要作用。     

人脑胶质瘤VEGF的表达和微血管检测及意义

目的探讨人脑胶质瘤中血管内皮细胞生长因子(VEGF)的表达与微血管数量(MVQ)和肿瘤良恶性程度的关系. 方法用免疫组织化学染色方法检测手术切除石蜡包埋的47例人脑胶质瘤(Ⅰ～Ⅱ级22例,Ⅲ级15例,Ⅳ级10 例)组织中的VEGF蛋白表达情况和MVQ数量,借助显微镜观察其阳性细胞数和阳性血管数; 另外,分别取脑外伤后开颅内减压术中切除的正常脑组织10例作为对照组. 结果①正常脑组织未检测到VEGF蛋白的表达,而MVQ数量少 ,表达强度弱;②各级别胶质瘤组织中均有VEGF和MVQ表达,主要表达于肿瘤细胞的胞浆和血管内皮细胞胞膜中;③3组胶质细胞瘤中VEGF的表达阳性率分别为22.2%、86.7%、90%、Ⅰ～Ⅱ级组与其它两组间差异有显著性意义(p<0.05;p<0.01),VEGF表达阳性组的MVQ平均值(46.8±12.4)明显高于阴性组MVQ值 (22.4±11.5)(p<0.01);④VEGF的表达与MVQ相关(r=0.75, p <0.001). 结论①VEGF在脑胶质瘤血管生成中起重要作用 ,能促进胶质瘤血管的形成;②VEGF和MVQ与胶质瘤良恶性程度明显相关,可作为脑胶质瘤病理诊断的补充指标;③VEGF可作为治疗脑胶质瘤的靶向,为胶质瘤的基因治疗提供指导方向.     

Immunohistochemical Expression of Vascular Endothelial Growth Factor and Vascular Endothelial Growth Factor Receptor in Canine Cutaneous Fibrosarcomas

The expression of five markers associated with tumour angiogenesis, proliferation and apoptosis was studied in 24 canine cutaneous fibrosarcomas. Tumours were assigned histological grades and were immunohistochemically evaluated for the expression of vascular endothelial growth factor (VEGF) and vascular endothelial growth factor receptor-2 (VEGFR-2). Additionally, intra-tumour microvessel density (iMVD) was assessed by immunohistochemical labelling for expression of von Willebrand factor (vWf) and tumour proliferation index (PI) was measured following labelling of Ki-67 antigen. Finally, tumour apoptotic index (AI) was determined by application of the terminal deoxynucleotidyl transferase (TdT)-mediated dUTP end-labelling method (TUNEL). VEGF and VEGFR-2 expression were detected in 22/24 (92%) and 24/24 (100%) of fibrosarcomas, respectively. There was correlation between VEGF and VEGFR-2 expression (r = 0.51) and between histological grade and PI (r = 0.82). A significant difference in PI between tumours of different histological grade was found (P < 0.05). The median PI in grade 2 and 3 tumours (30.6 and 54.7, respectively) was significantly higher than in grade 1 tumours (6.4). Therefore, only PI correlates significantly with the histological grade of canine cutaneous fibrosarcomas. The potential for autocrine activity for VEGF exists in canine cutaneous fibrosarcomas, as VEGF and VEGFR-2 expression was found in most tumours.     

In Vitro Expression of Vascular Endothelial Growth Factor and Its Receptors by Placental Macrophages

The expression of VEGF and membrane-bound and soluble forms of the VEGF-R1 receptor in cultured placental macrophages (trimesters I and III of pregnancy) was studied by flow cytometry, cytometric bead array, and ELISA. Nearly all population of placental macrophages (98%) was capable of producing VEGF during the early and late gestational periods. However, the expression of cellular VEGF-R1 varied from 3.4 to 92%. VEGF secretion was relatively low in the first and third trimesters (0.5 and 1.1 pg/105 cells, respectively). Cultured placental macrophages produced soluble receptor sVEGF-R1 in the first and third trimesters (86.4 and 36.4 pg/105 cells, respectively). Stimulation with LPS was followed by a 4-fold increase in sVEGF-R1 secretion. Our results indicate that placental macrophages are involved in the autocrine and paracrine regulation in chorionic villi. The data suggest that these cells have a physiological and pathogenetic role in gestation.     

Human Herpesvirus-8-Transformed Endothelial Cells Have Functionally Activated Vascular Endothelial Growth Factor/Vascular Endothelial Growth Factor Receptor

Kaposi's sarcoma is a vascular tumor commonly associated with human immunodeficiency virus (HIV)-1 and human herpesvirus (HHV-8) also known as Kaposi's sarcoma-associated herpesvirus. The principal features of this tumor are abnormal proliferation of vascular structures lined with spindle-shaped endothelial cells. HHV-8 may transform a subpopulation of endothelial cells in vitro via viral and cellular gene expression. We hypothesized that among the cellular genes, vascular endothelial growth factors (VEGFs) and their cognate receptors may be involved in viral-mediated transformation. We have shown that HHV-8-transformed endothelial cells (EC-HHV-8) express higher levels of VEGF, VEGF-C, VEGF-D, and PlGF in addition to VEGF receptors-1, -2, and -3. Furthermore, antibodies to VEGF receptor-2 inhibited cell proliferation and viability. Similarly, inhibition of VEGF gene expression with antisense oligonucleotides inhibited EC-HHV-8 cell proliferation/viability. The growth and viability of primary endothelial cells and a fibroblast cell line however were unaffected by either the VEGF receptor-2 antibody or the VEGF antisense oligodeoxynucleotides. VEGF and VEGF receptors are thus induced in EC-HHV-8 and participate in the transformation. Inhibitors of VEGF may thus modulate the disease process during development and progression.     

Vascular Endothelial Growth Factor (VEGF) Expression in Human Pituitary Adenomas and Carcinomas

Vascular endothelial growth factor (VEGF) is a key mediator of endothelial cell proliferation, angiogenesis, and vascular permeability. Little is known about its expression in human pituitary adenomas. We examined 148 human pituitary adenomas for VEGF protein expression by immunohistochemistry. The strongest immunoreactivity was present in GH adenomas, corticotroph, silent corticotroph, silent subtype 3, and nononcocytic null cell adenomas. GH adenomas treated with octreotide strained less intensely than did untreated tumors. Relatively weak staining was present in PRL, gonadotroph, thyrotroph, and oncocytic null cell adenomas in the same sections showed evidence of down-regulation of VEGF protein expression in adenomas. Pituitary carcinomas usually had stronger staining than adenomas. In situ hybridization studies with oligonucleotide probes showed positive staining in all groups with stronger staining in GH, ACTH, TSH, and gonadotroph adenomas and in pituitary carcinomas. These results indicate that VEGF expression is more prominent in certain adenoma subtypes, that decreased expression occurs in adenomas as compared to nontumorous pituitary and that carcinomas show increased VEGF expression relative to adenomas suggesting up-regulation of VEGF during pituitary tumor progression.     

Polarized Vascular Endothelial Growth Factor Secretion by Human Retinal Pigment Epithelium and Localization of Vascular Endothelial Growth Factor Receptors on the Inner Choriocapillaris : Evidence for a Trophic Paracrine Relation

The retinal pigment epithelium (RPE) maintains the choriocapillaris (CC) in the normal eye and is involved in the pathogenesis of choroidal neovascularization in age-related macular degeneration. Vascular endothelial growth factor-A (VEGF) is produced by differentiated human RPE cells in vitro and in vivo and may be involved in paracrine signaling between the RPE and the CC. We investigated whether there is a polarized secretion of VEGF by RPE cells in vitro. Also, the localization of VEGF receptors in the human retina was investigated. We observed that highly differentiated human RPE cells, cultured on transwell filters in normoxic conditions, produced two- to sevenfold more VEGF toward their basolateral side as compared to the apical side. In hypoxic conditions, VEGF-A secretion increased to the basal side only, resulting in a three- to 10-fold higher basolateral secretion. By immunohistochemistry in 30 human eyes and in two cynomolgus monkey eyes, KDR (VEGFR-2) and flt-4 (VEGFR-3) were preferentially localized at the side of the CC endothelium facing the RPE cell layer, whereas flt-1 (VEGFR-1) was found on the inner CC and on other choroidal vessels. Our results indicate that RPE secretes VEGF toward its basal side where its receptor KDR is located on the adjacent CC endothelium, suggesting a role of VEGF in a paracrine relation, possibly in cooperation with flt-4 and its ligand. This can explain the known trophic function of the RPE in the maintenance of the CC and its fenestrated permeable phenotype and points to a role for VEGF in normal eye functioning. Up-regulated basolateral VEGF secretion by RPE in hypoxia or loss of polarity of VEGF production may play a role in the pathogenesis of choroidal neovascularization.     

血管内皮生长因子D在卵巢上皮癌组织内的表达与淋巴结转移的关系

目的观察血管内皮生长因子D(vascular endothelial growth factor D,VEGF-D)在卵巢上皮癌组织内的表达,探讨VEGF-D在卵巢癌淋巴管生成中的作用及其与淋巴结转移的关系。方法取人卵巢上皮癌组织78例,免疫组化法观察VEGF-D在卵巢上皮癌组织内的表达情况。以淋巴管内皮特异性标记物D2-40标记淋巴管,计数癌组织内淋巴管数密度。结果VEGF-D蛋白主要表达于卵巢癌细胞胞浆内,在淋巴结转移组卵巢癌组织内的表达水平明显高于无淋巴结转移组(P<0.01)。淋巴结转移组卵巢癌组织内的淋巴管数密度明显高于无淋巴结转移组(P<0.01)。结论VEGF-D表达与卵巢癌淋巴管数密度及淋巴结转移之间具有显著的相关性。     

Immunohistochemical Expression of Vascular Endothelial Growth Factor in Canine Mammary Tumours

The histopathological and clinical aspects of canine mammary tumours (CMTs) have been widely studied, but the variation in the biological behaviour of these neoplasms hampers the identification of prognostic factors. Sustained angiogenesis has been suggested to be one of the most important factors underlying tumour growth and invasion. This process involves the action of several growth factors including vascular endothelial growth factor (VEGF). The present study characterizes the relationship between immunohistochemical expression of VEGF and gross (e.g. size and tissue fixation) and microscopical (e.g. type, growth, necrosis, lymphoid infiltration, lymph node metastasis, histological grade and proliferation index) features of CMTs. Forty-eight benign and 64 malignant CMTs were evaluated. Statistical analysis failed to show a significant relationship between VEGF expression and the pathological features, suggesting that VEGF expression occurs in both benign and malignant tumours and is independent of histological type, proliferation, tissue invasion or local metastatic capacity.