Site-dependent expression of vascular endothelial growth factor, angiogenesis and proliferation in human gastric carcinoma

To determine the role of site of tumor implantation on tumor angiogenesis, we implanted gastric cancer cells in the orthotopic (stomach) and ectopic (subcutaneous) locations in nude mice. Tumors in the stomach demonstrated greater vascularization, higher levels of vascular endothelial growth factor (VEGF) expression, and greater proliferation compared with tumors in the subcutaneous tissues. These data suggest that the relationships among the expression of VEGF, vascularization, and proliferation of human gastric cancer cells are regulated by the organ microenvironment. In addition, VEGF may provide a target for anti-angiogenic therapy for gastric cancers.     

EGCG对胃癌血管新生中VEGF信号通路的多靶点作用

目的：探讨EGCG对胃癌血管生成抑制作用及其信号通路。方法：建立裸鼠异位胃癌模型,经腹腔注射EGCG,检测肿瘤生长及肿瘤组织微血管密度;不同浓度EGCG处理胃癌细胞24 h,检测胃癌VEGF蛋白和mRNA表达及VEGF分泌;同时不同浓度EGCG处理脐静脉内皮细胞,检测内皮细胞生长、迁移和体外小管形成。结果：EGCG显著抑制胃癌生长和肿瘤血管生成,平均肿瘤抑制率60.4%;EGCG显著抑制胃癌VEGF蛋白、mRNA表达和VEGF分泌;EGCG时间和剂量依赖性地抑制VEGF诱导的内皮细胞增殖,同时也剂量依赖性地抑制VEGF诱导的内皮细胞的迁移和小管生成。结论：EGCG多靶点作用于VEGF信号通路,抑制胃癌生长和血管生成。     

天然14肽生长抑素联合5-Fu对胃癌移植瘤的抑制作用

目的 观察14肽生长抑素(SST-14)及其联合5-Fu对BGC-823、MKN-28人胃癌细胞移植瘤生长抑制及血管内皮生长因子(VEGF)表达的影响。方法 构建BGC-823、MKN-28人胃癌细胞移植瘤模型,随机分为对照组、SST-14组、5-Fu组、联合组,腹腔注射药物治疗3周后处死裸鼠获取肿瘤组织。测量瘤体重量,计算抑瘤率;免疫组化及Western blot检测瘤组织VEGF的表达。结果 其他三组较对照组均可抑制肿瘤生长,联合组较SST-14、5-Fu单纯用药组抑制作用显著(P＜0.05)。免疫组化及Western blot结果显示,与对照组相比,其他三组瘤组织VEGF表达下降(P＜0.05);其中联合组较SST-14组、5-Fu组显著下降(P＜0.05)。结论 14肽生长抑素联合5-Fu能够有效抑制不同分化程度胃癌细胞移植瘤生长,且优于单纯用药组,两药具有协同抑制作用,可能通过下调VEGF的表达,抑制肿瘤血管生成。     

RUNX3 inhibits the expression of vascular endothelial growth factor and reduces the angiogenesis, growth, and metastasis of human gastric cancer.

PURPOSE: Recent studies indicated that RUNX3 exhibits potent antitumor activity. However, the underlying molecular mechanisms of this activity remain unclear. In the present study, we used a gastric cancer model to determine the effect of RUNX3 expression on tumor angiogenesis. EXPERIMENTAL DESIGN: The effects of increased RUNX3 expression on vascular endothelial growth factor (VEGF) expression in and angiogenic potential of human gastric cancer cells were determined in vitro and in animal models. RUNX3 and VEGF expression was determined in 120 human gastric cancer specimens and their relationship was analyzed. RESULTS: RUNX3 gene transfer suppressed VEGF expression in human gastric cancer cells. Down-regulation of VEGF expression correlated with a significantly impaired angiogenic potential of human gastric cancer cells. Furthermore, RUNX3 restoration inhibited tumor growth and metastasis in animal models, which was consistent with inhibition of angiogenesis as determined by evaluating VEGF expression and tumor microvessel formation. In gastric cancer specimens, loss or decrease in RUNX3 expression inversely associated with increased VEGF expression and elevated microvessel formation. CONCLUSIONS: Our clinical and experimental data provide a novel molecular mechanism for the antitumor activity of RUNX3 and may help design effective therapy targeting RUNX3 pathway to control gastric cancer growth and metastasis.     

VEGF靶向治疗在胃癌中的临床研究进展

血管内皮生长因子（VEGF）是已知最强的刺激血管生成因子之一,其通过刺激血管内皮细胞增殖和血管通透性增加,促进肿瘤血管的形成。在实体肿瘤的发生、发展和转移中起重要作用。近年来以VEGF受体和VEGF传导通路中酪氨酸激酶为靶点的药物研究在胃癌治疗中有较大进展,是分子靶向治疗的热点。     

VEGF receptor antisense therapy inhibits angiogenesis and peritoneal dissemination of human gastric cancer in nude mice

The efficacy of a phosphorothioate antisense oligonucleotide (ASO) for KDR/Flk-1 (KDR/Flk-1-ASO), an endothelial cell-specific vascular endothelial growth factor (VEGF) receptor, was investigated on the peritoneal dissemination and angiogenesis of a human gastric cancer cell line in nude mice. Green fluorescent protein (GFP)-transduced NUGC-4 (NUGC-4-GFP) human gastric cancer cells were implanted into the peritoneal cavity of nude mice. KDR/Flk-1-ASO, -SO, or phosphate-buffered saline was administrated from days 7 to 14, 200 microg/mouse, once a day. The mice were sacrificed on day 28. Disseminated peritoneal tumor nodules expressing GFP were visualized by fluorescence microscopy. KDR/Flk-1-ASO significantly decreased the extent of peritoneal dissemination of the tumors. The number of cells undergoing apoptosis was significantly increased in the KDR/Flk-1-ASO-treated tumors. Microvessel density was significantly reduced in the KDR/Flk-1-ASO-treated tumor nodules. The KDR/Flk-1 antisense strategy, therefore, decreases tumor dissemination apparently by inhibiting angiogenesis.     

CH50多肽真核表达载体pCH510的构建、表达及体内趋化和抑瘤作用

目的：探讨血管内皮生长因子的表达与肿瘤血管生成的关系。方法：将VEGF165正、反义RNA表达载体导入人胃癌细胞,观察接种VEGF高表达和低表达胃癌细胞裸鼠移植瘤的生长情况,并对移植瘤进行组织学检查,检测其血管密度、组织增生及环死程度等变化。结果：VEGF正义转染细胞所致移植瘤的生长速度明显快于反义转染细胞所致的移植瘤;组织学检查发现,正义转染细胞移植瘤的血管密度显著高于的转染细胞所致的肿瘤。结论：血管皮生长因子通过启动血管生成而促进肿瘤的生长,阻断血管内皮生长因子的产生可以抑制肿瘤的生长。     

血管内皮生长因子的表达和血管生成与人胃癌移植瘤生长的关系

探讨血管内皮生长因子的表达与肿瘤血管生成的关系。方法 :将VEGF165正、反义RNA表达载体导入人胃癌细胞 ,观察接种VEGF高表达和低表达胃癌细胞裸鼠移植瘤的生长情况 ,并对移植瘤进行组织学检查 ,检测其血管密度、组织增生及坏死程度等变化。结果 :VEGF正义转染细胞所致移植瘤的生长速度明显快于反义转染细胞所致的移植瘤 ;组织学检查发现 ,正义转染细胞移植瘤的血管密度显著高于反义转染细胞所致的肿瘤。结论 :血管内皮生长因子通过启动血管生成而促进肿瘤的生长 ,阻断血管内皮生长因子的产生可以抑制肿瘤的生长。     

Avastin对胃癌裸鼠原位移植模型血管生成的影响

背景与目的:血管内皮生长因子(vascularendothelialgrowthfactor,VEGF)和肿瘤的生长和转移密切相关,本实验通过VEGF单克隆抗体Avastin联合或不联合氟尿嘧啶(5-fluorouracil,5-FU),对人类胃癌裸鼠原位种植模型的肿瘤生长和转移进行干预治疗,从而探讨Avastin对胃癌生长、转移和血管生成的抑制作用。方法:应用原位移植方法建立裸鼠胃癌转移模型,术后10天将裸鼠随机分为4组:对照组、5-FU单药组、Avastin单药组和联合用药组。经过6周的治疗,对裸鼠原位肿瘤的瘤重、抑瘤率、肿瘤微血管密度、凋亡指数以及肝脏转移灶进行检测和分析。结果:和对照组相比,5-FU单药组、Avastin单药组和联合用药组原位移植肿瘤重量明显降低,抑瘤率分别为37.52%,58.76%和98.51%。微血管密度Avastin单药组和联合用药组均比对照组明显减少(8.40±1.26和7.20±1.23vs15.30±1.06),而5-FU组与对照组之间没有显著的差别;Avastin单药组和联合用药组的凋亡指数比对照组明显升高[(11.50±1.58)%和(13.60±1.35)%vs(4.70±1.70)%]。联合应用Avastin和5-FU对肝脏转移灶具有明显的抑制作用,而其他3组的抑制肝转移效果没有明显的差别。结论:抗VEGF抗体Avastin通过抑制肿瘤新生血管的生成而诱导胃癌细胞凋亡,进而显著抑制裸鼠原位肿瘤的生长。联合应用Avastin和5-FU不仅对原位肿瘤的生长抑制最为明显,而且对肝脏转移有显著的抑制作用。因此,联合应用Avastin和传统的细胞毒化疗药物对胃癌的治疗效果更显著。     

The significance of placenta growth factor in angiogenesis and clinical outcome of human gastric cancer

Placenta growth factor (PlGF) is a member of the vascular endothelial growth factor (VEGF) family of proangiogenic factors and its overexpression has been linked to pathological angiogenesis. We studied the relationship between the expression of PlGF and VEGF in human gastric cancer tissues and microvessel density (MVD), as well as clinical outcome in 79 patients with gastric cancer by using an enzyme immunoassay for PlGF and VEGF expression levels in gastric cancers and surrounding non-cancerous mucosa. PlGF protein levels were significantly higher in tumor than in the corresponding non-tumorous mucosa (median value 48.5 vs 9.8 pg/mg, P < 0.001). In contrast, VEGF protein levels were not (66.7 vs 80.7 pg/mg, P = 0.522). VEGF expression level was not significantly correlated with MVD, patient survival, and clinicopathological factors except Lauren classification in this study. PlGF may be an important angiogenic factor in human gastric cancer, and PlGF expression level was significantly correlated with serosal invasion, positive lymph node metastases, tumor stages, and patient survival.     

胃癌组织中Sonic Hedgehog和VEGF表达及临床意义的研究

目的:探讨胃腺癌中Sonic Hedge-hog(Shh)和VEGF的表达及临床意义。方法:应用免疫组化法检测45例胃癌组织及15例癌旁胃黏膜组织中Shh和VEGF的表达。结果:Shh在胃癌组织中阳性表达率为66.7%,在中、低分化胃癌中的表达高于高分化胃癌中的表达,与组织分化程度相关,P<0.01,在癌旁胃黏膜组织中Shh表达为阴性或弱阳性(15.3%);VEGF在胃癌组织中的阳性表达率(71.1%)显著高于癌旁胃黏膜组织中的阳性表达率(26.7%),P<0.01,与肿瘤分化程度、淋巴结转移呈正相关,P<0.05。Shh和VEGF在胃癌组织中的表达存在相关性(0.01相似文献   

Anti‐angiogenic therapies for gastric cancer

Tumor angiogenesis plays an important role in cancer cell proliferation and metastasis. In gastric cancer, among the numerous clinical trials investigating various anti‐angiogenic therapies, such as antivascular endothelial growth factor (VEGF) or anti‐VEGF receptor (VEGFR)‐2 monoclonal antibodies, VEGF‐Trap and VEGFR tyrosine kinase inhibitors, the anti‐VEGFR‐2 antibody ramucirumab was shown to prolong overall survival not only as a single agent but also in combination with paclitaxel as a second‐line chemotherapy. Additionally, apatinib, a selective VEGFR‐2 tyrosine kinase inhibitor, prolonged survival as a third‐line or later treatment option in patients with advanced gastric cancer. Preliminary results of studies investigating ramucirumab plus immune checkpoint inhibitors in gastric cancer were encouraging, and further investigations are ongoing. In China, apatinib in combination with cytotoxic agents is being investigated for systemic chemotherapy or maintenance therapy as an earlier treatment option. The clinical activity in gastric cancer of the multikinase inhibitor regorafenib was suggested in a randomized phase II study. A global phase III trial comparing regorafenib with placebo is currently ongoing. Further studies of anti‐angiogenic therapy combined with not only chemotherapy but also immune checkpoint inhibitors are also being pursued, providing hope for improved survival in patients with gastric cancer.     

榄香烯脂质体对人胃癌细胞HGC-27的体内外作用的初步研究

背景与目的：近年来,许多研究表明榄香烯脂质体在临床治疗消化道肿瘤及其恶性胸腹水中应用广泛。本研究结合体内和体外实验旨在观察榄香烯脂质体对人胃癌细胞HGC-27生长的抑制作用。方法：在体外实验中,应用机器视觉-全自动活细胞观测分析系统(Cell-IQ)对不同浓度下的榄香烯脂质体进行观测,以筛选出对人胃癌HGC-27细胞产生抑制作用的最佳浓度,并通过流式细胞术分析在最佳浓度下,榄香烯脂质体对人胃癌细胞HGC-27凋亡的影响。在胃癌腹膜转移的裸鼠模型中,观察榄香烯脂质体、顺铂(cisplatin,DDP)等药物对裸鼠腹膜肿瘤指数(peritoneal cancer index,PCI)的影响,并用免疫组化检测CD31标记的肿瘤微血管密度(microvessel density,MVD)及血管内皮生长因子(vascular endothelial growth factor,VEGF)在肿瘤中的表达,以期对榄香烯脂质体抑制胃癌HGC-27细胞腹膜转移的机制进行探讨。结果：榄香烯脂质体作用于人胃癌细胞HGC-27后,Cell-IQ分析抑制作用随浓度增加,逐渐增强,以100 μg/mL为最佳,榄香烯脂质体浓度再增高,其抑制肿瘤作用不再增强。最佳作用时间为4~19 h。应用流式细胞术检测,100 μg/mL榄香烯脂质体作用于人胃癌HGC-27细胞24 h后,肿瘤细胞凋亡率为45%,对照组仅有0.019%。处理组的细胞凋亡率明显高于对照组。人胃癌腹膜转移裸鼠模型建立后给予榄香烯脂质体等药物干预,腹膜转移瘤PCI指数有明显差异,其中以联合治疗组下降明显,免疫组化检测发现CD31-MVD及VEGF蛋白表达与对照组差异无统计学意义(P>0.05)。结论：榄香烯脂质体对于人胃癌细胞有明确抑制作用,最佳质量浓度为100 μg/mL,最佳作用时间为4~19 h;榄香烯脂质体对人胃癌裸鼠腹腔转移有明确预防作用;榄香烯脂质体对人胃癌细胞抑制作用的主要机制可能为诱导凋亡。     

促血管生成素-2对胃癌血管生成的双向效应

目的　探讨促血管生成素 2 (Ang 2 )在胃癌血管生成中的作用。方法　运用RT PCR和S P免疫组化方法检测Ang 2mRNA、血管内皮生长因子 (VEGF)、CD34蛋白在 36例胃癌及其相应癌旁胃黏膜组织中的表达。结果　胃癌组织及其相应癌旁胃黏膜组织均见有Ang 2mRNA阳性表达 ,胃癌组织Ang 2mRNA的总体表达水平与微血管密度 (MVD)未见明显相关。胃癌组织Ang 2mRNA表达水平低于癌旁胃黏膜组织者 2 7例 ,其癌组织中 ,Ang 2mRNA的表达水平与MVD呈正相关 (r=0 .4 11,P <0 .0 5 ) ;同时 ,VEGF阳性表达者的MVD(45 .4 5± 10 .30 )明显高于VEGF阴性染色者 (30 .15± 8.6 9,P <0 .0 5 ) ,即在Ang 2表达上调的情况下VEGF促进血管生成。胃癌组织Ang 2mRNA表达水平高于癌旁组织者 9例 ,其癌组织中Ang 2mRNA的表达水平与肿瘤组织的MVD呈负相关 (r =- 0 .75 8,P <0 .0 5 ) ,VEGF的阳性表达者与阴性染色者间 ,MVD差异无显著性 ,即Ang 2抑制血管生成与VEGF的表达无相关性。结论　Ang 2对胃癌血管生成具有双向调节作用。     

The function and mechanism of COX-2 in angiogenesis of gastric cancer cells

Background

Here we aimed to investigate the effect of COX-2 siRNA on proliferation and angiogenesis of gastric cancer cells.

Methods

The gastric cancer cell line SGC7901 was transfected with COX-2 siRNA, then the growth and angiogenesis of cells were detected by in vitro and in vivo assay. Human microarray, RT-PCR and western blot were used to identify differentially expressed angiogenesis-related molecules in cells with decreased expression of COX-2.

Results

Down-regulation of COX-2 could significantly inhibit the in vitro and in vivo growth of gastric cancer cells, and suppress the migration and tube formation of human umbilical vein endothelial cells. Totally 23 angiogenesis-related molecules were found involved in COX-2-induced angiogenesis suppression. The results of RT-PCR and western blot showed that down-regulation of COX-2 might inhibit VEGF, Flt-1, Flk-1/KDR, angiopoietin-1, tie-2, MMP2 and OPN.

Conclusions

COX-2 might mediate tumor angiogenesis and growth, and could be considered as a target for gastric cancer therapy.     

幽门螺杆菌感染与胃癌中VEGF的表达及肿瘤血管形成的关系

目的探讨幽门螺杆菌(Hp)感染与胃炎、胃粘膜不典型增生和胃癌组织中血管内皮生长因子(VEGF)的表达及微血管密度(MVD)之间的关系.方法采用Warthin-Starry嗜银染色法检测39例胃癌组织,24例胃粘膜不典型增生组织和33例胃炎组织中的Hp;采用免疫组化S-P法检测组织中VEGF的表达,抗CD 34单克隆抗体标记血管内皮细胞,根据CD 34阳性的血管内皮细胞计数来测定MVD.结果 Hp、VEGF和MVD在慢性胃炎、胃粘膜不典型增生和胃癌组中的表达呈递增关系,每两组间比较均有显著性差异;VEGF阳性表达组MVD明显高于VEGF阴性组;Hp阳性组VEGF和MVD的表达明显高于Hp阴性组.结论 Hp感染可增加VEGF的表达,诱导组织中新生血管的形成,促进胃癌的发生.     

靶向VEGF/VEGFR通路治疗胃癌的研究进展

胃癌是目前全球最常见的恶性肿瘤之一,早期诊断率低,预后差,手术及放化疗对进展期胃癌的疗效有限。自1971年Folkman首先提出实体肿瘤的发展和转移离不开新生血管后,抗血管新生方面的研究就一直是肿瘤学的热点。血管内皮生长因子（VEGF）是已知的被多种实体肿瘤分泌的、最强的血管调控生长因子和信号传递因子,VEGF高表达是胃癌的特征之一。VEGF及其受体VEGFR在胃癌的发生、发展中发挥了重要作用。因此,靶向VEGF/VEGFR信号通路的治疗有望在胃癌的综合治疗方面取得重大突破。本文就VEGF/VEGFR信号转导路径及胃癌抗血管治疗的最新研究进展作一简要综述。