目的 通过复制人肝癌细胞株HepG2裸鼠皮下移植瘤模型，观察绿茶提取物表没食子儿茶素没食子酸酯（EGCG）干预对HepG2移植瘤新生血管生成的影响。 方法 瘤体接种复制HepG2移植瘤模型，荷瘤裸鼠20只随机分组，实验组给予EGCG溶液每日20 mg/（kg·只），腹腔注射3周，对照组给予等量灭菌注射用水3周，末次用药24 h，后处死裸鼠，剥离移植瘤。常规病理切片观察移植瘤组织结构；逆转录-聚合酶链式反应和免疫组织化学法检测移植瘤缺氧诱导因子-1α（HIF-1α）、血管内皮生长因子（VEGF）mRNA及蛋白表达，并通过检测CD34表达计数瘤组织微血管密度（MVD）。 结果 组织病理学观察实验组移植瘤见大量坏死区，瘤体内血管数量明显少于对照组；实验组HIF-1α、VEGF mRNA及蛋白表达水平比对照组均明显下调（P＜0.05），实验组MVD比对照组明显下降（P＜0.05）。 结论 EGCG可抑制荷瘤裸鼠HepG2移植瘤新生血管生成。
ObjectiveTo investigate the expression of keratinocyte growth factor (KGF) and cyclooxygen-ase-2 (COX-2) protein and microvessel density (MVD), and to explore their function and mechanism in the multistep process of gastric cancer. MethodsThe expressions of KGF and COX-2 protein in 64 samples of gastric cancer and 30 cases of normal gastric mucosa tissues were detected by immunohistochemistry. The MVD was detected by staining the endothelial cells in microvessles using anti-CD34 antibody. ResultsThe positive rate of KGF and COX-2 protein expression in gastric cancer were 65.6% (42/64) and 79.7% (51/64), respectively, which was significantly higher than that in normal gastric mucosa tissues 〔(23.3%, 7/30), P=0.046; (13.3%, 4/30), P=0.008〕. The MVD of gastric cancer was 31.8±8.0, which was significantly higher than that of normal gastric mucosa tissues (14.3±6.1), P=0.000. The MVD in gastric cancer with coexpressive KGF and COX-2 protein was 35.9±5.7, which was significant higher than that with non-coexpressive KGF and COX-2 protein (25.7±7.0), P=0.000. Both the expression of KGF and COX-2 protein were related to the invasion of serosa, lymph node metastasis and TNM staging (Plt;0.05, Plt;0.01). The MVD of gastric cancer tissues was related to lymph node metastasis and TNM staging (Plt;0.05), but unrelated to patient’s age, gender, and differentiation of tumor (Pgt;0.05). The co-expression of KGF and COX-2 protein was frequently found in patients with deeper invasion of serosa, lymph node metastasis, and higher TNM staging (Plt;0.05), but which was not associated withpatient’sage, gender, and differentiation of tumor (Pgt;0.05). The expression of KGF protein was positively correlated to the expression of COX-2 protein (r=0.610, P=0.000). There was positive correlation between MVD and the expression of KGF (r=0.675, P=0.000) and COX-2 protein (r=0.657, P=0.000) in gastric cancer, respectively. ConclusionKGF and COX-2 highly expressed by gastric cancer, which may be involved in the invasion and metastasis of gastric cancer by synergisticly promoting the angiogenesis.
Objective To evaluate the effect of vascular endothelial growth factor (VEGF) on tumor angiogenesis, and its usage in tumor therapy.Methods The recent literatures about VEGF and angiogenesis were reviewed and analyzed. The advances of VEGF study were summarized. The effects of anti-angiogenesis in tumor biological therapy were introduced.Results Angiogenesis had been identified as an important factor for promoting tumor growth. VEGF was a basic and pivotal factor in tumor angiogenesis. The anti-angiogenesis treatments aimed at VEGF, including the applications of VEGF inhibitor and gene therapy of adenovirus medium, had got great progress. Conclusion VEGF is a leading factor of tumor angiogenesis, the anti-angiogenesis therapy aimed at VEGF has probably provided a new chance to malignant tumor treatment.
ObjectiveTo investigate the expression of cyclooxygenase-2 (COX-2) and vascular endothelial growth factor (VEGF) in human pancreatic adenocarcinoma and their correlation with clinicobiological behavior.MethodsThe expression of COX-2 and VEGF in 51 cases of human pancreatic ductal adenocarcinoma were detected with immunohistochemistry of Envision.ResultsExpression of COX-2 and VEGF in pancreatic ductal adenocarcinoma were 74.5% and 68.6%, respectively; no expression of COX-2 and VEGF in adjacent normal tissue was detected. Both COX-2 and VEGF expression in clinical stage Ⅲ-Ⅳ were much higher than those in clinical stage Ⅰ-Ⅱ, and also higher in positive group of lymph node metastasis than in negative group as well (Plt;0.05). None of them had relation with histological grades, age, sex, tumor size and location. The expression of COX-2 was closely correlated with VEGF (r=0.411, Plt;0.01).ConclusionCOX-2 and VEGF may play a pivotal role in tumorigenesis and tumor progression in pancreatic cancer, they may provide new targets for therapy of pancreatic cancer.
ObjectiveTo analyze the concentrations of vascular endothelial growth factor (VEGF) and pigment epithelium-derived factor (PEDF) in aqueous humor of patients with proliferative diabetic retinopathy (PDR) before and after intravitreal injection of ranibizumab. MethodsTwenty-five eyes of 20 PDR patients were collected as the PDR group. Twenty-five eyes of 21 senile cataract patients were collected as the control group. There were no statistical significance in gender (χ2=0.223), age (Z=-1.555) and intraocular pressure (Z=-0.225) between the two groups (P > 0.05). Samples of aqueous humor (0.1 ml) were collected just before and 7 days after the injection of ranibizumab in PDR group. Samples of aqueous (0.1 ml) humor were collected just before cataract surgery in control group. The concentrations of VEGF and PEDF in the aqueous humor were measured by enzyme-linked immunosorbent assay. ResultsThe VEGF and PEDF concentration in the aqueous humor were reduced significantly after intravitreal injection of ranibizumab in PDR group (Z=-4.072, -4.319; P < 0.05). The concentrations of VEGF and PEDF in the aqueous humor before intravitreal injection of ranibizumab in PDR group were significantly higher than the control group (Z=-5.228, 4.706; P < 0.05). The VEGF concentration in the aqueous humor after intravitreal injection of ranibizumab in PDR group were similar to control group (Z=-1.557, P > 0.05). However, the concentration of PEDF in the aqueous humor after intravitreal injection of ranibizumab in PDR group still higher than control group (Z=-2.475, P < 0.05). The ratio of VEGF/PEDF before and after intravitreal injection of ranibizumab was statistically different (Z=-2.058, P < 0.05), but was the same between PDR group and control group (Z=-0.456, -0.844; P > 0.05). The aqueous humor concentrations of VEGF and PEDF were not significantly correlated with each other, neither in PDR group (r=-0.195, -0.174; P > 0.05) nor in control group (r=-0.286, P > 0.05). ConclusionsAqueous humor concentrations of VEGF and PEDF are significantly elevated in eyes with PDR. Intravitreal injection of ranibizumab significantly decreased the VEGF and PEDF in the aqueous humor after 7 days.
Objective To explore the inhibitory effects of r-k4k5 on retinal neovascularization. Methods Eighty-eight one-week-old C57BL/6J mice were put into the environment with 75% oxygen for 5 days to establish models of vascular proliferation retinopathy. One eye of each mouse received an intravitreal injection of 500 ng of r-k4k5 (large-dosage group) and of 250 ng of r-k4k5(small-dosage group), and the same volume of BSS was injected into the other eye of the mice both in these two groups as a control. The ADPase histochemical staining was used for retinal flatmount to observe changes of retinal vessels. The inhibitory effects of r-k4k5 on retinal neovascularization were evaluated by counting the endotheliocyte nuclei of new vessels extending from retina to vitreous in the tissue-slice. Results Regular distributions and reduced density of retinal blood vessels in eyes in the treatment group were found in retinal flatmount. The number of the endotheliocyte nuclei of new vessels extending from retina to vitreous was less in the eyes in the treatment group than which in control group (Plt;0.001). The nuclei of new blood vessels in the large-dosage group were less than which in small-dosage group (Plt;0.001). No histologic evidence of retinal toxicity or inflammatory response was found in the tissue-slice after the injection of r-k4k5. Conclusions Retinal neovascularization can be inhibited by intravitreal injection of r-k4k5,which suggests that intravitreal injection of r-k4k5 may have potential therapeutic benifits in retinal vascular disease. (Chin J Ocul Fundus Dis，2003，19：121-124)
OBJECTIVE To review the fundamental research and the experimental study of vascular endothelial growth factor (VEGF). METHODS The laboratory information and experimental study of VEGF were extensively reviewed. RESULTS VEGF, as a mitogen specifically for endothelial cells, could bly stimulate angiogenesis as well as vascular permeability, especially in hypoxia state. Experimentally, survival area and viability of flaps could be increased significantly when exogenous VEGF was applied in the form of protein or cDNA. CONCLUSION VEGF provides a new way for therapeutic angiogenesis in reparative and reconstructive surgery.
Anti-vascular endothelial growth factor (VEGF) drugs, including monoclonal antibodies (such as bevacizumab and ranibizumab) and fusion protein agents (such as aflibercept and conbercept) have been clinically proven to be effective to treat exudative age-related macular degeneration AMD). However, there are still some patients do not or poorly respond to the initial anti-VEGF agents, usually after several injections, ophthalmologists may switch to another anti-VEGF agent. In general, switching of anti-VEGF agent is considered for recurrent AMD, AMD resistance to anti-VEGF treatments. Current switching protocols include the replacement of monoclonal antibodies with fusion protein agents, the replacement of fusion protein agents with monoclonal antibodies, the substitution of one monoclonal antibody with another one, and the replacement of monoclonal antibodies with fusion protein agents and switching back with monoclonal antibodies. However, current researches on the switching of anti-VEGF drugs for exudative AMD are mostly retrospective and single-arm studies, and there are some differences in the results of different studies. Therefore, for patients with exudative AMD who do not respond to or respond poorly to anti-VEGF drugs, the efficacy of switching of anti-VEGF drugs is uncertain right now. Switching of anti-VEGF agents may improve the retinal anatomical outcome of the affected eye but may not necessarily improve visual acuity. Thus it is an option in the clinical practice to treat AMD. To determine the benefits of above mentioned switching regimens, randomized controlled clinical trials with large sample number and long study period will be needed.
【Abstract】Objective To investigate the correlation between the expression of fibronectin (FN) in extracellular matrix (ECM) and angiogenesis of gastric carcinoma.Methods The expressions of FN and vascular endothelial growth factor (VEGF) in 20 specimens of normal gastric tissue (normal group) and 80 specimens of gastric carcinoma tissue(gastric carcinoma group) were detected by EnVisonTM immunohistochemical technique. Tumor microvessel densit y (MVD) was evaluated by using antiCD34 antibody as an endothelial marker by the same technique as well. Results The immune complex of FN stained in brown were distributed around glands and in connective tissue of gastric specimens. In normal group, the staining of FN formed intact linear structure at basement membrane and presented regular striae form in connective tissue. In gastric carcinoma group, the integrity of linear structure of FN staining at basement membrane were destroyed to different extent and the staining of FN in connective tissue were changed deeper and distributed irregularly. The expression of VEGF and the value of MVD in the gastric carcinoma group was higher than those in normal group’s(P＜0.01, P＜0.01, respectively).This study indicated, that in gastric carcinoma group, the degree of FN expression in connective tissue had statistically positive correlations with the degree of VEGF expression and MVD value(P＜0.01, P＜0.05, respectively). Whereas the destruction extent of linear structure of FN staining at basement membrane showed no correlation with VEGF expression and MVD value(Pgt;0.05, Pgt;0.05, respectively).Conclusion The higher expression of FN in connective tissue of gastric carcinoma may well play a critical role in its process of angiogenesis and vasculogenesis. There may be an cooperative interactions between FN and VEGF in the process of angiogenesis and vasculogenesis of gastric carcinoma.