Expression and significance of pigment epithelium-derived factor and vascular endothelial growth factor in colorectal adenoma and cancer

BACKGROUND The incidence and mortality of colorectal cancer(CRC)are among the highest in the world,and its occurrence and development are closely related to tumor neovascularization.When the balance between pigment epithelium-derived factors(PEDF)that inhibit angiogenesis and vascular endothelial growth factors(VEGF)that stimulate angiogenesis is broken,angiogenesis is out of control,resulting in tumor development.Therefore,it is very necessary to find more therapeutic targets for CRC for early intervention and later treatment.AIM To investigate the expression and significance of PEDF,VEGF,and CD31-stained microvessel density values(CD31-MVD)in normal colorectal mucosa,adenoma,and CRC.METHODS In this case-control study,we collected archived wax blocks of specimens from the Digestive Endoscopy Center and the General Surgery Department of Chengdu Second People's Hospital from April 2022 to October 2022.Fifty cases of specimen wax blocks were selected as normal intestinal mucosa confirmed by electronic colonoscopy and concurrent biopsy(normal control group),50 cases of specimen wax blocks were selected as colorectal adenoma confirmed by electronic colonoscopy and pathological biopsy(adenoma group),and 50 cases of specimen wax blocks were selected as CRC confirmed by postoperative pathological biopsy after inpatient operation of general surgery(CRC group).An immunohistochemical staining experiment was carried out to detect PEDF and VEGF expression in three groups of specimens,analyze their differences,study the relationship between the two and clinicopathological factors in CRC group,record CD31-MVD in the three groups,and analyze the correlation of PEDF,VEGF,and CD31-MVD in the colorectal adenoma group and the CRC group.The F test or adjusted F test is used to analyze measurement data statistically.Kruskal-Wallis rank sum test was used between groups for ranked data.The chi-square test,adjusted chi-square test,or Fisher's exact test were used to compare the rates between groups.All differences between groups were compared using the Bonferroni method for multiple comparisons.Spearman correlation analysis was used to test the correlation of the data.The test level(α)was 0.05,and a two-sided P<0.05 was considered statistically significant.RESULTS The positive expression rate and expression intensity of PEDF were gradually decreased in the normal control group,adenoma group,and CRC group(100%vs 78%vs 50%,χ^(2)=34.430,P<0.001;++~++vs+~++vs-~+,H=94.059,P<0.001),while VEGF increased gradually(0%vs 68%vs 96%,χ^(2)=98.35,P<0.001;-vs-~+vs++~+++,H=107.734,P<0.001).In the CRC group,the positive expression rate of PEDF decreased with the increase of differen-tiation degree,invasion depth,lymph node metastasis,distant metastasis,and TNM stage(χ^(2)=20.513,4.160,5.128,6.349,5.128,P<0.05);the high expression rate of VEGF was the opposite(χ^(2)=10.317,13.134,17.643,21.844,17.643,P<0.05).In the colorectal adenoma group,the expression intensity of PEDF correlated negatively with CD31-MVD(r=-0.601,P<0.001),whereas VEGF was not significantly different(r=0.258,P=0.07).In the CRC group,the expression intensity of PEDF correlated negatively with the expression intensity of CD31-MVD and VEGF(r=-0.297,P<0.05;r=-0.548,P<0.05),while VEGF expression intensity was positively related to CD31-MVD(r=0.421,P=0.002).CONCLUSION It is possible that PEDF can be used as a new treatment and prevention target for CRC by upregulating the expression of PEDF while inhibiting the expression of VEGF.

Anti-vascular endothelial growth factor drugs combined with laser photocoagulation maintain retinal ganglion cell integrity in patients with diabetic macular edema: study protocol for a prospective, non-randomized, controlled clinical trial

The integrity of retinal ganglion cells is tightly associated with diabetic macular degeneration that leads to damage and death of retinal ganglion cells,affecting vision.The major clinical treatments for diabetic macular edema are anti-vascular endothelial growth factor drugs and laser photocoagulation.However,although the macular thickness can be normalized with each of these two therapies used alone,the vision does not improve in many patients.This might result from the incomplete recovery of retinal ganglion cell injury.Therefore,a prospective,non-randomized,controlled clinical trial was designed to investigate the effect of anti-vascular endothelial growth factor drugs combined with laser photocoagulation on the integrity of retinal ganglion cells in patients with diabetic macular edema and its relationship with vision recovery.In this trial,150 patients with diabetic macular edema will be equally divided into three groups according to therapeutic methods,followed by treatment with anti-vascular endothelial growth factor drugs,laser photocoagulation therapy,and their combination.All patients will be followed up for 12 months.The primary outcome measure is retinal ganglion cell-inner plexiform layer thickness at 12 months after treatment.The secondary outcome measures include retinal ganglion cell-inner plexiform layer thickness before and 1,3,6,and 9 months after treatment,retinal nerve fiber layer thickness,best-corrected visual acuity,macular area thickness,and choroidal thickness before and 1,3,6,9,and 12 months after treatment.Safety measure is the incidence of adverse events at 1,3,6,9,and 12 months after treatment.The study protocol hopes to validate the better efficacy and safety of the combined treatment in patients with diabetic macula compared with the other two monotherapies alone during the 12-month follow-up period.The trial is designed to focus on clarifying the time-effect relationship between imaging measures related to the integrity of retinal ganglion cells and best-corrected visual acuity.The trial protocol was approved by the Medical Ethics Committee of the Affiliated Hospital of Beihua University with approval No.(2023)(26)on April 25,2023,and was registered with the Chinese Clinical Trial Registry(registration number:ChiCTR2300072478,June 14,2023,protocol version:2.0).

Overexpression of vascular endothelial growth factor enhances the neuroprotective effects of bone marrow mesenchymal stem cell transplantation in ischemic stroke

Although bone marrow mesenchymal stem cells(BMSCs)might have therapeutic potency in ischemic stroke,the benefits are limited.The current study investigated the effects of BMSCs engineered to overexpress vascular endothelial growth factor(VEGF)on behavioral defects in a rat model of transient cerebral ischemia,which was induced by middle cerebral artery occlusion.VEGF-BMSCs or control grafts were injected into the left striatum of the infarcted hemisphere 24 hours after stroke.We found that compared with the stroke-only group and the vehicle-and BMSCs-control groups,the VEGF-BMSCs treated animals displayed the largest benefits,as evidenced by attenuated behavioral defects and smaller infarct volume 7 days after stroke.Additionally,VEGF-BMSCs greatly inhibited destruction of the blood-brain barrier,increased the regeneration of blood vessels in the region of ischemic penumbra,and reducedneuronal degeneration surrounding the infarct core.Further mechanistic studies showed that among all transplant groups,VEGF-BMSCs transplantation induced the highest level of brain-derived neurotrophic factor.These results suggest that BMSCs transplantation with vascular endothelial growth factor has the potential to treat ischemic stroke with better results than are currently available.

Serum vascular endothelial growth factor and cortisol expression to predict prognosis of patients with hypertensive cerebral hemorrhage

BACKGROUND Cerebral hemorrhage is a common and severe complication of hypertension in middle-aged and elderly men.AIM To investigate the correlation between vascular endothelial growth factor(VEGF)and cortisol(Cor)and the prognosis of patients with hypertensive cerebral hemorrhage.METHODS A hundred patients with hypertensive intracerebral hemorrhage were enrolled from January 2020 to December 2022 and assigned to the hypertensive intracerebral hemorrhage group.Another 100 healthy people who were examined at our hospital during the same period were selected and assigned to the healthy group.Peripheral venous blood was collected,and serum Cor and VGEF levels were measured through enzyme linked immunosorbent assay.RESULTS A statistically significant difference in serum Cor and VGEF levels was observed among patients with varying degrees of neurological impairment(P<0.05).Serum Cor and VGEF levels were significantly higher in the severe group than in the mild-to-moderate group.Cor and VEGF levels were significantly higher in patients with poor prognoses than in those with good prognoses.Multiple logistic regression analysis revealed that serum Cor and VGEF levels were independent factors affecting hypertensive intracerebral hemorrhage(P<0.05).CONCLUSION Cor and VGEF are associated with the occurrence and development of hypertensive cerebral hemorrhage and are significantly associated with neurological impairment and prognosis of patients.

Vascular endothelial growth factor protein and gene delivery by novel nanomaterials for promoting liver regeneration after partial hepatectomy

Partial hepatectomy(PH)can lead to severe complications,including liver failure,due to the low regenerative capacity of the remaining liver,especially after extensive hepatectomy.Liver sinusoidal endothelial cells(LSECs),whose proliferation occurs more slowly and later than hepatocytes after PH,compose the lining of the hepatic sinusoids,which are the smallest blood vessels in the liver.Vascular endothelial growth factor(VEGF),secreted by hepatocytes,promotes LSEC proliferation.Supplementation of exogenous VEGF after hepatectomy also increases the number of LSECs in the remaining liver,thus promoting the reestablishment of the hepatic sinusoids and accelerating liver regeneration.At present,some shortcomings exist in the methods of supplementing exogenous VEGF,such as a low drug concentration in the liver and the reaching of other organs.Moreover,VEGF should be administered multiple times and in large doses because of its short half-life.This review summarized the most recent findings on liver regeneration and new strategies for the localized delivery VEGF in the liver.

Vascular endothelial growth factor B improves impaired glucose tolerance through insulin-mediated inhibition of glucagon secretion

BACKGROUND Impaired glucose tolerance(IGT)is a homeostatic state between euglycemia and hyperglycemia and is considered an early high-risk state of diabetes.When IGT occurs,insulin sensitivity decreases,causing a reduction in insulin secretion and an increase in glucagon secretion.Recently,vascular endothelial growth factor B(VEGFB)has been demonstrated to play a positive role in improving glucose metabolism and insulin sensitivity.Therefore,we constructed a mouse model of IGT through high-fat diet feeding and speculated that VEGFB can regulate hyperglycemia in IGT by influencing insulin-mediated glucagon secretion,thus contributing to the prevention and cure of prediabetes.AIM To explore the potential molecular mechanism and regulatory effects of VEGFB on insulin-mediated glucagon in mice with IGT.METHODS We conducted in vivo experiments through systematic VEGFB knockout and pancreatic-specific VEGFB overexpression.Insulin and glucagon secretions were detected via enzyme-linked immunosorbent assay,and the protein expression of phosphoinositide 3-kinase(PI3K)/protein kinase B(AKT)was determined using western blot.Further,mRNA expression of forkhead box protein O1,phosphoenolpyruvate carboxykinase,and glucose-6 phosphatase was detected via quantitative polymerase chain reaction,and the correlation between the expression of proteins was analyzed via bioinformatics.RESULTS In mice with IGT and VEGFB knockout,glucagon secretion increased,and the protein expression of PI3K/AKT decreased dramatically.Further,in mice with VEGFB overexpression,glucagon levels declined,with the activation of the PI3K/AKT signaling pathway.CONCLUSION VEGFB/vascular endothelial growth factor receptor 1 can promote insulin-mediated glucagon secretion by activating the PI3K/AKT signaling pathway to regulate glucose metabolism disorders in mice with IGT.

Role of vascular endothelial growth factor B in nonalcoholic fatty liver disease and its potential value

Nonalcoholic fatty liver disease(NAFLD)refers to fatty liver disease caused by liver injury factors other than alcohol.The disease is characterized by diffuse fat infiltration,including simple steatosis(no inflammatory fat deposition),nonalcoholic fatty hepatitis,liver fibrosis,and so on,which may cause liver cirrhosis,liver failure,and even liver cancer in the later stage of disease progression.At present,the pathogenesis of NAFLD is still being studied.The"two-hit"theory,represented by lipid metabolism disorder and inflammatory reactions,is gradually enriched by the"multiple-hit"theory,which includes multiple factors,such as insulin resistance and adipocyte dysfunction.In recent years,vascular endothelial growth factor B(VEGFB)has been reported to have the potential to regulate lipid metabolism and is expected to become a novel target for ameliorating metabolic diseases,such as obesity and type 2 diabetes.This review summarizes the regulatory role of VEGFB in the onset and development of NAFLD and illustrates its underlying molecular mechanism.In conclusion,the signaling pathway mediated by VEGFB in the liver may provide an innovative approach to the diagnosis and treatment of NAFLD.

Expression of vascular endothelial growth factor and its receptors VEGFR-1 and 2 in gastrointestinal stromal tumors,leiomyomas and schwannomas

AIM: To investigate the role of vascular endothelial growth factor (VEGF) and its receptors VEGFR-1 and 2 in the growth and differentiation of gastrointestinal stromal tumors (GISTs). METHODS: Thirty-three GISTs, 15 leiomyomas and 6 schwannomas were examined by immunohistochemistry in this study. RESULTS: VEGF protein was expressed in the cytoplasm of tumor cells, and VEGFR-1 and 2 were expressed both in the cytoplasm and on the membrane of all tumors. Immunohistochemical staining revealed that 26 GISTs (78.8%), 9 leiomyomas (60.0%) and 3 schwannomas (50.0%) were positive for VEGF; 24 GISTs (72.7%), 12 leiomyomas (80.0%) and 4 schwannomas (66.7%) were positive for VEGFR-1; 30 GISTs (90.9%), 5 leiomyomas (33.3%) and 4 schwannomas (66.7%) were positive for VEGFR-2. VEGFR-2 expression was statistically different between GISTs and leiomyomas (p < 0.0001). However, there was no correlation between the expression of VEGF pathway componenets and the clinical risk categories. CONCLUSION: Our results suggest that the VEGF pathway may play an important role in the differentiation of GISTs, leiomyomas and schwannomas.

Abnormal expression of vascular endothelial growth factor (VEGF) and its clinical features in tissues of human lung cancer

Objective： Angiogennesis, the formation of new blood vessels from the existing vascular bed, is essential step for growth and invasion of primary rumor. Vascular endothelial growth factor （VEGF） is known to play crucial role in tumor angiogenesis. In the present study, we investigate the expression of VEGF and VEGF-mRNA in the angiogennesis, metastasis and prognosis of lung cancer. Methods： The VEGF cellular distributions and expression in 38 specimens of patients with lung cancer were investigated with immunohistochemistry stain technology. The total RNAs in 38 tissues of lung cancer was measured, then the levels of VEGF-mRNA expression were analyzed by a reverse-transcription polymerase chain reaction （RT-PCR） assay. The levels of VEGF in sera of patients with lung cancer, benign lung diseases and healthy controls were detected through Enzyme linked immunosorbent assay （ELISA） method. Results： The VEGF positive stain was 76% in 38 cases of lung cancer specimens. The 89% rate of VEGF stain was found for clinical stage Ⅲ cases and 92% for stage Ⅳ lung cancers. The significantly higher expression of VEGF was evidenced in patients with lymph node metastasis （84%）, distant metastasis （90%）, and lung cancers with lower histological differentiation （89%）, respectively. The expression level of total RNA was significantly higher in patients with lung cancers than that in their paracancerons or distant lung tissues. The VEGF expressions were tightly correlated with total RNA concentration of lung carcinoma （ P 〈 0.01 ）. The predominant expressions of VEGF121 and VEGF165 gene fragments were found in lung cancer specimens by RT-PCR analysis. No significant difference of serum VEGF levels was detected between cases with lung cancer and patients with benign diseases. However, the VEGF level of cases with benign diseases was decreased significantly after patients with anti-inflammation medication. Conclusion： The present data suggested that the rumor tissue VEGF expression and VEGF-mRNA analysis in patients with lung cancer be a useful indicator for angiogenesis and metastasis of lung cancer.

Expression of Vascular Endothelial Growth Factor (VEGF) in Human Osteosarcoma Cells Transfected with Adeno-associated Virus-antisense VEGF

Summary: The expression of protein vascular endothelial growth factor (VEGF) in osteosarcoma cells transfected with adeno-associated virus (rAAV)-antisense VEGF was studied to provide the foundation of osteosarcoma treatment through antivascularization. The rAAV-antisense VEGF at different doses (0, 20, 50, 100, 200, 240 μl) was transfected into osteosarcoma MG-63 cell. The cells and culture supernatants were collected before and after tansfection. The expression of VEGF protein was detected by using immunohistochemical staining (SP) and Western blot. SP and Western-blot tests revealed that the MG-63 Cells transfected with rAAV-antisense VEGF had less staining than those without transfection with rAAV-antisense VEGF, and the staining intensity was negatively correlated with the doses of genes. The corresponding A values of transfected genes with different doses of rAAV-antisense VEGF (0, 20, 50, 100, 200, 240 μl) were 86 614±13 776, 73 245±15 414, 61 078±12 124, 54 657±10 953, 39 802±11 308, 32 014±15 057 respectively, with the difference being significant (P<0.05). It was concluded that the expression of VEGF protein in MG-63 cells could be inhibited by rAAV-antisense VEGF.

Downregulation of transforming growth factor-<i>β</i>(TGF-<i>β</i>) and vascular endothelial growth factor (VEGF) in ehrlich ascites carcinoma-bearing mice using stearic acid-grafted carboxymethyl chitosan (SA-CMC)

The present study was conducted to investigate the use of stearic acid-grafted carboxymethyl chitosan(SA-CMC) as a downregulator for trans- forming growth factor-β (TGF- β) and vascular endothelial growth factor (VEGF) in Ehrlich ascites carcinoma (EAC)-bearing mice. The antitumor effect of stearic acid-grafted carboxymethyl chitosan was assessed by the estimation of TGF- β and VEGF in serum in addition to the estimation of tumor volume, median survival time (MST), percentage of increase in life span (ILS%) as well as the contents of total lipid, DNA and RNA in liver tissues. Hematological profiles (hemoglobin, red blood cells, and platelets) were also assessed. In addition, liver function tests and the redox status were estimated. TGF- β, VEGF, DNA, RNA, and malondialdehyde (MDA) levels, in addition to serum alanine transaminase (ALT) and gamma glutamyl transferase (GGT) activities as well as total white blood cells counts and tumor volume were all highly significantly increased (P < 0.001) in untreated EAC-bearing mice compared to controls. However, hematological profiles, total lipid in liver tissues and serum albumin were highly decreased in EAC-bearing mice compared to controls. All these parameters were restored to the normal levels in SA-CMC treated EAC-bearing mice com- pared to the untreated EAC-bearing mice. It is thus concluded that stearic acid-grafted carboxymethyl chitosan has a remarkable antitumor activity against EAC in Swiss albino mice through downregulation of TGF-β and VEGF.

THE EXPRESSIONS AND SIGNIFICANCES OF p15,p16 AND VASCULAR ENDOTHELIAL GROWTH FACTOR (VEGF) IN GASTRIC CARCINOMA

To investigate the relationships between the expressions of p15,p16 and vascular endothelial growth factor (VEGF) and gastric carcinoma(GC). Methods: Using Immunohistochemical staining to examine the expressions of p15, p16 and VEGF In archival wax-embedded specimens of 80 GC and 20 gastric benign disease (GBD). Results: The positive expression rate (PER) of p15 was significantly lower in GC than in GBD (43.75% VS. 69.23%, P<0.05). No relationship was found between PER of p15 and clinicopathologic factors. PER of p16 was 20% in GC, 55% in GBD (P<0.01). PER of p16 wasn't significantly different in gross types, histological types, with or without distant metastasis and pTNM stages. PER of p16 was 71.43% in invasive mucosa or submucosa group, 17.24% in invasive muscle group and 13.64% in invasive serosa group (P<0.01); 12.96% in GC with lymph nodes metastasis, 34.62% in GC without lymph node metastasis (P<0.05). PER of VEGF in GC was 75.00%, in GBD 7.69% (P<0.001), in ul-cerative type of GC and infiltrating

Integrin binding peptides facilitate growth and interconnected vascular-like network formation of rat primary cortical vascular endothelial cells in vitro

Neovascularization and angiogenesis in the brain are important physiological processes for normal brain development and repair/regeneration following insults. Integrins are cell surface adhesion receptors mediating important function of cells such as survival, growth and development during tissue organization, differentiation and organogenesis. In this study, we used an integrin-binding array platform to identify the important types of integrins and their binding peptides that facilitate adhesion, growth, development, and vascular-like network formation of rat primary brain microvascular endothelial cells. Brain microvascular endothelial cells were isolated from rat brain on post-natal day 7. Cells were cultured in a custom-designed integrin array system containing short synthetic peptides binding to 16 types of integrins commonly expressed on cells in vertebrates. After 7 days of culture, the brain microvascular endothelial cells were processed for immunostaining with markers for endothelial cells including von Willibrand factor and platelet endothelial cell adhesion molecule. 5-Bromo-2′-dexoyuridine was added to the culture at 48 hours prior to fixation to assess cell proliferation. Among 16 integrins tested, we found that α5β1, αvβ5 and αvβ8 greatly promoted proliferation of endothelial cells in culture. To investigate the effect of integrin-binding peptides in promoting neovascularization and angiogenesis, the binding peptides to the above three types of integrins were immobilized to our custom-designed hydrogel in three-dimensional(3 D) culture of brain microvascular endothelial cells with the addition of vascular endothelial growth factor. Following a 7-day 3 D culture, the culture was fixed and processed for double labeling of phalloidin with von Willibrand factor or platelet endothelial cell adhesion molecule and assessed under confocal microscopy. In the 3 D culture in hydrogels conjugated with the integrin-binding peptide, brain microvascular endothelial cells formed interconnected vascular-like network with clearly discernable lumens, which is reminiscent of brain microvascular network in vivo. With the novel integrin-binding array system, we identified the specific types of integrins on brain microvascular endothelial cells that mediate cell adhesion and growth followed by functionalizing a 3 D hydrogel culture system using the binding peptides that specifically bind to the identified integrins, leading to robust growth and lumenized microvascular-like network formation of brain microvascular endothelial cells in 3 D culture. This technology can be used for in vitro and in vivo vascularization of transplants or brain lesions to promote brain tissue regeneration following neurological insults.

Immunohistochemical Evaluation of Vascular Endothelial Growth Factor(VEGF)in Splenic Hemangiomas and Hemangiosarcomas in Dogs

Formation of new blood vessels is paramount for tumour growth and metastatic dissemination and vascular endothelial growth factor (VEGF) is one of the key regulators of this process. The purpose of this study was to evaluate the immunohistochemical expression of VEGF in 23 splenic hemangiosarcomas and 7 splenic hemangiomas in dogs. Blood tests performed previous to splenectomy were analysed for correlation with tumour VEGF expression. Results showed significantly higher VEGF expression in hemangiosarcomas than hemangiomas and lower hematocrit values and red cell count in dogs affected with malignant neoplasia (P < 0.05). These findings suggest the presence of high VEGF levels may be related to the malignant vascular proliferation seen in hemangiosarcomas.

Inhibition of VEGF-A expression in hypoxia-exposed fetal retinal microvascular endothelial cells by exosomes derived from human umbilical cord mesenchymal stem cells

Objective:This study aimed to investigate the potential of human umbilical cord mesenchymal stem cell(hucMSC)-derived exosomes(hucMSC-Exos)in inhibiting hypoxia-induced cell hyper proliferation and overexpression of vascular endothelial growth factor A(VEGF-A)in immature human fetal retinal microvascular endothelial cells(hfRMECs).Methods:Exosomes were isolated from hucMSCs using cryogenic ultracentrifugation and characterized through various techniques,including transmission electron microscopy,nanoparticle tracking analysis,bicinchoninic acid assays,and western blotting.The hfRMECs were identified using von Willebrand factor(vWF)co-staining and divided into four groups:a control group cultured under normoxic condition,a hypoxic model group,a hypoxic group treated with low-concentration hucMSC-Exos(75μg/mL)and a hypoxic group treated with high-concentration hucMSC-Exos(100μg/mL).Cell viability and proliferation were assessed using Cell Counting Kit-8(CCK-8)assay and EdU(5-ethynyl-2′-deoxyuridine)assay respectively.Expression levels of VEGF-A were evaluated using RT-PCR,western blotting and immunofluorescence.Results:Hypoxia significantly increased hfRMECs’viability and proliferation by upregulating VEGF-A levels.The administration of hucMSC-Exos effectively reversed this response,with the high-concentration group exhibiting greater efficacy compared to the lowconcentration group.Conclusion:In conclusion,hucMSC-Exos can dose-dependently inhibit hypoxia-induced hyperproliferation and VEGF-A overexpression in immature fetal retinal microvascular endothelial cells.

Advances of Study on Recombinant Vascular Endothelial Growth Factor

血管内皮生长因子 (Vascularendothelialgrowthfactor,VEGF)是 1 989年Ferrara等在牛垂体滤泡星状细胞体外培养液中首先纯化出来的。到目前为止已经发现了六个VEGF异构体 ,包括VEGF1 2 1 ,VEGF1 45,VEGF1 6 5,VEGF1 83 ,VEGF1 89,VEGF2 0 6。已经发现高亲和力的VEGF受体有两类 ,分别为Flt 1 (Fms liketyrosinekinase)和KDR(kinasedomainregion)。重点介绍了VEGF两个方面的应用前景。一方面用于治疗下肢缺血和心脏病 。

Expression of vascular endothelial growth factor and its role in oncogenesis of human gastric carcinoma

AIM To establish the role of vascular endothelial growth factor (VEGF) in the oncogenesisof human gastric carcinoma more directly.METHODS The expression of VEGF and its receptor kinase-domain insert containing receptor (KDR) in human gastric cancer tissue were observed by immunohistochemical staining. VEGF levels were manipulated in human gastric cancer cell using eukaryotic expression constructs designed to express the complete VEGF165 complimentary DNA in either the sense or antisense orientation. The biological changes of the cells were observed in which VEGF was up-regulated or downregulated.RESULTS VEGF-positive rate was 50%, and VEGF was mainly localized in the cytoplasm and membrane of the tumor cells, while KDR was mainly located in the membrane of vascular endothelial cells in gastric cancer tissues and peri-cancerous tissue. In 2 cases of 50 specimens, the gastric cancer cells expressed KDR,localized in both the cytoplasm and membrane.Introduction of VEGF165 antisense into human gastric cancer cells ( SGC-7901, immunofluorescence intensity,31.6%)) resulted in a significant reduction in VEGFspecific messenger RNA and total and cell surface VEGF protein ( immunofluorescence intensity, 8.9%)(P＜0.05). Conversely, stable integration of VEGF165 in the sense orientation resulted in an increase in cellular and cell surface VEGF (immunofluorescence intensity,75.4%) (P＜0.05). Lowered VEGF levels were associated with a marked decrease in the growth of nude mouse xenografted tumor (at 33 days postimplantation, tomor volume: 345.40 ± 136.31 mm3) (P＜0.05 vs control SGC7901 group: 1534.40 ± 362.88 mm3), whereas up-regulation of VEGF resulted in increased xenografted tumor size (at 33 days postimplantation, tomor volume: 2350.50 ± 637.70mm3) (P＜0.05 vs control SGC-7901 group).CONCLUSION This study provides direct evidence that VEGF plays an important role in the oncogenesis of human gastric cancer.

Reduction of tumorigenicity of SMMC-7721 hepatoma cells by vascular endothelial growth factor antisense gene therapy

AIM To test the hypothesis to block VEGFexpression of SMMC-7721 hepatoma cells mayinhibit tumor growth using the rat hepatomamodel.METHODS Amplifiy the 200 VEGF cDNAfragment and insert it into human U6 genecassette in the reverse orientation transcribingsmall antisense RNA which could specificallyinteract with VEGF165, and VEGF121 mRNA.Construct the retroviral vector containing thisantisense VEGF U6 cassette and package thereplication-deficient recombinant retrovirus.SMMC-7721 cells were transduced with thesevirus and positive clones were selected withG418. PCR and Southern blot analysis wereperformed to determine if U6 cassette integratedinto the genomic DNA of positive clone.Transfected tumor cells were evaluated for RNAexpression by ribonuclease protection assays.The VEGF protein in the supernatant of parentaltumor cells and genetically modified tumor cellswas determined with ELISA. In vitro and in vivogrowth properties of antisense VEGF cell clonein nude mice were analyzed.RESULTS Restriction enzyme digestion andPCR sequencing verified that the antisense VEGFRNA retroviral vector was successfullyconstructed. After G418 selection, resistantSMMC-7721 cell clone was picked up. PCR andSouthern blot analysis suggested that U6cassette was integrated into the cell genomicDNA. Stable SMMC-7721 cell clone transducedwith U6 antisense RNA cassette could express200bp small antisense VEGF RNA and secretereduced levels of VEGF in culture condition.Production of VEGF by antisense transgeneexpressing cells was 65 ± 10 ng / L per 106 cells,420 ± 45 ng/L per 106 cells in sense group and 485± 30 ng/L per 106 cells in the negative control group, (P＜0.05). The antisense-VEGF cell clone appeared phenotypically indistinguishable from SMMC-7721 cells and SMMC-7721 cells transfected sense VEGF. The growth rate of the antisense-VEGF cell clone was the same as the control cells. When S. C. was implanted into nude mice, growth of antisense-VEGF cell lines was greatly inhibited compared with control cells.CONCLUSION Expression of antisense VEGFRNA in SMMC-7721 cells could decrease thetumorigenicity, and antisense-VEGF genetherapy may be an adjuvant treatment forhepatoma.

The Effect of Simvastatin on mRNA Expression of Transforming Growth Factor-β1,Bone Morphogenetic Protein-2 and Vascular Endothelial Growth Factor in Tooth Extraction Socket

Aim To determine the effect of local simvastatin application on the mRNA expression level of transforming growth factor-β1 （TGF-β1）, bone morphogenetic protein-2 （BMP-2） and vascular endothelial growth factor （VEGF） in the tooth sockets of rat. Methodology Forty-eight male Wistar rats were randomly divided into experimental and control groups （n=24）. Polylactic acid/polyglycolic acid copolymer carriers, with or without simvastatin, were implanted into extraction sockets of right mandibular incisors. The expression of TGF-β1, BMP-2 and VEGF mRNA was determined by in situ hybridization in the tooth extraction socket at five days, one week, two weeks and four weeks after implantation. Results The fusiform stroma cells in the tooth extraction socket began to express TGF-β1, BMP-2 and VEGF mRNA in both experimental and control groups from one week after tooth extraction until the end of experiment. The expression of TGF-131 and BMP-2 mRNA in the experimental group was significantly up-regulated after one, two and four weeks, and expression of VEGF mRNA was significantly increased after one and two weeks compared with that in the control group. Conclusion The findings indicate that local administration of simvastatin can influence alveolar bone remodeling by regulating the expression of a school of growth factors which are crucial to osteogenesis in the tooth extraction socket.