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 strornal 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 VEGFRol and 2 were expressed both in the cytoplasm and on the membrane of all tumors. Irnrnunohistochernical staining revealed that 26 GISTs （78.8%）, 9 leiornyornas （60.0%） and 3 schwannornas （50.0%/were positive for VEGF; 24 GISTs （72.7%/, 12 leiornyornas （80.0%） and 4 schwannornas （66.7%） were positive for VEGFR-1; 30 GISTs （90.9%/, 5 leiornyornas （33.3%/and 4 schwannornas （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.

Expression of thymidine kinase mediated by a novel non-viral delivery system under the control of vascular endothelial growth factor receptor 2 promoter selectively kills human umbilical vein endothelial cells

AIM: To investigate the killing efficiency of a recombinant plasmid containing a thymidine kinase (TK) domain insert driven by the vascular endothelial growth factor receptor 2 (VEGFR2) promoter (KDR) on vascular endothelial cells.METHODS: The KDR-TK fragment was extracted from pBluescript Ⅱ KDR-TK plasmid by enzymatic digestion with Xho I and Sal I. The enhanced green fluorescence protein (EGFP) carrier was extracted from pEGFP by the same procedure. The KDR-TK was inserted into the pEGFP carrier to construct pEGFP-KDR-TK. Using ultrasound irradiation and microbubble, pEGFP-KDR-TK was transferred into human umbilical vein endothelial cells (HUVECs). The transient infection rate was estimated by green fluorescent protein (GFP) expression. Transfected HUVECs, non-transfected HUVECs, and HepG2 cells were cultured in the presence of different concentrations of ganciclovir (GCV), and the killing efficacy of HSV-TK/GCV was analyzed by 3-[4, 5-dimethylthiazol-2-yl]-2, 5-diphenyl tetrazolium bromide (MTT) assay. RESULTS: The recombinant pEGFP-KDR-TK was successfully constructed by inserting the KDR-TK fragment into the pEGFP carrier. Transfected HUVECs showed cytoplasmic green fluorescence, and the transient transfection rate was about 20.3%. Pools of G418-resistant cells exhibited a higher sensitivity to theprodrug/GCV compared to non-transfected HUVECs or non-transfected HepG2 cells, respectively. CONCLUSION: KDR promoter and the suicide gene/prodrug system mediated by diagnostic ultrasound combined with microbubble can significantly kill HUVECs. Such therapy may present a novel and attractive approach to target gene therapy on tumor vessels.

Streptozotocin induced diabetic retinopathy in rat and the expression of vascular endothelial growth factor and its receptor

·AIM: To establishtherat model of streptozotocin (STZ)- induced diabetic retinopathy (DR), which is the most common cause of visual loss and blindness in patients with diabetes, and observe the gene expression of vascular endothelial growth factor (VEGF) and its receptors during the development of DR. ·METHODS: A rat model of diabetes was established by intraperitoneal injection of STZ. The diabetic rats were housed for 2, 3 and 4 months after the development of diabetes. Retinal histopathological observation was performed. The retinal vessels were observed by immunofluorescence staining by CD31. The mRNA expression of VEGF, VEGF receptor 1 and 2 (VEGFR1/2) in rat retina was detected by reverse transcription - polymerase chain reaction (RT-PCR) analysis. · RESULTS: Retinal histopathological observation showed the morphological changes of inner nuclear layer (INL) and outer nuclear layer (ONL) at any time -point, and also demonstrated the increased new vessels at both 3, 4 months after the development of diabetes. The CD31 staining results showed that the number of vessels was increased in the retinas of diabetic rats at both 3 and 4 months after the development of diabetes. As compared to the normal rats, the mRNA expression of VEGF was increased in retinas of diabetic rats at 3 months after the development of diabetes, while VEGFR1 and VEGFR2 mRNA expression was increased at 2, 3 and 4 months after the development of diabetes.·CONCLUSION:Takentogether,ourresultsdemonstrated that DR was occurred at 3 months after the development of diabetes, and the mRNA expression of VEGF, VEGFR1 and VEGFR2 were increased in the process of DR. The present study further evidenced the involvement of VEGF and its receptors in the process of DR. ·

Molecular Modeling Studies of Vascular Endothelial Growth Factor Receptor Tyrosine Kinase Inhibitors Combining Molecular Docking and 3D-QSAR Methods

The vascular endothelial growth factor （VEGF） and its receptor tyrosine kinases VEGFR-2 or kinase insertdomain receptor （KDR） have emerged as attractive targets for the design of novel anticancer agents. In the present work, molecular docking method combined with three dimensional quantitative structure-activity relationships （comparative molecular field analysis （CoMFA） and comparative molecular similarity indice analysis （CoMSIA）） to analyze the possible interactions between KDR and those derivatives which acted as selective inhibitors. The CoMFA and CoMSIA models gave a cross-validated coefficient Q2 of 0.713 and 0.549, non-cross-validated R2 values of 0.974 and 0.878, and predicted R2 values of 0.966 and 0.823, respectively. The 3D contour maps generated by the CoMFA and CoMSIA models were used to identify the key structural requirements responsible for the biological activity. The information obtained from 3D-QSAR and docking studies were very helpful to design novel selective inhibitors of KDR with desired activity and good chemical property.

EXTERNALIZATION AND INTERNALIZATION OF CARDIAC ENDOTHELIN RECEPTORS DURING DIFFERENT PHASES OF SEPSIS IN RAT

To study the redistribution of endothelin- 1 (ET- 1) receptors in two subcellular organelles , the sarcolemmal membrane and the light vesicle, of rat heart during the progression of sepsis. Methods. Sepsis was induced by cecal ligation and puncture (CLP). ET1 receptor was assayed by using [125I]- ET1 binding. Marker enzyme activities, protein yield, and dry- to- wet weight ratio of cardiac membranes were measured. Results. Septic rat heart exhibited two distinct phases: an initial hyperdynamic phase( 9h after CLP; early stage of sepsis) followed by a hypodynamic (18h after CLP, late stage of sepsis) phase. [125I]- ET1 binding study showed that during early stage of sepsis, the Bmax of ET1 receptors was increased by 30％ in sarcolemma but decreased by 19％ in light vesicles, while during late stage of sepsis, the Bmax was decreased by 24％ in sarcolemma but increased by 38％ in light vesicles.The total binding of sarcolemma and light vesicles was increased by 25％ during early stage of sepsis but decreased by 17％ during late stage of sepsis. Conclusions. These data indicated that ET1 receptors in the rat heart were externalized from light vesicles to sarcolemmal membranes during early hyperdynamic phase while internalized from surface membranes to intracellular compartment during late hypodynamic phase of sepsis.

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 oncogenesis of 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 VEGF(165) complimentary DNA in either the sense or antisense orientation. The biological changes of the cells were observed in which VEGF was up-regulated or down-regulated. 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 VEGF(165) antisense into human gastric cancer cells (SGC-7901, immunofluorescence intensity, 31.6%)) resulted in a significant reduction in VEGF-specific messenger RNA and total and cell surface VEGF protein (immunofluorescence intensity, 8.9%) (P【0.05). Conversely, stable integration of VEGF(165) 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, tumor volume: 345.40 +/- 136.31 mm3)(P【0.05 vs control SGC-7901 group: 1534.40 +/- 362.88 mm3), whereas up-regulation of VEGF resulted in increased xenografted tumor size (at 33 days postimplantation, tumor volume: 2350.50 +/- 637.70 mm3) (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.

Induction of vascular endothelial growth factor receptor expression in human umbilical vein endothelial cells after repeated bevacizumab treatment in vitro

AIM： To investigate the mechanism underlying the loss of responsiveness to anti-vascular endothelial growth factor（VEGF） treatment after repeated injections for choroidal neovascularization, VEGF and VEGF receptor（VEGFR） expressions were evaluated following repeated bevacizumab treatments in hypoxic human umbilical vein endothelial cells（HUVECs） in vitro.METHODS： HUVECs were incubated under hypoxic conditions in two media of different bevacizumab concentrations（1.0 or 2.5 mg/m L） for 17 h, and then in a new medium without bevacizumab for 7h. This procedure was repeated twice more. A culture with an identical volume of excipients served as the control. Cytotoxicity and cell proliferation were assessed using 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide and Ki-67 assays, respectively. Levels of VEGF and VEGFR were assessed using enzyme-linked immunosorbent assay and Western blot respectively.RESULTS： Cytotoxic effects were not reported for either bevacizumab concentration. Cell proliferation was not reduced after anti-VEGF treatments. VEGF level after single treatment was significantly higher than that of the control and after repeated treatments. Phosphorylated VEGFR-2 expression increased significantly after singleand repeated bevacizumab treatments compared with the control. The 1.0 mg/m L bevacizumab induced significantly higher expressions of VEGFR-2 than the 2.5 mg/m L in single and repeated treatment groups.CONCLUSION： Bevacizumab treatment of HUVECs elevated VEGFR expression in both single and repeated treatments, indicating a mechanism for the reduced efficacy of anti-VEGF therapy in ocular neovascular disorders.

Effects of Estrogen Level on the Function of Vascular Endothelial Cells and Expression of Vascular Cell Adhesion Molecule-1(?)

Objectives To ob-serve the effect of different estrogen levels on the secretory function of vascular endothelial cells of female rats, and study the effect of modulation of estrogen level on the expression of vascular cell adhesion molecule - 1 and the concentration of estrogen receptor in vascular endothelial cells. Methods Radioim-munology was used to measure the serum concentration of endothelin and PGI2, and copper - cadmium reduction was employed to measure the serum content of nitrogen monoxide. Radioligand binding and flowcy-tometry were used to measure the expression of estrogen receptor and vascular cell adhesion molecule (VCAM - 1) of vascular endothelial cells respectively. Results 1. The serum concentration of nitric oxide and PGI2 decreased when the ovaries of female rats were removed. In ovariectomized rats, given estrogen, the concentration rose ( P < 0. 05), but the plasma concentration of endothelin was adverse to it. 2. The concentration of estrogen receptor of vascular endothelial cells decreased remarkably when the ovaries of female rats were removed. When given estrogen, it increased. 3. The percent of expressed VCAM - 1 increased significantly after interleukin - 1βoperated on the cells, but 17 -βestradiol at 3 × 10-8 - 10-6 mol/l all decreased the percent. Conclusions Estrogen level can influence the secretion of nitrogen monoxide, PGI2 and endothlin of vascular endothelial cells, and also influence the concentration of estrogen receptor of vascular endothelial cells. 17 -β Estradiol at 3 × 10-8 -10-6 M can decrease the elevation of VCAM - 1 of vascular endothelial cells induced by interleukin - 1β.

The Expression of Estrogen Receptor is Dependent on the Estrogen Level and Associated with Cholesterol - Rich Diet in Female Rat's Heart and Vascular Endothelial Cells

Objective To study the effects of estrogen level and cholesterol - rich diet on the expression of estrogen receptor (ER) in cardiovascular tissues including vascular endothelial cells (VEC) of female rats. Methods The receptor binding assay (RBA) was adopted to measure the estrogen receptor level in aortic wall, heart and vascular endothelial cells of female rats on a cholesterol - rich diet. A ra-dioimmunoassay was employed to measure the level of serum estradiol. Results The number of ER significantly decreased in hearts, aorta and vascular endothelial cells in the ovariectomized rats and the rats on a cholesterol - rich diet. In contrast, the administration of estrogen somewhat restored the expression of ER. Conclusions For female rats, the level of estrogen affects the expression of ER in cardiovascular system. The number of ER decreases along with the decrease in the level of estrogen. A cholesterol - rich diet also can decrease the expression of ER in cardiovascular system of female rats.

Extended survival with metastatic pancreatic cancer under fruquintinib treatment after failed chemotherapy:Two case reports

BACKGROUND Pancreatic cancer is a highly malignant disease.After decades of treatment progress,the current five-year survival rate for patients is still less than 10%.For later-line treatment,the treatment options are even more limited.Anti-angiogenic drugs can improve progression-free survival in patients with advanced pancreatic cancer.Preclinical data show that fruquintinib might improve the prognosis of advanced pancreatic cancer by targeting angiogenesis and lymphopoiesis,improving the abnormal vascular structure,and modulating the tumour immune microenvironment.CASE SUMMARY We present two cases of third-line fruquintinib monotherapy that brought an extraprolonged progress-free survival(PFS)of 10 months.Patient 1 took adjuvant gemcitabine-based and first-line nab-paclitaxel-based chemotherapy and then used local radiotherapy combined with programmed cell death 1 receptor(PD-1).Each line lasted approximately 7 months.Moreover,the patient took third-line fruquintinib,which was followed by stable disease for 10 months,during which no additional adverse effect was observed.The patient later refused to take fruquintinib due to difficulty urinating and lower abdominal pain after the coronavirus disease 2019(COVID-19)infection.The patient died in February 2023.Patient 2 also took two prior lines of chemotherapy and then local radiotherapy combined with S-1.After confirmed disease progression,the patient experienced a continuous partial response after using fruquintinib monotherapy in the third line.After the patient had COVID-19 in December 2022,fruquintinib was discontinued.The patient died in January 2023 due to disease progression.CONCLUSION Both cases achieved a PFS benefit from later-line single-agent fruquintinib therapy.With its better safety profile,fruquintinib may be worth exploring and studying in more depth as a later-line treatment for pancreatic cancer patients.

Identification of a Novel VEGFR-3 Missense Mutation in a Chinese Family with Hereditary Lymphedema Type I

A novel mutation of vascular endothelial growth factor receptor gene （VEGFR-3）, was identified in a four-generation Chinese family with hereditary lymphedema type I （HL-I）. Genetic linkage analysis was performed on the known genetic locus for HL-I with a panel of polymorphic markers, and then mutations were screened out by direct sequencing. By genotyping, the family showed the linkage to HL-I locus on 5q35.3. Mutation screening analysis of the exons encoding the intracellular kinase domains of VEGFR-3, revealed a novel missense mutation D1055V. This mutation cosegregated with the disease phenotype in the family and was not found in 100 normal controls. This finding has expanded the spectrum of the VEGFR-3 gene mutations causing HL-I, and will be useful for further genetic consultation and genetic diagnosis.

Current and emerging therapies in unresectable and recurrent gastric cancer

Gastric cancer is one of the most lethal cancers worldwide despite many advances and options in therapy. As it is often diagnosed at an advanced stage, prognosis is poor with a median overall survival of less than twelve months. Chemotherapy remains the mainstay of treatment for these patients but it confersonly a moderate survival advantage. There remains a need for new targeted treatment options and a way to better define patient populations who will benefit from these agents. In the past few years, there has been a better understanding of the biology, molecular profiling, and heterogeneity of gastric cancer. Our increased knowledge has led to the identification of gastric cancer subtypes and to the development of new targeted therapeutic agents. There are now two new targeted agents, trastuzumab and ramucirumab, that have recently been approved for the treatment of advanced and metastatic gastric cancer. There are also many other actively investigated targets, including epidermal growth factor receptor, the phosphatadylinositol 3-kinase/protein kinase B/mammalian target of rapamycin pathway, c-Met, poly ADP-ribose polymerase, and immune checkpoint inhibition. In this review, we discuss the current management of advanced gastric cancer as well as emerging targeted therapies and immunotherapy.

Targeted agents for second-line treatment of advanced hepatocellular carcinoma

Over the past ten years,sorafenib,a multikinase inhibitor,has been the standard of care for patients with unresectable hepatocellular carcinoma(HCC)and wellpreserved liver function.Recently,lenvatinib,a different multikinase inhibitor,was shown to be non-inferior to sorafenib,in terms of survival,while all other agents previously tested failed to prove non-inferiority(or superiority)when compared to sorafenib.Similarly,in the second-line setting,most investigational drugs failed to provide better survival outcomes than placebo.However,in the last 2 years three positive phase III trials have been published in this setting.The RESORCE trial,a phase III study evaluating regorafenib in HCC patients who experienced disease progression after first-line treatment with sorafenib,showed better outcomes with regorafenib compared to placebo.More recently,the phase III CELESTIAL trial demonstrated the superiority of cabozantinib,a multikinase inhibitor targeting vascular endothelial growth factor receptor,MET,and AXL,vs placebo in the second-and third-line setting in patients progressing on or intolerant to sorafenib.The survival benefits of a sustained anti-angiogenic inhibition were demonstrated also with ramucirumab in the phase III REACH-2 trial in patients previously treated with sorafenib and who had high baseline alpha-fetoprotein levels.Overall,the adverse events reported in these trials were in line with the known safety profiles of the tested agents.After nearly a decade of a certain degree of stagnation,we are now witnessing a period of novel therapeutic advances with multikinase inhibitors and monoclonal antibodies that will likely change the treatment scenario of HCC.

Clinical Significance of VEGF-C and VEGFR-3 Expression in Non-small Cell Lung Cancer

The relationship between vascular endothelial growth factor-C （VEGF-C）/vascular endothelial growth factor receptor 3 （VEGFR-3） expression and clinicopathologic features of the patients with non-small cell lung cancer （NSCLC） was investigated. The expression of VEGF-C and VEGFR-3 was assessed in 65 patients with NSCLC by immunohistochemistry. The significance of VEGF-C and VEGFR-3 expression was analyzed statistically. The results showed that VEGF-C and VEGFR-3 were highly expressed in cytoplasm and membrane in lung cancer tissues with the positive rate being 55.4 % and 52.3 % respectively, while there was no expression in the normal lung tissues. The expression of VEGF-C was significantly increased in adenocacinoma as compared to other types of NSCLC （P〈0.05）. The VEGFR-3 expression was closely related with lymph node metastasis （P〈0.01） and TNM stage （P〈0.05）. There was a positive correlation between the VEGF-C and VEGFR-3 expression in NSCLC patients （r=-0.658, P〈0.01）. It is suggested that VEGFR-3 plays an important role in the lymphatic metastasis of NSCLC. The interaction between VEGF-C and VEGFR-3 may be deeply involved in the mechanism of lung cancer metastasis.

Ischemic preconditioning protects against ischemic brain injury

In this study, we hypothesized that an increase in integrin αβand its co-activator vascular endothelial growth factor play important neuroprotective roles in ischemic injury. We performed ischemic preconditioning with bilateral common carotid artery occlusion for 5 minutes in C57BL/6J mice. This was followed by ischemic injury with bilateral common carotid artery occlusion for 30 minutes. The time interval between ischemic preconditioning and lethal ischemia was 48 hours. Histopathological analysis showed that ischemic preconditioning substantially diminished damage to neurons in the hippocampus 7 days after ischemia. Evans Blue dye assay showed that ischemic preconditioning reduced damage to the blood-brain barrier 24 hours after ischemia. This demonstrates the neuroprotective effect of ischemic preconditioning. Western blot assay revealed a significant reduction in protein levels of integrin αβ, vascular endothelial growth factor and its receptor in mice given ischemic preconditioning compared with mice not given ischemic preconditioning 24 hours after ischemia. These findings suggest that the neuroprotective effect of ischemic preconditioning is associated with lower integrin αβand vascular endothelial growth factor levels in the brain following ischemia.

Molecular targeting to treat gastric cancer

Trastuzumab that targets human epidermal growth factor receptor 2 (HER2) protein is the only approved molecular targeting agent for treating gastric cancer in Japan and the outcomes have been favorable. However, trastuzumab is effective for only 10% to 20% of the population with gastric cancer that expresses HER2 protein. Molecular targeting therapy with bevacizumab against vascular endothelial growth factors (VEGF) and with cetuximab and panitumumab against the epidermal growth factors pathway that have been approved for treating colorectal cancer are not considered effective for treating gastric cancer according to several clinical trials. However, ramucirumab that targets VEGF receptor-2 prolonged overall survival in a large phase III clinical trial and it might be an effective molecular targeting therapy for gastric cancer. The significance of molecular targeting therapy for gastric cancer remains controversial. A large-scale randomized clinical trial of novel molecular targeting agents with which to treat gastric cancer is needed.

Intravitreal injection of resveratrol inhibits laser-induced murine choroidal neovascularization

AIM:To determine the effects of intravitreal resveratrol(RSV)on murine laser-induced choroidal neovascularization(CNV).METHODS:The toxicity of RSV to choroidal endothelial cell(CEC)was measured using thiazolyl blue tetrazolium bromide(M一)assay.Effects of RSV on choroidal endothelial cell(CEC)migration were evaluated with a modified Boyden chamber assay,while tube formation was evaluated in a 2-D gel assay.CNV was induced by laser photocoagulation in mice.The effects of intravitreal injection of RSV on CNV development were evaluated by fluorescein angiography(FA),confocal analysis of isolectin B4 labeled choroidal flat mounts,and histologic examination of CNV membranes.Immunostaining was used to analyze the expression and phosphorylation of vascular endothelial growth factor receptor 2(VEGFR2).RESULTS:No significant cell toxicity was observed in CEC if the concentration of RSV was less than 200 pmol/L(P>0.05).RSV inhibited vascular endothelial growth factor(VEGF)-induced CEC migration(P<0.05)and tube formation(P<0.05)invitro.Furthermore,intravitrealinjectionof RSV significantly inhibited laser induced CNV formation in mice.The FA leakage,CNV volume and CNV area analysis revealed that there were 41%,45%,and 58%reduction in RSV-treated eyes(1.691±0.1032,178163±78623μm^3 and 6508±619.0μm^2,respectively)compared with those in control(2.724±0.08447,379676±98382μm3and16576±2646μm^2,respectively;P<0.05).Phospho-VEGFR2expression was much weaker in the sections of CNV lesions in RSV injected mice compared with that in control(P<0.05).CONCLUSION:Intravitreal injection of RSV exerts an inhibitory effect on CNV,which may through suppressing endothelial cell migration,tube formation and VEGFR2 phosphorylation.

Apatinib as an alternative therapy for advanced hepatocellular carcinoma

Angiogenesis plays an important role in the occurrence and development of tumors.Registered tyrosine kinase inhibitors targeting vascular endothelial growth factor reduce angiogenesis.Apatinib,a tyrosine kinase inhibitor,can specifically inhibit vascular endothelial growth factor receptor 2,showing encouraging anti-tumor effects in a variety of tumors including advanced hepatocellular carcinoma(HCC).This article intends to review the clinical research and application prospects of apatinib in the field of HCC.

Effect of VEGF on Neural Differentiation of Human Embryonic Stem Cells in vitro

The effects of vascular endothelial growth factor （VEGF） on neural differentiation of human embryonic stem cells （hESCs） in vitro and the possible mechanism were observed. The hESCs lines, TJMU1 and TJMU2, were established and stored by our laboratory, hESCs differentiated into neuronal cells through embryonic body formation. In this induction process, hESCs were divided into three groups： group A, routine induction; group B, routine induction＋10 ng/mL VEGF; group C, routine in- duction＋10 ng/mL VEGF＋10 ng/mL VEGFR2/Fc. OCT4, Nestin and GFAP in each group were de- tected by RT-PCR, and the cells expressing Nestin and GFAP were counted by immunofluorescence. The percentage of Nestin positive cells in group B was significantly higher than in groups A and C, while the percentage of GFAP positive cells in group B was significantly lower than in groups A and C （P〈0.01）. There was no significant difference between groups A and C （P〉0.05）. It was concluded that VEGF, via VEGFR2, stimulated the neural differentiation of hESCs in vitro.

Expression of VEGFR2 and NRP-1 in non-small cell lung cancer and their clinical significance

Objective： Vascular-targeted therapy is gradually becoming more appealing for patients with lung cancer. It is unclear whether vascular endothelial growth factor receptor 2（VEGFR2） and neuropilin-1（NRP-1） can be biomarkers for clinical treatment. We aimed to investigate the expression levels of VEGFR2 and NRP-1 in human non-small cell lung cancer（NSCLC） and their clinical significance by observing patient prognosis. Methods： VEGFR2 and NRP-1 were assessed by immunohistochemistry（IHC） in 40 patients with NSCLC and in 10 patients with benign lesions of lung; kinase insert domain receptor（KDR） and NRP-1 copy number gain（CNG） was assessed by fluorescence in situ hybridization（FISH）. The distributions of overall survival（OS） and progression-free survival（PFS） were estimated using the Kaplan-Meier method and compared between groups by log-rank test.Results： Rates of positive immunostaining for VEGFR2 and NRP-1 were 58% and 55%, respectively. KDR and NRP-1 CNG（＋） were detected in 32.5% and 30% of tumors, respectively. Levels of both VEGFR2 and NRP-1 in lung tumors were significantly different than in the control tissue（χ2=11.22, P=0.001; χ2=9.82, P=0.001, respectively）; similar results were obtained using CNGs（χ2=4.39, P=0.036; χ2=3.95, P=0.046, respectively）. Statistically significant correlations were observed with histological grade, clinical TNM stage and the lymph node status（P〈0.05）, but not age, gender or pathology type（P〉0.05）. VEGFR2 showed a strong correlation with NRP-1（Rs=0.68, P=0.00）; similar results were observed with KDR and NRP-1 CNG（Rs=0.32, P=0.04）. Significant differences in OS and PFS were observed between the groups with higher VEGFR2 and NRP-1 and those with lower expression（P〈0.05）. Conclusions： According to these data, VEGFR2 and NRP-1 are highly expressed in NSCLC. We can conclude that they play a key role in NSCLC occurrence, development and metastasis and are associated with patient prognosis（P〈0.05 for OS and PFS）. This information will be beneficial for clinical antiangiogenic treatment in NSCLC.