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1.
Vascular endothelial growth factor (VEGF) and its receptors (VEGFR) have been implicated in promoting solid tumor growth and metastasis via stimulating tumor-associated angiogenesis. Here we show that certain "liquid" tumors such as acute myeloid leukemia not only produce VEGF but also express functional VEGFR, resulting in an autocrine loop for tumor growth and propagation. In addition, the leukemia-derived VEGF can also stimulate the production of growth factors, including interleukin 6 (IL6) and granulocyte-macrophage colony stimulating factor (GM-CSF), by human endothelial cells, which in turn further promotes the growth of leukemia cells (the paracrine loop). A fully human anti-VEGFR2 (or kinase insert domain-containing receptor, KDR) antibody, IMC-2C6, strongly blocks KDR/VEGF interaction and neutralizes VEGF-stimulated activation of KDR in endothelial cells. In a system where leukemia cells are co-cultured with endothelial cells, IMC-2C6 inhibits both the production of IL6 and GM-CSF by endothelial cells and the growth of leukemia cells. Finally, IMC-2C6 effectively blocks VEGF-induced migration of KDR+ human leukemia cells, and when administered in vivo, significantly prolonged survival of mice inoculated with KDR+ human leukemia cells. Taken together, our data suggest that anti-KDR antibodies may have broad applications in the treatment of both solid tumors and certain types of leukemia.  相似文献   

2.
Monoclonal antibody (Ab) directed against the vascular endothelial growth factor, one of the major inducers of angiogenesis, can inhibit tumor growth in mice. Treatment of cancer patients with monoclonal Ab requires large-scale production of the clean Ab and frequent application of the Ab. This might be improved by using single-chain Ab fragments (scFvs), which can be produced in large quantities in bacteria and are attractive for gene therapeutic approaches. Here we describe anti-vascular endothelial growth factor scFvs derived from a human phage-display library able to block the vascularization of the chorioallantoic membrane of chick embryos and reduce the growth of s.c. tumors in nude mice. This work opens the way to develop gene therapy-based strategies using a scFv to treat angiogenesis-dependent diseases.  相似文献   

3.
PURPOSE: Inhibition of angiogenesis can influence tumor cell invasion and metastasis. We previously showed that blockade of vascular endothelial growth factor receptor-2 (VEGFR-2) with the monoclonal antibody DC101 inhibited intracerebral glioblastoma growth but caused increased tumor cell invasion along the preexistent vasculature. In the present study, we attempted to inhibit glioma cell invasion using a monoclonal antibody against the epidermal growth factor receptor (EGFR), which in the context of human glioblastomas, has been implicated in tumor cell invasion. In addition, we analyzed whether blockade of vascular endothelial (VE)-cadherin as a different antiangiogenic target could also inhibit glioblastoma angiogenesis and growth. EXPERIMENTAL DESIGNS: Nude mice who received intracerebral glioblastoma xenografts were treated using monoclonal antibodies against VEGFR-2 (DC101), EGFR (C225), and VE-cadherin (E4G10) either alone or in different combinations. RESULTS: Increased tumor cell invasion provoked by DC101 monotherapy was inhibited by 50% to 66% by combined treatment with C225 and DC101. C225 inhibited glioblastoma cell migration in vitro, but had no effect on the volume of the main tumor mass or on tumor cell proliferation or apoptosis in vivo, either alone or in combination with DC101. The anti-VE-cadherin monoclonal antibody E4G10 was a weaker inhibitor of tumor angiogenesis and growth than DC101, and also caused a weaker increase in tumor cell invasion. CONCLUSIONS: Inhibition of angiogenesis achieved by blocking either VEGFR-2 or VE-cadherin can cause increased glioma cell invasion in an orthotopic model. Increased tumor cell invasion induced by potent inhibition of angiogenesis with DC101 could be inhibited by simultaneous blockade of EGFR.  相似文献   

4.
Both Epidermal Growth Factor Receptor (EGFR) and the Vascular Endothelial Growth Factor Receptor 2 (VEGFR2) play critical roles in tumorigenesis. We hypothesized co-targeting EGFR and VEGFR2 using a bispecific antibody might have significant therapeutic potential. Here,we designed and produced a human IgG-like bispecific antibody (Bi-Ab) based on the variable regions of cetuximab (an anti-EGFR antibody) and mAb-04 (an anti-VEGFR2 antibody developed in our lab) . The Bi-Ab was found to inhibit the proliferation, survival and invasion of cancer cells via ablating phosphorylation of receptor and downstream signaling. In vivo efficacy was demonstrated against established HT-29 and SKOV-3 xenografts grown in nude mice. Studies revealed our Bi-Ab was able to restrain xenografted tumor growth and prolong survival of mice through inhibiting cell proliferation,promoting apoptosis and anti-angiogenesis. In contrast to cetuximab or mAb-04 alone, our Bi-Ab exhibits enhanced antitumor activity and has equal or slightly superior activity to their combination (Combi). It shows promise as a therapeutic agent, especially for use against tumors EGFR and/or VEGFR2 over-expressing malignancies.  相似文献   

5.
Vascular endothelial growth factor receptor 2 (VEGFR2) is highly expressed in tumor‐associated endothelial cells, where it modulates tumor‐promoting angiogenesis, and it is also found on the surface of tumor cells. Currently, there are no Ab therapeutics targeting VEGFR2 approved for the treatment of prostate cancer or leukemia. Therefore, development of novel efficacious anti‐VEGFR2 Abs will benefit cancer patients. We used the Institute of Cellular and Organismic Biology human Ab library and affinity maturation to develop a fully human Ab, anti‐VEGFR2‐AF, which shows excellent VEGFR2 binding activity. Anti‐VEGFR2‐AF bound Ig‐like domain 3 of VEGFR2 extracellular region to disrupt the interaction between VEGF‐A and VEGFR2, neutralizing downstream signaling of the receptor. Moreover, anti‐VEGFR2‐AF inhibited capillary structure formation and exerted Ab‐dependent cell‐mediated cytotoxicity and complement‐dependent cytotoxicity in vitro. We found that VEGFR2 is expressed in PC‐3 human prostate cancer cell line and associated with malignancy and metastasis of human prostate cancer. In a PC‐3 xenograft mouse model, treatment with anti‐VEGFR2‐AF repressed tumor growth and angiogenesis as effectively and safely as US FDA‐approved anti‐VEGFR2 therapeutic, ramucirumab. We also report for the first time that addition of anti‐VEGFR2 Ab can enhance the efficacy of docetaxel in the treatment of a prostate cancer mouse model. In HL‐60 human leukemia‐xenografted mice, anti‐VEGFR2‐AF showed better efficacy than ramucirumab with prolonged survival and reduced metastasis of leukemia cells to ovaries and lymph nodes. Our findings suggest that anti‐VEGFR2‐AF has strong potential as a cancer therapy that could directly target VEGFR2‐expressing tumor cells in addition to its anti‐angiogenic action.  相似文献   

6.
Using an orthotopic intracerebral model, we investigated whether systemic treatment with DC101, a monoclonal antibody against vascular endothelial growth factor receptor (VEGFR)-2, could inhibit angiogenesis and the growth of human glioblastoma cells in severe combined immunodeficient mice. Intraperitoneal treatment with DC101, control IgG, or PBS was initiated either on day 0 or, in another series, on day 6 after tumor cell implantation, and animals were killed approximately 2 weeks after tumor cell injection. Tumor volumes in animals treated with DC101 were reduced by 59 and 81% compared with IgG and PBS controls, respectively (P < 0.001), when treatment was initiated immediately, and similar results were obtained when treatment started on day 6. Microvessel density in tumors of DC101-treated animals was reduced by at least 40% compared with animals treated with control IgG or PBS (P < 0.01). We observed a reduction in tumor cell proliferation and an increase in apoptosis in DC101-treated animals (P < 0.001). However, in mice treated with DC101, we also noticed a striking increase in the number and total area of small satellite tumors clustered around, but distinct from, the primary. These satellites usually contained central vessel cores, and tumor cells often had migrated over long distances along the host vasculature to eventually reach the surface and spread leptomeningeally. We conclude that systemic antagonization of VEGFR-2 can inhibit glioblastoma neovascularization and growth but can lead to increased cooption of preexistent cerebral blood vessels. Therefore, a combination of different treatment modalities which also include anti-invasive therapy may be needed for an effective therapy against glioblastoma, and the use of an antibody against VEGFR-2 may be one effective component.  相似文献   

7.
Using an orthotopic intracerebral model from our established HM55-BGIV-101 tumor line, we investigated the antitumor effect on the angiogenesis and growth of human glioblastoma after treatment with monoclonal antibody DC101 against the vascular endothelial growth factor receptor-2 and monoclonal antibody C225 against the epidermal growth factor receptor. Nude mice bearing intracerebral glioblastoma xenografts were treated intraperitoneally with DC101 and C225 either alone or in combination. Histopathological analysis of solid tumor volume, satellite tumor number, microvessel density, tumor cell proliferation, and apoptosis was performed. In the DC101-treated group, solid tumor volume and microvessel density were reduced by 59.7 and 64%, respectively; tumor cell proliferative activity was reduced by 53.2% and the apoptotic index (AI) was increased by 66.7%; satellite tumor number was enhanced by 84.4%. C225 alone reduced satellite tumor number by 43.3%, but had no effect on solid tumor volume, microvessel density, tumor cell proliferation, and apoptosis. C225 combined with DC101 not only reduced solid tumor volume, microvessel density, tumor cell proliferative activity, and increased AI, but also reduced satellite tumor number. Inhibition of angiogenesis achieved by DC101 can cause increased tumor cell invasiveness. In our studies this increased tumor cell invasiveness was inhibited simultaneously by C225, which provides a theoretical basis for treatment of glioblastoma by the method of combining drugs with different pharmacological activity.  相似文献   

8.
目的 :检测血管内皮生长因子(vascularendothelialgrowthfactor ,VEGF)和基质金属蛋白酶 -2 (matrixmetalloproteinase 2 ,MMP 2 )在大肠癌组织中的表达及其与肿瘤进展的关系。方法 :应用免疫组化SP法检测了 18例正常大肠黏膜、18例大肠腺瘤样息肉和 5 1例大肠癌组织中VEGF、MMP 2的表达。结果 :大肠腺瘤样息肉、大肠癌中VEGF、MMP 2阳性表达率显著高于正常大肠黏膜组织 ,P <0 0 5。VEGF、MMP 2阳性表达率与大肠癌的淋巴结转移、Duke’s分期有关 ,P <0 0 5。VEGF、MMP 2在大肠癌中的表达有相关性 ,P<0 0 5。结论 :VEGF、MMP 2可能成为反映大肠癌进展的生物学指标及其治疗的理想靶点  相似文献   

9.
血管内皮生长因子部分多肽抗血管生成的研究   总被引:2,自引:0,他引:2  
Li X  Zeng W  Zhang Y 《中华肿瘤杂志》2002,24(5):448-450
目的:观察血管内皮生长因子(VEGF)部分多肽(3-4外显子)抗血管生成的作用。方法:抽提LoVo细胞总RNA,进行RT-PCR,克隆VEGF部分多肽cDNA,构建VEGF部分多肽原核表达载体,用限制性酶切和DNA测序进行鉴定,通过聚丙烯酰胺凝胶电泳(SDS-PAGE)分析表达产物,表达产物经亲和层析纯化后,以人脐静脉内皮细胞(HUVEC)和鸡胚尿囊膜(CAM)血管测定其生物学活性。结果:表达产物以可溶性分子形成存在于菌体中,具有良好的抗原性和特异性,并具有抑制HUVEC增殖及CAM血管形成的活性。结论:VEGF部分多肽具有竞争抑制血管生成的功能,在肿瘤生物靶向治疗中具有一定潜在的价值。  相似文献   

10.
PURPOSE OF REVIEW: Targeted therapies are emerging as potentially important therapeutic interventions in the treatment of advanced colorectal cancer. There have been considerable developments in this field within the past few years, with some agents entering the clinic and others soon to follow. Monoclonal antibodies against important tumorigenic targets have been in development for over a decade. Recently, cetuximab and bevacizumab have generated significant interest and are the focus of this review. RECENT FINDINGS: Cetuximab, a monoclonal antibody against the epidermal growth factor receptor, and bevacizumab, a monoclonal antibody against vascular endothelial growth factor, have now been subject to rigorous assessment within several clinical studies, including a large randomized phase II study of cetuximab and a randomized phase III study of bevacizumab. The demonstration of efficacy and safety with these agents has led to the issue of licenses for cetuximab in Switzerland and bevacizumab in the United States. SUMMARY: These results have led to a rapid expansion of further studies to define the role of these antibodies and to aid their future integration with conventional approaches for the management of advanced colorectal cancer.  相似文献   

11.
血管内皮生长因子(VEGF)是一种序列高度保守、高度特异性的促血管内皮细胞生长因子,广泛分布于人和动物体内的大脑、肾脏、肝脏、脾脏、胰腺和骨骼等组织中,对内皮细胞具有强烈的促有丝分裂作用,刺激血管内皮细胞增殖和血管通透性增加,促进新生血管形成。VEGF通过与血管内皮细胞表面受体(VEGFR)特异性结合发挥生物学效应。抑制VEGF及VEGFR的活性可以减缓或阻滞骨肉瘤侵袭和转移。研究表明,VEGF及VEGFR对肿瘤血管及淋巴管的生成及肿瘤侵袭和转移起重要作用。本文对VEGF及VEGFR与骨肉瘤血管与淋巴管生成及其侵袭与转移的关系作一综述。  相似文献   

12.
PURPOSE: Vascular endothelial growth factor A (VEGF-A) and vascular endothelial growth factor receptor 2 (VEGFR2) are often coexpressed in breast cancer, and potentially affect cellular pathways and key proteins such as the estrogen receptor (ER) targeted by endocrine treatment. We therefore explored the association between adjuvant tamoxifen treatment in breast cancer and expression of VEGF-A and VEGFR2, as well as human epidermal growth factor receptor 2 (HER2), which represents a candidate gene product involved in tamoxifen resistance. PATIENTS AND METHODS: Immunohistochemical expression of tumor-specific VEGF-A, VEGFR2, and HER2 was evaluated in tumor specimens from premenopausal breast cancer patients randomly assigned to 2 years of tamoxifen or no treatment (n = 564), with 14 years of follow-up. Hormone receptor status was determined in 96% of the tumors. RESULTS: VEGF-A, VEGFR2, and HER2 were assessable in 460, 472, and 428 of the tumors, respectively. In patients with ER-positive and VEGFR2-low tumors, adjuvant tamoxifen significantly increased recurrence-free survival (RFS; [HR] hazard ratio for RFS, 0.53; P = .001). In contrast, tamoxifen treatment had no effect in patients with VEGFR2-high tumors (HR for RFS, 2.44; P = .2). When multivariate interaction analyses were used, this difference in treatment efficacy relative to VEGFR2 expression status was statistically significant for both ER-positive (P = .04) plus ER-positive and progesterone receptor-positive tumors. We found no significant difference in tamoxifen treatment effects in relation to VEGF-A or HER2 status. CONCLUSION: Tumor-specific expression of VEGFR2 was associated with an impaired tamoxifen effect in hormone receptor-positive premenopausal breast cancer. Tamoxifen in combination with VEGFR2 inhibitors might be a novel treatment approach for VEGFR2-expressing breast cancer, and such a treatment might restore the tamoxifen response.  相似文献   

13.
Angiogenesis plays a key role in tumor growth and metastasis. The transforming growth factor alpha (TGF-alpha)-epidermal growth factor receptor (EGFR) autocrine pathway controls in part the production of angiogenic factors such as vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) in cancer cells. In this study, we have evaluated the antiangiogenic and antitumor activity of monoclonal antibody (MAb) C225, an anti-EGFR chimeric human-mouse MAb, alone and in combination with a human VEGF antisense (AS) 21-mer phosphorothioate oligonucleotide (VEGF-AS) in human GEO colon cancer cells. MAb C225 treatment determined a dose-dependent inhibition of VEGF, bFGF, and TGF-alpha production by GEO cells in vitro. Treatment with VEGF-AS caused a selective inhibition in VEGF expression by GEO cells in vitro. Treatment of immunodeficient mice bearing established, palpable GEO xenografts for 3 weeks with VEGF-AS or with MAb C225 determined a cytostatic reversible inhibition of tumor growth. In contrast, a prolonged inhibition of tumor growth was observed in all mice treated with the two agents, in combination with a significant improvement in mice survival compared with controls (P < .001), to MAb C225 (P < .001), or to VEGF-AS (P < .001) treated mice. All mice died within 4, 6, and 8 weeks after tumor cell injection in the control, VEGF-AS and MAb C225 groups, respectively. In contrast, 50% of mice treated with the combination of VEGF-AS and MAb C225 were alive at 13 weeks. Ten % of mice treated with VEGF-AS plus MAb C225 were alive at 20 weeks and had no histological evidence of GEO tumors. Immunohistochemical analysis of GEO tumor xenografts demonstrated a significant reduction of VEGF expression after treatment with VEGF-AS with a parallel reduction in microvessel count. MAb C225 treatment determined a reduction in the expression of VEGF, bFGF, and TGF-alpha with a reduction in microvessel count. Finally, a significant potentiation in inhibition of VEGF expression and little or no microvessels were observed in GEO tumors after the combined treatment with the two agents.  相似文献   

14.
Huang G  Yang L  Yang J  Liu H  Yang Z 《中华肿瘤杂志》2002,24(6):564-565
目的 研究肝细胞癌 (HCC)中表皮生长因子 (EGF)与血管内皮生长因子 (VEGF)过量表达的关系。方法 通过免疫组化SABC法 ,检测 36例HCC组织及其相应癌旁肝组织和 6例正常肝组织中EGF、VEGF和微血管密度的表达 ,并对这些指标进行相关分析。离体实验中 ,用重组人EGF刺激人肝癌细胞系HepG2 ,采用半定量逆转录PCR检测VEGF的表达情况。结果  36例HCC组织中 ,EGF和VEGF表达阳性率分别为 75 .0 %和 88.9%。Spearman等级相关分析显示 ,HCC组织中EGF的表达与VEGF的表达具有明显的正相关关系 (r=0 .4 6 2 ,P <0 .0 1)。重组人EGF可以以浓度和时间依赖性的方式诱导HepG2 细胞中VEGF的转录。结论 HCC中EGF的表达是VEGF过量表达的基本原因之一。  相似文献   

15.
 目的 探讨胶质瘤患者血清血管内皮生长因子(VEGF)及其受体Flt-1和KDR水平变化,为评价胶质瘤治疗效果,判断预后寻找一种科学的生物学标志物。方法 收集治疗前后胶质瘤患者、脑转移癌患者和健康对照者血清,进行VEGF,Flt-1和KDR水平的检测,SPSS11.5统计软件包对数据进行t检验和相关分析。结果 (1)治疗前脑胶质瘤和脑转移瘤患者血清VEGF水平明显高于健康对照组; 脑胶质瘤患者组和脑转移瘤患者组血清Flt-1水平明显高于健康对照组;脑胶质瘤患者组血清KDR水平明显高于健康对照组; 治疗后缓解的胶质瘤患者组VEGF和Flt-1水平明显低于治疗前。差异均有统计学意义。(2) VEGF与Flt-1和KDR有显著的相关性。结论 胶质瘤患者血清中VEGF及其受体的检测,可作为胶质瘤辅助诊断、治疗效果监测和预后判断的重要生物学指标。  相似文献   

16.
Li R  Xiong DS  Shao XF  Xu YF  Zhu ZP  Yang CZ 《中华肿瘤杂志》2005,27(4):209-212
目的研制能够封闭血管内皮生长因子(VEGF)受体KDR的单克隆抗体,探讨其体外抑制VEGF165诱导的生物学活性。方法以原核表达的KDR胞外Ⅲ区融合蛋白免疫Balb/c小鼠,采用传统杂交瘤技术制备抗KDR胞外Ⅲ区单克隆抗体,采用ELISA和FACS方法鉴定其抗原结合特异性,采用免疫沉淀和[^3H]-TdR掺入的方法分析该单克隆抗体阻断VEGF165刺激内皮细胞表面KDR酪氨酸激酶受体磷酸化,抑制VEGF165岱诱导内皮细胞增殖的活性。结果抗KDR胞外Ⅲ区单抗Ycom1D3不仅能与可溶性KDR结合,亦可与细胞表面表达的KDR结合,并可竞争性抑制VEGF165与可溶性KDR的相互作用,阻断VEGF165刺激内皮细胞表面KDR酪氨酸激酶受体磷酸化,显著抑制由VEGF165诱导脐静脉内皮细胞的增殖。结论抗KDR胞外Ⅲ区单抗Ycom1D3可通过封闭KDR而抑制VEGF活性,在肿瘤及其他血管新生疾病治疗中具有潜在的应用前景。  相似文献   

17.
PURPOSE: Antiangiogenic therapy is now considered to be one of promising approaches to treat various types of cancer. In this study, we examined the possibility of developing antiangiogenic cancer vaccine targeting vascular endothelial growth factor receptor 1 (VEGFR1) overexpressed on endothelial cells of newly formed vessels in the tumor. EXPERIMENTAL DESIGN: Epitope-candidate peptides were predicted from the amino acid sequence of VEGFR1 based on their theoretical binding affinities to the corresponding HLAs. The A2/Kb transgenic mice, which express the alpha1 and alpha2 domains of human HLA-A*0201, were immunized with the epitope candidates to examine their effects. We also examined whether these peptides could induce human CTLs specific to the target cells in vitro. RESULTS: The CTL responses in A2/Kb transgenic mice were induced with vaccination using identified epitope peptides restricted to HLA-A*0201. Peptide-specific CTL clones were also induced in vitro with these identified epitope peptides from peripheral blood mononuclear cells donated by healthy volunteers with HLA-A*0201. We established CTL clones in vitro from human peripheral blood mononuclear cells with HLA-A*2402 as well. These CTL clones were shown to have potent cytotoxicities in a HLA class I-restricted manner not only against peptide-pulsed target cells but also against target cells endogenously expressing VEGFR1. Furthermore, immunization of A2/Kb transgenic mice with identified epitope peptides restricted to HLA-A*0201 was associated with significant suppression of tumor-induced angiogenesis and tumor growth without showing apparent adverse effects. CONCLUSIONS: These results strongly suggest that VEGFR1 is a promising target for antiangiogenic cancer vaccine and warrants further clinical development of this strategy.  相似文献   

18.
Acquired resistance to antiangiogenic drugs has emerged as a potentially important issue in clinical settings; however, the underlying molecular and cellular mechanism of resistance to vascular endothelial growth factor receptor 2 (VEGFR2) tyrosine kinase inhibitor (TKI) remains largely unclear. We evaluated the cellular characteristics of human umbilical vein endothelial cell (HUVEC) clones, which are resistant to VEGFR2-TKI (Ki8751) to elucidate this mechanism of resistance to antiangiogenic drugs. Resistant HUVEC clones were 10-fold more resistant to VEGFR2-TKI than the parental cells and they exhibited an almost complete absence of VEGF-mediated cellular proliferation. The mRNA expression analysis revealed that expression of VEGFR1, VEGFR2 and VEGFR3 was lower in resistant clones, while that of several angiogenic ligands was increased. The protein expression of VEGFR2 was markedly down-regulated in two (R5 and R6 clone) out of five resistant clones. Focusing on the R5 clone, VEGF stimulation did not increase the phosphorylation of VEGFR2 or the dimerization of VEGFR2. The inhibition of phospho-AKT by VEGFR2-TKI was also weakened more than 10-fold in the R5 clone. Finally, a microarray analysis revealed that some angiogenesis-associated, and some angiogenesis-specific genes, including platelet endothelial cell adhesion molecule 1 (PECAM1)/CD31, homeobox A9 (HOXA9), and endothelial cell-specific molecule 1 (ESM1), were remarkably down-regulated in all the resistant clones compared with the parental cells. HUVEC clones resistant to VEGFR2-TKI exhibited down-regulation of VEGFR2, a decreased signal response to VEGF stimulation, and the loss of vascular endothelial markers. These results strongly suggest that an escape from VEGFR2 signaling-dependency is one of the cellular mechanisms of resistance to VEGFR2-TKI in vascular endothelial cells.  相似文献   

19.
PURPOSE: Standard treatments have modest effect against pancreatic cancer, and current research focuses on agents targeting molecular pathways involved in tumor growth and angiogenesis. This study investigated the interactions between ZD6474, an inhibitor of tyrosine kinase activities of vascular endothelial growth factor receptor-2 and epidermal growth factor receptor (EGFR), gemcitabine, and ionizing radiation in human pancreatic cancer cells and analyzed the molecular mechanisms underlying this combination. EXPERIMENTAL DESIGN: ZD6474, ionizing radiation, and gemcitabine, alone or in combination, were given in vitro to MIA PaCa-2, PANC-1, and Capan-1 cells and in vivo to MIA PaCa-2 tumor xenografts. The effects of treatments were studied by the evaluation of cytotoxicity, apoptosis, cell cycle, EGFR and Akt phosphorylation, modulation of gene expression of enzymes related to gemcitabine activity (deoxycytidine kinase and ribonucleotide reductase), as well as vascular endothelial growth factor immunohistochemistry and microvessel count. RESULTS: In vitro, ZD6474 dose dependently inhibited cell growth, induced apoptosis, and synergistically enhanced the cytotoxic activity of gemcitabine and ionizing radiation. Moreover, ZD6474 inhibited phosphorylation of EGFR and Akt and triggered cell apoptosis. PCR analysis showed that ZD6474 increased the ratio between gene expression of deoxycytidine kinase and ribonucleotide reductase. In vivo, ZD6474 showed significant antitumor activity alone and in combination with radiotherapy and gemcitabine, and the combination of all three modalities enhanced MIA PaCA-2 tumor growth inhibition compared with gemcitabine alone. CONCLUSIONS: ZD6474 decreases EGFR and Akt phosphorylation, enhances apoptosis, favorably modulates gene expression in cancer cells, and acts synergistically with gemcitabine and radiotherapy to inhibit tumor growth. These findings support the investigation of this combination in the clinical setting.  相似文献   

20.
目的:探讨血管内皮生长因子(VEGF)及其受体(KDR)的表达与非小细胞肺癌(NSCLC)血管形成的关系。方法:分别应用免疫组织化学S-P法和原位分子杂交法检测62例NSCLC组织和16例肺的良性瘤样病变组织中的VEGF和KDR mRNA的表达,并对血管进行染色、计数。结果:62例肺癌组织中46例有VEGF的表达(占74.29%),阳性表达位于肿瘤细胞胞膜及胞质;KDR mRNA在49例中有阳性表达(占79.03%),阳性表达位于肿瘤血管内皮细胞、肿瘤细胞胞膜及胞质。VEGF和KDR mRNA的表达与有无淋巴结转移和临床病理分期密切相关;VEGF和KDR mRNA阳性表达组微血管密度明显高于阴性表达组,P〈0.01。结论:VEGF和KDR的表达与NSCLC的发生、发展和转移可能密切相关,可作为评估NSCLC患者预后的一项指标。  相似文献   

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