Combination antiangiogenic therapy: increased efficacy in a murine model of Wilms tumor

BACKGROUND/PURPOSE: Antibody to vascular endothelial growth factor (anti-VEGF) suppresses tumor growth and metastasis in experimental Wilms tumor. However, tumor growth accelerates if antibody is withdrawn. As recently shown, low-dose, frequently administered topotecan, a topoisomerase-1 inhibitor, has anti-angiogenic activity. The authors hypothesized that combined topotecan/anti-VEGF therapy would suppress tumor growth and metastasis more durably than either agent alone. METHODS: Xenografts were induced by intrarenal injection of human Wilms tumor cells in athymic mice (n = 59). Mice were divided into control (n = 10), anti-VEGF (n = 16), topotecan (n = 17), and topotecan plus anti-VEGF (n = 16) groups. All control and half the treated mice were killed at week 6. Remaining ("rebound") mice were maintained without treatment until week 8. Tumor vasculature was mapped by fluorescein angiography/PECAM immunostaining. Endothelial apoptosis was assessed by TUNEL assay. RESULTS: 6 weeks: Tumor weights were reduced significantly in treated mice (P <.003 v control). Seven of ten control and 1 of 25 treated mice displayed lung metastases (P <.003). Rebound tumors were largest in topotecan-only, intermediate in antibody-treated, and smallest in combination-treated mice. Immunostaining and angiography results showed sparse vascularity in treated xenografts. Endothelial apoptosis was observed only in treated tumors. CONCLUSION: Combination low-dose topotecan and anti-VEGF antibody therapy is antiangiogenic and suppresses tumor growth and metastasis in experimental Wilms tumor more durably than either agent alone.     

All angiogenesis is not the same: Distinct patterns of response to antiangiogenic therapy in experimental neuroblastoma and Wilms tumor

BACKGROUND/PURPOSE: Neuroblastoma and Wilms tumor exhibit different patterns of metastasis, invasion, and therapeutic response. Vascular endothelial growth factor (VEGF) is an angiogenic factor expressed in both tumors. The authors hypothesized that because the clinical behavior of these tumors differs, the response to anti-VEGF therapy would be distinct, and tumor vascular architectures would reflect this distinction. METHODS: Xenografts were induced by intrarenal injection of cultured cells in athymic mice. After 1 week, anti-VEGF antibody or vehicle were administered for 5 weeks before sacrifice. Additional animals were maintained for 3 weeks after termination of antibody injections to assess rebound growth of tumors. Fluorescein angiography was performed in selected animals. RESULTS: Neuroblastoma control and treated tumor weights were not significantly different (1.48 g v 0.77 g, P =.34). By comparison, as previously reported, antibody-treated Wilms tumors were growth inhibited. Angiograms of treated (but not control) neuroblastomas displayed novel rounded structures at vessel branches, which the authors term terminal vascular bodies (TVBs). Wilms tumor vessels displayed no such alteration. CONCLUSIONS: Neuroblastoma xenografts are less effectively suppressed by anti-VEGF antibody than Wilms tumors. Neuroblastoma vascular architecture displays a novel alteration during antibody administration, which attenuates when antibody is withdrawn. These studies suggest that angiogenesis is differently regulated in experimental neuroblastoma and Wilms tumor.     

纳米血管内皮生长因子在治疗下肢缺血促进血管再生成中的作用

目的　利用家兔后肢缺血模型 ,观察纳米材料聚乳酸聚乙醇酸共聚物 (poly dl lactic co glycolicacid ,PLGA) ,包载血管内皮生长因子 (VEGF16 5 )基因 ,经局部肌肉注射后 ,外源基因在局部缺血组织中的转染及强度 ,以及缺血部位的血管新生状况。　方法　制备VEGF16 5 真核表达质粒 ,制备包载VEGF16 5 基因的纳米粒子 ,并检测其理化性质和体外释放曲线。建立家兔后肢缺血模型 2 4只 ,其中4只为对照组 ,只行股动脉及其分支结扎切断术 ;2只为空白纳米粒子组 ,局部缺血肌肉注射空白纳米粒子 ;10只应用裸质粒VEGF16 5 转染 ,8只采用纳米技术包载VEGF16 5 转染。直接缺血部位肌肉内多点注射 ,进行局部定位基因转染。术后 14d行血管造影 ,了解缺血部位侧枝形成情况。处死兔子 ,取股二头肌 ,内收大肌 ,做病理切片 ,免疫组化染色 ,观察VEGF16 5 的表达 ,测定毛细血管密度。应用逆转录 聚合酶链反应了解VEGF16 5 在骨骼肌中的表达 ,并对不同的转染技术进行半定量分析。　结果　转基因治疗 14d后 ,转染VEGF基因组血管造影可见明显新生血管和侧枝循环形成 ,免疫组化染色可见VEGF16 5 蛋白表达水平增高 ,缺血肌肉血管数增多 ,纳米VEGF16 5 治疗组与裸质粒VEGF16 5 治疗组的毛细血管密度明显高于对照组 ,有显著性差异 (P     

Vascular endothelial growth factor as prognostic factor in renal cell carcinoma

PURPOSE: Vascular endothelial growth factor (VEGF) has been recognized as an important constituent of vascularization and growth of solid tumors. Serum VEGF levels were evaluated and correlated to clinicopathologic findings and clinical outcome in patients with renal cell carcinoma (RCC). MATERIALS AND METHODS: Serum samples were collected before surgery in 164 patients with RCC. Levels of VEGF165 protein in sera were measured using a quantitative ELISA. Univariate and multivariate analyses were performed. RESULTS: The VEGF165 level in serum was significantly increased (p = 0.0001) in patients with RCC (median 343.4 pg./ml.) compared with the control patients (median 103.8 pg./ml.). The level of VEGF165 in serum correlated to clinical stage and histopathological grade. Patients with VEGF165 levels below median value had significantly longer survival time than patients with higher levels (p = 0.0001). This was also shown when VEGF165 was analyzed in univariate Cox regression (p = 0.0001). The impact of VEGF165 on survival was especially shown in patients having tumors with vein invasion (pT3b-c N0 M0) and in patients with clinical stages I - III (p = 0.0240 and p = 0.0023, respectively). When using multivariate analysis, only tumor stage and grade remained as independent prognostic variables. CONCLUSIONS: In RCC, serum VEGF165 level was significantly correlated to tumor stage and grade. Increased levels were correlated to adverse survival. Although, VEGF did not remain as an independent prognostic factor in multivariate analysis the levels of VEGF165 in serum was found useful for the identification of patients with potentially progressive disease especially for those with vein invasion.     

Therapeutic angiogenesis in chronically ischemic porcine myocardium: comparative effects of bFGF and VEGF

BACKGROUND: Both vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) have been used in preclinical studies to induce new blood vessel growth in ischemic cardiac muscle with promising results. However, clinical trials have been much less convincing and further work is needed. This study expands on prior work by comparing the long-term proangiogenic effects of direct intramyocardial (IM) injection of bFGF, as well as IM and intravenous (IV) VEGF in a porcine model of chronic hibernating myocardium. METHODS: Mini-swine with proximal 90% left circumflex (LCx) coronary stenosis subtending chronically ischemic, viable (hibernating) myocardium by positron emission tomography (PET) and dobutamine stress echocardiography (DSE) were randomized to IM bFGF (n = 5), IM VEGF(165) (n = 5), IV VEGF(165) (n = 5), IM vehicle (n = 5), or sham redo-thoracotomy (n = 4). The bFGF protein was administered in a total dose of 1.35 microg divided into 30 IM injections. IM VEGF(165) protein was administered in a total dose of 15 microg/kg divided into 30 injections; IV VEGF(165) was given at a dose of 50 ng. kg(-1). min(-1) for 200 minutes at three 72-hour intervals (30 microg/kg total dose). After 3 and 6 months the PET and DSE studies were repeated, and the animals were sacrificed for tissue vascular density and angiogenic protein analysis. RESULTS: Myocardial blood flow (MBF) by PET was significantly improved 3 months posttreatment in the IM bFGF and IM VEGF(165) groups, differences that were sustained at 6 months. There was no significant increase in MBF 3-months posttreatment in the IV VEGF(165) group; however, at 6 months MBF was significantly improved. No change in MBF was seen in the IM vehicle or sham groups. Regional wall motion at rest and peak stress in the LCx region demonstrated small but statistically significant improvements by 6 months in the IM bFGF and IV VEGF(165) groups only; no improvement was seen in the IM VEGF(165), IM vehicle, or sham groups. Quantitative vascular density was significantly increased in the LCx regions of all treatment groups (IM bFGF, IM VEGF(165), IV VEGF(165)) 6-months postoperatively. No significant increase in LCx region myocardial bFGF or VEGF protein levels was seen in the treated animals at 6 months. CONCLUSIONS: The IM bFGF, IM VEGF(165), and IV VEGF(165) all improve regional perfusion and vascular density 6-months posttherapy in the animal model utilized. Functional improvements were less consistent. Both bFGF and VEGF(165) may be useful therapies for improving regional perfusion in chronically ischemic myocardium, although combination therapy with additional growth factors or cellular therapies may be necessary if concomitant improvements in function are to be seen.     

Suppression of primary tumor growth in a mouse model of human neuroblastoma

BACKGROUND/PURPOSE: Neuroblastoma is the most common tumor of the abdomen in children. Consistently effective treatments are lacking for aggressive disease. The authors previously reported that therapy with anti-vascular endothelial growth factor (VEGF) antibodies suppresses both growth and metastasis in an experimental model of Wilms' tumor. The authors hypothesized that, in a parallel model of neuroblastoma, anti-VEGF treatment would inhibit (1) growth and (2) metastasis. METHODS: Primary tumors were established in the kidneys of nude mice. In cohort 1 (n = 42), mice were killed at 3 time-points, and tissues were evaluated histologically. Tumors were assayed for VEGF. In cohort 2 (n = 28), anti-VEGF antibody or vehicle was administered. Tumor weights and the incidence of metastases in the 2 groups were compared. VEGF deposition was evaluated by immunohistochemistry. RESULTS: Mice displayed large tumors with liver and lung metastases. VEGF levels in tumors increased over time. Antibody-treated animals displayed significantly smaller tumors, but incidence and size of metastases were unaffected. VEGF was localized to tumor stroma immunohistochemically, with no difference in pattern observed in control and antibody-treated tumors. CONCLUSIONS: Anti-VEGF antibodies inhibit primary tumor growth in experimental neuroblastoma, but not metastasis. This may contrast with the effect of the same antibody in a parallel model of Wilms' tumor.     

Inhibition of vascular endothelial cell growth factor suppresses the in vivo growth of human prostate tumors

The LNCaP human prostate cancer cell line is androgenand stromal-dependent for in vivo growth. We co-inoculated LNCaP cells with human fetal fibroblasts, isolated from prostate, bone (male), and lung (male and female) derived from 18- to 22-week-old human fetal tissue, into non-castrate male nude mice. Co-inoculation of LNCaP with fetal prostatic fibroblasts resulted in high tumor take rates (27 of 30, or 90%) 6 to 8 weeks after subcutaneous co-inoculation. Serum prostate specific antigen (PSA) values correlated strongly with wet tumor weight (r=0.86). The fetal fibroblast enhancement of tumor take rates in vivo was neither gender- nor organ-specific. Fetal fibroblast-conditioned medium (CM) did not have a significant proliferative effect on LNCaP cell growth in vitro. Areas of angiogenesis were demonstrable in all tumors, with blood vessels arising at the interface between stromal and tumor cells. The fetal fibroblasts, but not the LNCaP cells, expressed significant amounts of the mRNA and protein for vascular endothelial cell growth factor (VEGF). Treatment of tumor-bearing animals with neutralizing antibodies to VEGF resulted in significant tumor growth suppression. These findings indicate that VEGF is an important mediator of stromal-induced enhancement of human prostate cancer cell growth in vivo.     

Pathological angiogenesis in a murine model of human Wilms' tumor.

BACKGROUND/PURPOSE: Pathological vascular architecture is a feature of neoangiogenic processes such as diseases of the retina and tumor growth. The authors hypothesized that experimental human Wilms' tumors would display a vascular architecture similar to retinal diseases that are driven by vascular endothelial growth factor (VEGF). METHODS: Human Wilms' tumors were established in the right kidneys of nude mice. After 4.5 weeks of tumor growth, fluorescein angiograms were performed before death. Representative sections of tumors and contralateral, control kidneys were evaluated by fluorescent microscopy. RESULTS: Fluorescein angiograms demonstrated a characteristic pathological architecture. Vascular tortuosity, capillary tufting, and hemorrhage were noted. These features were not present in normal kidneys. CONCLUSIONS: Vascular architecture of Wilms' tumor displays the specific features previously described in diseases of the retina, which have been shown to be driven by VEGF, suggesting that neoangiogenesis in this model is also VEGF driven.     

Ad-aVEGF165基因在裸鼠体内对人皮肤恶性黑色素瘤的影响

目的 探讨Ad-aVEGF165基因转染对裸鼠体内人恶性黑色素瘤生长的影响。方法 裸鼠皮下接种人恶性黑色素瘤细胞（A375），1周后瘤块形成并转种和分组干预。随机分为PBS组、Ad-GFP组、Ad-aVEGF组，进行大体观察和组织形态学观察，检测Ad-aVEGF165基因的表达、微血管密度、凋亡指标的变化。结果 成功地建立了裸鼠荷瘤模型；Ad-aVEGF165能抑制体内肿瘤的生长，没有观察到明显的毒副作用；组织学切片能观察GFP基因的表达。Ad-aVEGF组有较多的组织坏死，但其对A375，细胞的凋亡没有明显的影响。Ad-aVEGF165能够抑制A375细胞VEGF的表达，并导致肿瘤的MVD明显减少。结论 Ad-aVEGF165干预人恶性黑色素瘤是可行的，其机理是通过局部缺血而不是通过凋亡起作用的。     

Comparison of vascular endothelial growth factor and fibroblast growth factor-2 in a swine model of endothelial dysfunction.

OBJECTIVE: Growth factor based angiogenesis, with or without cell therapy, is a promising therapeutic modality for patients with coronary artery disease. We compared the relative efficacies of surgically delivered vascular endothelial growth factor (VEGF) and fibroblast growth factor-2 (FGF-2) in a swine model of hypercholesterolemia-induced endothelial dysfunction which captures many of the pathophysiologic abnormalities of human coronary disease. METHODS: Yucatan mini-swine (20-30 kg), fed a high cholesterol diet (total 20 weeks), underwent circumflex ameroid placement to create chronic myocardial ischemia, followed three weeks later by perivascular administration of VEGF (2 microg; n=6), FGF-2 (100 microg; n=6), or placebo (n=7) in the ischemic territory. Normocholesterolemic animals (n=7) served as controls. Four weeks later, endothelial function, collateral-dependent perfusion, as well as myocardial protein and mRNA levels of angiogenic mediators were assessed. RESULTS: Endothelial dysfunction was observed in all hypercholesterolemic animals as impaired microvessel relaxation in response to adenosine diphosphate and VEGF. VEGF administration improved baseline-adjusted collateral-dependent perfusion at rest (-0.03+/-0.05 vs -0.12+/-0.04, VEGF vs placebo, p=0.09), but FGF-2 delivery caused a significantly greater improvement in perfusion compared to either group (+0.15+/-0.03, p<0.05 vs HC-placebo and HC-VEGF) at rest. Molecular analysis revealed increased eNOS expression (135%+/-8%, p=0.03 vs placebo) in all growth factor treated animals and increased expression of FGF-2 receptor, FGFR1 (65+/-26%, p=0.04 vs placebo), in FGF-2 treated animals. No significant changes were demonstrated in other angiogenic mediators including Akt, Syndecan-4. CONCLUSIONS: In the setting of hypercholesterolemic endothelial dysfunction, FGF-2 is more effective than VEGF at enhancing collateral-dependent perfusion and thus, may be a better candidate than VEGF for angiogenic therapy in patients with end-stage CAD.     

Inhibition of in vivo tumor angiogenesis and growth via systemic delivery of an angiopoietin 2-specific RNA aptamer

BACKGROUND: Cellular events mediated by the Tie2 receptor are important to tumor neovascularization. Despite the complex interplay of the best-characterized Tie2 ligands, angiopoietins 1 and 2, Ang2 is purportedly "proangiogenic" in the presence of vascular endothelial growth factor. We examined whether in vivo administration of an RNA aptamer that specifically blocks Ang 2 would inhibit tumor angiogenesis and growth. METHODS: Ang2-mediated Tie2 receptor phosphorylation was assessed in vitro in the absence and presence of aptamer coupled to polyethylene glycol. IN VIVO ANGIOGENESIS ASSAY: CT26 murine colon carcinoma cells expressing green fluorescent protein were delivered into mouse dorsal skinfold window chambers. Animals received daily intraperitoneal injections of phosphate-buffered saline, low-dose (Ang2 aptamer-LD; 1 mg/kg/d), or high-dose aptamer (Ang2 aptamer-HD; 10 mg/kg/d). Vascular length density was measured under fluorescence microscopy. PRIMARY TUMOR GROWTH: CT26 cells expressing luciferase were injected into flanks of BALB/c mice to allow tumor growth monitoring by bioluminescence imaging. Animals received continuous phosphate-buffered saline or aptamer (1 mg/kg/d) via ALZET pumps. Tumors were assessed for CD31/PECAM-1 immunostaining and Hoechst dye uptake. RESULTS: Pegylated aptamer inhibited Tie2 phosphorylation. Systemic aptamer administration reduced vascular length density (P < or = 0.03) and decreased bioluminescence emission (P < 0.04), corresponding to 50% decrease in tumor volume (P = 0.04). Control tumors displayed abundant vascular marker staining, in contrast to tumors from aptamer-treated animals. CONCLUSIONS: in vivo administration of a clinically relevant, pegylated RNA aptamer specifically designed against Ang2 inhibited tumor angiogenesis and growth. These findings support targeted Ang2 inhibition as a relevant anti-angiogenic, anti-neoplastic strategy.     

VEGF antisense therapy inhibits tumor growth and improves survival in experimental pancreatic cancer

BACKGROUND: Vascular endothelial growth factor (VEGF), a key mediator of angiogenesis, is overexpressed in pancreatic cancer. This study evaluated VEGF production in pancreatic cancer cells and the effect of VEGF antisense on growth and angiogenesis of human pancreatic cancer in a nude mouse model. METHODS: In vitro: VEGF in cell culture supernatant of pancreatic cancer cells (AsPC-1, poorly differentiated; HPAF-2, moderately differentiated) was assessed by enzyme-linked immunosorbent assay. In vivo: A VEGF antisense oligonucleotide (AS-3) was synthesized. One-mm(3) fragments of subcutaneous pancreatic cancer donor tumors were implanted into the pancreas of nude mice also receiving AS-3 (10 mg/kg/day) or vehicle intraperitoneally for 14 weeks. Primary tumor volume, metastasis, and VEGF in plasma and ascites were determined at autopsy. Microvessel density was analyzed in CD31-stained tumors. RESULTS: In vitro: Both pancreatic cancer cell lines secreted VEGF protein (AsPC-1, 4200 +/- 40 pg/10(6) cells; HPAF-2, 8120 +/- 60 pg/10(6) cells). In vivo: AS-3 reduced tumor volume in the HPAF-2 group (860 +/- 140 vs 3830 +/- 590 mm(3)) and metastatic spread in both groups (AsPC-1, 6.5 +/- 0.8 vs 16.7 +/- 0.9 points; HPAF-2, 2.5 +/- 0.2 vs 8.3 +/- 1.5 points). Tumor volume was not different in the AsPC-1 group (1050 +/- 80 vs 1400 +/- 150 mm(3)). Survival was increased in the AsPC-1 group. Plasma levels of VEGF and microvessel density in tumors were significantly reduced in treated animals. Only control animals (50%) developed ascites with high VEGF concentrations. CONCLUSIONS: Human pancreatic cancer cells secrete VEGF at biologically relevant high levels. AS-3 therapy normalizes plasma VEGF and decreases neoangiogenesis, thereby reducing tumor growth and metastasis and improving survival. AS-3-treated animals developed no ascites, suggesting decreased vascular permeability by reducing VEGF expression in pancreatic cancer cells.     

VEGF-mediated angiogenesis of human pheochromocytomas is associated to malignancy and inhibited by anti-VEGF antibodies in experimental tumors

BACKGROUND: Pheochromocytomas are well-vascularized tumors of the adrenal medulla. In human pheochromocytomas, angiogenesis has been associated with tumor progression. The mechanisms, however, are unknown. METHODS: Surgical specimens of benign, invasive, and metastatic human pheochromocytomas (n = 10/5/5) were immunostained for vascular endothelial growth factor (VEGF) and CD34, to determine VEGF expression and microvessel density (vascular surface density, [VSD]). In PC12-pheochromocytoma cells, VEGF messenger RNA and protein were analyzed by Northern blotting and enzyme immunoassay; biologic activity by human umbilical vein endothelial cell-proliferation assay. Inhibition of angiogenesis of PC12 xenografts by 2 neutralizing anti-VEGF antibodies (C20-pAB, M461-mAB) was evaluated by VEGF expression, VSD, and mitotic activity. RESULTS: VEGF expression and VSD were significantly higher in metastatic pheochromocytomas (VEGF 37.1 +/- 10.9% vs 20.7 +/- 9%, VSD 26.2 +/- 8 vs 13.5 +/- 3.3 1/mm). VEGF messenger RNA and protein were confirmed in PC12 cells and stimulated by nerve growth factor. Conditioned PC12 medium increased human umbilical vein endothelial cell proliferation more than 2-fold. Xentrotransplanted PC12 cells had marked VEGF expression and angiogenesis, which was inhibited by anti-VEGF antibodies (VEGF-expression by 29 and 38%, VSD by 43 and 46%, P <.05). CONCLUSION: Higher VEGF expression and microvessel density in malignant pheochromocytomas suggest VEGF-mediated angiogenesis to be related to tumor progression. Angiogenesis of PC12 xenografts is mediated by VEGF. Neutralizing anti-VEGF antibodies inhibit angiogenesis in experimental pheochromocytomas and may have potential for treating nonresectable pheochromocytomas.     

p53 accumulation in favorable-histology Wilms tumor is associated with angiogenesis and clinically aggressive disease

Background/Purpose: Unfavorable histology (UH) in Wilms tumor has been linked to malfunction of the p53 tumor suppressor gene, which regulates (1) the endogenous angiogenesis suppressor thrombospondin-1 (TSP-1) and (2) vascular endothelial growth factor (VEGF). The authors hypothesized that clinically aggressive favorable histology Wilms tumor (FH), like UH, but distinct from standard-risk FH disease, would display altered p53/TSP-1 function and upregulated angiogenesis. Methods: Three Wilms tumor specimens manifesting different histology and clinical behavior were obtained: clinically aggressive UH, clinically aggressive FH, and standard-risk FH disease. Xenografts were induced intrarenally in athymic mice. P53, TSP-1, and VEGF status and neovascularity were assessed in tumor tissues. Lungs were evaluated for metastasis. Results: Clinically aggressive FH Wilms tumor displayed progressive alteration in p53/TSP-1 status and upregulation of VEGF. Such alteration was observed in the UH tumor, but was absent from the standard-risk FH tumor. Xenografts from clinically aggressive tumors displayed brisk neoangiogenesis and yielded lung metastases. Conclusions: This is the first report of altered p53/TSP-1 function in association with clinically aggressive behavior in FH Wilms tumor. These characteristics were not observed in parallel studies of a nonaggressive FH tumor. Loss of wild-type p53 function may contribute to disease progression in FH Wilms tumor, in part by upregulation of VEGF.     

Effects of direct injection of dehydrated ethanol on PC3 human prostate cancer cells in nude mice: Preliminary study

OBJECTIVES: The effect of direct local injection of dehydrated ethanol on hormone-independent prostatic carcinoma cells (PC3 cells) implanted in nude mice was investigated. METHODS: PC3 tumors were implanted subcutaneously into 30 nude mice. Three weeks later, dehydrated ethanol was injected directly into the tumors. Twenty-three animals received an injection of ethanol at a volume of 40 microL, 80 microL, or 160 microL, and were divided into a low-dose group (n = 11) and a high-dose group (n = 12) on the basis of the ethanol/tumor volume ratio (<30% versus> or =30%). The control group (n = 7) was injected with 40 microL of physiological saline. The tumor volume before treatment was 324.9 +/- 110.9 mm(3) and was assessed as well as 1 day, 4 days, 1 week, 2 weeks, and 3 weeks after injection. Then the changes of tumor volume were compared between the two ethanol groups (low-dose group and high-dose group) and the control group. Histological examination was performed for up to 3 weeks after injection. RESULTS: Assessment of tumor volume showed that the ethanol/tumor volume ratio was 16.1 +/- 5.3% in the low-dose group (n = 5) and 51.8 +/- 20.3% in the high-dose group (n = 6). Tumor growth was significantly inhibited after 1 and 2 weeks in the ethanol groups compared with the control group (n = 3). After 3 weeks, there was a tendency for tumor regrowth in the low-dose group, but growth inhibition was maintained in the high-dose group. Histological examination showed tumor degeneration and necrosis with feeding vessel obstruction in the acute phase. CONCLUSIONS: Local injection of dehydrated ethanol regressed tumors of prostatic carcinoma cells in nude mice, with the degeneration of tumor cells and occlusion of feeding vessels.     

Anti-VEGF antibody in experimental hepatoblastoma: suppression of tumor growth and altered angiogenesis

Background: Hepatoblastoma is the most common primary hepatic malignancy of childhood, frequently presenting as advanced disease. Vascular endothelial growth factor (VEGF) is an endothelial mitogen and survival factor critical to growth and angiogenesis in many human cancers. Inhibition of VEGF effectively suppresses tumorigenesis in multiple experimental models. The authors hypothesized that anti-VEGF antibody would alter vascular architecture and impede tumor growth in experimental hepatoblastoma. Methods: The Institutional Animal Care and Use Committee of Columbia University approved all protocols. Xenografts were established in athymic mice by intrarenal injection of cultured human hepatoblastoma cells. Anti-VEGF antibody (100 [mu ]g/dose) or vehicle was administered intraperitoneally 2 times per week for 5 weeks. At week 6, 10 control/treated mice were killed and remaining animals maintained without treatment until week 8. Tumor weights were compared by Kruskal-Wallis analysis, and vascular alterations ascertained by fluorescein angiography and specific immunostaining. Results: Anti-VEGF antibody significantly inhibited tumor growth at 6 weeks (1.85 g +/[minus ] 0.60 control, 0.05 +/[minus ] 0.03 antibody, P [lt ] .0003). In comparison with controls, treated xenografts showed decreased vascularity and dilated surviving vessels with prominent vascular smooth muscle elements. Conclusions: Specific anti-VEGF therapy inhibits neoangiogenesis and significantly suppresses tumor growth in experimental hepatoblastoma. Surviving vasculature displays dilation and increased vascular smooth muscle. Anti-VEGF agents may represent new therapeutic alternatives for children with advanced disease. J Pediatr Surg 38:308-314.     

血管内皮生长因子及其受体mRNA在乳腺癌组织中的表达

目的　研究血管内皮生长因子及其受体FLT 1、FLK 1mRNA在乳腺癌组织中的表达及与临床病理因素的相关性。　方法　采用逆转录聚合酶链反应技术对手术的 47例乳腺癌标本 ,11例乳腺良性病变标本中血管内皮生长因子 (VEGF)及其受体FLT 1、FLK 1mRNA的表达进行检测。结果　在良、恶性乳腺组织中均检测到VEGF12 1、165mRNA的表达 ,在乳腺癌组织中表达水平分别为0 42 0± 0 13 3、0 2 91± 0 0 94高于良性乳腺组织 0 196± 0 0 67(P =0 0 0 0 )、0 2 0 6± 0 0 5 8(P =0 0 0 1) ;在乳腺癌组织中 ,VEGF12 1mRNA表达高于VEGF165mRNA(P =0 0 0 0 ) ,而在良性乳腺组织中两者表达水平差异无显著性意义 (P =0 666)。FLT 1、FLK 1mRNA在部分乳腺癌组织中表达 ,分别为 3 8 3 %(18/4 7)和 2 5 5 % (12 /4 7) ,而在良性乳腺组织中未见表达。乳腺癌组织中VEGF12 1、VEGF165、FLT 1、FLK 1mRNA表达与患者年龄、肿块大小、淋巴结转移状况、肿瘤分期及雌、孕激素受体状况之间无明显相关性。　结论　乳腺癌组织中VEGF12 1、165及其受体FLT 1、FLK 1mRNA表达水平上调 ,提示其在乳腺癌的血管生成中起着重要作用。