Novel endogenous angiogenesis inhibitors and their therapeutic potential

Angiogenesis, the formation of new blood vessels from the pre-existing vasculature is essential for embryonic development and tissue homeostasis. It also plays critical roles in diseases such as cancer and retinopathy. A delicate balance between pro- and anti-angiogenic factors ensures normal physiological homeostasis. Endogenous angiogenesis inhibitors are proteins or protein fragments that are formed in the body and have the ability to limit angiogenesis. Many endogenous angiogenesis inhibitors have been discovered, and the list continues to grow. Endogenous protein/peptide inhibitors are relatively less toxic, better tolerated and have a lower risk of drug resistance, which makes them attractive as drug candidates. In this review, we highlight ten novel endogenous protein angiogenesis inhibitors discovered within the last five years, including ISM1, FKBPL, CHIP, ARHGAP18, MMRN2, SOCS3, TAp73, ZNF24, GPR56 and JWA. Although some of these proteins have been well characterized for other biological functions, we focus on their new and specific roles in angiogenesis inhibition and discuss their potential for therapeutic application.     

海洋溴酚BTDE抑制内皮细胞血管生成的研究

目的 探究海洋溴酚化合物双（2,3,6-三溴-4,5-二羟基苄基）醚（BTDE）处理肿瘤细胞和肿瘤相关巨噬细胞所获得的条件培养基对内皮细胞血管生成的影响。方法 MTT法检测BTDE对肿瘤相关巨噬细胞RAW264.7增殖的影响；Transwell实验检测BTDE对细胞迁移和侵袭的影响；明胶酶谱法检测BTDE对细胞分泌的基质金属蛋白酶9（MMP9）活性的影响；Western Blot检测BTDE对细胞中β-catenin、VEGF表达的影响；体外获取BTDE处理肺癌A549后的条件培养基（BTDE/A549-CM）和处理肿瘤相关巨噬细胞RAW264.7后的条件培养基（BTDE/RAW264.7-CM），采用Transwell和Tube formation实验检测条件培养基对人脐静脉内皮细胞HUVEC迁移和成管的影响。结果 BTDE抑制RAW264.7细胞的迁移、侵袭和分泌的MMP9活性；BTDE/A549-CM和BTDE/RAW264.7-CM抑制HUVEC细胞的迁移和血管生成，血管内皮细胞的血管生成率在5 μM和10 μM BTDE/A549-CM处理下为75.0％和23.8％，在2.5 μM，5 μM和?10 μM BTDE/RAW264.7-CM处理下为54.1％，35.69％和18.8％。 结论 海洋溴酚BTDE处理肺癌细胞A549和肿瘤相关巨噬细胞RAW264.7后的条件培养基能够抑制血管内皮细胞HUVEC的迁移和血管生成，提示BTDE有潜力发展为临床抗肿瘤血管生成治疗药物。     

活血化瘀与肿瘤转移机制探讨

血瘀证是恶性肿瘤患者中常见证型,运用活血化瘀法的治疗长久以来在临床和基础研究中争议颇多。分析了肿瘤抗血管治疗研究现状,并在前人基础上提出了活血化瘀与肿瘤血管正常化理论的相关性的新假设。     

川芎嗪联合三氧化二砷对人急性早幼粒细胞白血病HL-60细胞增殖的影响

目的 探讨川芎嗪(TMP)联合三氧化二砷(As2O3)对人急性早幼粒细胞白血病(APL)细胞株HL-60增殖的影响及其治疗APL的作用机制.方法 采用HL-60和脐带内皮细胞系ECV-304两种细胞株,分为空白组、TMP组、As2O3组、TMP+ As2O3组,每组设4个复孔,经TMP单独或联合As2O3作用后,应用噻唑蓝(MTT)实验测定HL-60细胞增殖变化;检测HL-60细胞血管内皮生长因子(VEGF) mRNA和蛋白表达;台盼蓝染色计数绘制ECV-304细胞生长曲线;流式细胞仪检测ECV-304细胞早期凋亡率;倒置显微镜观察ECV-304细胞贴壁情况.结果 TMP能明显抑制HL-60、ECV-304细胞增殖,且能加强As2O3抑制增殖的作用;VEGF mRNA和蛋白表达在TMP与As2O3联合处理后明显减少;TMP与As2O3均能诱导ECV-304细胞早期凋亡,降低细胞贴壁能力,联合作用后效果均明显增强.结论 TMP联合As2O3抑制APL HL-60细胞增殖作用增强,抗血管新生是其治疗APL的可能机制.     

半枝莲化学成分及抑制血管生成活性的研究

 目的 研究半枝莲的化学成分及其抑制血管生成活性。方法 采用硅胶柱色谱、sephadex LH-20凝胶柱色谱分离纯化化合物,运用理化反应和波谱分析鉴定化合物的结构。采用斑马鱼抑制血管生成模型测试化合物的活性。结果 从半枝莲体积分数75%乙醇提取物中的乙酸乙酯萃取部分中分离得到了9个化合物,分别为：汉黄芩素,4′-羟基汉黄芩素,芹菜素,黄芩素,柚皮素,木樨草素,异鼠李素,野黄芩苷,黄芩苷,其中异鼠李素有明显的抑制血管生成活性。结论 抑制血管生成是半枝莲抗肿瘤作用的途径之一。     

Rituximab, bevacizumab and CHOP (RA-CHOP) in untreated diffuse large B-cell lymphoma: safety, biomarker and pharmacokinetic analysis

Bevacizumab is a humanized monoclonal antibody directed against vascular endothelial growth factor (VEGF-A). Non-Hodgkin's lymphoma patients with high serum VEGF levels have an inferior survival compared to patients with low VEGF levels. Bevacizumab was administered through a central line at 15 mg kg^-1 IV on day 1 followed by rituximab (R) and CHOP on day 2 for cycle 1 and day 1 for cycles 2 - 8. Serum levels of bevacizumab and R were measured at specified time points to assess pharmacokinetics (PK). Plasma and urine samples were also analysed for VEGF. Tumor samples were stained for VEGF, CD31 and factor VIII by immunohistochemistry. Thirteen patients with newly-diagnosed DLBCL received a total of 88 cycles (range 2 - 8, median 7). Best response included five CR, six PR, one SD and one PD with an overall response rate of 85% and complete response rate of 38%. The 12-month PFS is 77% and a median follow-up of 16.9 months for the surviving patients. All tumor samples stained strongly positive for VEGF and there was a marginal association between baseline plasma VEGF and response (p = 0.04). Patients with higher plasma VEGF levels were generally younger and had bulky disease. Micro-vessel density did not correlate with presenting disease characteristics, VEGF expression or response. The PK of bevacizumab and rituximab were not influenced by combined treatment. In this patient population, treatment with RA-CHOP did not result in any episodes of grade 3 or 4 proteinuria, heart failure or hemorrhage. The RA-CHOP combination was generally well tolerated and safe.     

Targeting Angiogenic Pathways Involving Tumor–stromal Interaction to Treat Advanced Human Prostate Cancer

Interfering with and preventing tumor angiogenesis is an attractive therapeutic approach for treating cancer metastases. This commentary presents treatment strategies that may enhance the effectiveness of anti-angiogenic therapy by selectively targeting newly sprouting and immature vessels, inhibiting the production of angiogenic factors, and disrupting extracellular matrices. We propose several clinical paradigms, including hormonal ablation, intermittent androgen suppression, chemotherapy, and radiation therapy, that injure nascent vasculature and interrupt the cancer cell–stromal relationship, thereby potentiating the efficacy of experimental anti-angiogenic agents. These stromal–epithelial interactions play an important role in the development, proliferation and dissemination of prostate cancer, as well as guiding the processes of tumor neovascularization. Successful utilization and targeting of tumor angiogenesis requires an increased understanding of tumor cell–stromal cell–endothelial cell relationships, most notably the intricate intracellular signalling cascades mediated by growth factors and the extracellular matrix.     

醋酸甲羟孕酮对卵巢癌裸鼠移植瘤的抗血管生成作用

目的 观察醋酸甲羟孕酮(MPA)对人卵巢癌裸鼠移植瘤内血管生成及肿瘤细胞的抑制作用。方法 将人卵巢癌COC1细胞制成裸鼠移植瘤模型,肿瘤形成后,将30只裸鼠随机分成对照组和2个治疗组,每组各10只。2个治疗组分别皮下注射MPA 60 mg/kg、120mg/kg,2次/周,共4周,对照组注射相同体积生理盐水。测定抑瘤率,用Ⅷ因子多克隆抗原抗体测定肿瘤内微血管密度(MVD),用光学显微镜和透射电子显微镜进行形态学观察。结果 MPA对人卵巢癌裸鼠移植瘤的抑瘤率和新生微血管的抑制作用呈明显的剂量依赖关系。MPA剂量60 mg/kg治疗组,抑瘤率为23.8％;120 mg/kg治疗组,抑瘤率为43.8％。对照组MVD为5.14±0.74;MPA 60 mg/kg治疗组为3.64±0.02,120 mg/kg治疗组为2.11±0.12,与对照组比较,差异有显著性(P<0.05,P<0.01)。两个治疗组间,差异亦有极显著性(P<0.01)。实验组可见大量的凋亡细胞、凋亡小体及变性坏死,而对照组少见。结论 MPA对人卵巢癌COC1细胞裸鼠移植瘤内的肿瘤细胞及新生微血管具有明显抑制作用,并呈现剂量-效应关系。其对肿瘤细胞的作用,可能是抑制和破坏了肿瘤区新生血管的生长,阻断血供所产生的结果,而不是直接对肿瘤细胞的作用。     

Inhibition of B16 Melanoma Growth <Emphasis Type="Italic">in vivo</Emphasis> by Retroviral Vector-Mediated Human Ribonuclease Inhibitor

Human ribonuclease inhibitor (hRI) can inhibit angiogenesis by reversibly binding angiogenin, a member of the RNaseA superfamily, and by suppressing the expression of basic fibroblast growth factor (bFGF). Angiogenesis is necessary for the growth and metastasis of tumors. To study the links between hRI, angiogenesis, and melanoma growth, the hRI gene was intravenously administered to mice in a recombinant retroviral vector, and expression of the hRI gene was induced to block melanoma angiogenesis. Expression, distribution, and contribution of the target gene in mice were assayed. The results showed that the tumors of mice in the hRI treatment group grew slower with less vascularity than those of mice in control groups. The introduced hRI gene inhibited tumor growth without causing significant side effects in the animals. More hRI expression in vimentin-positive cells of the tumor than in melanoma cells suggested that mesenchymal cells in the fibrous envelope of the tumor play important roles in this gene therapy.     

Chorioallantoic membrane capillary bed: A useful target for studying angiogenesis and anti-angiogenesis in vivo

The chick embryo chorioallantoic membrane (CAM) is an extraembryonic membrane that is commonly used in vivo to study both angiogenesis and anti-angiogenesis. This review 1) summarizes the current knowledge about the structure of the CAM's capillary bed; 2) discusses the controversy about the existence of a single blood sinus or a capillary plexus underlying the chorionic epithelium; 3) describes a new model of the CAM vascular growth, namely the intussusceptive mode; 4) reports findings regarding the role played by endogenous fibroblast growth factor-2 in CAM vascularization; and 5) addresses the use and limitations of the CAM as a model for studying angiogenesis and anti-angiogenesis. Anat Rec 264:317–324, 2001. © 2001 Wiley-Liss, Inc.