Spatial and Temporal Regulation of Angiogenesis

血管生成的时空调节

• 批准号: 6851946
• 负责人: HAROLD FISHER DVORAK
• 金额: $ 32.51万
• 依托单位: BETH ISRAEL DEACONESS MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-06-13 至 2007-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6851946
• 关键词: angiogenesis; blood vessels; clinical research; metastasis; neoplasm /cancer blood supply; thrombospondins; vascular endothelial growth factors

DESCRIPTION (provided by applicant): This program project focuses on the structure and function of tumor blood vessels from many angles: roles and functions of angiogenic cytokines and endogenous inhibitors in tumors and in surrogate tumor blood vessels, the gene expression induced by these factors and their role in tumor angiogenesis, and the impact of angiogenic cytokines and angiogenesis on tumor progression. This proposal outlines a series of experiments that focus on one of major signaling pathways downstream of the major angiogenic cytokines, the Akt pathway, as a mediator of many tumor blood vessel abnormalities: their large size, poor support, increased permeability and instability. Our preliminary data demonstrate that Akt signaling in physiological angiogenesis involves a very precise switching 'on' and 'off of the Akt signal. However, when this 'off switch is inhibited, the resulting vessels recapitulate many aspects of tumor blood vessels, vessels of other vascular anomalies and 'mother vessels', a term coined by Dr. Dvorak to describe blood vessels formed by overexpression of VEGF-A and other cytokines. This grant application seeks to explore the role of Akt in 'mother vessel'/'tumor vessel' formation, and the impact of downstream Akt targets on the individual features and functions of these abnormal blood vessels. We also propose to explore the mechanism behind our novel finding that TSP-1 modulates Akt signaling. This project is written for 3 years to enable it to fold into the existing funding schedule of this program project. Aims: 1. Test the hypothesis that upregulation of Akt activity is sufficient to recapitulate the structure and function of abnormal blood vessels reminiscent of tumor vessel in a non-tumor environment 2. Identify the downstream signaling pathways that mediate Akt affects 3. Explore the mechanisms of Thrombospondins on Akt signaling. COLLABORATING INSTITUTIONS (S): Massachusetts General Hospital, Boston, MA Children's Hospital, Boston, MA PROGRESS DURING THE CURRENT FUNDING PERIOD: This program has now completed its second year. During this period 17 publications have resulted from program related studies. A number of these have appeared in high impact journals and 11 list multiple authors who are part of this Program Project. Overall progress has been excellent. Project 1, "Structure and Function of New Blood Vessels," is directed by Dr. Harold Dvorak, in conjunction with Dr. Laura Benjamin. The studies under Specific Aim 1 where the investigators characterized new blood vessel induction by VEGF-A versus PIGF, VEGF-A/PIGF heterodynamers and FGF, are now completed and the work published in Nature Medicine. Specific Aim 2 is to employ inducible gene expression in mammary tumors to overexpress or not express the angiogenic factors studied under Specific Aim 1. These studies are underway and have resulted in two publications. Specific Aim 2 will use chip technology to profile genes that are differentially expressed in 'mother' vessels in response to local overexpression of VEGF-A or PIGF. Several novel genes have been characterized in the first two years of the project and many other potentially important genes also identified. Two manuscripts are in preparation describing this work. Project 2, Signaling Pathways that Determine Vascular Structure and Function, is the newly proposed project in this supplement and is considered in detail below. It is noted that Dr. Benjamin is a co-author of six of the 17 publications listed, several of which are very relevant to proposed supplement Project 2. Project 3, "Role of Placental Growth Factor in Normal and Neoplastic Skin Angiogenesis," is led by Dr. Michael Detmar. Specific Aim 1 is a study of the role of PIGF in skin vasculaturation and in experimental skin inflammation employing transgenic animal models. A novel transgenic mouse model for the targeted overexpression of human PIGF-2 in basal epidermal keratinocytes and other cells has been made. Studies of these animals have resulted in a paper published in Blood. Specific Aim 2 will employ these models to study chemically-induced skin cancer. Initial results suggest that PIGF plays a role in epithelial tumorigenesis. Specific Aim 3 will employ transfected PIGF and semaphorin D gene constructs to study the effects of modulating angiogenesis on the growth of human squamous cell carcinoma xenotransplants. Stably transfected cell lines have been obtained to pursue this aim and data are now being collected on these models. Project 4, "Inhibition of Angiogenesis by Thrombospondin-1," is led by Dr. Jack Lawler with the participation of Dr. R. Khosravi-far and Dr. S. Parangi. Specific Aim 1 seeks to characterize the CD36 receptor complex on endothelial cells to which TSP-1 binds. Specific Aim 2 will study mechanisms involved in TSP-1-induced apoptosis. Work is progressing on these aims, but appears quite preliminary. Dr. Lawler is co-author of three papers that report work on the ligand TSP-1 which have appeared in high impact journals. In addition, there are four cores (Administration, Morphology, Cell Biology, and Genomics) which are all operational and fulfill their role in the overall Program Project. Overall progress, as noted above, has been excellent.

描述(申请人提供)：本项目从多个角度关注肿瘤血管的结构和功能：血管生成细胞因子和内源性抑制物在肿瘤和替代肿瘤血管中的作用和功能，这些因素诱导的基因表达及其在肿瘤血管生成中的作用，以及血管生成细胞因子和血管生成对肿瘤进展的影响。这项提案概述了一系列实验，重点放在主要血管生成细胞因子下游的主要信号通路之一Akt通路上，作为许多肿瘤血管异常的媒介：它们体积大，支持能力差，通透性增加和不稳定。我们的初步数据表明，在生理性血管生成中，Akt信号涉及到非常精确的“开”和“关”Akt信号。然而，当这个“关”开关被抑制时，所产生的血管概括了肿瘤血管、其他血管异常的血管和“母血管”的许多方面，这是德沃夏克博士创造的一个术语，用来描述由VEGF-A和其他细胞因子的过度表达形成的血管。这项拨款申请旨在探索Akt在“母血管”/“肿瘤血管”形成中的作用，以及下游Akt靶点对这些异常血管的个体特征和功能的影响。我们还建议探索我们新发现的TSP-1调制Akt信号的机制。该项目为期3年，以使其能够合并到该计划项目的现有资金时间表中。目的：1.验证Akt活性上调足以概括非肿瘤环境中异常血管的结构和功能的假说2.确定介导Akt作用的下游信号通路3.探讨血栓蛋白对Akt信号的作用机制。 合作机构(S)：马萨诸塞州波士顿马萨诸塞州总医院 马萨诸塞州波士顿儿童医院 本供资期间的进展情况：该方案现已完成第二年。在此期间，有17种出版物是与项目相关的研究成果。其中一些已经出现在影响较大的期刊上，其中11个列出了参与该计划项目的多位作者。总体进展是极好的。项目1“新血管的结构和功能”由哈罗德·德沃夏克博士和劳拉·本杰明博士共同指导。在特定目标1下的研究中，研究人员比较了VEGF-A与PIGF、VEGF-A/PIGF异构体和成纤维细胞生长因子诱导新血管的特征，这些研究现已完成，并发表在《自然医学》杂志上。特定目的2是利用乳腺肿瘤中可诱导的基因表达来过度表达或不表达在特定目的1下研究的血管生成因子。这些研究正在进行中，并已发表了两篇论文。SPICAL AIM 2将使用芯片技术来分析在“母”血管中差异表达的基因，以回应局部过表达的VEGF-A或PIGF。在该项目的头两年里，已经确定了几个新基因的特征，并确定了许多其他潜在的重要基因。两份描述这部作品的手稿正在准备中。 项目2，确定血管结构和功能的信号通路，是本补充材料中新提出的项目，将在下文详细讨论。据指出，本杰明博士是所列17种出版物中6种出版物的合著者，其中几种出版物与拟议的补编项目2非常相关。 项目3，“胎盘生长因子在正常和肿瘤皮肤血管生成中的作用”，由Michael Detmar博士领导。具体目标1是利用转基因动物模型研究PIGF在皮肤血管生成和实验性皮肤炎症中的作用。建立了人PIGF-2在基底层角质形成细胞和其他细胞靶向过表达的转基因小鼠模型。对这些动物的研究已经在《血液》杂志上发表了一篇论文。《特定目标2》将利用这些模型来研究化学诱导的皮肤癌。初步结果表明，PIGF在上皮性肿瘤的发生中起作用。特异靶3将利用转染的PIGF和信号素D基因构建，研究调控血管生成对人鳞癌异种移植瘤生长的影响。为了实现这一目标，已经获得了稳定转基因的细胞系，目前正在收集关于这些模型的数据。 项目4“血栓反应蛋白-1抑制血管生成”由Jack Lawler博士领导，R.Khosravi-Far博士和S.Parangi博士参与。特定目的1试图表征与TSP-1结合的内皮细胞上的CD36受体复合体。《特定目的2》将研究TSP-1诱导细胞凋亡的机制。实现这些目标的工作正在取得进展，但似乎还处于初步阶段。劳勒博士是三篇论文的合著者，这三篇论文报道了配体TSP-1的研究成果，这三篇论文已经发表在高影响力的期刊上。 此外，还有四个核心(管理、形态、细胞生物学和基因组学)，它们都是可操作的，并在整个计划项目中发挥其作用。如上所述，总体进展良好。