VEGF AND RELATED PROTEINS IN AIDS RELATED KAPOSI SARCOMA

描述：(摘自申请者摘要)卡波西氏肉瘤(KS)是与HIV感染有关的最常见的肿瘤。KS是一种血管增生性疾病，最初表现为多处病变。在没有艾滋病毒感染的其他环境中，也会出现相同的肿瘤，包括主要见于东欧老年男性的经典肿瘤，非洲患者，肾移植接受者，以及由糖皮质激素疾病引起的医源性肿瘤。临床上，KS是一个不同的病程，似乎与免疫缺陷的严重程度无关。KS在高度血管生成的肿瘤中，似乎是内皮细胞起源的。Gill等人在过去的研究中证明，血管生成因子bFGF、VEGF和IL8以及血管生成诱导物IL6、TGFbeta、IL1β和TNFpha都在KS细胞中表达，最近的研究表明，在培养的KS细胞中，VEGF是一种自分泌因子、渗透因子和生存因子。他还发现，所有已知的血管内皮生长因子家族和血管内皮生长因子受体家族成员在KS细胞系和KSHV感染的EC培养物中都有表达。他认为，血管内皮生长因子是KS的关键生长因子，而血管内皮生长因子/血管内皮生长因子受体蛋白代表所有KS生长因子级联反应的汇聚点。因此，他建议既要证明这一点，又要确定KS Y-1梭形细胞系和最近开发的KSHV感染的Flore等人的BMEC系统中单个VEGF/VEGF-R家族成员的作用，并确认所有这些蛋白在原代KS肿瘤组织中的表达。针对以下三个具体目标提出了一套全面的实验方案。具体目的1是利用特异性试剂来定义和比较血管内皮生长因子A、血管内皮生长因子B、血管内皮生长因子C、血管内皮生长因子D和PIGF的表达和作用，包括使用反义硫代寡核苷酸抑制剂和血管内皮生长因子受体抗体来检测对细胞增殖、迁移和存活的影响。新的特定目标2涉及与正常的HUVEC或皮肤细胞相比，在KS细胞中发现的ERK激活的结构性水平显著增加(明显的下游血管内皮生长因子效应)的重要性。这是否是细胞生存所必需的，KSHV感染是否也作为一个适当的关键事件诱导ERK激活，以及在MAPK信号转导的其他阶段进行药物干预，将被研究。新的特异性目标3是试图通过分别阻断所有三个环路并研究其对细胞生长、迁移、凋亡和第二信使活性的影响，来建立IL1β和IL6自分泌生长因子作用与VEGF生存信号有关的层次结构和可能的趋同性。

DESCRIPTION: (Adapted from Applicant's Abstract) Kaposi's Sarcoma (KS) is the most common tumor associated with HIV infection. KS represents a vascular proliferation characterized by multiple lesions at initial presentation. an identical tumor develops in other settings without HIV infection, including the classic form seen predominantly in older Eastern European men, an African form, renal transplant recipients, and iatrogenically induced by glucocorticoids disease. Clinically, KS is a heterogeneous course that appears to be independent of the severity of immunodeficiency. KS in highly vascular angiogenic tumor that appears to be of endothelial cell origin. Gill's group has demonstrated in the past that angiogenic factors bFGF, VEGF and IL8 and inducers of angiogenesis IL6, TGFbeta, IL1beta and TNFalpha are all expressed in KS cells and more recently that VEGF is an autocrine factor, a permeability factor and a survival factor for KS cells in culture. He has also found that all known members of the VEGF family and VEGF-R family are expressed in both KS cell lines and KSHV infected EC cultures. He proposes that VEGF is the critical growth factor for KS and that VEGF/VEGF-R proteins represent the convergence points for all KS growth factor cascades. Therefore, he proposes to both demonstrate this and define the roles of individual VEGF/VEGF- R family members in both the KS Y-1 spindle cell line and in the recently developed KSHV infected BMEC system of Flore et al, as well as confirm expression of all of these proteins in primary KS tumor tissue. A comprehensive set of experiments focused on the following three Specific Aims are proposed. Specific Aim 1 is designed to use specific reagents to define and compare the expression and roles of VEGF-A, VEGF-B, VEGF-C, VEGF-D and PIGF, including the use of antisense phosphorothioate oligonucleotide inhibitors and VEGF-R antibodies to examine effects on cell proliferation, migration and survival. The new Specific Aim 2 involves an investigation of the importance of the greatly increased constitutive levels of ERK activation (an apparent downstream VEGF effect) found in KS cells compared to normal HUVEC or skin cells. Whether this is needed for cell survival and whether KSHV infection also induces ERK activation as a appropriate critical event will be examined as well as pharmacological intervention at other stages of MAPK signal transduction. New Specific Aim 3 represents an attempt to establish the hierarchy and possible convergence of IL1beta and IL6 autocrine growth factor action in relation to VEGF survival signaling by individually blocking all three loops and studying the impact on cell growth, migration, apoptosis and second messenger activity.