VEGF AND RELATED PROTEINS IN AIDS RELATED KAPOSI SARCOMA

描述：（改编自申请人的摘要）卡波西肉瘤（KS）是与HIV感染相关的最常见的肿瘤。KS代表血管增生，其特征在于在最初表现为多个病变。在没有HIV感染的情况下，在其他情况下也会发生相同的肿瘤，包括主要见于东欧老年男性的经典型、非洲型、肾移植受者和由糖皮质激素疾病引起的医源性肿瘤。在临床上，KS是一个异质性的过程，似乎是独立的免疫缺陷的严重程度。KS在高血管生成肿瘤中表现为内皮细胞起源。Gill的小组过去已经证明血管生成因子bFGF、VEGF和IL 8以及血管生成诱导剂IL 6、TGF β、IL 1 β和TNF α都在KS细胞中表达，最近还证明VEGF是培养的KS细胞的自分泌因子、渗透因子和存活因子。他还发现VEGF家族和VEGF-R家族的所有已知成员在KS细胞系和KSHV感染的EC培养物中表达。他提出VEGF是KS的关键生长因子，并且VEGF/VEGF-R蛋白代表所有KS生长因子级联的汇聚点。因此，他提出既要证明这一点，又要确定单个VEGF/VEGF-R家族成员在KS Y-1纺锤体细胞系和Flore等最近开发的KSHV感染的BMEC系统中的作用，以及证实所有这些蛋白质在原发性KS肿瘤组织中的表达.一套全面的实验集中在以下三个具体目标的建议。Specific Aim 1旨在使用特异性试剂来定义和比较VEGF-A、VEGF-B、VEGF-C、VEGF-D和PIGF的表达和作用，包括使用反义硫代磷酸寡核苷酸抑制剂和VEGF-R抗体来检查对细胞增殖、迁移和存活的影响。新的特异性目的2涉及与正常HUVEC或皮肤细胞相比在KS细胞中发现的ERK激活（明显的下游VEGF效应）的组成性水平大大增加的重要性的研究。这是否是细胞存活所需的，以及KSHV感染是否也诱导ERK活化作为适当的关键事件，将被检查以及在MAPK信号转导的其他阶段的药理学干预。新的特异性目的3代表了通过单独阻断所有三个环并研究对细胞生长、迁移、凋亡和第二信使活性的影响来建立与VEGF存活信号相关的IL 1 β和IL 6自分泌生长因子作用的层次结构和可能的会聚。

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.