VEGF AND RELATED PROTEINS IN AIDS RELATED KAPOSI SARCOMA

描述：（改编自申请人摘要）卡波西肉瘤（KS）是最常见的与HIV感染相关的肿瘤。KS表现为血管增生，最初表现为多发病变。在没有HIV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形式、非洲形式、肾移植接受者以及由糖皮质激素疾病引起的医源性肿瘤。在临床上，KS是一种异质性病程，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。Gill的团队在过去已经证明了血管生成因子bFGF， VEGF和IL8以及血管生成诱导因子IL6， tgf β， il1 β和TNFalpha都在KS细胞中表达，最近VEGF是培养的KS细胞的自分泌因子，渗透性因子和存活因子。他还发现，所有已知的VEGF家族成员和VEGF- r家族成员都在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，VEGF/VEGF- r蛋白代表了所有KS生长因子级联的收敛点。因此，他建议证明这一点，并确定个体VEGF/VEGF- R家族成员在KS Y-1梭形细胞系和Flore等人最近开发的KSHV感染BMEC系统中的作用，并确认所有这些蛋白在原发性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。Specific Aim 1旨在使用特定试剂来定义和比较VEGF-A、VEGF-B、VEGF-C、VEGF-D和PIGF的表达和作用，包括使用反义硫代寡核苷酸抑制剂和VEGF-R抗体来检测对细胞增殖、迁移和存活的影响。新的特异性目标2涉及研究与正常HUVEC或皮肤细胞相比，在KS细胞中发现的ERK激活（一种明显的下游VEGF效应）的组成水平的显著增加的重要性。这是否是细胞存活所需要的，KSHV感染是否也诱导ERK激活作为一个适当的关键事件，以及在MAPK信号转导的其他阶段进行药物干预，都将被研究。New Specific Aim 3试图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，建立与VEGF存活信号相关的il1 β和IL6自分泌生长因子作用的层次结构和可能的趋同。

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.