EPIDERMAL GROWTH FACTOR RECEPTORS AND PANCREATIC CANCER

描述：（申请人摘要）胰腺导管腺癌（PDAC）是 致命的疾病分子机制决定了它的 生物攻击性还有待阐明。我们确定PDAC 肿瘤细胞表达高水平的表皮生长因子（EGF）受体 （EGFR）和相关受体（ErbB-2、-3、-4）。我们现在假设 EGFR家族的过度活化以基本方式有助于 PDAD的病理学为了验证这一假设，我们将阻断受体 在培养的胰腺癌细胞中通过该家族的每个成员的信号传导 线，使用高度具体的显性否定的方法，结合 我们最近建立的腺病毒基因传递系统。信号将接下来 通过这个家庭的多个成员阻止，以确定 信号传导途径被单一受体阻断剂与组合受体阻断剂减弱， 该途径调节有丝分裂并赋予对失巢凋亡的抗性。在 在体内，我们将评估受体阻断对肿瘤生长的影响， 转移，以确定是否过度激活EGFR家族 信号传导有助于PDAC的这些生物学特性。更 明确定义了介导EGFR家族作用的信号传导成分，我们 将使用显性负性结构和化学抑制剂来抑制 这些途径的特定下游组分，以及编码 以组成性方式具有活性的蛋白质。为了定义新的信号 我们将使用中国仓鼠卵巢细胞， 具有相对正常的基因背景， EGFR，但已经用编码野生型或EGFR的cDNA稳定转染的细胞， 变体人EGFR。因此，我们将深入了解 这些高度同源的受体在有丝分裂、失巢凋亡和 侵略性评估PDAC中受体异源二聚化的可能性 在体内，我们将使用激光捕获显微切割和定量聚合酶 链反应（PCR）来测定相同癌细胞中的表达水平， EGFR家族的所有四个成员。如果我们排除基因扩增 体内过表达的机制，我们将证实我们培养的细胞 细胞系过度表达这些受体，这是由于细胞系中转录增强的结果。 核试验研究然后我们将描述它们的转录控制 为了开发第二代病毒载体， 优先靶向胰腺癌细胞。

DESCRIPTION: (Applicant's abstract) Pancreatic ductal adenocarcinoma (PDAC) is a devastatingly lethal disease. The molecular mechanisms that dictate its biological aggressiveness are yet to be elucidated. We determined that PDAC tumor cells express high levels of the epidermal growth factor (EGF) receptor (EGFR) and related receptors (ErbB-2, -3, -4). We now hypothesize that excessive activation of the EGFR family contributes in a fundamental manner to the pathobiology of PDAD. To test this hypothesis, we will block receptor signaling through each member of this family in cultured pancreatic cancer cell lines, using a highly specific dominant-negative approach in conjunction with our recently established adenoviral gene delivery system. Signaling will next be blocked through multiple members of this family in order to determine which signaling pathways are attenuated by single versus combined receptor blockades, which pathways modulate mitogenesis and which confer resistance to anoikis. In vivo, we will assess effects of receptor blockade on tumor growth and metastasis in order to determine whether excessive activation of EGFR family signaling contributes to these biological characteristics of PDAC. To more clearly define the signaling components that mediate EGFR family actions, we will use dominant-negative constructs and chemical inhibitors to suppress specific downstream components of these pathways, and constructs encoding proteins that are active in a constitutive manner. To define novel signaling pathways that are modulated by EGFR, we will use Chinese hamster ovary cells that have a relatively normal gene background and that are devoid of endogenous EGFR, but that have been stably transfected with a cDNA encoding a wild type or variant human EGFR. We will thus gain insight into the biological roles of these highly homologous receptors with respect to mitogenesis, anoikis and invasiveness. To assess the potential for receptor heterodimerization in PDAC in vivo, we will use laser capture microdissection and quantitative polymerase chain reaction (PCR) to assay in the same cancer cells the levels of expression of all four members of the EGFR family. If we exclude gene amplification as a mechanism for in vivo overexpression, we will confirm that our cultured cell lines overexpress these receptors as a result of enhanced transcription in nuclear-run-on studies. We will then characterize their transcriptional control elements in order to develop second generation viral vectors that are preferentially targeted to pancreatic cancer cells.