MOLECULAR DISSECTION OF TUMOR INVASION

描述：（申请人的描述） 该项目的长期目标是提高我们诊断和诊断的能力 阻止人类癌症最致命的阶段，获得侵入性 状态。人们对细胞侵袭的分子机制知之甚少，因为 目前还没有开发出强大的模型系统来分析这一过程。我们 使用果蝇遗传学来开发卵室形态发生作为 强大的细胞和组织模型，用于剖析细胞的分子机制 入侵。卵室非常适合分析细胞侵袭，因为 它们简单的架构提供了一种易于评分的分析方法。 这个提议 重点关注保守肿瘤抑制因子 Discs-large (Dlg) 在 抑制细胞侵袭。人类 Dlg 同源物 SAP97 与 APC 结合，是最 结直肠癌中常见的突变基因，而另一个 人类 Dig 同源物 ZO-1 在大多数侵入性病毒中特异性丢失 乳腺肿瘤。 Dlg、SAP97 和 ZO-1 是具有三个 PDZ 的支架蛋白 域、SH3域和GuK域。 PDZ 域对于 抑制果蝇细胞侵袭，并直接与蛋白质结合 特别参与抑制果蝇和 人体组织，包括细胞粘附分子 FasII/NCAM 和 Egf 受体（EgfR）。 另一个保守分子 Kekkonl (Keki) 与两者结合 Dlg PDZ 和 EgfR，但其在细胞侵袭中的作用仍有待确定。 这些结果表明 D1g 组织和调节大量的 控制正常细胞迁移和抑制肿瘤细胞的蛋白质 入侵。 以下具体目标利用分子组合 遗传学、细胞生物学和生物化学，深入了解 D1g 如何 蛋白质家族组织和调节超分子组装，以防止 细胞侵袭。目标 1 是确定各个 Dig 域在 阻断细胞侵袭。目标 2 是确定 PDZ 结合蛋白 FasII 如何 Kek1与Dlg配合阻断细胞侵袭。目标 3 是确定 Dlg 和 EgfR 信号通路之间的关键相互作用。目标 4 是 确定 Dlg 侵袭细胞绕过正常细胞的细胞途径 迁移途径。目标 5 是表征其他候选 D1g PDZ 结合 蛋白质。这个模型系统很强大，因为关键分子和 类似于人类疾病的细胞过程已经被发现。 的 能够以强大的方式分析保守的肿瘤抑制基因和癌基因 细胞侵袭实验将揭示超分子的结构和功能 阻止细胞侵袭的组装。这项工作可能会揭示细胞和 阻止肿瘤细胞侵袭的分子靶标作为癌症治疗的一种手段。

DESCRIPTION: (Applicant's Description) The long-term goal of this project is to improve our ability to diagnose and block the most lethal phase of human cancer, acquisition of the invasive state. Little is known about the molecular mechanisms of cell invasion because no powerful model systems have been developed for analyzing this process. We have used Drosophila genetics to develop egg chamber morphogenesis as a powerful cell and tissue model for dissecting the molecular mechanisms of cell invasion. Egg chambers are exceptional for analyzing cell invasion because their simple architecture provides an easy to score assay. This proposal focuses on the role of the conserved tumor suppressor Discs-large (Dlg) in suppressing cell invasion. The human Dlg homolog SAP97 binds to APC, the most commonly mutated gene in colorectal cancer, while another human Dig homolog, ZO-1, is specifically lost in the majority of invasive breast tumors. Dlg, SAP97, and ZO-1 are scaffolding proteins have three PDZ domains, an SH3 domain, and a GuK domain. The PDZ domains are crucial for suppressing cell invasion in Drosophila, and directly bind to proteins that are specifically involved in suppressing cell invasion in both Drosophila and human tissues, including the cell adhesion molecules FasII/NCAM and the Egf receptor (EgfR). Another conserved molecule, Kekkonl (Keki), binds to both Dlg PDZ and EgfR, but it role in cell invasion remains to be established. These results suggest that D1g organizes and regulates a large assembly of proteins in controlling normal cell migration and suppressing tumor cell invasion. The following specific aims utilize a combination of molecular genetics, cell biology, and biochemistry to obtain insight into how the D1g family of proteins organize and regulate a supramolecular assembly to prevent cell invasion. Aim 1 is to determine the role of individual Dig domains in blocking cell invasion. Aim 2 is to determine how PDZ-binding proteins FasII and Kek1 cooperate with Dlg to block cell invasion. Aim 3 is to determine critical interactions between Dlg and the EgfR signaling pathway. Aim 4 is to determine the cellular routes by which Dlg invasive cells bypass normal migration pathways. Aim 5 is characterize additional candidate D1g PDZ-binding proteins. This model system is strong because both key molecules and a cellular process that resembles human disease have been identified. The ability to analyze conserved tumor suppressors and oncogenes in a powerful cell invasion assay will reveal the structure and function of a supramolecular assembly that blocks cell invasion. This work is likely to uncover cell and molecular targets to block tumor cell invasion as a means of cancer therapy.