GROWTH FACTOR RECEPTOR SIGNALING IN BREAST CANCER

信号转导通路和网络最近被证明是癌症治疗的有吸引力的靶点。Gleevac, herceptin(TM), C225， Irressa和CCI779在相应信号通路异常的患者亚群中均诱导了显着的，无毒性的反应，分别是bcrabl (Gleevac), ErbB-2（也称为HER-2/neu， herceptin(TM)）， EGFR （C225和Irressa）和PI-3K通路（CCI779）。新型分子疗法的开发和利用需要对肿瘤中存在的信号畸变有详细的了解。该计划项目资助（PPG）旨在了解在乳腺肿瘤进展中起关键作用的几个关键分子的信号通路。本PPG的直接目标是通过详细了解ErbB-2/PI-3K/Akt信号转导通路或“节点网络”在乳腺癌的发生和发展过程中，以及它们对乳腺癌发展的贡献来表征这些信号转导通路。该PPG由一个行政核心支持的四个互动项目组成。这四个项目中的每一个都有自己独特的一套具体目标，这些目标针对共同的主题，并且相互依赖于PPG中其他项目的组成部分。项目1的重点是akt介导的efl信号传导及其在乳腺癌细胞生长和肿瘤进展中的作用。项目1将评估Akt的两个关键样品，即p21 cip1/ waf1和MDM2。项目2计划利用两种特性良好的转基因小鼠模型，表达乳腺上皮中与PI-3K通路解偶联的PyV mT突变体或活化的erbB-2。Project 3将验证PI-3K的p85调控亚基通过招募Racl、Pakl等相互作用分子，在乳腺癌的发生和发展调控中发挥关键作用的假设。项目4将研究乳腺癌细胞中ErbB-2对GJM的调控和抗凋亡作用。待验证的假设是，ErbB-2对多种GJM调节因子（p21cip1/WAF1上调、Cdc2-Y15-p和survivin上调）的影响可导致GJM解除调控，从而有助于抗凋亡。PPG的长期目标是改善人类乳腺癌的诊断和治疗策略，特别是为更好地设计治疗乳腺癌的基本原理药物提供知识。

Signaling transduction pathways and networks have recently proven to be attractive targets for cancer therapy. Gleevac, herceptin (TM), C225, Irressa, and CCI779 have all induced remarkable, non-toxic responses in a subset of patients where abnormalities in the appropriate signaling pathway are present, respectively, bcrabl (Gleevac), ErbB-2 (also known as HER-2/neu, herceptin(TM)), EGFR (C225 and Irressa), and the PI-3K pathway (CCI779). The development and utilization of novel molecular therapeutics requires a detailed understanding of the signaling aberrations present in tumors. This program project grant (PPG) aims at understanding signaling pathways of a few key molecules that play critical roles in breast tumor progression. The immediate goals of this PPG are to characterize the ErbB-2/PI-3K/Akt signaling transduction pathways or "network of nodes" in the initiation and progression of breast cancer through understanding these signaling pathways in details, and their contributions to development of breast cancer. This PPG consists of four interactive projects supported by one administrative core. Each of the four projects has its own unique set of specific aims that target at the common theme and are interdependent on components of other projects in the PPG. Project 1 focuses on the role of Akt-mediatefl signaling and its contribution to the cell growth and tumor progression in breast cancer cells. Project 1 will evaluate two critical snbstrates of Akt, namely, p21 cip1/WAF1and MDM2. Project 2 plans to exploit two well-characterized transgenic mouse models expressing either mutant PyV mT de-coupled from the PI-3K pathway or activated erbB-2 in themammary epithelium. Project 3 will test the hypothesis that the p85 regulatory subunit of PI-3K plays a critical role in the regulation of breast cancer initiation and progression through its ability to recruit Racl, Pakl and other interacting molecules. Project 4 will investigate GJM deregulation and antiapoptosis by ErbB-2 in breast cancer cells. The hypothesis to be tested is that the effects of ErbB-2 on multiple GJM regulators (p21cip1/WAF1 upregulation, Cdc2-Y15-p and survivin upregulation) can lead to GJM deregulation that contributes to anti-apoptosis. The long-term goals of this PPG are to improve strategies for the diagnosis and treatment of human breast cancer, especially in providing knowledge for better design rationale drugs to combat breast cancer.