Combination of Radiation with Multi-Target Molecular Therapy for Cancer

背景和意义生长因子受体在许多癌症中过表达 并且它们的存在与不良预后相关。生长因子信号传导的激活 途径导致增殖、运动性和对化疗和放疗的抵抗力增加 治疗最近已经表明，肿瘤细胞对针对肿瘤细胞的治疗的抗性是由肿瘤细胞对靶向治疗的抗性引起的。 阻断单个生长因子信号通路可能是由与另一个生长因子信号通路的串扰引起的。 生长因子途径例如，IGF途径的激活干扰抗EGF途径 疗法直到最近，适当的软件工具和足够的计算机能力才使 成为可用的，允许信号传导途径的定量计算探索， EGF/IGF途径。我们建议使用建模和仿真软件， 专门开发用于定量探索复杂的信号通路。 它能够自动地转换一组数学表示， 信号通路内的双分子相互作用， 完整的生化网络该软件已成功地用于预测以前 真核细胞化学感受G蛋白偶联信号通路的未知方面。后 在实验室验证中，将计算机模型应用于生长因子信号通路 将为更好地了解它们的相互作用和对环境的综合影响提供手段。 肿瘤对放疗和化疗的反应有助于设计有效的多靶点 通过阻断这些通路的选定信号分子来实现靶向治疗的方法。 实验程序模型的开发和定量模拟基于 可用的文献数据，信号通路的详细计算模型（最初EGF 和IGF）将使用SIMMUNE创建，SIMMUNE是一种用于生物化学建模的计算机系统， 模拟生物化学相互作用。该模型将用于模拟细胞反应 生长因子和可能的治疗干预的计算探索， 选择性阻断这些通路。其他模拟技术，包括应用 可以应用图论、布尔网络、蒙特卡罗模拟等，这取决于 手头的问题，实验数据的可用性，以及我们的计算兴趣 生物学合作者模型的体外验证模拟的预测将是 与应用干预对肿瘤细胞的影响相比， 与感兴趣的信号传导途径相关，并使用 分子生物学方法，包括信号分子的蛋白质印迹，高密度 “反相”蛋白裂解物微阵列、RT-PCR和比较基因 表情分析将优先考虑新的定量方法。的体外测试 多靶点干扰EGF和IGF信号通路的治疗效果 联合放疗和化疗的多靶点方法， 模拟最适合单独使用或提供最有效的靶乳房致敏 将使用毒性和克隆形成试验在体外测试肿瘤细胞对放射或化学疗法的敏感性。 存活测定。这些实验将确定最佳组合和时机， 进一步在体内测试。治疗性药物的最佳组合的体内测试 原发性和转移性乳腺癌动物模型将用于测试 单独和联合阻断每种受体的信号通路的治疗功效 组合，通过计算机模拟优化并通过体外测试验证。 优化的分子靶向单独或与化疗和化疗联合的效果 将研究放射治疗。一个简单的模型结合EGF，IGF， 和胰岛素途径已被创建并用于模拟差异的结果 刺激/阻断这些通路。描述这一第一步的手稿 三个路径之间串扰的迭代实验-计算建模已经被 发表于Science Signaling

Background and Significance Growth factor receptors are overexpressed in many cancers and their presence correlates with poor prognosis. Activation of growth factors signaling pathways results in increased proliferation, motility and resistance to chemo - and radiation therapies. It has been shown recently that the resistance of tumor cells to therapy aimed at blocking individual growth factor signaling pathways may be caused by cross-talk with another growth factor pathway. For example, activation of IGF pathway interferes with anti-EGF pathway therapy. Only very recently, appropriate software tools and sufficient computer power have become available that allow a quantitative computational exploration of signaling pathways as complex as the EGF/IGF pathway. We propose to use modeling and simulation software which has been developed specifically to allow quantitative exploration of complex signaling pathways. It is capable of automatically transforming sets of diagrammatical representations of bimolecular interactions within signaling pathways into quantitative simulations of the complete biochemical network. The software has successfully been used to predict previously unknown aspects of eukaryotic chemosensory G-protein coupled signaling pathway. After verification in the laboratory, the computer model applied to growth factor signaling pathways will provide means for a better understanding of their interactions and the combined effect on tumor response to radiation and chemotherapy facilitating design of an efficient multi-target approach to targeted therapy by blocking selected signaling molecules of these pathways. Experimental procedures Development of the model and quantitative simulations Based on available literature data, a detailed computational model of signaling pathways (initially EGF and IGF) will be created using SIMMUNE, a computer system for biochemical modeling and simulation of biochemical interactions. The model will be used to simulate cellular response to growth factors and computational exploration of possible therapeutic interventions aiming at selective blocking of these pathways. Other simulation techniques, including application of graph theory, boolenian networks, Mote Carlo simulations, etc, may be applied, depending on the problem at hand, availability of experimental data, and interest of our computational biology collaborators. In vitro verification of the model Prediction of the simulation will be compared with the effects of applied interventions on tumor cells such as gene expression associated with signaling pathways of interest and activation of selected proteins using molecular biology methods including western blots of signaling molecules, high density 'reverse-phase' protein lysate microarrays, RT-PCR, and comparative gene expression analysis. Preference will be given to new quantitative methods. In vitro testing of the therapeutic efficacy of multitarget interference with EGF and IGF signaling pathways alone on in combination with radiation and chemotherapy The multitarget approach identified by the simulations as optimal for stand-alone or providing most potent sensitization of target breast tumor cells to radiation or chemotherapy will be tested in vitro using toxicity and clonogenic survival assays. These experiments will identify the optimal combinations and timing to be further tested in vivo. In vivo testing of the optimal combinations of therapeutic interventions Primary and metastatic breast cancer animal models will used to test the therapeutic efficacy of blocking signaling pathways for each receptor alone and in combination, as optimized by the computer simulations and validated by the in vitro testing. The effects of optimized molecular targeting alone or in combinations with chemo- and radiation therapy will be investigated. Accomplishments A simplistic model combing EGF, IGF, and Insulin pathways have been created and used to simulate the results of differential stimulation/blockage of these pathways. A manuscript describing this first step towards iterative experiment-computation modeling of the crosstalk between the three pathways has been submitted for publication in Science Signaling