Chemical Genetics of TGF-Beta Signal Transduction

描述（由申请人提供）：拟议的研究基于以下假设：抑制转化生长因子β（TGF β）信号转导通路可在某些癌症中提供有效和特异性干预。TGF β与多种人类疾病有关，包括癌症、免疫调节、伤口愈合和组织修复。在癌症中，TGF β促进肿瘤细胞的进展和扩散。肿瘤来源的TGF β可以通过直接作用于癌细胞、通过诱导血管生成、通过局部或全身免疫抑制以及通过促进侵袭的基质组织的改变来辅助致瘤性。提出了一种化学遗传学方法来产生和表征干预TGF β信号传导的肽适体。工作假设是TGF β反应的选择性扰动可以通过理解磷酸化Smad（Smad-P）复合物与其他蛋白质的特异性相互作用来实现，并且选择性干预策略可以通过干扰Smad-P相互作用的特定子集来实现。具体目标包括使用十五个已知的Smad相互作用基序来产生干扰对TGF β信号转导的特异性应答的肽适体，表征适体的溶液结合性质，通过定向和随机诱变进行结构-功能分析，以及在细胞中表达适体以评估其对介导的基因表达的影响。拟议的研究将提供新的策略和试剂，用于干扰介导的信号通路，用于识别在特定病理状态下可能重要的靶相互作用，以及用于识别Smad-P的良好配体结构。

DESCRIPTION (provided by applicant): The proposed research is based on the hypothesis that inhibition of the transforming growth factor beta (TGFbeta) signal transduction pathway can provide efficacious and specific intervention in some cancers. TGFbeta has been implicated in a broad variety of human diseases including cancer, immunoregulation, wound healing and tissue repair. In cancer, TGFbeta facilitates the progression and spread of tumor cells. The tumor-derived TGFbeta can aid tumorigenicity by direct actions on the cancer cell, by induction of angiogenesis, by local or systemic immunosuppression, and by alterations of stromal tissue that facilitate invasiveness. A chemical genetics approach is proposed to generate and characterize peptide aptamers that intervene in TGFbeta signaling. The working hypothesis is that selective perturbation of TGFbeta responses may be achieved by understanding the specific interactions of phosphorylated Smad (Smad-P) complexes with other proteins and that selective intervention strategies are possible by interfering with a specific subset of Smad-P's interactions. The specific aims include the use of fifteen known Smad interaction motifs to generate peptide aptamers that perturb specific responses to TGFbeta signal transduction, characterization of the solution binding properties of the aptamers, structure-function analysis by directed and random mutagenesis and expression of the aptamers in cells to evaluate their effects on Mediated-mediated gene expression. The proposed research will provide new strategies and reagents for perturbing the Mediated signaling pathway, for identifying target interactions that may be important in specific pathological states, and for identifying structures that are good ligands for Smad-P.