Non-canonical signal pathway for Crk in breast cancer

乳腺癌中 Crk 的非经典信号通路

基本信息

批准号：
8402232
负责人：
RAYMOND B BIRGE
金额：
$ 32.37万
依托单位：
UNIV OF MED/DENT OF NJ-NJ MEDICAL SCHOOL
依托单位国家：
美国
项目类别：
财政年份：
2012
资助国家：
美国
起止时间：
2012-07-12 至 2017-04-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8402232
关键词：
Adaptor Signaling Protein Address Adenocarcinoma Affinity Apoptotic Behavior Binding Binding Sites Biological Assay Biological Process Biology Breast Breast Cancer Cell Cancer Patient Cancer Prognosis Cancer cell line Cell physiology Cell-Cell Adhesion Cells Chickens Clinical Research Data Detection Development EGF gene Embryo Epidermal Growth Factor Receptor Eukaryotic Cell Fatty acid glycerol esters Fibroblasts Generations Glioblastoma Guanine Nucleotide Exchange Factors Human Immigration Intervention Lung Malignant - descriptor Malignant Neoplasms Mediating Modeling N-terminal Names Neoplasm Metastasis Oncogene Proteins Ovarian PTB Domain Pathway interactions Phosphorylation Phosphorylation Site Phosphotransferases Play Positive Lymph Node Predisposition Prognostic Marker Property Protein Binding Protein Tyrosine Kinase Proteins Receptor Protein-Tyrosine Kinases Recruitment Activity Regulation Research Role SH3 Domains Screening procedure Signal Pathway Signal Transduction Signal Transduction Pathway Small Interfering RNA Stomach Stomach Carcinoma Structure Testing Therapeutic Translating Tyrosine Tyrosine Phosphorylation Tyrosine Phosphorylation Site base cancer cell cell behavior cell growth cell motility cell transformation cis trans isomerization clinically significant in vivo innovation malignant breast neoplasm malignant phenotype member mouse model mutant novel overexpression polyclonal antibody protein complex protein expression protein function protein protein interaction proto-oncogene protein c-crk sarcoma src Homology Region 2 Domain stoichiometry synovial sarcoma therapeutic development therapeutic target triple-negative invasive breast carcinoma tumor

项目摘要

DESCRIPTION (provided by applicant): The Src Homology 2 (SH2) and Src Homology 3 (SH3) domain-containing protein Crk is the prototypical member of a class of adaptor proteins that play essential roles in signaling downstream of tyrosine kinases. By promoting the assembly of protein complexes mediated by the SH2 and SH3 domains, evidence accumulated over the past two decades has elucidated a canonical pathway for Crk signaling whereby the SH2 domain binds tyrosine phosphorylated proteins and the N-terminal SH3 domain (SH3N) binds guanine-nucleotide exchange factors that activate Rac1, Rap1, and Ras. The clinical significance of Crk in human cancer has been enumerated in recent years, as Crk is frequently over-expressed in several different cancers, including breast, ovarian, gastric, lung, glioblastoma, and sarcomas and siRNA-mediated knockdown of Crk reverses the malignant and metastatic features of these cancers. These observations have led to a new urgency to understand the mechanisms by which Crk promotes malignant transformation in the hope that new information can be exploited to develop therapeutics, particularly for tumors with a predisposition towards invasion and metastasis. In this application we have identified a new signaling paradigm for Crk by the identification of two previously uncharacterized tyrosine phosphorylation sites located within the carboxyl-terminal SH3 (SH3C) domain, an atypical SH3 domain that has no clear biological function. Tyr251 is located in the highly conserved RT-loop of the Crk SH3C while Tyr239 is located at the boundary of the linker and SH3C and comprises a region of Crk implicated in the negative regulation and auto-clamping of the SH3C to the SH3N. The central hypothesis to be tested is that in addition to its conventional role as an adaptor protein, Crk has an unorthodox, non-canonical role in signaling by virtue of being phosphorylated on Tyr239 and Tyr251 in the SH3C, phosphorylation which will define new binding sites for proteins with SH2 or PTB domains, and hence engage novel phosphorylation dependent signaling pathways. Since both Tyr251 and Tyr239 show elevation in tyrosine phosphorylation upon EGF stimulation, and the Y251F Crk mutant has a diminished ability to promote cell migration and invasion towards EGF compared to WT Crk, we hypothesize that mechanistic studies will be immediately relevant to invasive triple negative breast cancer cells that have elevated EGFR. These studies may have important implications in the development of therapeutic strategies to profile and target Crk-expressing tumors, but also provide rationale for exploring this biology in a wide spectrum of human cancers. PUBLIC HEALTH RELEVANCE: Src Homology-2 (SH2) and Src Homology-3 (SH3) containing proteins are among the most versatile proteins in eukaryotic cells, and critically important for signaling in human cancers. The research outlined in this proposal defines a new function for the Crk oncogene product. In recent years, an emerging body of evidence suggests that Crk proteins are overexpressed in human tumors and the expression levels correlate with aggressive and malignant behavior of cancer cells. These properties of Crk proteins make them potential cancer prognosis markers and therapeutic targets.

描述（由申请人提供）：SRC同源性2（SH2）和SRC同源性3（SH3）含结构域的蛋白CRK是一类衔接蛋白的典型成员，它们在酪氨酸激酶下游信号下的信号传导中起着重要作用。通过促进由SH2和SH3结构域介导的蛋白质复合物的组装，在过去的二十年中积累的证据阐明了CRK信号传导的规范途径，SH2结构域结合酪氨酸磷酸化的蛋白质和N-末端SH3域（SH3N）结合了Guanine， - 激活Rac1，Rap1和Ras的核苷酸交换因子。 CRK在人类癌症中的临床意义近年来已经列举了，因为CRK经常在几种不同的癌症中过度表达，包括乳腺癌，卵巢，胃，胃，肺，糖母细胞瘤和肉瘤，以及siRNA介导的CRK的CRK逆转逆转性逆转性。这些癌症的转移特征。这些观察结果导致了新的紧迫性，以了解CRK促进恶性转化的机制，希望可以利用新信息来开发治疗疗法，特别是对于对侵袭和转移倾向的肿瘤。在此应用中，我们通过鉴定位于羧基末端SH3（SH3C）结构域内的两个先前未表征的酪氨酸磷酸化位点来鉴定CRK的新信号范式，这是一个没有明确的生物学功能的非典型SH3结构域。 Tyr251位于CRK SH3C的高度保守的RT环中，而Tyr239位于接头和SH3C的边界上，并包括与SH3C负面调节和自动缩短到SH3N的CRK区域。要测试的中心假设是，除了其作为衔接蛋白的常规作用外，CRK还通过在SH3C中在Tyr239和Tyr251上磷酸化，在信号传导中具有非正统的非传统作用，它将定义新的新结合位点对于具有SH2或PTB结构域的蛋白质，因此参与新型磷酸化依赖性信号通路。由于Tyr251和Tyr239在EGF刺激时均显示酪氨酸磷酸化的升高，并且Y251F CRK突变体的能力降低了与WT CRK相比，促进细胞迁移和侵入EGF的能力降低，我们假设机械性研究将与入侵性的Triple Triple Triple Triple Triple Triple Triple Triph Triple Triple Triph triple triple Triple Triple Triple Triple Triple乳房相关EGFR升高的癌细胞。这些研究可能对发展和靶向表达CRK的肿瘤的治疗策略的发展具有重要意义，但也为在广泛的人类癌症中探索这种生物学提供了理由。公共卫生相关性：含有蛋白质的SRC同源性-2（SH2）和SRC同源性3（SH3）是真核细胞中用途最广泛的蛋白质之一，对于人类癌症的信号至关重要。该提案中概述的研究定义了CRK Oncogene产品的新功能。近年来，新出现的证据表明，CRK蛋白在人肿瘤中过表达，表达水平与癌细胞的侵略性和恶性行为相关。 CRK蛋白的这些特性使它们成为潜在的癌症预后标志物和治疗靶标。