Non-canonical Wnt-Receptor Signaling and Targeted Therapies

ROR 1是Wnt 5a的受体，其可以诱导非经典Wnt信号传导，激活Rho GTP酶， 增强白血病细胞迁移、增殖和存活。ROR 1的高水平表达可以加速 在转基因小鼠模型中白血病的发生和发展， CLL患者的疾病和较短的生存期。CLL细胞还表达其他发育限制性蛋白。 Wnt 5a受体，即ROR 2和RYK，其可以促进CLL中的非经典Wnt信号传导。我们 假设阐明了ROR 1、ROR 2和 RYK将定义非经典Wnt信号传导的临床相关生物标志物，并确定新的靶点， 疗法此外，抑制非经典Wnt信号传导可能具有治疗应用， 或与其它新开发的抑制B细胞受体信号传导或BCL 2的靶向疗法组合。 为此，我们有以下具体目标：（目的1）探究非经典的信号通路 CLL中的Wnt受体-我们将定义响应Wnt 5a而募集到ROR 1/2的蛋白质，并确定 信号传导所需的结构域。我们将研究RYK对Wnt 5a信号传导的贡献， CLL，确定SH 3结合蛋白、14-3-3 β或Ca 2 +/钙调蛋白（CaM）依赖性蛋白激酶的作用 II（CaMKII）在ROR 1依赖性信号传导中的作用，并检查ROR 1激酶对非钙依赖性信号传导的贡献和功能。 典型的Wnt信号传导。(AIM 2）检查CLL细胞的非典型Wnt受体的共表达 并确定Wnt信号的相对水平-我们将检查CLL患者的血液样本， 具有高、低或可忽略的ROR 1血浆Wnt 5a表达的细胞， ROR 2和RYK，以及用于白血病细胞激活经典和非经典Wnt信号传导。我们也将 检查所选CLL样品和细胞系的转录组的新描述的干性指数， 其依赖于ROR 1信号传导。我们还将检查经典β-连环蛋白之间的串扰， 依赖性Wnt信号通路和非经典的β-连环蛋白非依赖性通路，这可能是 受ROR 1、ROR 2或RYK相对表达的影响，或受新产生的mAb处理的影响 特异于ROR 2或RYK。(AIM 3）检查ROR 1信号传导对肿瘤发生的贡献。 CLL中对靶向治疗的抗性-我们将检测ROR 1，ROR 2， 和RYK在从患者中收集的系列CLL样品中的耐药性之前，期间和之后， 靶向治疗并评估cirmtuzumab和BCL 2拮抗剂之间协同作用的潜力， 维奈托克

ROR1 is a receptor for Wnt5a, which can induce non-canonical Wnt-signaling, activate Rho GTPases, and enhance leukemia-cell migration, proliferation, and survival. High-level expression of ROR1 can accelerate development and progression of leukemia in transgenic mouse models and associates with more aggressive disease and shorter survival of patients (pts) with CLL. CLL cells also express other developmentally-restricted Wnt5a-receptors, namely ROR2 and RYK, which can contribute to non-canonical Wnt-signaling in CLL. We hypothesize that elucidation of the structure-function-relationships involved in signaling by ROR1, ROR2, and RYK will define clinically relevant biomarkers for non-canonical Wnt-signaling and identify novel targets for therapy. Moreover, inhibition of non-canonical Wnt-signaling could have therapeutic applications, either alone or in combination with other newly developed targeted therapies that inhibit B-cell-receptor-signaling or BCL2. For this, we have the following specific aims: (AIM 1) Interrogate the signaling-pathways of non-canonical Wnt receptors in CLL - We will define the proteins recruited to ROR1/2 in response to Wnt5a and determine the structural domains required for signaling. We will examine the contribution of RYK to Wnt5a-signaling in CLL, determine the role of SH3-binding proteins, 14-3-3ζ, or Ca2+/calmodulin (CaM)-dependent protein kinase II (CaMKII) in ROR1-dependent signaling, and examine the contribution and function of ROR1 kinase to non- canonical Wnt-signaling. (AIM 2) Examine CLL cells for co-expression of non-canonical Wnt-receptors and determine the relative levels of Wnt-signaling - We will examine the blood samples of pts with CLL cells that have high, low, or negligible expression of ROR1 for plasma Wnt5a, leukemia-cell expression of ROR2 and RYK, and for leukemia-cell activation of canonical and non-canonical Wnt signaling. We also will examine the transcriptomes of selected CLL samples and cell lines for the newly described stemness index, which is dependent on ROR1-signaling. We also will examine for cross-talk between the canonical β-catenin- dependent Wnt-signaling pathway and the non-canonical, β-catenin-independent pathway, which may be influenced by the relative expression of ROR1, ROR2, or RYK, or by treatment with newly generated mAbs specific for ROR2 or RYK. (AIM 3) Examine the contribution of ROR1-signaling to the development of resistance to targeted therapies in CLL - We will examine expression-levels and function of ROR1, ROR2, and RYK in serial CLL samples collected from pts before, during, and after development of resistance to targeted therapies and evaluate the potential for synergy between cirmtuzumab and the BCL2 antagonist, venetoclax.