Targeting plasma membrane spatial dynamics to suppress aberrant Wnt signaling

总结 Wnt信号通路的失调与多种组织中的癌症有关。比如说， 大多数结直肠癌（CRC）病例（约90%）与异常Wnt信号相关，部分原因是 突变（>80%）与结肠腺瘤性息肉病（APC）相关，APC是一种多功能肿瘤抑制因子 基因不幸的是，使用药物靶向异常Wnt信号传导的尝试仍然面临多重障碍， 肿瘤细胞靶向性差，与所需长期治疗相关的负面副作用， 了解作用机制。因此，迫切需要进一步评估无毒 Wnt靶向治疗方法。因此，该提议寻求开发新型膜靶向 减轻结肠异常Wnt信号传导的治疗方法。科学前提支持 对Wnt受体质膜空间动力学的拟议研究是基于Wnt 受体及其信号传导是突变APC背景下CRC发展所必需的 背景这一目标得到了我们新发现的支持，表明APC突变引起的异常 Wnt信号传导与细胞质膜中的生物物理扭曲相关，从而促进Wnt信号传导。 受体纳米簇和下游信号传导。我们还证明了选择膜 有针对性的膳食生物活性物质（MTDB）可以通过纠正癌症来恢复正常的质膜信号传导， 导致细胞表面的生物物理扭曲。为了解开复杂的膜基 癌症预防策略，我们建议使用新的小鼠，果蝇（果蝇）和人类结肠类器官 模型系统，以阐明MTDBs重塑细胞质膜的潜在机制 抑制异常的Wnt信号 在目标1中，我们将进一步探讨突变的（致癌的）APC如何扰乱胆固醇稳态， 结肠隐窝，从而增加质膜秩序和脂筏依赖性时空动力学。 在目标2中，我们将检验我们的假设，即致癌APC诱导的胆固醇稳态改变， Wnt信号相关受体的时空组织（纳米簇），从而促进 异常信号目的3将检查MTDB减弱异常Wnt信号传导和结肠炎的能力。 与致癌APC相关的肿瘤形成表型部分通过“正常化”质膜生物物理 特性. 在完成我们提出的工作后，我们希望精确地阐明MTDBs治疗 修饰细胞膜以抑制异常Wnt信号传导和结肠中的肿瘤形成。我们提出 我们重塑质膜Wnt受体纳米簇的新方法是一种可行的CRC预防方法， 或治疗策略。

SUMMARY Dysregulation of the Wnt signaling pathway has been linked to cancer in multiple tissues. For example, most colorectal cancer (CRC) cases (~90%) are associated with aberrant Wnt signaling, due in part to mutations (>80%) associated with Adenomatous polyposis coli (APC), a multi-functional tumor suppressor gene. Unfortunately, attempts to target aberrant Wnt signaling using drugs still face multiple hurdles due to poor tumor cell targeting, negative side effects associated with required long-term treatments and a poor understanding of the mechanisms of action. Consequently, there is an urgent need to further assess non-toxic Wnt targeted therapeutic approaches. Therefore, this proposal seeks to develop novel membrane targeted therapeutic approaches to abate abnormal Wnt signaling in the colon. The scientific premise that supports the proposed research on Wnt receptor plasma membrane spatial dynamics is based on the fact that Wnt receptors and their signaling are required for CRC development within the context of a mutant APC background. This goal is supported by our novel discovery indicating that APC mutations causing abnormal Wnt signaling are associated with biophysical distortions in the cell plasma membrane, thereby promoting Wnt receptor nanoclustering and downstream signaling. We have also demonstrated that select membrane targeted dietary bioactives (MTDBs) can restore normal plasma membrane signaling by correcting cancer- causing biophysical distortions in the cell surface. In order to unravel the intricacies of membrane-based cancer prevention strategies, we propose to use novel mouse, Drosophila (fruit fly) and human colon organoid model systems to elucidate the underlying mechanisms by which MTDBs reshape the cell plasma membrane to suppress aberrant Wnt signaling. In Aim 1, we will further probe how mutated (oncogenic) APC perturbs cholesterol homeostasis in the colonic crypt, thereby increasing plasma membrane order and lipid raft-dependent spatiotemporal dynamics. In Aim 2, we will test our hypothesis that oncogenic APC-induced changes in cholesterol homeostasis alters the spatiotemporal organization (nanoclustering) of Wnt signaling-associated receptors, thereby promoting aberrant signaling. Aim 3 will examine the ability of MTDBs to attenuate aberrant Wnt signaling and colonic neoplasia phenotypes associated with oncogenic APC in part by “normalizing” plasma membrane biophysical properties. Upon completion of our proposed work, we expect to elucidate precisely how MTDBs therapeutically modify the cell membrane to suppress aberrant Wnt signaling and tumor formation in the colon. We propose that our novel approach to reshape plasma membrane Wnt receptor nanoclusters is a feasible CRC prevention or therapeutic strategy.