Targeting plasma membrane spatial dynamics to suppress aberrant Wnt signaling

摘要 Wnt信号通路的失调与多种组织中的癌症有关。例如, 大多数结直肠癌(CRC)病例(~90%)与Wnt信号异常有关，部分原因是 与多功能肿瘤抑制因子结肠腺瘤性息肉病(APC)相关的突变(&gt；80%) 吉恩。不幸的是，使用药物靶向异常的Wnt信号的尝试仍然面临着多重障碍，因为 肿瘤细胞靶向性差，与所需长期治疗相关的负面副作用，以及 对作用机制的理解。因此，迫切需要进一步评估无毒 WNT靶向治疗方法。因此，本建议寻求开发具有靶向性的新型膜 减少结肠中异常Wnt信号的治疗方法。支持的科学前提 Wnt受体质膜空间动力学的研究是基于Wnt 受体和它们的信号是在突变的APC背景下发生CRC所必需的 背景资料。这一目标得到了我们的新发现的支持，该发现表明APC突变导致异常 WNT信号与细胞膜的生物物理扭曲有关，从而促进WNT 受体纳米聚集和下游信号传递。我们还演示了选择膜 靶向膳食生物活性物质(MTDB)可以通过纠正癌症- 导致细胞表面的生物物理扭曲。为了揭开以膜为基础的复杂的 癌症预防策略，我们建议使用新的小鼠、果蝇(果蝇)和人结肠有机化合物 用于阐明MTDBs重塑细胞膜的潜在机制的模型系统 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 结肠隐窝，从而增加质膜有序性和脂筏依赖的时空动力学。 在目标2中，我们将检验我们的假设，即致癌的apc诱导的胆固醇稳态改变改变。 Wnt信号相关受体的时空组织(纳米聚集)，从而促进 异常信号。目标3将检查MTDB减弱异常Wnt信号和结肠的能力 与致癌APC相关的肿瘤表型部分是通过使质膜生物物理“正常化”实现的 属性。 在我们拟议的工作完成后，我们希望确切地阐明MTDB是如何治疗的 修改细胞膜以抑制异常的Wnt信号和结肠中的肿瘤形成。我们建议 我们重塑质膜Wnt受体纳米簇的新方法是一种可行的结直肠癌预防方法 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.