Lysosomal metabolism as a targetable driver of pancreatic cancer

项目摘要 三阴性乳腺癌(TNBC)是一种侵袭性亚型，占新发乳腺癌的15%-20% 确诊的乳腺癌病例。由于缺乏已知的分子靶点，TNBC的治疗选择如下 有限，30%-50%的患者对标准护理产生抵抗力。我的目标是更好地理解新陈代谢 对TNBC细胞的依赖性，以揭示可用于治疗的新靶点。TNBC细胞倾向于 存在于类间充质状态，在此期间经历了上皮到间充质的转变(EMT) 细胞获得了更具运动性和侵袭性的表型。因为EMT与较差的乳腺癌有关 预后，了解分子驱动因素和在此过程中的适应将确定有针对性的 转移性癌细胞的依赖性。MicroRNA-200C(miR-200C)被公认为是一种 容易在TNBC中丢失的EMT。以miR-200C为工具推动TNBC细胞向更上皮样细胞分化 表型，我发现在EMT过程中胆固醇代谢发生了新的变化。这个项目 描述了EMT如何调节胆固醇代谢以及这些变化的功能后果。 在这笔赠款的F99部分，我确定了miR-200C逆转EMT如何改变胆固醇 代谢蛋白，包括低密度脂蛋白受体(LDLR)和Niemann-Pick-C1型 (NPC1)。低密度脂蛋白受体负责内吞低密度脂蛋白颗粒，低密度脂蛋白颗粒是胆固醇的主要来源 乳腺肿瘤细胞。在内吞囊泡与溶酶体融合后，NPC1是特定需要的 胆固醇从溶酶体到其他细胞成分的加工和运输。这些变化表明 对胆固醇间充质样与上皮样TNBC的需求改变，其后果是 在本项目的目标1B中进行了评估。我的初步数据还表明，NPC1的活动对 TNBC细胞在体外的存活情况。在目标1B中，我概述了了解总体胆固醇摄取和 在EMT过程中的细胞内胆固醇水平，并描绘了NPC1对TNBC细胞活力的关键作用。这 首次在EMT和乳腺癌中建立LDLR和NPC1的依赖和表达改变 进步。 在拟议项目的K00阶段，我将扩展我对以下代谢需求的兴趣 转移级联反应。我将深入研究细胞外机械信号是如何由 细胞外基质(ECM)在转移过程中驱动代谢适应，促进肿瘤的侵袭和迁移。 此外，我将评估细胞的EMT表型是否影响这些适应。获得更好的 了解癌细胞代谢如何支持细胞外基质的改变以及机械需求 在转移过程中遇到的将为肿瘤内治疗靶点的发展提供洞察力 新陈代谢。

Project Summary Triple Negative Breast Cancer (TNBC) is an aggressive subtype representing 15-20% of newly diagnosed breast cancer cases. Due to a lack of known molecular targets, treatment options for TNBC are limited, and 30-50% of patients acquire resistance to standard care. I aim to better understand the metabolic dependencies of TNBC cells to reveal novel targets that could be exploited therapeutically. TNBC cells tend to exist in a mesenchymal-like state, having undergone epithelial-to-mesenchymal transition (EMT) during which cells acquire a more motile and invasive phenotype. Because EMT is associated with poor breast cancer prognosis, understanding the molecular drivers and adaptations during this process will identify targetable dependencies of metastatic cancer cells. microRNA-200c (miR-200c) is well-established as a suppressor of EMT that tends to be lost in TNBC. Using miR-200c as a tool to push TNBC cells into a more epithelial-like phenotype, I have identified novel changes to cholesterol metabolism occurring during EMT. This project delineates how EMT regulates cholesterol metabolism and the functional consequences of these changes. In the F99 portion of this grant, I establish how reversal of EMT by miR-200c alters cholesterol metabolism proteins including the low-density-lipoprotein (LDL) receptor (LDLR) and Niemann-Pick-Type-C1 (NPC1). LDLR is responsible for endocytosing LDL particles, which are the primary source of cholesterol for breast tumor cells. After fusion of endocytic vesicles with the lysosome, NPC1 is specifically required for the processing and transport of cholesterol from lysosomes to other cellular components. These changes suggest an altered demand for cholesterol mesenchymal-like versus epithelial-like TNBC, the consequences of which are evaluated in Aim 1B of this project. My preliminary data also demonstrates that NPC1 activity is critical to survival of TNBC cells in vitro. In Aim 1B, I outline experiments to understand overall cholesterol uptake and intracellular cholesterol levels during EMT and delineate the critical role of NPC1 on TNBC cell viability. This work is the first to establish altered dependency and expression of LDLR and NPC1 in EMT and breast cancer progression. In the K00 phase of the proposed project, I will expand on my interest in the metabolic requirements of the metastatic cascade. I will move into investigating how extracellular mechanical cues driven by the extracellular matrix (ECM) drive metabolic adaptations to promote invasion and migration during metastasis. Further, I will evaluate whether the EMT phenotype of cells influences these adaptations. Gaining a better understanding of how cancer cell metabolism supports changing ECM and how mechanical demands encountered during metastasis will provide insights into development of therapeutic targets within tumor metabolism.