Understanding breast cancer progression as a defect in the mechanics of tissue self-organization

将乳腺癌进展理解为组织自组织机制的缺陷

• 批准号: 10395995
• 负责人: ANDREI GOGA
• 金额: $ 56.62万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN FRANCISCO
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-05-01 至 2025-04-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10395995
• 关键词: AKT inhibition; Adhesions; Architecture; Basement membrane; Binding Sites; Bioinformatics; Biological Assay; Breast; Breast Cancer Cell; Breast Cancer Prevention; Breast Epithelial Cells; Cell Adhesion Molecules; Cell Lineage; Cells; Chemicals; Clinical; Complex; Dangerousness; Defect; Disease; Disease Marker; Disease Progression; Drug Targeting; Duct (organ) structure; Entropy; Epithelial; Epithelial Cells; Extracellular Matrix; Extracellular Matrix Proteins; Genes; Genetic; Genetic Transcription; Genetically Engineered Mouse; Goals; Human; Image; In Situ; In Vitro; Invaded; Lead; Lobule; Malignant Neoplasms; Mammaplasty; Mammary Gland Parenchyma; Mammary gland; Mass Spectrum Analysis; Measurement; Measures; Mechanics; Mediating; Molecular; Mutation; Myoepithelial; Noninfiltrating Intraductal Carcinoma; Operative Surgical Procedures; Organoids; PIK3CA gene; Pathway interactions; Patients; Penetration; Peptide Hydrolases; Phenotype; Polycomb; Positioning Attribute; Probability; Proliferating; Property; Publishing; Risk; Signal Transduction; Statistical Mechanics; Structure; System; Temperature; Testing; Therapeutic; Time; Tissue Engineering; Tissue Model; Tissues; Western Blotting; Woman; breast cancer progression; cell motility; cell type; cellular engineering; drug development; experimental study; in vivo; infiltrating duct carcinoma; inhibitor; innovation; interfacial; lens; malignant breast neoplasm; mammary epithelium; mathematical model; mechanical energy; mouse model; neoplastic cell; overtreatment; predictive modeling; prevent; programs; reconstitution; self organization; single-cell RNA sequencing; small hairpin RNA; three dimensional cell culture; tumor; tumor progression

ABSTRACT A progressive breakdown in the bilayered structure of the mammary gland is the hallmark of all breast cancers, but the structural change that occurs between ductal carcinoma in situ (DCIS) and invasive ductal carcinoma (IDC) is of particular importance because it represents a major inflection point in risk for patients. Breast cancers originate in the inner luminal layer of the mammary epithelium, where transformed luminal epithelial cells (LEP) proliferate to fill the ducts and lobules in DCIS. Surprisingly, LEP in DCIS have acquired all the necessary genetic aberrations to invade, but remain constrained within the tissue by an intact outer myoepithelial (MEP) layer—a group of cells that forms a dynamic barrier blocking access of the in situ tumor to the basement membrane (BM, the specialized extracellular matrix (ECM) that surrounds the mammary epithelium). Thus, we propose that translocation of transformed LEP past the MEP layer, and not genetic mutations, is a key rate- limiting step in progression to IDC. Here, we aim to identify the physical and molecular changes that must occur in LEP to facilitate this structural transition. We approach this challenge through the lens of mammary epithelial self-organization. We previously demonstrated that normal human LEP and MEP can self-organize in vitro, and that the capacity of MEP to exclude LEP from the BM is determined by hard-wired and lineage-specific interfacial tensions at each cell-cell and cell-ECM interface. We showed using experiments and mathematical modeling that the LEP-ECM interface is highly unfavorable energetically compared to the MEP-ECM interface, which prevents LEP from positioning themselves next to the BM. We hypothesize the existence of a rate-limiting and high-energy structural intermediate during the progression of DCIS to IDC, where LEP translocate into the MEP layer, next to the BM. We propose a statistical mechanical framework for understanding how perturbations to the interfacial properties and dynamics of tumor cells facilitate the formation of this intermediate. Specifically, we predict that changes to the LEP-ECM interfacial energy are a critical physical change necessary to promote basal translocation of transformed LEP. Preliminary studies support this hypothesis: we found that a frequently dysregulated gene—PIK3CA—disrupts self-organization when activated in LEP by rendering the LEP-ECM interface more energetically favorable. In this proposal, we will determine whether this and other physical changes to LEP are necessary for their basal translocation, and identify the molecular changes downstream of PIK3CA that give rise to these physical changes. We will test our hypothesis using complementary in vitro and in vivo experimental systems: using organoids reconstituted from human reduction mammoplasty tissues and genetically engineered mouse models. Our long-term goal is to reveal the changes that promote and inhibit progression from DCIS to IDC. Better physical and molecular predictors of progression would benefit DCIS patients who would otherwise be over-treated, as only a third of DCIS cases progress to IDC. Further, blocking LEP translocation would represent a therapeutic strategy to prevent breast cancer progression.

抽象的 乳腺双层结构的进行性破坏是所有乳腺癌的标志， 但导管原位癌 (DCIS) 和浸润性导管癌之间发生的结构变化 (IDC) 特别重要，因为它代表了患者风险的主要拐点。乳腺癌 起源于乳腺上皮的内腔层，其中转化的腔上皮细胞（LEP） 增殖以填充导管原位癌 (DCIS) 中的导管和小叶。令人惊讶的是，DCIS 中的 LEP 已获得所有必要的条件 遗传畸变侵入，但仍被完整的外肌上皮 (MEP) 限制在组织内 层——形成动态屏障的一组细胞，阻止原位肿瘤进入基底 膜（BM，包围乳腺上皮的特殊细胞外基质（ECM））。因此，我们 提出转化的 LEP 通过 MEP 层的易位，而不是基因突变，是关键的速率- 限制进展为 IDC 的步骤。在这里，我们的目标是确定必须发生的物理和分子变化 LEP 来促进这种结构转型。我们通过乳腺上皮透镜来应对这一挑战 自组织。我们之前证明正常人类 LEP 和 MEP 可以在体外自组织，并且 MEP 将 LEP 从 BM 中排除的能力是由硬连线和谱系特定的界面决定的 每个细胞-细胞和细胞-ECM 界面处的张力。我们通过实验和数学建模来展示 与 MEP-ECM 接口相比，LEP-ECM 接口在能量上非常不利， 防止 LEP 将自己定位在 BM 旁边。我们假设存在速率限制和 DCIS 发展为 IDC 过程中的高能结构中间体，其中 LEP 易位至 MEP 层，紧邻BM。我们提出了一个统计力学框架来理解扰动如何 肿瘤细胞的界面特性和动力学促进了这种中间体的形成。具体来说，我们 预测 LEP-ECM 界面能的变化是促进 转化的 LEP 的基础易位。初步研究支持了这一假设：我们发现，经常 失调基因 PIK3CA 在 LEP 中激活时会通过渲染 LEP-ECM 来破坏自组织 界面更加积极有利。在这个提案中，我们将确定这个和其他物理 LEP 的变化对于其基础易位是必要的，并确定 LEP 下游的分子变化 PIK3CA 引起这些物理变化。我们将使用互补的体外和 体内实验系统：使用从人体缩小乳房成形术组织中重建的类器官和 基因工程小鼠模型。我们的长期目标是揭示促进和抑制的变化 从 DCIS 进展为 IDC。更好的物理和分子进展预测因素将有利于 DCIS 患者可能会被过度治疗，因为只有三分之一的 DCIS 病例会进展为 IDC。进一步地，阻止 LEP 易位代表了一种预防乳腺癌进展的治疗策略。