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: 10613917
• 负责人: ANDREI GOGA
• 金额: $ 48.8万
• 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/10613917
• 关键词: AKT inhibition; Acceleration; Adhesions; Architecture; Basement membrane; Binding Sites; Bioinformatics; Biological Assay; Breast; Breast Cancer Cell; Breast Cancer Prevention; Breast Epithelial Cells; Cell Adhesion Molecules; Cell Lineage; Cell Separation; Cells; Chemicals; Clinical; Complex; Dangerousness; Defect; Disease; Disease Marker; Disease Progression; Drug Targeting; Duct (organ) structure; Entropy; Epithelial Cell Proliferation; Epithelial Cells; Epithelium; Exclusion; Experimental Models; Extracellular Matrix; Extracellular Matrix Proteins; Genes; Genetic; Genetic Transcription; Genetically Engineered Mouse; Goals; Human; Image; In Situ; In Vitro; Invaded; 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; Property; Publishing; Risk; Signal Transduction; Statistical Mechanics; Structure; System; Temperature; Testing; Therapeutic; Tissue Engineering; Tissue Model; Tissues; Tumor Cell Invasion; Western Blotting; Woman; breast cancer progression; cell motility; cell type; cellular engineering; derepression; drug development; in vivo; infiltrating duct carcinoma; inhibitor; innovation; interfacial; lens; malignant breast neoplasm; mammary epithelium; mathematical model; mechanical drive; mechanical energy; mouse model; neoplastic cell; 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.

摘要 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)因为它代表了患者风险的一个主要转折点。乳腺癌 起源于乳腺上皮的内腔层，其中转化的内腔上皮细胞（LEP） 增殖以填充DCIS中的导管和小叶。令人惊讶的是，DCIS中的LEP已经获得了所有必要的 遗传畸变侵入，但仍被完整的外肌上皮（MEP）限制在组织内 层-一组细胞，形成动态屏障，阻止原位肿瘤进入基底 乳腺上皮细胞是由乳腺上皮细胞膜（BM，包围乳腺上皮的特化细胞外基质（ECM））组成的。因此我们 提出转化的LEP通过MEP层的移位，而不是基因突变，是一个关键速率- 发展到IDC的限制步骤。在这里，我们的目标是确定必须发生的物理和分子变化 以促进这一结构性转变。我们通过乳腺上皮细胞的透镜来应对这一挑战。 自组织我们以前证明，正常人LEP和MEP可以在体外自组织， MEP从BM中排除LEP的能力是由硬连线和谱系特异性界面决定的， 在每个细胞-细胞和细胞-ECM界面处的张力。我们通过实验和数学建模 LEP-ECM接口与MEP-ECM接口相比在能量上是非常不利的， 防止LEP将其自身定位在BM旁边。我们假设存在一个利率限制， 在DCIS向IDC进展过程中的高能结构中间体，其中LEP易位到MEP 层，旁边的BM.我们提出了一个统计力学框架，以了解如何扰动， 肿瘤细胞的界面性质和动力学促进该中间体的形成。我们特别 预测LEP-ECM界面能的变化是促进细胞生长所必需的关键物理变化。 转化LEP的基础易位。初步研究支持这一假设：我们发现， PIK 3CA基因在LEP中被激活时，通过使LEP-ECM 界面更积极有利。在这份提案中，我们将确定这一点和其他物理 LEP的变化是其基础易位所必需的，并确定LEP下游的分子变化。 PIK 3CA引起这些物理变化。我们将使用互补的体外实验来检验我们的假设， 体内实验系统：使用从人乳房缩小术组织重构的类器官， 基因工程小鼠模型。我们的长期目标是揭示促进和抑制 从DCIS到IDC。更好的进展的物理和分子预测因子将使DCIS受益 这些患者可能会被过度治疗，因为只有三分之一的DCIS病例进展为IDC。此外，封锁 LEP易位将代表预防乳腺癌进展的治疗策略。