Normal stem cells and their transition to disease in the skin

正常干细胞及其向皮肤疾病的转变

• 批准号: 9883718
• 负责人: Valentina Greco
• 金额: $ 44.15万
• 依托单位: YALE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-05-01 至 2022-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9883718
• 关键词: Address; Adopted; Affect; Animals; Behavior; Benign; CD69 antigen; Cancer Biology; Cancer Etiology; Cancerous; Cell Differentiation process; Cells; Communication; Development; Disease; Down-Regulation; Environment; Epithelial; Epithelial Cells; Epithelium; Exhibits; Gene Mutation; Genes; Genetic Transcription; Goals; Growth; Hair; Hair follicle structure; Heterogeneity; Homeostasis; Human; Image; Immunofluorescence Immunologic; In Situ; Individual; Injections; Laboratories; Lead; Location; Malignant - descriptor; Malignant Neoplasms; Mesenchymal; Modeling; Molecular; Mus; Mutate; Mutation; Nature; Normal tissue morphology; Oncogenic; Organ; Outcome; Pathway interactions; Phenotype; Physiological; Population; Population Dynamics; Positioning Attribute; Process; Role; Science; Signal Pathway; Signal Transduction; Signaling Molecule; Skin; Skin Neoplasms; Squamous cell carcinoma; Stromal Cells; Stromal Neoplasm; System; Testing; Therapeutic; Time; Tissues; Tretinoin; Tumor stage; Undifferentiated; Up-Regulation; Validation; Viral; Virus; Work; base; beta catenin; cancer therapy; cancer type; cell behavior; cell regeneration; cell transformation; cell type; epidermal stem cell; exome sequencing; experimental study; flexibility; genetic signature; imaging approach; in utero; in vivo; in vivo imaging; insight; interest; internal control; keratoacanthoma; knock-down; mouse model; mutant; new technology; novel; novel strategies; overexpression; perlecan; public health relevance; recruit; self-renewal; small hairpin RNA; stem; stem cell biology; stem cell differentiation; stem cells; transcriptome sequencing; tumor; tumor growth; tumor initiation

 DESCRIPTION (provided by applicant): Stem cells and their environment, the so-called niche, are critical components that sustain not only proper tissue homeostasis, but also diseased states such as cancer. The inability to follow the same cells over time in an intact animal is a bi challenge that has greatly limited our understanding of what goes awry during normal tissue homeostasis and the cellular behaviors exhibited in the initial stages of tumor growth. Specifically, this roadblock has hindered our ability to understand both the role of specific cells and how their location contributes to their growth, whether it be normal or cancerous. For the first time, we are now capable of addressing these questions since my lab has pioneered the use of live imaging in skin stem cell regeneration and established an approach that allows us to follow the same cells over time in an intact, live mouse. By these approaches we have learned that first, the location where stem cells reside influences their ability to contribute to growth. Second, as a consequence of a perturbation, such as loss of a stem cell pool, other cells can acquire a new ability to contribute to growth that they did not possess previously. Third, the induction of oncogenic mutations in clones, such as mutations that stabilize the Wnt effector β-catenin, will drive aberrant growths ultimately leading to tumor formation through the recruitment of non cell-autonomous wild-type cells. However, it is still unclear 1) what signaling mechanisms regulate the aberrant cellular behaviors that will eventually cause tumor development, 2) whether a cell's position within a tissue influences different tumoral outcomes, and 3) what early cell behaviors are adopted by stem and other cell types that lead to tumor development. To identify the aberrant stem cell/progenitor activities that cause cancer, we are using two contrasting human skin tumors; a benign and a malignant form, which we can faithfully recapitulate in a mouse model. We plan to 1) utilize cutting-edge exome and RNA sequencing approaches to identify target gene mutations associated with tumoral epithelial and stromal cell populations and 2) to assess the role of these genes towards cancer by in vivo overexpression and shRNA knockdown in the mouse via in utero injection and subsequent functional validation using our in vivo imaging approach. Together, these approaches will allow us to understand how novel and established target genes alter stem cell behaviors and identify the initial sequential steps that lead to malignant tumor growth. Understanding the mechanisms and signaling pathways underlying the role of stem cells in cancer holds great promise to transform current therapeutic strategies. Our plan aims to identify the relevant cells and genes that are responsible for skin tumor initiation, which may prove relevant for an extended application to other types of cancer.

 描述（由申请人提供）：干细胞及其环境，即所谓的生态位，是不仅维持适当组织稳态，而且维持癌症等疾病状态的关键组成部分。无法在完整动物中随时间推移跟踪相同细胞是一个双重挑战，这极大地限制了我们对正常组织稳态和肿瘤生长初始阶段所表现出的细胞行为的理解。具体来说，这个障碍阻碍了我们理解特定细胞的作用， 以及它们的位置如何影响它们的生长，无论是正常的还是癌性的。我们现在第一次能够解决这些问题，因为我的实验室率先在皮肤干细胞再生中使用活体成像，并建立了一种方法，使我们能够在完整的活小鼠中随着时间的推移跟踪相同的细胞。通过这些方法，我们已经了解到，首先，干细胞所在的位置影响它们促进生长的能力。第二，作为扰动的结果，例如干细胞库的损失，其他细胞可以获得新的能力来促进它们以前不具备的生长。第三，克隆中致癌突变的诱导，例如稳定Wnt效应子β-连环蛋白的突变，将驱动异常生长，最终通过募集非细胞自主的野生型细胞导致肿瘤形成。然而，目前尚不清楚1）什么信号传导机制调节最终导致肿瘤发展的异常细胞行为，2）细胞在组织中的位置是否影响不同的肿瘤结果，以及3）干细胞和其他细胞类型采用何种早期细胞行为导致肿瘤发展。为了识别导致癌症的异常干细胞/祖细胞活动，我们使用了两种对比鲜明的人类皮肤肿瘤;良性和恶性形式，我们可以在小鼠模型中忠实地重述。我们计划1）利用尖端的外显子组和RNA测序方法来鉴定与肿瘤上皮细胞和基质细胞群相关的靶基因突变，2）通过子宫内注射在小鼠中体内过表达和shRNA敲减，以及随后使用我们的体内成像方法进行功能验证，来评估这些基因对癌症的作用。总之，这些方法将使我们能够了解新的和已建立的靶基因如何改变干细胞行为，并确定导致恶性肿瘤生长的初始顺序步骤。了解干细胞在癌症中作用的机制和信号通路对于改变当前的治疗策略具有很大的希望。我们的计划旨在确定负责皮肤肿瘤起始的相关细胞和基因，这可能证明与其他类型癌症的扩展应用相关。