Uncovering the Molecular Basis of Phenotypic Diversification in BRAF-mutant Melanoma

揭示 BRAF 突变黑色素瘤表型多样化的分子基础

• 批准号: 9400986
• 负责人: Corey Eduardo Hayford
• 金额: $ 4.4万
• 依托单位: VANDERBILT UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-08-01 至 2020-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9400986
• 关键词: BRAF gene; Bacteria; Bhang; Biological Assay; Biological Models; Biological Process; Cell Line; Cells; Cellular biology; Characteristics; Complex; DNA; DNA Sequence Alteration; Data; Genetic Heterogeneity; Genome; Holidays; Laboratories; Lead; Malignant Neoplasms; Melanoma Cell; Molecular; Monitor; Patient-Focused Outcomes; Patients; Pharmaceutical Preparations; Pharmacotherapy; Phenotype; Population; Process; Proteins; RNA; Recurrence; Regulation; Research; Role; Source; Techniques; Technology; Time; cancer cell; cancer therapy; drug efficacy; environmental change; epithelial to mesenchymal transition; fitness; improved; mathematical model; melanoma; molecular marker; mutant; non-genetic; novel; phenotypic biomarker; response; stem cell differentiation; targeted treatment; theories; time use; transcriptome sequencing; treatment strategy; tumor; tumor heterogeneity

Tumor heterogeneity has been known to contribute to diverse patient outcomes in response to targeted therapies. It has primarily been studied in the context of genetic mutations that are either pre-existing or acquired in response to drug treatment. However, we have discovered signs of phenotypic diversification in normal conditions over time, which we think is driven by non- genetic processes. In order to study this diversification, we have used complimentary concepts from ecological theory known as bet-hedging and phenotypic plasticity. Briefly, we think cancer cell populations diversify their “bets” in normal conditions in order to increase chances of survival to any number of environmental changes. Underlying this theory, phenotypic plasticity suggests cells move around in a landscape of cell states, defined by molecular characteristics. These processes have been implicated in a variety of biological processes, including bacterial survival, stem cell differentiation, and epithelial-to-mesenchymal transitions. Preliminary data in the laboratory suggests complex drug-response dynamics in BRAF-mutant melanoma cell lines, likely resulting from non-genetic heterogeneity. Single-cell derived “clones” of the BRAF-mutant melanoma cell line SKMel5 have been generated and developed into cell sublines, which have shown differential phenotypes to drug treatment. In studying one of these sublines' response to BRAF inhibition, we have observed phenotypic diversification over time. Using a mathematical model that assumes phenotypic plasticity between non-genetically defined states, we have been able to form a theoretical basis for this experimental observation. In this proposal, we attempt to discern the existence of these states, identify molecular determinants, and monitor dynamic phenotypic diversification in real time.

已知肿瘤异质性导致不同的患者结局， 到靶向治疗。它主要是在基因突变的背景下研究的， 或者是预先存在的，或者是通过药物治疗获得的。但是我们发现了一些迹象 随着时间的推移，在正常条件下表型多样化，我们认为这是由非- 遗传过程为了研究这种多样化，我们使用了互补的概念 从生态学理论中被称为赌注对冲和表型可塑性。简单地说，我们认为癌症 在正常条件下，细胞群会使它们的“赌注”多样化，以增加存活的机会。 to any number数of environmental环境changes变化.根据这一理论，表型可塑性表明， 细胞在由分子特征定义的细胞状态的景观中移动。这些 过程涉及多种生物过程，包括细菌存活， 干细胞分化和上皮向间充质转化。初步数据， 一个实验室提示BRAF突变黑色素瘤细胞系中复杂的药物反应动力学， 非遗传异质性的结果。BRAF突变体的单细胞衍生“克隆” 黑素瘤细胞系SKMel 5已经产生并发展成细胞亚系，其具有 对药物治疗表现出不同的表型。在研究其中一个亚系对 通过BRAF抑制，我们观察到表型随时间的变化。使用数学 模型假设非遗传定义的状态之间的表型可塑性，我们已经 能够为这一实验观察提供理论基础。在这份提案中，我们试图 辨别这些状态的存在，识别分子决定因素，并监测动态 真实的时间表型多样化。