The Role of Long Non-coding RNAs in EMT and Cancer Stem Cells

项目总结/摘要 候选 杰森·赫什科维茨博士的研究生涯始于博士实验室的一名研究生。 查尔斯·佩鲁在查佩尔山。他的研究重点是对人类的大规模基因组比较， 乳腺癌亚型和基因工程小鼠乳腺肿瘤模型。本研究表明 尽管没有单一的小鼠模型概括了给定的人类亚型的所有表达特征，但许多小鼠模型都具有相同的表达特征。 人类亚型的定义特征在小鼠模型中是保守的， 用于临床前应用。杰森后来转到贝勒医学院（Baylor College of Medicine，简称BLM）做博士后 杰弗里罗森博士实验室的研究员在那里，他专注于研究 乳腺癌最初是在他的研究生工作中发现的。利用一种独特的小鼠模型，他已经确定， 与其他亚型的肿瘤相比，封闭蛋白低的肿瘤富含功能性癌症干细胞（CSC 这一模式中产生的。杰森的研究生培训为他提供了癌症基因组学方面的专业知识， 小鼠模型。他的博士后工作给了他干细胞研究的知识和技能， 乳腺发育和肿瘤发生。杰森的短期职业目标是现在把他 已经将其应用于长链非编码RNA（lncRNA）领域。为了接受这方面的培训， 在新的领域，Jason已经确定了另外两位杰出的共同导师，霍华德·张博士和乔治博士 卡林。未来两年的目标是让杰森接受必要的额外研究培训， 解决这个新的研究领域，以及宝贵的职业导师，他准备一个成功的职业生涯， 一个高级学术机构的独立调查员 环境 Jason是Jeffrey罗森博士实验室的博士后研究员， 细胞生物学，丹L。邓肯癌症中心和莱斯特和 苏·史密斯乳房中心培训中心是一个优秀的环境，让学员发展必要的技能， 成为成功的独立研究者。该学院拥有卓越的教师，中心和最先进的技术 核心设施坐落于特里昂法尔的中心地带，特里昂法尔酒店是游览罗马的最佳下榻酒店。 优秀的研究和临床机构，包括医学博士安德森癌症中心，UT休斯顿医疗 学校，莱斯大学和卫理公会医院研究所。这些机构作为补充， 科学资源、合作来源和研讨会。 研究 基因表达谱已被用于将人类乳腺肿瘤分为不同的，临床上- 相关的亚组，包括一种罕见的分子亚型称为claudin-low。与肿瘤相比 其他亚型，低密蛋白肿瘤具有较低的紧密连接和粘附连接基因表达，包括 claudin 3和E-cadherin，以及上皮间质转化（EMT）相关的高表达， 基因.我们最近发现，claudin低肿瘤富含功能性CSC。已经确定 在人类乳腺上皮细胞中诱导EMT赋予它们干细胞样特性。一起 这些证据表明EMT和CSC富集之间存在重要的分子和生物学联系。 低密蛋白肿瘤 最近的研究表明，大部分基因组被转录，即使只有不到2%的基因组被转录。 哺乳动物的基因组被编码区占据。这些转录物被称为非编码RNA（ncRNA） 因为它们没有蛋白质编码能力。人们一直在关注一类人的作用， 小的ncRNA，称为miRNA，在发育和癌症中。相比之下，对这片广袤的土地， 以lncRNA为代表的大部分转录本。最近的一个主题是，许多lncRNA的功能， 与染色质修饰复合物相互作用并控制染色质结构。尽管多种 lncRNA的功能作用涉及许多生物过程，仅在相对较少的情况下 这些都有明确的定义。lncRNA功能的精确机制细节仍然是一个谜， 需要探索。正如可以从lncRNA在转录调节中的作用所预期的那样，表观遗传 随着lncRNA的修饰和发展，越来越多的证据表明lncRNA在癌症中的失调。 包括我们在内的几个研究小组已经表明，乳腺癌干细胞对辐射的抵抗力更强， 与非CSC相比，化疗。我们假设lncRNA在EMT基因中起着关键作用， 表达程序部分由RNA介导的表观遗传调控控制，导致对 乳腺癌的常规治疗。更好地理解负责 EMT/CSC表型对于确定用于对抗CSC的治疗抗性的靶标是关键的， 可能与低密蛋白肿瘤特别相关。该项目的目标，使用几个模型系统和一个 大规模功能筛选的策略是首先确定，然后研究 调节低密蛋白乳腺肿瘤EMT/CSC表型的lncRNA

PROJECT SUMMARY/ABSTRACT Candidate Dr. Jason Herschkowitz began his research career as a graduate student in the laboratory of Dr. Charles Perou at UNC Chapel Hill. His research focus was on a large-scale genomic comparison of human breast cancer subtypes and genetically engineered mouse mammary tumor models. This study showed that although no single mouse model recapitulated all the expression features of a given human subtype, many of the defining characteristics of the human subtypes were conserved among the mouse models providing insight for their preclinical applications. Jason then moved to the Baylor College of Medicine (BCM) as a postdoctoral fellowship in Dr. Jeffrey Rosen's laboratory. There he has concentrated on studying the claudin-low subtype of breast cancer initially identified in his graduate work. Using a unique mouse model, he has determined that claudin-low tumors are enriched for functional cancer stem cells (CSCs) compared to tumors of other subtypes arising in this model. Jason's graduate training has provided him with an expertise in cancer genomics and mouse models. His postdoctoral work has given him the knowledge and skills involved in stem cell research, mammary gland development, and tumorigenesis. Jason's short-term career goals are to now take what he has learned and apply it to the field of long non-coding RNAs (lncRNAs). In order to receive training in this new area, Jason has identified two additional outstanding co-mentors in Dr. Howard Chang and Dr. George Calin. The goal of the next two years is for Jason to receive the additional research training necessary to tackle this new research area as well as valuable career mentorship to prepare him for a successful career as an independent investigator at a highly ranked academic institution. Environment Jason is a postdoctoral fellow in the laboratory of Dr. Jeffrey Rosen in the department of Molecular and Cellular Biology, part of the Dan L. Duncan Cancer Center and the Breast Research Program of the Lester and Sue Smith Breast Center. BCM is an outstanding environment for trainees to develop the necessary skills to become successful independent researchers. The college has exceptional faculty, centers, and state of the art core facilities. BCM is located in the heart of the Texas Medical Center and is walking distance to several outstanding research and clinical institutions including M.D. Anderson Cancer Center, UT Houston Medical School, Rice University, and the Methodist Hospital Research Institute. These institutions serve as additional scientific resources, sources of collaboration, and seminars. Research Gene expression profiling has been used to classify human breast tumors into distinct, clinically- relevant subgroups, including a rare molecular subtype referred to as claudin-low. Compared to tumors of other subtypes, claudin-low tumors have lower expression of tight and adherens junction genes, including claudin 3 and E-cadherin, and higher expression of epithelial to mesenchymal transition (EMT) associated genes. We recently found that claudin-low tumors are enriched for functional CSCs. It has been determined that inducing EMT in human mammary epithelial cells endows them with stem cell-like properties. Together these lines of evidence suggest important molecular and biological links between EMT and the CSC-enriched claudin-low tumors. Recent studies suggest that the majority of the genome is transcribed even though less than 2% of the mammalian genome is occupied by coding regions. These transcripts are called non-coding RNAs (ncRNAs) because they have no protein coding capacity. There has been a great deal of focus on the role of a class of small ncRNAs, called miRNAs, in development and cancer. In contrast, much less is known about the vast majority of transcripts represented by lncRNAs. One recent theme is that many lncRNAs function through interactions with chromatin modifying complexes and control chromatin architecture. While a variety of functional roles for lncRNAs have been implicated in many biological processes, only in relatively few cases have these been well defined. The precise mechanistic details of lncRNA function remain a mystery that needs exploration. As might be expected from the roles of lncRNAs in transcriptional regulation, epigenetic modifications, and development, there is increasing evidence of the misregulation of lncRNAs in cancer. Several groups, including ours, have shown that breast CSCs are more resistant to radiation and chemotherapy compared to non-CSCs. We hypothesize lncRNAs play a critical role in an EMT gene expression program governed in part by RNA-mediated epigenetic regulation leading to resistance to conventional therapies in breast cancer. An improved understanding of the molecular networks responsible for the EMT/CSC phenotype is critical for defining targets for combating the therapeutic resistance of CSCs, which may be especially pertinent to claudin-low tumors. The goal of this project, using several model systems and a strategy for large-scale functional screening, is to first identify and then investigate the mechanisms of action of lncRNAs that regulate the EMT/CSC phenotype of claudin-low breast tumors.