ROR1 as a Therapeutic Target in Acute Lymphoblastic Leukemia

Jeffrey泰纳博士在过去的15年里一直在分子和细胞生物学研究领域接受培训，他是暑期学生（普渡大学），本科研究助理（格林内尔学院），研究生（圣路易斯华盛顿大学）和博士后研究员（俄勒冈州健康与科学大学）。他研究了各种生物学领域，包括植物学，免疫学，微生物学和血液学/肿瘤学。这项研究已经在高影响力的期刊上累计发表了21篇手稿，如Nature Medicine，Journal of Clinical Investigation，Cancer Research，Proceedings of the National Academy of Science和Blood以及许多其他正在修订或准备的手稿。泰纳博士还在重要的国家会议上作口头报告和海报展示。泰纳博士的研究主题涉及靶癌基因和癌基因特异性疗法的鉴定，以便癌症治疗可以针对每个患者。为了实现这些目标，他创造了两种筛选技术，利用siRNA或小分子激酶抑制剂来识别功能重要的靶基因，以进行后续表征和基因组研究。使用这些技术，他已经确定了一个基因，ROR 1，这是一个候选的治疗目标，在所有急性淋巴细胞白血病患者的1;19染色体易位。该提案旨在描述该靶基因的过表达和信号传导机制，并确定用于治疗干预的基因特异性方式。泰纳博士的长期职业目标包括建立一个独立的研究实验室，专注于癌症研究和个性化医疗。 工作环境：俄勒冈州健康与科学大学骑士癌症研究所有165名主要的教师调查谁拥有跨调查领域的各种专业知识。泰纳博士的导师布莱恩·德鲁克博士是奈特癌症研究所的主任。Druker博士在癌症研究领域拥有超过20年的经验，并指导了许多学生和研究员成为独立研究者。本提案还包括Richard Goodman博士、Philip Streeter博士和Robert Searles博士的支持声明。累积起来，这些支持科学家以及骑士癌症研究所作为一个整体拥有所有的仪器，资源和专业知识，以开展本申请中提出的研究。 调研：用激酶抑制剂特异性靶向致癌信号传导通路，极大地改善了患有各种癌症诊断的患者的临床结果，最显著的是患有慢性髓性白血病的患者。为了将这种靶向治疗方法扩展到所有形式的癌症，必须首先识别和表征致病基因。为此，我们开发了一种基于RNAi的筛选方法，可以快速识别直接从白血病患者获得的原发癌细胞中的靶基因。使用这种筛选，我们已经确定了一种受体酪氨酸激酶ROR 1，它在所有t（1;19）阳性急性淋巴细胞白血病（ALL）患者中独特且一致地过表达，约占所有儿童ALL的5%和成人ALL病例的1-2%。ROR 1的沉默导致t（1;19）阳性ALL细胞的活力显著降低，但对其他儿科ALL细胞或正常白色血细胞的活力没有影响。此外，之前的慢性淋巴细胞白血病（CLL）研究（占成人白血病病例的约30%）已在大多数病例中鉴定出ROR 1过表达。ROR 1作为真正的治疗靶点的验证需要更好地理解ROR 1促进细胞转化的遗传调控和信号传导机制。然而，很少有人知道的调控元件，管理ROR 1的表达或ROR 1所采用的信号通路，以影响细胞活力，目前还没有可用的策略，ROR 1可以治疗靶向。在t（1;19）阳性ALL细胞中发现ROR 1过表达和ROR 1依赖性为研究这一问题提供了独特的工具。我们提出，一个多管齐下的方法来研究1）ROR 1表达的调节，2）ROR 1有助于转化的信号传导机制，3）抑制ROR 1的治疗策略的发展将阐明ROR 1依赖性恶性肿瘤，如t（1;19）阳性ALL或CLL的疾病发病机制，并为这些患者的治疗干预提供新的策略。 公共卫生相关性：我们已经发现，受体酪氨酸激酶，ROR 1，是独特的和一贯的过度表达的细胞从t（1;19）阳性急性淋巴细胞白血病（ALL）患者。ROR 1的表达是1;19阳性细胞存活所必需的，使其成为这些患者的新治疗靶点。阐明t（1;19）阳性ALL中ROR 1表达和信号传导的潜在机制将导致对疾病发病机制的更全面理解，并为治疗干预的新策略提供见解。

DESCRIPTION (provided by applicant): Candidate: Dr. Jeffrey Tyner has been training in the field of molecular and cellular biology research for the past 15 years as a summer student (Purdue University), undergraduate research assistant (Grinnell College), graduate student (Washington University in St. Louis), and post-doctoral fellow (Oregon Health & Science University). He has studied a diverse spectrum of biological fields including botany, immunology, microbiology, and hematology/oncology. This research has led to 21 cumulative published manuscripts in high-impact journals such as Nature Medicine, Journal of Clinical Investigation, Cancer Research, Proceedings of the National Academy of Science, and Blood as well as numerous other manuscripts in revision or preparation. Dr. Tyner has also presented his work in oral presentations and poster sessions at major national conferences. The theme of Dr. Tyner's research involves the identification of target oncogenes and oncogene-specific therapeutics, such that cancer therapies can be tailored to each individual patient. To accomplish these goals, he has created two screening techniques that make use of siRNA or small-molecule kinase inhibitors to identify functionally important target genes for follow-up characterization and genomic study. Using these techniques, he has identified a gene, ROR1, that is a candidate therapeutic target in all acute lymphoblastic leukemia patients with a 1;19 chromosomal translocation. This proposal aims to characterize the mechanisms of overexpression and signaling of this target gene and to identify gene-specific modalities for therapeutic intervention. Dr. Tyner's long-term career goals include establishment of an independent research lab with a focus on cancer research and personalized medicine. Environment: The Oregon Health & Science University Knight Cancer Institute has 165 primary faculty investigators who have expertise across a diverse spectrum of fields of inquiry. Dr. Tyner's mentor, Dr. Brian Druker, is the Director of the Knight Cancer Institute. Dr. Druker has over 20 years of experience in the field of cancer research and has mentored numerous students and fellows to independent investigator status. This proposal also includes statements of support from Dr. Richard Goodman, Dr. Philip Streeter, and Dr. Robert Searles. Cumulatively, these supporting scientists as well as the Knight Cancer Institute as a whole posses all the instrumentation, resources, and expertise to carry out the research proposed in this application. Research: Specific targeting of oncogenic signaling pathways with kinase inhibitors has vastly improved clinical outcomes for patients with a variety of cancer diagnoses, most notably patients with chronic myeloid leukemia. To expand this targeted-therapy approach to all forms of cancer, disease-causing genes must first be identified and characterized. Towards that end, we have developed an RNAi-based screen to rapidly identify target genes in primary cancer cells obtained directly from leukemia patients. Using this screen, we have identified a receptor tyrosine kinase, ROR1, that is uniquely and consistently overexpressed in all patients with t(1;19)-positive acute lymphoblastic leukemia (ALL), representing approximately 5% of all pediatric ALL and 1-2% of adult ALL cases. Silencing of ROR1 results in significantly decreased viability of t(1;19)-positive ALL cells, but has no effect on viability of other pediatric ALL cells or normal white blood cells. In addition, previous studies of chronic lymphocytic leukemia (CLL), which accounts for approximately 30% of adult leukemia cases, have identified ROR1 overexpression in the majority of cases. Validation of ROR1 as a bona fide therapeutic target necessitates a better understanding of the mechanisms of genetic regulation and signaling by which ROR1 contributes to cellular transformation. However, very little is known about the regulatory elements governing ROR1 expression or the signaling pathways employed by ROR1 to influence cellular viability, and there are currently no available strategies by which ROR1 can be therapeutically targeted. The finding of ROR1 overexpression and ROR1-dependence in t(1;19)-positive ALL cells offers unique tools to study this problem. We propose that a multi-pronged approach to studying 1) regulation of ROR1 expression, 2) signaling mechanisms through which ROR1 contributes to transformation, and 3) development of therapeutic strategies for inhibiting ROR1 will elucidate the disease pathogenesis of ROR1-dependent malignancies such as t(1;19)-positive ALL or CLL and offer new strategies for therapeutic intervention in these patients. PUBLIC HEALTH RELEVANCE: We have found that the receptor tyrosine kinase, ROR1, is uniquely and consistently overexpressed on cells from t(1;19)-positive acute lymphoblastic leukemia (ALL) patients. Expression of ROR1 is required for viability of 1;19-positive cells making it a novel therapeutic target for these patients. Elucidation of the mechanisms underlying ROR1 expression and signaling in t(1;19)-positive ALL will lead to more comprehensive understanding of disease pathogenesis and offer insights into new strategies for therapeutic intervention.