Role of p27 in chronic myeloid leukemia and its potential as a therapeutic target

p27 在慢性粒细胞白血病中的作用及其作为治疗靶点的潜力

• 批准号: 8300831
• 负责人: Anupriya Agarwal
• 金额: $ 14.15万
• 依托单位: OREGON HEALTH & SCIENCE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-07-15 至 2014-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8300831
• 关键词: Adhesions; Affect; Attenuated; Award; Biological Assay; Bone Marrow Cells; Brain; CD34 gene; Cancer Biology; Cell Cycle; Cell Cycle Progression; Cell Nucleus; Cell Proliferation; Cells; Chronic Myeloid Leukemia; Clinical; Complex; Cyclin-Dependent Kinases; Cytoplasm; Data; Defect; Disease; Disease Resistance; Down-Regulation; Drug resistance; Environment; Extramural Activities; Faculty; Funding; Future; Goals; Guanosine Triphosphate Phosphohydrolases; Health Sciences; Hematopoietic Neoplasms; Hematopoietic stem cells; Human; Imatinib; Immunoblotting; Immunofluorescence Immunologic; In Vitro; Institutes; Knowledge; Laboratories; Lead; Leadership; Link; Malignant Neoplasms; Mediating; Mentors; Modeling; Molecular; Molecular Target; Molecular and Cellular Biology; Mus; Nuclear; Oncogenes; Oncogenic; Oregon; Outcome; Pathogenesis; Pathway interactions; Patients; Philadelphia Chromosome; Phosphotransferases; Physiological; Postdoctoral Fellow; Process; Prognostic Marker; Protein Tyrosine Kinase; Reciprocal Translocation; Recurrence; Research; Research Infrastructure; Research Personnel; Research Training; Residual Tumors; Resistance; Role; S Phase; SKP2 gene; Signal Transduction; Skp2 Proteins; Solid; Staging; Stem cells; Students; Techniques; Testing; Therapeutic Intervention; Training; Training Programs; Transcript; Transgenic Mice; Transgenic Organisms; Tumor Suppressor Proteins; Tyrosine Kinase Inhibitor; Universities; Up-Regulation; Work; advanced disease; anticancer research; attenuation; base; bcr-abl Fusion Proteins; career; design; drug relapse; experience; human migration; improved; in vivo; inhibitor/antagonist; leukemia; leukemogenesis; metaplastic cell transformation; migration; mouse model; mutant; novel; novel strategies; outcome forecast; progenitor; public health relevance; response; small molecule; therapeutic target; tool; treatment strategy; tyrosine kinase ABL1; ubiquitin ligase

DESCRIPTION (provided by applicant): Career goals: Dr. Agarwal's long term goal is to elucidate novel molecular mechanisms in leukemia pathogenesis so that this knowledge can be applied to the discovery of new therapies resulting in improved clinical outcomes. Dr. Agarwal's career goal is to establish an independent laboratory focused on understanding cancer pathogenesis. For the K99 Pathway to Independence Award, Dr. Agarwal has described a five-year training program that will allow her to acquire the expertise needed to become a successful independent cancer researcher. During this award, she will be able to expand her knowledge in cancer biology, acquire expertise in a variety of novel techniques to be used in her future research, and generate a body of data as a basis for future studies and applications for extramural funding. Knowledge acquired and data produced during the K99/R00 award will be instrumental in achieving her long term goal. Environment: The Oregon Health & Science University Knight Cancer Institute has 165 primary faculty investigators with expertise across a diverse spectrum of fields. Dr. Agarwal's mentor, Dr. Brain 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. He will continue to provide intellectual and leadership training to Dr. Agarwal for the transition to a career as an independent researcher. Dr. Agarwal has gathered an excellent team of collaborators and advisors with the combined expertise to advise her on all aspects of the proposed study as well as on her career. In addition, the Knight Cancer Institute's infrastructure provides research training and enthusiastic support to post-doctoral fellows who are preparing themselves for a successful faculty career. Dr. Agarwal believes that the proposed project is well-suited to launch her independent research career in the field of leukemia pathogenesis. Research: The objective of the proposed study is to determine the mechanism of p27 deregulation in chronic myeloid leukemia (CML) and to establish the role of p27 in CML pathogenesis. CML is a disease of hematopoietic stem cells caused by BCR-ABL, a constitutively active tyrosine kinase that is the result of the 9;22 translocation. Most patients with early stage disease achieve durable responses upon treatment with imatinib, a small-molecule inhibitor of BCR-ABL. However, in the advanced stages of disease, drug resistance and relapse are frequent. Further, recurrence of active disease is common if therapy is stopped. Therefore identification of additional molecular targets suitable for therapeutic intervention may allow us to develop novel treatment strategies designed to overcome disease resistance and eradicate residual disease. Earlier studies showed that BCR-ABL promotes unregulated cell cycle progression and cell proliferation by impairing the function of p27, a tumor suppressor and a regulator of cyclin dependent kinase. However, the detailed mechanism of p27 deregulation remains to be clearly defined. Dr. Agarwal's preliminary data suggests that, in primary CML cells, p27 deregulation involves both downregulation in the nucleus and increased cytoplasmic mislocalization. While nuclear p27 appears to be under the control of BCR-ABL kinase activity, imatinib fails to decrease cytoplasmic p27 levels, suggesting that this process is regulated in a kinase-independent fashion. The low nuclear-to-cytoplasmic p27 ratio in CML progenitors is reminiscent of findings in several types of solid cancers, where such ratios are associated with a poor prognosis. Dr. Agarwal proposes that increased cytoplasmic p27 levels contribute to BCR-ABL- mediated leukemogenesis in CML. In support of this, Dr. Agarwal shows that lack of p27 decreases disease latency in a murine CML model, while experimentally reducing cytoplasmic p27 levels with forced nuclear localization of p27 prolongs survival of leukemic mice. These findings are consistent with a tumor suppressor function of nuclear p27 and a concomitant oncogenic function of cytoplasmic p27. These results also suggest that restoring nuclear p27 expression and reducing cytoplasmic expression may counteract BCR-ABL-induced cellular transformation. In total, Dr. Agarwal's preliminary findings have led to a hypothesis in which BCR-ABL disrupts p27 function by simultaneously inhibiting its nuclear tumor suppressor function and promoting its cytoplasmic oncogenic function. This hypothesis will be tested by three carefully designed specific aims that utilize both in vitro and in vivo approaches: 1) Dr. Agarwal will apply molecular and cellular biology tools to determine the mechanisms by which BCR-ABL upregulates cytoplasmic p27. 2) She will dissect the role of nuclear and cytoplasmic p27 for BCR-ABL-driven leukemogenesis using p27 transgenic murine leukemia models. 3) She will delineate the signaling mechanism(s) by which cytoplasmic p27 mediates cellular transformation of human CML cells by testing the effect of cytoplasmic p27 on invasion and survival pathways. Dr. Agarwal's work will lead to an improved understanding of the role of p27 in CML pathogenesis and provide a platform for developing new approaches to treat CML. Since disruption of physiological p27 function is a common theme in human cancers, findings from this study may have implications beyond CML.

职业目标：Agarwal博士的长期目标是阐明白血病发病机制中的新分子机制，以便将这些知识应用于发现新疗法，从而改善临床结果。Agarwal博士的职业目标是建立一个专注于了解癌症发病机制的独立实验室。对于K99独立之路奖，Agarwal博士描述了一个为期五年的培训计划，该计划将使她获得成为一名成功的独立癌症研究人员所需的专业知识。在此期间，她将能够扩大她在癌症生物学方面的知识，获得各种新技术的专业知识，用于她未来的研究，并生成一系列数据作为未来研究和申请校外资助的基础。在K99/R 00获奖期间获得的知识和产生的数据将有助于实现她的长期目标。 工作环境：俄勒冈州健康与科学大学奈特癌症研究所拥有165名主要研究人员，他们在各个领域都有专业知识。Agarwal博士的导师Brain Druker博士是Knight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。他将继续为Agarwal博士提供智力和领导力培训，以便过渡到独立研究员的职业生涯。Agarwal博士聚集了一个优秀的合作者和顾问团队，他们拥有综合的专业知识，就拟议研究的各个方面以及她的职业生涯向她提供建议。此外，骑士癌症研究所的基础设施提供研究培训和热情支持博士后研究员谁是自己准备一个成功的教师职业生涯。Agarwal博士认为，该项目非常适合她在白血病发病机制领域的独立研究生涯。 研究：本研究的目的是确定p27在慢性粒细胞白血病（CML）中失调的机制，并确定p27在CML发病机制中的作用。 CML是由BCR-ABL引起的造血干细胞疾病，BCR-ABL是一种组成型活性酪氨酸激酶，是9;22易位的结果。BCR-ABL的小分子抑制剂伊马替尼治疗早期患者，多数获得持久的疗效，但晚期患者易出现耐药和复发。此外，如果停止治疗，活动性疾病的复发是常见的。因此，鉴定适合于治疗性干预的其他分子靶点可能使我们能够开发旨在克服疾病抗性和根除残留疾病的新治疗策略。早期的研究表明，BCR-ABL通过损害p27（一种肿瘤抑制因子和细胞周期蛋白依赖性激酶的调节因子）的功能，促进不受调节的细胞周期进程和细胞增殖。然而，p27去调控的详细机制仍有待明确定义。 博士Agarwal的初步数据表明，在原代CML细胞中，p27失调涉及细胞核中的下调和细胞质错误定位的增加。虽然核p27似乎是在BCR-ABL激酶活性的控制下，伊马替尼未能降低细胞质p27水平，表明这一过程是以激酶非依赖性方式调节的。CML祖细胞中的低核质p27比率使人想起几种类型的实体癌中的发现，其中这种比率与不良预后相关。Agarwal博士提出，细胞质p27水平增加有助于BCR-ABL介导的CML白血病发生。为了支持这一点，Agarwal博士表明，缺乏p27减少了小鼠CML模型中的疾病潜伏期，同时实验性地降低了细胞质p27水平，强制p27核定位提高了白血病小鼠的存活率。这些发现与细胞核p27的肿瘤抑制功能和细胞质p27的伴随致癌功能一致。这些结果还表明，恢复核p27表达和减少胞质表达可能会抵消BCR-ABL诱导的细胞转化。总的来说，Agarwal博士的初步发现导致了一种假设，即BCR-ABL通过同时抑制其核肿瘤抑制功能和促进其细胞质致癌功能来破坏p27功能。这一假设将通过三个精心设计的具体目标进行测试，这些目标利用体外和体内方法：1）Agarwal博士将应用分子和细胞生物学工具来确定BCR-ABL上调细胞质p27的机制。2)她将使用p27转基因小鼠白血病模型，剖析细胞核和细胞质p27在BCR-ABL驱动的白血病发生中的作用。3)她将通过检测细胞质p27对侵袭和存活途径的影响来描述细胞质p27介导人类CML细胞转化的信号传导机制。Agarwal博士的工作将有助于更好地理解p27在CML发病机制中的作用，并为开发治疗CML的新方法提供平台。由于生理p27功能的破坏是人类癌症中的一个共同主题，因此这项研究的发现可能具有超越CML的意义。