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

项目摘要/摘要 职业目标：阿加瓦尔博士的长期目标是阐明白血病的新分子机制 发病机制使这些知识可以应用于发现新的治疗方法，从而改进 临床结果。阿加瓦尔博士的职业目标是建立一个独立的实验室，专注于 了解癌症的发病机制。对于K99独立之路奖，阿加瓦尔博士描述了 为期五年的培训计划将使她获得成为一名成功人士所需的专业知识 独立癌症研究人员。在这个奖项期间，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，以便在她未来的研究中使用，并产生 数据作为今后研究和申请外部资金的基础。获取的知识和数据 在K99/R00奖项期间制作的作品将有助于实现她的长期目标。 环境：俄勒冈健康与科学大学奈特癌症研究所有165名初级教员 拥有不同领域专业知识的调查人员。Agarwal博士的导师Brain Druker博士是 奈特癌症研究所所长。德鲁克博士在癌症领域有20多年的经验。 研究，并指导了许多学生和研究员成为独立调查员。他将继续 为Agarwal博士提供智力和领导力培训，以过渡到独立的职业生涯 研究员。Agarwal博士已经召集了一支优秀的合作者和顾问团队， 就拟议研究的所有方面以及她的职业生涯向她提供专业意见。此外，《骑士》 癌症研究所的基础设施为博士后研究员提供研究培训和热情支持 他们正在为成功的教职生涯做准备。阿加瓦尔博士认为，拟议的项目是 非常适合在白血病发病机制领域开展独立的研究生涯。 研究：拟议研究的目标是确定p27去调控在慢性阻塞性肺疾病中的作用机制。 并探讨p27在CML发病机制中的作用。 慢性粒细胞白血病是一种由bcr-abl引起的造血干细胞疾病，bcr-abl是一种具有结构性活性的酪氨酸激酶， 是9；22易位的结果。大多数早期疾病患者在 用bcr-abl小分子抑制剂伊马替尼治疗。然而，在疾病的晚期， 耐药性和复发是经常发生的。此外，如果接受治疗，活动性疾病的复发是常见的。 停下来了。因此，识别更多适合于治疗干预的分子靶点可能会 美国将开发新的治疗策略，旨在克服疾病抗药性并根除残留 疾病。早期研究表明，bcr-abl促进未受调控的细胞周期进程和细胞 P27是一种肿瘤抑制因子，也是一种细胞周期蛋白依赖性激酶的调节因子，它通过破坏p27的功能实现细胞增殖。 然而，p27去调控的具体机制仍有待明确。 Agarwal博士的初步数据表明，在原代CML细胞中，p27的解除调控涉及到 核内表达下调，细胞质错位增加。而核p27似乎是 在bcr-abl激酶活性的控制下，伊马替尼不能降低胞浆p27水平，提示 这一过程是以一种不依赖于激酶的方式调节的。慢性粒细胞白血病p27核浆比低 先驱者让人想起在几种类型的实体癌症中的发现，在这些癌症中，这样的比例与 预后不良。Agarwal博士提出，细胞质p27水平的增加有助于bcr-abl介导的 慢性粒细胞白血病的白血病发生。为了支持这一点，阿加瓦尔博士表明，缺乏p27可以缩短疾病潜伏期。 小鼠慢性粒细胞白血病模型，同时通过强制p27核定位实验降低胞浆p27水平 延长白血病小鼠的存活时间。这些发现与核的肿瘤抑制功能相一致。 P27和伴随的细胞质p27的致癌功能。这些结果还表明，恢复 核内p27表达和胞浆表达减少可能对抗bcr-abl诱导的细胞 转型。总而言之，阿加瓦尔博士的初步发现导致了一种假说，即BCR-ABL干扰 P27通过抑制其核肿瘤抑制功能和促进其胞浆功能发挥作用 致癌作用。这一假设将通过三个精心设计的具体目标来检验，这三个目标利用了 体外和体内方法：1)阿加瓦尔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)她将剖析核能和核电的作用 P27转基因小鼠白血病模型用于bcr-abl驱动的白血病发生的细胞质p27。3)她 将阐明细胞质p27介导人类细胞转化的信号机制(S) 通过检测细胞质p27对慢性粒细胞白血病细胞侵袭和存活途径的影响。阿加瓦尔博士的工作将 加深对p27在慢性粒细胞白血病发病机制中作用的理解，并为 开发治疗慢性粒细胞白血病的新方法。由于生理p27功能中断是 对于人类癌症，这项研究的发现可能具有超越慢性粒细胞白血病的影响。

PROJECT SUMMARY/ABSTRACT 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.