Oncogenic Disruption of Circadian Rhythm and Chronotherapy

项目摘要 长期目标：该提案的第一个目标是将Myc确定为昼夜节律的破坏者 癌症的节律，并探讨这一发现对肿瘤细胞生长和新的 治疗方法。第二个目标是在Chi Dang博士的指导下培养Brian Altman博士 在宾夕法尼亚大学。布莱恩将接受癌症代谢和昼夜节律领域的培训 通过获得新的研究技能，演讲，与实验室同事和教授讨论，研讨会 关于负责任的研究行为、教学经验、出席会议和准备 手稿这些将准备布赖恩过渡到职业生涯作为一个独立的学术研究者。 背景：哺乳动物的昼夜节律是由一系列分子调控的24小时周期， 反馈回路虽然许多癌症扰乱了昼夜节律，但目前还没有分子基础 以确定哪些癌症改变或缺乏节律，以及昼夜节律紊乱的影响， 对癌细胞生长和存活的影响尚不清楚。将致癌基因鉴定为与 昼夜节律的破坏将大大有助于开发未来的战略，以针对这些癌症， 时间疗法或定时施用癌症治疗以增加有效性并降低毒性。Myc 是一种致癌转录因子，在多种血癌和实体瘤中易位或扩增。 我们已经证明，Myc通过与癌细胞培养物中的 与昼夜节律相关蛋白使用相同的启动子并改变昼夜节律基因表达。所以我们 假设癌症中的昼夜节律被Myc的致癌性过表达破坏， 破坏为细胞提供了特定的生长优势，我们可以利用这一途径， 通过特异性靶向细胞凋亡途径以慢性方式治疗癌症。 具体目的/研究设计：（1）确定Myc过表达对昼夜节律的影响 对小鼠(2)研究新型Myc靶点Rev-erb？对肿瘤细胞和异种移植物生长的作用。(3)研究 凋亡基因振荡的重要性和细胞凋亡靶向凋亡途径， 昼夜节律依赖的方式。为了实现这些目标，昼夜节律基因表达和振荡将是 在Myc驱动的肝癌小鼠模型中测量，与正常肝组织相比， 发光昼夜节律监测接下来，我将使用代表至少三种癌症的细胞系 作为异种移植物，通过观察细胞/肿瘤来研究上调的Rev-erb？在Myc驱动的癌症中的作用。 生长，基因表达的改变，以及Rev-erb？控制的特定代谢途径。最后要 在肿瘤细胞系和小鼠中使用遗传和蛋白质分析研究凋亡途径的振荡 肿瘤以及功能敏感性测定，以帮助我确定如何最好地利用Myc破坏， 基于对细胞凋亡的振荡敏感性的昼夜节律到对肿瘤的时间特异性治疗。

Project Summary Long Term Goals: The first objective of this proposal is to identify Myc as a disrupter of circadian rhythm in cancer and explore the implications of this finding for tumor cell growth and the development of new therapy approaches. The second objective is to train Brian Altman, PhD under the mentorship of Dr. Chi Dang at the University of Pennsylvania. Brian will be trained in the fields of cancer metabolism and circadian rhythm through acquisition of new research skills, presentations, discussions with labmates and professors, seminars on responsible research conduct, teaching experience, attendance at conferences, and preparation of manuscripts. These will prepare Brian to transition to a career as an independent academic investigator. Background: Circadian rhythms in mammals are 24 hour cycles regulated by a series of molecular feedback loops. While many cancers have disrupted circadian rhythms, there is currently no molecular basis to identify which cancers have altered or absent rhythms, and the implications of disrupted circadian rhythm on cancer cell growth and survival are not well understood. Identifying an oncogene as being associated with circadian disruption would greatly aid in developing future strategies to target these cancers with chronotherapy, or timed administration of cancer treatment to increase effectiveness and reduce toxicity. Myc is an oncogenic transcription factor translocated or amplified in a variety of blood cancers and solid tumors. We have already shown that Myc specifically disrupts circadian rhythm in cancer cell cultures by binding to the same promoters used by circadian-associated proteins and altering circadian gene expression. Therefore, we hypothesize that circadian rhythms in cancers are disrupted by oncogenic overexpression of Myc, that this disruption provides a specific growth advantage to cells, and that we can take advantage of this pathway to treat cancers in a chronotherapeutic manner by specifically targeting the apoptotic pathway. Specific Aims / Study Design: (1) To determine the effect of Myc overexpression on circadian rhythm in mice. (2) To study the role the novel Myc target Rev-erb¿ on tumor cell and xenograft growth. (3) To study the importance of oscillation of apoptotic genes and pharmacologically target the apoptotic pathway in a circadian-dependent manner. To carry out these aims, circadian gene expression and oscillation will be measured in a Myc-driven mouse model of liver cancer compared to normal liver tissue by real-time luminescent circadian monitoring. Next, I will use cell lines representing at least three kinds of cancer as well as xenografts to study the role of upregulated Rev-erb¿ in Myc driven cancers by looking at cell / tumor growth, alterations in gene expression, and specific metabolic pathways that Rev-erb¿ controls. Finally, I will study oscillation of the apoptotic pathway using genetic and protein analysis in tumor cell lines and mouse tumors as well as a functional sensitivity assay to help me determine how we can best use Myc-disruption of circadian rhythm to time specific therapy to tumors based on oscillating sensitivity to apoptosis.