Exploring a new therapeutic approach through targeting epigenetic enzymes in ALL

描述(由申请人提供)：拟议的培训补助金将有助于改善首席研究员(PI)的教育和职业目标，并将导致癌症表观遗传学领域的重要发现，旨在提高T细胞白血病的治疗潜力。高达25%的儿童急性淋巴细胞白血病(ALL)一线治疗失败，他们的预后很差，治愈率只有20%。虽然后来复发的患者预后较好，但大多数人最终死于这种疾病(总体治愈率为40%至50%)。通常情况下，中枢神经系统受累、较低的缓解率和再诱导率以及进入缓解期的早期二次复发是治疗的重要障碍，而更激进的治疗类型，包括骨髓移植，一般达到耐受极限，中毒死亡率高。 从3%到19%不等。此外，T细胞急性淋巴细胞白血病(T-ALL)中Notch通路的直接抑制(T-ALL)也受到胃肠道毒性的困扰。这一建议的假设是，表观遗传药物可以用作急性淋巴细胞白血病的靶向治疗，特别是在经典化疗和/或放射治疗失败的情况下。利用小鼠模型和原代人类样本，我们最近在T-ALL中发现了多梳抑制复合体2(PRC2)成员的失活遗传改变，并揭示了抑制标记组蛋白3赖氨酸27(H3K27me3)的水平在白血病发生中的重要性。我们还产生了关于两个H3K27me3去甲基酶JUMONJI D3(JMJD3或KDM6B)和UTX(或KDM6A)在同一疾病中显著但相反的作用的强有力的数据。JMJD3是致癌过程的促进剂，而UTX是肿瘤抑制因子，尽管它们执行相同的酶作用。使用一种特定的化学抑制剂，我们能够杀死T细胞白血病， 髓系白血病和生理细胞。此外，我们还发现代谢基因家族琥珀酸脱氢酶(SDH)是UTX的转录靶点。由于这些基因已被证明在内分泌源性肿瘤中发挥肿瘤抑制作用，我们根据强有力的初步结果推测，UTX的部分作用是通过SDH家族过滤的。在这项建议的K99阶段，我们的目标是：1)识别和表征白血病中包含NOTCH1和JMJD3的致癌拓扑域(TD)；2)将特定的TD与疾病进展(预后模型)相关联；3)确定UTX的相互作用伙伴；4)了解SDH在T细胞白血病中的分子和生理作用；以及5)对两种模拟人类疾病中UTX突变的动物(小鼠)进行基本的表型分析。在这个项目的K99阶段的执行过程中，PI将学习染色体构象捕获技术、荧光原位杂交(FISH)和基本代谢分析的技术技能，他还将提高他在基本生物信息学(高通量数据)分析方面的知识。在R00阶段，候选人将使用K99阶段产生的技能和工具，在诊断/复发疾病的样本中使用GSKJ4抑制剂来对抗去甲基酶，并将变化与样本中的表达和表型变化相关联，作为模型交互的原则证明。此外，PI将通过对所产生的小鼠模型的遗传、代谢、生化和表观遗传学研究，全面分析UTX的肿瘤抑制作用。综上所述，我们将建立染色质模型来测试当前的药物，并从角度出发探索代谢途径，以了解癌症代谢和表观遗传学之间的联系，并在未来发现新的治疗靶点。我们相信这些发现也可以应用于其他类型的癌症，因为我们探索的机制是普遍存在的。PI召集了一个由经验丰富的合作者和他的导师组成的广泛小组。这项计划还包括与他的顾问委员会成员的定期会议、生物信息学课程、网络、拨款申请和负责任的研究行为，以及关于上述学科(肿瘤新陈代谢、癌症基因模型)的会议，因此他传达了自己的想法并建立了合作关系。总体而言，K99奖项加上导师和合作者的经验以及纽约大学朗格尼医学中心的先进环境，将为PI提供创新工具，继续他在白血病表观遗传学和新陈代谢之间的相互作用的独立职业生涯。

DESCRIPTION (provided by applicant): The proposed training grant will facilitate the improvement of the education and career goals of the principal investigator (PI) as well as will lead to important findings in the field of cancer epigenetics with the aim to increase the therapeutic potential in T cell leukemia. Up to 25% of children with acute lymphoblastic leukemia (ALL) will fail frontline therapy and their prognosis is dismal with only 20% cure rate. Although prognosis is better for patients with later relapses, the majority eventually succumbs to the disease (overall cure rate 40 to 50%). Usually, central nervous system (CNS) involvement, lower remission and re-induction rates and early second relapse for those who enter remission are important obstacles in the way to treatment whereas more aggressive types of therapy, including bone marrow transplantation, reached tolerability limits with toxic death rates generally ranging from 3-19%. Also direct inhibition of Notch pathway in T cell ALL (T-ALL) has been plagued by gastrointestinal toxicity. The hypothesis of this proposal is that epigenetic drugs can be used as a targeted therapy against acute lymphoblastic leukemia, especially when classic chemotherapy and/or irradiation have failed. Using mouse models and primary human samples, we recently identified inactivating genetic alterations of members of the polycomb repressive complex 2 (PRC2) in T-ALL and revealed the importance of the levels of the repressive mark trimethylation of histone 3 lysine 27 (H3K27me3) in leukemogenesis. We have also generated strong data on the prominent but contrasting roles of two H3K27me3 demethylases JUMONJI D3 (JMJD3 or KDM6B) and UTX (or KDM6A) in the same disease. JMJD3 is a facilitator of the oncogenic process whereas UTX is a tumor suppressor although they execute the same enzymatic action. Using a specific chemical inhibitor we were able to kill T cell leukemia, sparing myeloid leukemia and physiological cells. Moreover we have identified that the family of metabolic genes succinate dehydrogenase (SDH) is transcriptional target of UTX. As these genes have been shown to play tumor suppressor roles in tumors of endocrine origin, we hypothesize, based on strong preliminary results, that a part of UTX action is filtered through SDH family. In the K99 phase of this proposal we aim to: 1) Identify and characterize the oncogenic topological domains (TD) containing NOTCH1 and JMJD3 in leukemia, 2) associate specific TD with disease progression (prognostic model), 3) identify interacting partners for UTX, 4) understand the molecular and physiological roles of SDH in T cell leukemia and 5) to generate and perform basic phenotypic analysis of two animals (mice) modeling mutations of UTX in human disease. During the execution of the K99 phase of this project, the PI will acquire technical skills on chromosome conformation capture techniques, fluorescent In situ hybridization (FISH) and basic metabolic analysis and he will also improve his knowledge on basic bioinformatics (high-throughput data) analysis. In the R00 phase, the candidate will use the skills and tools produced during the K99 phase, use the GSKJ4 inhibitor against demethylases in samples from diagnosis/relapse disease and associate changes with expression and phenotypic changes in the sample as a proof-of-principle for the model interactions. Moreover the PI will fully analyze the tumor suppressor role of UTX through genetic, metabolic, biochemical and epigenetic studies of the generated mouse models. In summary we will set up chromatin models for testing of current drugs and explore metabolic pathways with the perspective to understand the connection between metabolism and epigenetics in cancer and discover new therapeutic targets in the future. We believe that these findings can be applied to other types of cancer, as the mechanisms we explore are universal. The PI has brought together an extensive panel of experienced collaborators and his mentor. This plan includes also regular meetings with members of his advisory board, courses on bioinformatics, networking, grant writing and responsible conduct of research as well as conferences on the aforementioned disciplines (tumor metabolism, genetic models of cancer) so he conveys his ideas and set up collaborations. Overall, the K99 award together with the mentor's and collaborator's experience and the advanced environment of Langone Medical Center at New York University will provide the PI with innovative tools to continue his independent career on the crosstalk between epigenetics and metabolism in leukemia.