Exploring a new therapeutic approach through targeting epigenetic enzymes in ALL

描述（由申请人提供）：拟提供的培训经费将促进首席研究员（PI）的教育和职业目标的改善，并将导致癌症表观遗传学领域的重要发现，旨在增加T细胞白血病的治疗潜力。高达25%的急性淋巴细胞白血病（ALL）患儿在一线治疗失败，其预后令人沮丧，治愈率仅为20%。虽然晚期复发的患者预后较好，但大多数最终死于疾病（总治愈率为40 - 50%）。通常，中枢神经系统（CNS）受累、缓解和再诱导率较低以及进入缓解期的患者早期第二次复发是治疗的重要障碍，而更积极的治疗类型，包括骨髓移植，通常达到耐受性极限，毒性死亡率较高

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.