A novel strategy for transcriptional reprogramming of lymphoid leukemia cells

淋巴细胞白血病细胞转录重编程的新策略

• 批准号: 10543999
• 负责人: BRUNO CALABRETTA
• 金额: $ 52.92万
• 依托单位: THOMAS JEFFERSON UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-01-01 至 2026-12-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10543999
• 关键词: Acute Promyelocytic Leukemia; Acute leukemia; Affect; Apoptosis; Arsenic Trioxide; B-Cell Leukemia; B-Lymphocytes; Binding; Biological; Blast Cell; Cancer Biology; Cell Aging; Cell Cycle Inhibition; Cell Death; Cell Differentiation process; Cell Line; Cell Maturation; Cell Reprogramming; Cell Survival; Cells; Chromatin; Chromatin Structure; DNA; DNA Binding; DNA biosynthesis; Data; Differentiation Therapy; EZH2 gene; Epigenetic Process; Exhibits; Failure; Foundations; Gene Targeting; Genes; Genetic Transcription; Genome; Goals; Hematopoietic stem cells; Heterogeneity; Immunodeficient Mouse; Immunophenotyping; Induction of Apoptosis; Knowledge; Laboratories; Leukemic Cell; Ligand Binding; Ligands; Lymphoblastic Leukemia; Lymphoid; Lymphoma cell; Molecular; Mus; Mutate; Mutation; Nature; Nucleic Acid Regulatory Sequences; Nucleosomes; Outcome; Patient-Focused Outcomes; Patients; Physical condensation; Process; Proliferating; Publishing; Repression; Role; Sampling; Solid; Specific qualifier value; Structure; T cell differentiation; T-Cell Leukemia; Testing; Therapeutic Agents; Tretinoin; Work; Xenograft procedure; cancer cell; cancer therapy; clinical application; cytokine; experience; gene repression; genome-wide; histone methyltransferase; in vivo; inhibitor; leukemia; leukemia/lymphoma; mouse model; neoplastic cell; novel; novel strategies; pharmacologic; programs; receptor; self-renewal; small molecule; stem cells; transcription factor; transcriptional reprogramming; treatment strategy

Abstract Lymphoid B-ALL and TCLL leukemia consists of leukemic blast cells (LBCs) arrested at early stages of differentiation which exhibit high proliferative potential and capability for self-renewal. The idea to induce reprogramming of leukemic and other cancer cells, leading to cell maturation and senescence, gained high popularity, but its clinical applications are rarely successful and are mainly limited to the therapy of the APL leukemia with ATRA and arsenic trioxide. This strategy may have been unsuccessful due to a gap in the knowledge of the mechanisms through which transcriptional reprogramming occurs. Our published data suggest that normal hematopoietic progenitor cells (HPCs) undergo transient de-condensation of chromatin to allow lineage-specific transcription factors (TFs) to bind to their gene targets and to activate new transcriptional programs, leading to cell differentiation. This transient de-condensation occurs through very low accumulation of H3K27me3, on DNA just after DNA replication. H3K27me3 is a mark of the most condensed arrays of nucleosomes in the genome and is found at regulatory regions of all repressed genes. Our results suggest that tested cultured and primary lymphoid B-ALL and TCLL cells have lost this inherent ability to ‘open’ nascent chromatin, thus creating a barrier for their transcriptional reprogramming. In this proposal, we will test a new reprogramming strategy, which overcomes these barriers of reprogramming-based therapies and may lead to elimination of leukemic cells. The key feature of this new strategy is the first step, which includes pharmacological inhibition of the H3K27me3 histone methyltransferases (HMTs) EZH1/EZH2, thus creating de- condensed structure of nascent chromatin at regulatory regions of all genes. At the second step, we will use small molecules to activate endogenous inducible TFs, which can then readily bind to their target genes due to the de-condensed structure of nascent chromatin. Tumor cells, including leukemic cells, are commonly known to accumulate mutations in inducible TFs and receptors; thus, screens of small molecule inducers for a variety of TFs/receptors will be performed to determine the best possible inducer for distinct subtypes of B-ALL. Preliminary results suggest that induction by small molecule inducers leads to transcriptional reprogramming of cell lines and primary B-ALL and TCLL cells, changes in their immunophenotype and apoptosis. Moreover, this strategy strongly suppresses lymphoid leukemia burden in mice. The goal of this project is to develop a widely applicable treatment strategy for transcriptional reprogramming and loss of cell viability for many types of lymphoid leukemic cells. To this end, we propose to: 1. Extend and generalize the lymphoid leukemic cells reprogramming approach; 2. Examine the mechanisms and biological outcomes of reprogramming of lymphoid leukemic cells; 3. Examine the effects of our treatment strategy in vivo.

摘要 淋巴样B-ALL和TCLL白血病由白血病原始细胞(LBC)组成，在白血病的早期阶段被阻断 分化表现出较高的增殖潜能和自我更新能力。诱人的想法 白血病和其他癌细胞的重新编程导致细胞成熟和衰老，获得了很高的 但其临床应用很少成功，主要局限于APL的治疗。 白血病伴全反式维甲酸和三氧化二砷。这一战略可能没有成功，因为在 关于转录重编程发生的机制的知识。我们公布的数据 提示正常的造血祖细胞(HPC)经历了染色质的瞬时解缩 允许谱系特异性转录因子(TF)与其基因靶标结合并激活新的转录因子 程序，导致细胞分化。这种瞬时解凝结是通过极低的积累量进行的。 H3K27me3，在DNA复制后的DNA上。H3K27me3是最浓缩的数组的标志 核小体存在于基因组中，存在于所有被抑制基因的调控区。我们的结果表明 经过测试的培养和原代淋巴B-ALL和TCLL细胞已经失去了这种固有的打开新生细胞的能力 染色质，从而为它们的转录重编程创造了障碍。在这个提案中，我们将测试一个新的 重新编程战略，这克服了基于重新编程的疗法的这些障碍，并可能导致 消除白血病细胞。这一新战略的关键特征是第一步，其中包括 H3K27me3组蛋白甲基转移酶(HMTs)EZH1/EZH2的药理抑制作用 所有基因调控区新生染色质的浓缩结构。在第二步，我们将使用 小分子激活内源性可诱导的TF，然后可以容易地结合到他们的目标基因，因为 新生染色质的去凝集结构。肿瘤细胞，包括白血病细胞，是众所周知的 在可诱导的转录因子和受体中积累突变；因此，对各种小分子诱导剂进行筛选 为了确定不同亚型B-ALL的最佳诱导剂，将进行转录因子/受体的评估。 初步结果表明，小分子诱导剂诱导导致转录重编程 细胞系和原代B-ALL和TCLL细胞，其免疫表型和细胞凋亡的变化。此外，这一点 强烈抑制小鼠淋巴细胞性白血病负担的策略。这个项目的目标是开发一个广泛的 转录重编程和多种类型细胞活力丧失的适用治疗策略 淋巴样白血病细胞。为此，我们建议：1.推广和推广淋巴白血病细胞 重新编程的方法；2.研究淋巴系统重新编程的机制和生物学结果 3.在体内检验我们的治疗策略的效果。