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.

抽象的 淋巴细胞 B-ALL 和 TCLL 白血病由在早期阶段停滞的白血病母细胞 (LBC) 组成。 具有高度增殖潜力和自我更新能力的分化。诱导的想法 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 流行，但其临床应用很少成功，主要局限于 APL 的治疗 白血病与 ATRA 和三氧化二砷。这一策略可能因资金缺口而失败。 了解转录重编程发生的机制。我们公布的数据 表明正常造血祖细胞（HPC）会经历染色质的短暂去浓缩 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。这种短暂的解凝结是通过非常低的积累发生的 DNA复制后DNA上的H3K27me3。 H3K27me3 是最密集阵列的标志 基因组中的核小体，存在于所有受抑制基因的调控区域。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“打开”新生细胞的固有能力 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 重编程策略，克服了基于重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点是第一步，其中包括 H3K27me3 组蛋白甲基转移酶 (HMT) EZH1/EZH2 的药理学抑制，从而产生去- 所有基因调控区域新生染色质的浓缩结构。在第二步中，我们将使用 小分子来激活内源诱导型转录因子，然后它可以很容易地结合到它们的靶基因上，因为 新生染色质的解压缩结构。肿瘤细胞，包括白血病细胞，是众所周知的 在诱导型转录因子和受体中积累突变；因此，筛选各种小分子诱导剂 将进行 TF/受体的分析以确定 B-ALL 不同亚型的最佳诱导剂。 初步结果表明，小分子诱导剂的诱导导致转录重编程 细胞系和原代 B-ALL 和 TCLL 细胞，其免疫表型和凋亡的变化。而且，这 该策略强烈抑制小鼠的淋巴白血病负担。该项目的目标是开发一个广泛的 适用于多种类型的转录重编程和细胞活力丧失的治疗策略 淋巴细胞白血病细胞。为此，我们建议： 1. 淋巴白血病细胞的延伸和推广 重新编程方法； 2. 检查淋巴重编程的机制和生物学结果 白血病细胞； 3. 检查我们的治疗策略在体内的效果。