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: 10392174
• 负责人: BRUNO CALABRETTA
• 金额: $ 54万
• 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/10392174
• 关键词: Acute Promyelocytic Leukemia; Acute leukemia; Affect; Apoptosis; Arsenic Trioxide; B-Cell Acute Lymphoblastic Leukemia; B-Cell Leukemia; B-Lymphocytes; B-cell precursor acute lymphoblastic leukemia cell; Binding; Biological; Blast Cell; Cancer Biology; Cell Aging; Cell Cycle; Cell Death; Cell Differentiation process; Cell Line; Cell Maturation; 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; Lead; 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; Pharmacology; Physical condensation; Process; Publishing; Role; Sampling; Solid; Structure; T cell differentiation; T-Cell Leukemia; Testing; Therapeutic Agents; Tretinoin; Work; Xenograft procedure; base; cancer cell; cancer therapy; clinical application; cytokine; experience; genome-wide; histone methyltransferase; in vivo; inhibitor; leukemia; leukemia/lymphoma; mouse model; neoplastic cell; novel; novel strategies; 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 淋巴样B-ALL和TCLL白血病由在早期阶段停止的白血病细胞（LBC）组成 差异化暴露了自我更新的高增殖潜力和能力。影响的想法 重新编程白血病和其他癌细胞，导致细胞的成熟和感受，升高 受欢迎程度，但其临床应用很少成功，主要仅限于APL的治疗 白血病和ATRA和砷三氧化物。由于存在差距，此策略可能没有成功 了解转录重编程的机制。我们已发布的数据 表明正常的造血祖细胞（HPC）经历染色质的短暂性去向 允许谱系特异性转录因子（TFS）与其基因靶标结合并激活新的转录 程序，导致细胞分化。这种短暂的去向敏通过非常低的积累发生 在DNA复制后，在DNA上的H3K27me3。 H3K27me3是最凝结阵列的标志 基因组中的核小组，在所有反射基因的调节区域中都发现。我们的结果表明 经过测试的培养和原代淋巴样B-ALL和TCLL细胞失去了这种“开放”新生的遗传性 染色质，从而为其转录重编程产生障碍。在此提案中，我们将测试一个新的 重编程策略，它克服了这些基于重编程的疗法的障碍，并可能导致 消除白血病细胞。该新策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 在所有基因的调节区域的新生染色质的凝结结构。在第二步，我们将使用 小分子激活内源性诱导型TF，然后由于其易于结合其靶基因 新生染色质的脱凝结结构。包括白血病细胞在内的肿瘤细胞是众所周知的 在诱导的TF和接收器中积累突变；因此，小分子诱导剂的筛选 将执行TF/受体的of，以确定B-all的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 细胞系和原发性B-ALL和TCLL细胞，其免疫表型和凋亡的变化。而且，这 策略强烈抑制小鼠中的淋巴性白血病。该项目的目的是开发一个广泛的 适用的治疗策略，用于转录重编程和许多类型的细胞活力丧失 淋巴白血病细胞。为此，我们提出：1。扩展和推广淋巴白血病细胞 重编程方法； 2。检查淋巴样重编程的机制和生物学结果 白血病细胞； 3。检查体内治疗策略的影响。