Clonal dynamics and chemoresistance mechanisms of minimal residual disease in acute leukemia

项目摘要。 急性白血病是侵袭性的血液肿瘤，是儿童和儿童最常见的恶性肿瘤 青少年。尽管治愈率在过去50年里稳步提高，因为 强化化疗方案，今天20%的儿童急性淋巴细胞白血病(ALL)患者将 复发或发展成顽固性疾病。此外，急性髓系白血病(AML)的治疗结果是 治愈率在65%-70%之间，情况更糟。尽管在表征方面取得了很大的进展 白血病的遗传和分子基础，介导耐药和疾病进展的特定机制 复发在很大程度上仍是未知的。因此，基因组图谱分析表明，显著的基因 复发率的异质性与复杂的联合化疗方案一起使用 治疗，使得很难直接确定大多数复发相关突变在耐药中的确切作用。 我的中心假设是控制自我更新的基因突变、信号和表观遗传机制， 对压力和阻力的反应集中在推动收购的有限数量的主监管者身上 耐药的持久性表型在最小的残留疾病和最终复发。这样做的目的是 建议确定缓解和复发相关的转录和表观遗传学的具体作用 调节剂作为儿童急性白血病耐药持续表型和化疗耐药的驱动因素 白血病。这些研究将对我们理解有助于治疗的机制产生影响 失败，并将促进旨在根除高风险最小残留的治疗的基本原理设计 疾病和预防白血病复发。为此，我提出以下具体目标：目标1 (指导阶段)：通过单细胞突变图谱询问微小残留病的影响 所有复发的成分和克隆动力学；目标2(指导/独立阶段)：识别和靶向 单细胞转录和表观遗传状态的主要调节者推动所有持续性、疾病进展 和目标3(独立阶段)：绘制和确定遗传、转录和表观遗传驱动因素的目标 儿童急性髓系白血病微小残留病和白血病复发的风险。为了解决这些问题，我将使用 诊断-缓解-复发相合的白血病原发样本和白血病异种移植 单细胞基因组学、转录组学和表观基因组学在功能上表征融合机制 驱使残留病、耐药性和复发率降至最低。这些分析将为Master的功能测试提供信息 调节和指导单细胞反向遗传CRISPR筛查以确定特定基因作为驱动因素的作用 化疗耐药和复发。这些结果最终将有助于合理设计改进的治疗方法 对这种毁灭性的儿童疾病的治疗。

Project Summary. Acute leukemias are aggressive hematological tumors and the most common malignancy in children and adolescents. Though cure rates have steadily improved over the last 50 years with the implementation of intensive chemotherapy regimens, today 20% of pediatric acute lymphoblastic leukemia (ALL) patients will relapse or develop refractory disease. Moreover, therapeutic outcomes in acute myeloid leukemia (AML) are significantly worse with cure rates in the range of 65-70%. Despite much progress in the characterization of the genetic and molecular basis of leukemia, the specific mechanisms mediating resistance, disease progression and relapse remain largely unknown. Thus, genomic profiling analyses have shown marked genetic heterogeneity at relapse which together with the complex combination chemotherapy protocols used in treatment, make it difficult to directly assign precise roles in resistance for most of relapse-associated mutations. My central hypothesis is that genetic mutations, signaling and epigenetic mechanisms controlling self-renewal, response to stress and resistance converge on a restricted number of master regulators that drive the acquisition of a drug-tolerant persistent phenotype at minimal residual disease and ultimately relapse. The objective of this proposal is to establish the specific role of remission- and relapse-associated transcriptional and epigenetic regulators as drivers of drug-tolerant persistent phenotypes and chemotherapy resistance across pediatric acute leukemias. These studies will be impactful to our understanding of the mechanisms conducive to therapeutic failure and will facilitate the rationale design of therapies directed to the eradication of high-risk minimal residual disease and the prevention of leukemia relapse. Towards this goal I propose the following specific aims: Aim 1 (mentored phase): To interrogate by single cell mutational profiling the impact of minimal residual disease composition and clonal dynamics in ALL relapse; Aim 2 (mentored/independent phase): To identify and target master regulators of single cell transcriptional and epigenetic states driving ALL persistence, disease progression and relapse; and Aim 3 (independent phase): To map and target genetic, transcriptional and epigenetic drivers of minimal residual disease and leukemia relapse in pediatric AML. To address these questions, I will use diagnostic-remission-relapse matched leukemia primary samples and leukemia xenografts, combined with single-cell genomics, transcriptomics and epigenomics to functionally characterize convergent mechanisms driving minimal residual disease, resistance and relapse. These analyses will inform functional testing of master regulators and direct single-cell reverse genetic CRISPR screens to define the role of specific genes as drivers of chemoresistance and relapse. These results will ultimately facilitate the rational design of therapies to improve the treatment of this devastating childhood disease.