Molecular Pathology of t-AML

随着治愈率的提高，与治疗相关的急性髓系白血病(t-AML)的发生率持续增加 对于各种各样的癌症都有所改善。不幸的是，t-AML是一种高度侵袭性的疾病，很少见。 可治愈，使用当前治疗方法的中位总存活率不到10%。详细的细胞遗传学 T-AML的分子研究，部分由该计划项目资助，提供了重要的 对这种疾病的潜在分子发病机制的洞察，包括失去长臂或 在大多数患者中，5[-5/del(5q)]和/或7[-7/del(7q)]染色体完全丢失，且频率较高 AML1/RUNX1、Flt3、MLL、NRAS、cKit和P53突变。然而，全额的 负责t-AML发展的协作性病变仍有待确定。我们相信 在分子水平上定义有助于t-的发展的全部改变的补充 AML不仅将提高我们准确诊断这种疾病的能力，而且还应该有助于确定 分子“阿喀琉斯跟腱”，可以针对其开发靶向治疗。的长期目标是 这个项目是为了确定t-AML中发生的基因改变的补充性。这一目标将是 通过两个具体的目标来追求：(1)识别从身体获得的遗传拷贝数改变t- 并阐明其在细胞转化中的作用机制；以及(2)鉴定 在选定的癌症相关基因子集中获得的体细胞获得的序列突变。后者将 包括已知癌症基因和经鉴定具有拷贝数改变或改变的基因 表达配置文件。这些特定的目标将使用高分辨率全基因组的组合来实现 对获得的200多个t-AML样本进行拷贝数分析和靶向重测序 通过患者访问、数据管理、统计分析和组织培养核心(核心A)。 拷贝数分析将使用Affymetrix全基因组人类SNP阵列6.0进行，该阵列 提供&lt；5 kb的分辨率。重要的是，匹配的生殖系样本要么是可用的，要么将是 由每个患者的骨髓基质成纤维细胞或反应性T细胞扩增而产生，使我们能够 最终确定所识别的拷贝数改变是否是从身体上获得的。基因突变 被确定为反复拷贝数改变的目标将使用FISH或基因组来确认 定量聚合酶链式反应，并将进行测序，以确定是否存在任何点突变。被识别的人 然后，通过评估基因对细胞转化的贡献，直接评估基因对细胞转化的贡献 对正常造血干细胞生长分化及其协同能力的影响 已知的致癌病变可诱发白血病。

The frequency of therapy-related acute myeloid leukemia (t-AML) continues to increase as the cure rates for a wide-variety of cancers improves. Unfortunately, t-AML is a highly aggressive disease and is rarely curable, with median overall survival rates using current therapies of less than 10%. Detailed cytogenetic and molecular studies of t-AML, in part supported by this program project grant, have provided important insights into the underlying molecular pathogenesis of this disease including the loss of the long arm or total loss of chromosomes 5 [-5/del(5q)] and/or 7 [-7/del(7q)] in the majority of patients, and the frequent mutation of AML1/RUNX1, FLT3, MLL, NRAS, cKIT, and p53. However, the full complement of cooperating lesions responsible for the development of t-AML remains to be defined. It is our belief that defining at a molecular level the total complement of alterations that contribute to the development of t- AML will not only enhance our ability to accurately diagnosis this disease, but should also help to define the molecular "Achilles heels" against which targeted therapy can be developed. The long-term goal of this project is to identify the complement of genetic alterations that occur in t-AML. This objective will be pursued through two specific aims: (1) To identify somatically acquired genetic copy number alterations t- AML and to elucidate their mechanistic contribution to cellular transformation; and (2) To identify somatically acquired sequence mutations in a selected subset of cancer related genes. The latter will include known cancer genes and genes identified as either having copy number alterations or altered expression profiles. These specific aims will be pursued using a combination of high resolution genomewide copy number analysis and targeted resequencing on a cohort of over 200 t-AML samples obtained through the Patient Access, Data Management, Statistical Analysis, and Tissue Culture Core (Core A). Copy number analysis will be performed using Affymetrix Genome-Wide human SNP Array 6.0, which provides a resolution of <5 kb. Importantly, matched germ line samples are either available or will be generated by expansion of BM stromal fibroblasts or reactive T-cells for every patient, allowing us to definitively determine if an identified copy number change is somatically acquired. Gene mutations that are identified as the targets of recurrent copy number alterations will be confirmed using FISH or genomic quantitative PCR, and will be sequenced to identify the presence of any point mutations. The identified genes will then be directly assessed for their contribution to cellular transformation by evaluating their effect on normal hematopoietic stem cell growth and differentiation, and on their ability to cooperate with known oncogenic lesions to induce leukemia.