Characterization of Myeloid Tumor Suppressor Genes on Chromosome 5

5 号染色体上的骨髓肿瘤抑制基因的特征

• 批准号: 8319536
• 负责人: MICHELLE M LE BEAU
• 金额: $ 31.22万
• 依托单位: UNIVERSITY OF CHICAGO
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-09-01 至 2013-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8319536
• 关键词: 5q31; 7q22; A Mouse; Acute Myelocytic Leukemia; Alkylating Agents; Alleles; Biochemical; Bone Marrow Cells; Candidate Disease Gene; Cells; Characteristics; Chicago; Chromosomes, Human, Pair 5; Chromosomes, Human, Pair 7; Collaborations; Cytogenetic Map; Cytotoxic Chemotherapy; DNA Sequence Rearrangement; Development; Disease; Dysmyelopoietic Syndromes; Engineering; Equilibrium; Erythropoiesis; Etiology; Frequencies; Gene Mutation; Genes; Genomics; Hematopoiesis; Hematopoietic; Human; Individual; Induced Mutation; Insertional Mutagenesis; Lead; Libraries; Malignant - descriptor; Maps; Methylation; Modeling; Molecular Analysis; Molecular Profiling; Mus; Mutation; Mutation Analysis; Myelogenous; Myeloid Leukemia; Myelopoiesis; Myeloproliferative disease; Non-Malignant; Outcome; Pathogenesis; Pathway interactions; Patients; Play; Proteins; Representational Oligonucleotide Microarray Analysis; Retroviridae; Risk; Role; Series; Small Interfering RNA; Stress; Suppressor Genes; Techniques; Therapy-Related Acute Myeloid Leukemia and Myelodysplastic Syndrome; Transcript; Tumor Suppressor Genes; Unbalanced Translocation; Universities; chromosome 5q loss; insight; leukemia; leukemogenesis; loss of function; mouse model; novel therapeutics; transcription factor

Therapy-related myelodysplastic syndrome (t-MDS) and acute myeloid leukemia (t-AML) are late complications of cytotoxic therapy of both malignant and non-malignant diseases. Characteristic recurring abnormalities of chromosomes 5 and/or 7 are frequently noted in t-MDS/t-AML. In the University of Chicago series of 306 patients with t-MDS/t-AML, we observed loss of 5q or 7q in 214 (70%) patients examined. In previous studies, we defined a 970 kb commonly deleted segment (CDS) within 5q31 flanked by D5S479 and D5S500. In subsequent studies, we generated a complete transcript map of this CDS, and identified and cloned 20 genes. Our mutation analysis of all candidate genes within the CDS of 5q has not revealed inactivating mutations in the remaining alleles, nor is there evidence of transcriptional silencing via DMA methylation, observations that are compatible with a haploinsufficiency model. By using mouse models, we have determined that EGR1, a candidate tumor suppressor gene (TSG) within the CDS of 5q, acts by haploinsufficiency and cooperates with mutations induced by alkylating agents to induce myeloid leukemias. Moreover, EGR1, which encodes a transcription factor, is involved in murine stress erythropoiesis. We hypothesize that 5q31 contains one or more myeloid TSGs that act by haploinsufficiency. In Aim 1, we will examine the role of Egr1 in hematopoiesis and leukemogenesis in our mouse model by identifying mutations that cooperate with Egr1 in the pathogenesis of myeloid disorders, and interrogating human t- AMLs for mutations of the genes identified. In Aim 2, we will evaluate whether loss of multiple genes within the CDS of 5q plays a role in leukemogenesis by generating conditional and germline mice with a deletion of the region syntenic to the CDS, and we will use mice with heterozygous and homozygous deletions to identify candidate genes within the CDS, as well as other genes that cooperate with the deletion in leukemogenesis. In Aim 3, we will refine the smallest CDS of 7q22, and define additional deleted segments of 7q by using cytogenetic mapping techniques and molecular analysis of copy number changes to examine leukemias with deletions or translocations of 7q (collaboration with Projects 2 and 4). The identification of myeloid leukemia genes from the CDSs of 5q and 7q represent a high experimental priority due to the high frequency of these abnormalities, and the poor outcome associated with these abnormalities, as well as the ramifications toward identifying individuals at risk for the development of t-AML, and in the selection of the appropriate therapy for treatment of the primary malignant disease. Finally, understanding the biochemical functions of the encoded proteins may provide insights into myelopoiesis and leukemic transformation, and may ultimately lead to the development of rational new therapeutics.

治疗相关性骨髓增生异常综合征（t-MDS）和急性髓性白血病（t-AML）是晚期 恶性和非恶性疾病的细胞毒性治疗的并发症。特征递归 在t-MDS/t-AML中经常注意到染色体5和/或7的异常。在芝加哥大学 在306例t-MDS/t-AML患者中，我们观察到214例（70%）患者的5 q或7 q丢失。在 在前期的研究中，我们在5 q31内定义了一个970 kb的常缺失片段（CDS），其侧翼为D5 S479 D5S500在随后的研究中，我们生成了该CDS的完整转录图谱，并鉴定了 克隆了20个基因我们对5 q CDS内所有候选基因的突变分析没有显示 失活突变的其余等位基因，也没有证据表明转录沉默通过DMA 甲基化，与单倍不足模型相容的观察结果。通过使用小鼠模型，我们 已经确定EGR 1，5 q CDS内的候选肿瘤抑制基因（TSG），通过以下方式起作用： 单倍不足，并与烷化剂诱导的突变协同作用，诱导骨髓性白血病。 此外，编码转录因子的EGR 1参与小鼠应激红细胞生成。 我们假设5 q31包含一个或多个髓系TSG，通过单倍不足发挥作用。在目标1中， 我们将在我们的小鼠模型中检测Egr 1在造血和白血病发生中的作用， 在骨髓疾病的发病机制中与Egr 1合作的突变，并询问人类t- 确定的基因突变的AML。在目标2中，我们将评估是否有多个基因的丢失， 5 q的CDS在白血病发生中起作用，通过产生缺失 该区域同线的CDS，我们将使用小鼠与杂合和纯合缺失， 鉴定CDS内的候选基因，以及与缺失协同作用的其他基因， 白血病发生在目标3中，我们将细化7 q22的最小CDS，并定义额外的删除片段 利用细胞遗传学作图技术和分子生物学分析技术检测7 q的拷贝数变化 白血病与删除或易位的7 q（合作项目2和4）。 从5 q和7 q的CDS中鉴定髓系白血病基因代表了高实验性的 由于这些异常的高频率，以及与这些异常相关的不良结局， 异常，以及对识别有发展t-AML风险的个体的影响， 以及选择适当的治疗方法来治疗原发性恶性疾病。最后， 理解编码蛋白的生化功能可以提供对骨髓生成的了解， 白血病转化，并最终可能导致合理新疗法的开发。