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: 8120884
• 负责人: MICHELLE M LE BEAU
• 金额: $ 32.63万
• 依托单位: UNIVERSITY OF CHICAGO
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/8120884
• 关键词: 5q31; 7q22; A Mouse; 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; 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.

与治疗相关的骨髓增生综合征（T-MDS）和急性髓细胞性白血病（T-AML）迟到 恶性和非恶性疾病的细胞毒性疗法并发症。特征重复 染色体5和/或7的异常在T-MDS/T-AML中经常注意到。在芝加哥大学 一组306例T-MDS/T-AML患者，我们观察到214例（70％）患者的5q或7q损失。在 先前的研究，我们定义了一个970 KB，通常在5q31内置于D5S479的5q31之内 和D5S500。在随后的研究中，我们生成了该CD的完整成绩单图，并确定了 并克隆了20个基因。我们对5Q CD中所有候选基因的突变分析尚未揭示 其余等位基因的灭活突变，也没有通过DMA转录沉默的证据 甲基化，与单倍不足模型兼容的观测值。通过使用鼠标，我们 已经确定EGR1是5Q CD的候选肿瘤抑制基因（TSG） 单倍不足，并与烷基化剂诱导的突变合作诱导髓样白血病。 此外，编码转录因子的EGR1参与了鼠应力红细胞生成。 我们假设5q31包含一个或多个通过单倍弥补作用的髓样TSG。在AIM 1中， 我们将通过鉴定EGR1在造血和白血病中的作用，通过鉴定 与EGR1合作在髓样疾病发病机理中的突变，并询问人类T- 鉴定基因突变的AML。在AIM 2中，我们将评估是否丢失多个基因 5Q的CD通过产生有条件的和种系小鼠，在白血病中起作用 与CD的区域同步，我们将使用杂合和纯合删除的小鼠与 识别CD中的候选基因，以及与缺失合作的其他基因 白血病。在AIM 3中，我们将完善7q22的最小CD，并定义额外的删除段 通过使用细胞遗传学映射技术和拷贝数变化的分子分析以检查7q 删除或易位7Q的白血病（与项目2和4的合作）。 从5Q和7Q的CDSS鉴定髓样白血病基因代表高实验 由于这些异常的高频率而引起的优先级，而与这些异常相关的结果很差 异常，以及识别有T-AML发展风险的个体的后果， 并选择适当治疗原发性恶性疾病的疗法。最后， 了解编码蛋白质的生化功能可能会提供对髓鞘的见解和 白血病转变，最终可能导致理性的新疗法发展。