MOLECULAR TARGETS OF TRANSLOCATION T(4;14) IN MULTIPLE MYELOMA PATHOGENESIS

多发性骨髓瘤发病机制中 T(4;14) 易位的分子靶点

• 批准号: 9187811
• 负责人: MICHAEL H TOMASSON
• 金额: $ 30.96万
• 依托单位: UNIVERSITY OF IOWA
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-01-01 至 2018-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9187811
• 关键词: 13q; 13q14; Affect; American; Antibodies; B-Cell Development; B-Lymphocytes; Biological Assay; Bone Marrow; Cancer Biology; Cancer Control; Cancer Etiology; Cell Compartmentation; Cell Line; Cells; Cessation of life; Chromosomal translocation; Chromosomes, Human, Pair 13; Complementary DNA; DNA Sequence; Data; Development; Diagnosis; Disease; Etiology; Event; Gene Targeting; Genes; Genetic; Hematologic Neoplasms; Human; Immunodeficient Mouse; Injectable; Knockout Mice; Length; Malignant - descriptor; Malignant Neoplasms; Maps; Measures; Mediating; Messenger RNA; MicroRNAs; Modeling; Molecular Target; Mouse Strains; Multiple Myeloma; Mus; Mutation; Oncogenes; Orphan; Oxidative Stress; Pathogenesis; Patients; Phenotype; Plasma; Protein Binding Domain; RB1 gene; RNA Binding; Reactive Oxygen Species; Resistance; Retinoblastoma; Role; Sampling; Series; Small Nucleolar RNA; Small RNA; Spleen; Structure; Structure of germinal center of lymph node; Testing; Tissues; Transformed Cell Line; Transplantation; United States; Untranslated RNA; WHSC1 gene; cancer type; cell growth; chemotherapy; experimental study; histone methyltransferase; in vivo; insight; knock-down; mutant; non-oncogenic; novel; novel therapeutic intervention; outcome forecast; overexpression; protein expression; public health relevance; recombinase-mediated cassette exchange; small hairpin RNA; transcriptome sequencing; tumor

DESCRIPTION (provided by applicant): Multiple Myeloma (MM) is the second most common hematologic malignancy in the United States, diagnosed in approximately 14,500 Americans each year, and is responsible for 2% of all cancer deaths (SEER.cancer.gov). MM is an incurable malignancy of antibody-secreting plasma B-cells whose etiology is poorly understood. Chromosomal translocation t(4;14)(p16.3;q32.33) is associated with shorter overall survival and is found in 15% of MM patients. The candidate oncogene WHSC1 (MMSET) at 4p16.3 encodes a histone methyltransferase over-expressed as a result of the t(4;14) in MM cells. Surprisingly, over-expression of WHSC1 cDNA's failed to transform cell lines or to induce any phenotype when expressed in mice. We identified ACA11, an orphan box H/ACA small nucleolar RNA (snoRNA) encoded hosted within WHSC1 at 4p16.3, to be up-regulated in cell lines and MM patient samples harboring t(4;14). ACA11 modulates oxidative stress, contributes to MM cell growth and confers resistance to chemotherapy. ACA11 is a novel oncogenic non-coding RNA and is also expressed in other cancer types. Mutations that cooperate with t(4;14) in myeloma initiation are unknown, but chromosome 13 deletions (Del(13)) are highly correlated with the t(4;14) in MM. Del(13) is found in 85-94% of patients with t(4;14) and associated with poor prognosis. We mapped a minimally deleted region in MM patient samples to the retinoblastoma (RB1) gene at 13q14. Our model is that ACA11 expression cooperates with RB1 loss to cause poor-prognosis MM. We propose to characterize the role of ACA11 in multiple myeloma. Specific Aim 1: Cooperation between ACA11 and the histone methyltransferase WHSC1. We hypothesize that ACA11 cooperates with MMSET protein expression in myeloma pathogenesis and that WHSC1 histone methyltransferase activity is required for cooperation. We will co-express wild-type WHSC1 or HMT-dead WHSC1 alone or with ACA11 in cell lines and mice. Specific Aim 2: Aim 2: How does ACA11 affect levels of ROS and sensitivity to chemotherapy? What domains and partners of ACA11 are required for these effects? Our data suggest that ACA11 modulates reactive oxygen species and resistance to chemotherapy in myeloma. We will determine which residues of ACA11 are required for this function. We hypothesize that ACA11 RNA binding residues will be dispensable for ACA11's oxidative stress function, but that ACA11's protein-binding domains will be critical. Specific Aim 3: ACA11-mediated malignant transformation in the context of Rb1 deletion. The long arm of chromosome 13 is deleted in 50% of all MM patients, and in 90% of patients with the t(4;14). We hypothesize that RB1 loss cooperates with the t(4;14) in myeloma pathogenesis. We will test the effects of ACA11 and WHSC1 expression on B-cell development, oxidative stress and transformation in the context of Rb1 deficiency. Lastly, we will [identify target genes of t(4;14) by RNA- sequencing patient samples.] A betting understanding of how the t(4;14) contributes to myelomagenesis has broad implications to cancer biology and will facilitate the development of novel therapeutic approaches to patients with poor-prognosis MM.

描述（由申请人提供）：多发性骨髓瘤（MM）是美国第二大最常见的血液恶性肿瘤，每年约有14,500名美国人被诊断出来，占所有癌症死亡人数的2% （see .cancer.gov）。MM是一种无法治愈的抗体分泌浆b细胞恶性肿瘤，其病因尚不清楚。染色体易位t(4;14)（p16.3;q32.33）与较短的总生存期相关，在15%的MM患者中发现。候选癌基因WHSC1 （MMSET）在4p16.3编码组蛋白甲基转移酶，在MM细胞中由于t（4;14）而过度表达。令人惊讶的是，当在小鼠中表达时，过表达的WHSC1 cDNA不能转化细胞系或诱导任何表型。我们发现了一种名为ACA11的孤儿箱H/ACA小核核RNA (snoRNA)，编码于WHSC1的4p16.3位点，在细胞系和MM患者样本中表达上调（4;14）。ACA11调节氧化应激，促进MM细胞生长并赋予化疗抗性。ACA11是一种新型的致癌非编码RNA，在其他类型的癌症中也有表达。骨髓瘤发生过程中与t（4;14）协同的突变尚不清楚，但13号染色体缺失（Del(13)）与MM中的t（4;14）高度相关。85-94%的t（4;14）患者中存在Del(13)，且与预后不良相关。我们在MM患者样本中定位了视网膜母细胞瘤（RB1）基因13q14的最小缺失区域。我们的模型是ACA11的表达与RB1的缺失共同导致预后不良的MM。我们建议描述ACA11在多发性骨髓瘤中的作用。具体目标1:ACA11与组蛋白甲基转移酶WHSC1的合作。我们假设ACA11在骨髓瘤发病过程中与MMSET蛋白表达合作，WHSC1组蛋白甲基转移酶活性是合作所必需的。我们将野生型WHSC1或hmt死亡WHSC1单独或与ACA11在细胞系和小鼠中共表达。特异性目的2：目的2:ACA11如何影响ROS水平和化疗敏感性？这些作用需要ACA11的哪些结构域和伙伴？我们的数据表明，ACA11调节骨髓瘤中的活性氧和对化疗的耐药性。我们将确定ACA11的哪些残基是这个功能所必需的。我们假设ACA11的RNA结合残基对于ACA11的氧化应激功能是必不可少的，但ACA11的蛋白质结合结构域将是关键的。特异性目标3：在Rb1缺失的背景下aca11介导的恶性转化。50%的MM患者13号染色体长臂缺失，90%的t患者13号染色体长臂缺失（4;14）。我们假设RB1缺失在骨髓瘤发病过程中与t（4;14）协同作用。我们将测试在Rb1缺乏的情况下ACA11和WHSC1表达对b细胞发育、氧化应激和转化的影响。最后，我们将通过患者样本的RNA测序来鉴定t（4;14）的靶基因。对t（4;14）如何促进骨髓瘤形成的正确理解对癌症生物学具有广泛的意义，并将促进对预后不良MM患者的新治疗方法的开发。