Cooperating genes in inv (16) acute myeloid leukemia

描述(申请人提供)：Cbfb-MYH11融合癌基因常见于急性髓系白血病(AML)。我们的长期目标是阐明决定Cbfb-MYH11介导的白血病进展的分子机制，以便为改进治疗方案的设计提供靶点。我们的一般假设是Cbfb-MYH11的表达减少了造血干细胞的分化和增殖，而协同突变会影响与增殖和生存相关的程序。我们已经确定Cbfb-MYH11与其他突变协同诱发AML。我们已经建立了一个有条件的小鼠模型，表明融合基因的表达降低了造血祖细胞的分化和增殖能力，并在髓系中创造了白血病前体细胞。此外，我们还鉴定了协同基因，如转录因子Plag1和PlagL2以及microRNA簇miR17-92，结果表明转录因子PlagL2的组成性表达在Cbfb-MYH11存在的情况下扩增了髓系祖细胞并诱导了AML。基于这些发现，本研究的具体目的是：(1)确定PlagL2在造血祖细胞增殖和自我更新中的作用。我们将使用竞争性再繁殖和系列移植试验来评估(A)PlagL2缺失和(B)结构性PlagL2表达在长期造血干细胞中的影响。(2)明确PlagL2在白血病进展中的作用机制。初步实验表明，PlagL2可诱导MPL/JAK2和转化生长因子-β信号传导。我们将结合体内和生化分析来确定PlagL2在(A)MPL/JAK2和(B)转化生长因子-β途径中作用的分子机制。此外，我们将测试Plag的表达是否对白血病的维持是必要的。(3)探讨microRNAs在CBF-SMMHC介导的急性髓系白血病中的作用。初步的遗传学证据表明，Micro-RNAs与Cbfb-MYH11在白血病进展过程中具有协同作用。我们将使用体内实验来确定microRNA转化的机制。

DESCRIPTION (provided by applicant): The CBFB-MYH11 fusion oncogene is frequently found in acute myeloid leukemia (AML). Our long term goal is to elucidate the molecular mechanisms that determine CBFB-MYH11-mediated leukemia progression in order to provide targets for the design of improved therapies. Our general hypothesis is that CBFB-MYH11 expression reduces hematopoietic stem cell differentiation and proliferation, and that cooperating mutations affect programs associated with proliferation, and survival. We have determined that Cbfb-MYH11 induces AML in cooperation with other mutations. We have created a conditional mouse model to show that expression of the fusion gene reduced the differentiation and proliferation ability of hematopoietic progenitors and created leukemia precursors in the myeloid compartment. Furthermore, we have identified cooperating genes, such as the transcription factors Plag1 and PlagL2 and the microRNA cluster miR17-92, and shown that constitutive expression of the transcription factor PlagL2 expanded myeloid progenitors and induced AML in the presence of Cbfb-MYH11. Based on these findings, the specific aims of this proposal are to: (1) determine PlagL2 role in proliferation and self-renewal of hematopoietic progenitors. We will use competitive repopulation and serial transplantation assays to assess the effect of (a) PlagL2-loss, and (b) constitutive PlagL2 expression, in long term-hematopoietic stem cells. (2) define the mechanism of PlagL2 function in leukemia progression. Preliminary experiments indicated that PlagL2 induces Mpl/Jak2 and TGF-beta signaling. We will combine in vivo and biochemical assays to determine the molecular mechanism of PlagL2 function in the (a) Mpl/Jak2 and (b) TGF-beta pathways. In addition, we will test whether Plag expression is necessary for maintenance of leukemia. (3) determine the role of micro-RNAs in CBF-SMMHC -mediated acute myeloid leukemia. Preliminary genetic evidence indicated that micro-RNAs can cooperate with Cbfb-MYH11 in leukemia progression. We will use in vivo assays to identify the mechanism of microRNA transformation.