Role of Nuclear Transport in Acute Leukemia

描述（由申请人提供）：候选人是一名医生-科学家 最近被任命为终身助理教授在系 西北大学医学院病理学系。 重点（80） 将是对核运输及其在核运输中的作用的基础研究， 白血病;其余的致力于临床血液病理学和教学。 核孔蛋白（nucleoporin）Nup 98基因是一个常见的靶点， 急性髓性白血病（AML）的染色体重排， 以髓样分化失败为特征。 这些重排 产生嵌合蛋白，其中最好的特征是Nup 98-HOXA 9。 Nup 98嵌合体引起白血病的机制尚不清楚。 核孔蛋白，沿着核转运蛋白（输入蛋白），是这一机制的一部分 的 介导核质转运。 骨髓分化是 由需要核转运的转录因子（TF）调节 到达他们在原子核内的目的地。 在这些TF中，AML 1 和RAR-α在正常骨髓分化和 急性髓细胞白血病 有大量证据表明， AML 1和RAR-α在细胞核内的分布有助于 AML的发病机制。 我们的假设是Nup 98基因重排导致 通过破坏介导AML的转录因子的核输入， 髓样分化 关注Nup 98-HOXA 9对细胞核的影响， AML 1和RAR-α的运输和髓样分化，我们将：（I） 描述Nup 98和核转运蛋白在AML 1核输入中的作用， RAR-α (ii)通过以下方式确定Nup 98-HOXA 9是否会破坏该过程： 监测AML 1和RAR的核输入、定位和活性， 在用诱导型Nup 98-H 0XA 9构建体稳定转染的细胞中检测α。 我们的假设预测AML 1和RAR-α的核输入减少和/或 改变其核内分布和转录活性 在Nup 98-HOXA 9的诱导下。 (iii)确定Nup 98-H 0XA 9对 HL 60髓系分化过程中髓系特异性基因转录 细胞 髓样分化伴随着转录的增加， 一些基因如CD 11b和CD 18，以及其他基因如 髓过氧化物酶（MPO）。 我们的假设预测Nup 98-HOXA 9将 抵制这些倾向。 我们将监测Nup 98-HOXA 9的效果， 内源性和瞬时转染的CD 11b、CD 18和MPO的分化 发起人。 查看整个发起人将提供一个全球评估， Nup 98-HOXA 9对骨髓转录的影响。

DESCRIPTION (provided by applicant): The candidate is a physician-scientist recently appointed as a tenure-track Assistant Professor in the Department of Pathology at Northwestern University Medical School. His major focus (80 percent) will be basic research into nuclear transport and its role in leukemia; with the rest dedicated to clinical hematopathology and teaching. The nuclear pore protein (nucleoporin) Nup98 gene is a frequent target of chromosomal rearrangements in acute myelogenous leukemia (AML), a disease characterized by failure of myeloid differentiation. These rearrangements produce chimeric proteins, the best characterized of which is Nup98-HOXA9. T h e mechanism by which Nup98 chimeras cause leukemia is not known. Nucleoporins, along with karyopherins (importins), are part of the machinery that mediates nucleocytoplasmic transport. Myeloid differentiation is regulated by transcription factors (TFs) that need the nuclear transport machinery to reach their destinations inside the nucleus. Of these TFs, AML1 and RAR-alpha play a central role in both normal myeloid differentiation and AML. There is substantial evidence that a decrease and/or abnormal distribution of AML1 and RAR-alpha within the nucleus contribute to the pathogenesis of AML. Our hypothesis is that Nup98 gene rearrangements cause AML by disrupting the nuclear import of the transcription factors that mediate myeloid differentiation. Focusing on the effect of Nup98-HOXA9 on the nuclear trafficking of AML1 and RAR-alpha and myeloid differentiation, we will: (I) Delineate the role of Nup98 and karyopherins in the nuclear import of AML1 and RAR-alpha. (ii) Determine whether Nup98-HOXA9 disrupts this process by monitoring the nuclear import, localization, and activity of AML1 and RAR- alpha in cells stably transfected with an inducible Nup98-HOXA9 construct. Our hypothesis predicts reduced nuclear import of AML1 and RAR-alpha and/or alteration in their intranuclear distribution and transcriptional activity upon induction of Nup98-HOXA9. (iii) Determine the effect of Nup98-HOXA9 on myeloid-specific gene transcription during myeloid differentiation of HL60 cells. Myeloid differentiation is accompanied by increased transcription of some genes such as CD11b and CD18 and decreased transcription of others such as myeloperoxidase (MPO). Our hypothesis predicts that Nup98-HOXA9 would counteract these tendencies. We will monitor the effect of Nup98-HOXA9 during differentiation on endogenous and transiently transfected CD11b, CD18, and MPO promoters. Looking at entire promoters will provide a global assessment of the effects of Nup98-HOXA9 on myeloid transcription.