REGULATION OF EXPRESSION OF C-MYB IN LEUKEMIAS

描述：(改编自研究人员摘要)c-myb癌基因 在未成熟的造血细胞中高水平表达 白血病。白血病细胞似乎对反义更敏感 抑制c-myb的表达比正常的造血细胞都要强。 尽管很明显白血病细胞需要增加c-myb的表达 对于增殖来说，导致这种情况的分子机制增加了 表达方式是未知的。这项提案的目标是确定 转录调控的分子机制 C-myb基因在正常和恶性血细胞中的表达。1. 转录调控的分子机制的鉴定 C-myb在正常T细胞中的表达。T细胞活化导致表达增加 C-myb基因的表达。他们将在体内进行足迹，在体外进行蛋白质-DNA 结合研究和瞬时转染实验研究 C-myb基因的转录调控。2.身份证明 白血病细胞c-myb转录调控的分子机制。 目标1中描述的研究将在符合以下条件的白血病样本上进行 表达高水平的c-myb mRNA和细胞系将用于 瞬时转染法实验。中确定的调节蛋白 白血病细胞将与正常T细胞中鉴定的细胞进行比较。3. 第一内含子在c-myb转录调控中的作用。他们有 结果表明，在第一内含子中存在一个正调控区域。他们 将继续研究这一点，并调查它在 白血病细胞。他们还将确定是否阻止转录 延伸位于第一内含子或转录起始点。4. C-myb甲基化状态的测定。CpG的甲基化 二核苷酸被认为参与了基因沉默机制。他们 将决定c-myb的甲基化状态 活化的T细胞，在不表达c-myb的HeLa细胞中，在白血病中 细胞。通过这些信息，他们希望发现c-myb是如何表达的。 解除对白血病的管制，并开始了解这如何有助于 恶变。

DESCRIPTION: (adapted from the investigator's abstract) The c-myb oncogene is expressed at high levels in immature hematopoietic cells and in many leukemias. Leukemic cells appear to be more sensitive to antisense inhibition of c-myb expression than normal hematopoietic cells are. Although it is clear that leukemic cells require increased c-myb expression for proliferation, the molecular mechanisms that lead to this increased expression are not known. The goal of this proposal is to determine the molecular mechanisms responsible for the transcriptional control of the c-myb gene in both normal and malignant hematopoietic cells. 1. Identification of the molecular mechanisms of transcriptional control of c-myb in normal T cells. Activation of T cells causes increased expression of c-myb mRNA. They will perform in vivo footprinting, in vitro protein-DNA binding studies, and transient transfection experiments to study the transcriptional regulation of the c-myb gene. 2. Identification of the molecular mechanism of transcriptional control of c-myb in leukemic cells. Studies as described in Aim 1 will be performed on leukemic samples that express high levels of c-myb mRNA and cell lines will be used for the transient transfection experiments. The regulatory proteins identified in leukemic cells will be compared to those identified in normal T cells. 3. Role of the first intron in the transcriptional control of c-myb. They have shown that a positive regulatory region exists in the first intron. They will continue to study this and also investigate the role it plays in leukemic cells. They will also determine whether the block to transcription elongation is in the first intron or at the transcription start site. 4. Determination of the methylation status of c-myb. Methylation of CpG dinucleotides is thought to be involved in a gene silencing mechanism. They will determine the methylation status of c-myb in both quiescent and activated T cells, in HeLa cells which do not express c-myb, and in leukemic cells. With this information they hope to discover how c-myb expression is deregulated in leukemias and to begin to understand how this contributes to malignant transformation.