PROTEIN PATTERNS IN LEUKEMIC CELLS

白血病细胞中的蛋白质模式

基本信息

批准号：
3170148
负责人：
SAMIR M HANASH
金额：
$ 21.4万
依托单位：
UNIVERSITY OF MICHIGAN AT ANN ARBOR
依托单位国家：
美国
项目类别：
财政年份：
1983
资助国家：
美国
起止时间：
1983-02-01 至 1997-01-31
项目状态：
已结题

项目摘要

This resubmission of a competing renewal application builds on accomplishments made during prior support and progress made in the past year, dealing with the characterization of two novel polypeptides in acute lymphoblastic leukemia (ALL) that were detected using two-dimensional polyacrylamide gel electrophoresis (2-D PAGE). One polypeptide, designated OP18 was identified as a highly conserved novel proliferation regulated cytosolic phosphoprotein that appears to be involved in signal transduction. Unlike other proliferation regulated proteins we have identified, OP18 is overexpressed at the protein and RNA levels in All relative to nonleukemic proliferating lymphoid cells. It is also phosphorylated to a much lesser extent in acute leukemia cells. In this application, we propose to determine the role of OP18 in lymphoid proliferation and to define more precisely the basis for differences in OP18 phosphorylation observed between normal lymphoid cells and acute leukemia, using well defined normal lymphoid cell populations obtained from thymus and bone marrow. Having completed genomic sequencing of Op18, we also propose to study the regulation of Op18 gene expression by identifying cis-acting elements using functional assays; by identifying transcription factors involved in activation of the Op18 gene; and determining which if any may be responsible for its overexpression in leukemia. Three polypeptides (L2,L3,L4) expressed in pre-B ALL, a maturation defined subtype which accounts for most cases of ALL, were identified as the phosphorylated and unphosphorylated forms of a heat shock protein hsp27, not previously known to be constitutively expressed in lymphoid cells outside of the heat shock response. In pre-B ALL, phosphorylation of hsp27 occurs to a variable extent among patients. We have ascertained through follow up that diminished phosphorylation of hsp27 associated with poor prognosis. We propose to study the mechanism of phosphorylation of hsp27; to identify phosphorylation sites; and to generate monoclonal antibodies to hsp27 phosphopeptides to allow studies of hsp27 in bone marrow B lymphoid precursors and to more precisely determine the extent of variability of hsp27 phosphorylation in pre-B ALL. Clinical as well as laboratory features of ALL, which are a part of a leukemia database we have developed, will be investigated to identify which features may correlate with Op18 and hsp27 phosphorylation. The studies proposed are aimed at providing a better understanding of the deregulated cell proliferation in ALL and of the biochemical basis of heterogeneity observed between patients with pre-B ALL.

竞争续订申请的这种重新提交基于在过去的支持和过去取得的进步期间取得的成就一年，处理急性中两个新型多肽的表征使用二维检测到的淋巴细胞白血病（全）聚丙烯酰胺凝胶电泳（2-D页）。一个多肽，指定的OP18被确定为高度保守的新型增殖调节的胞质磷蛋白似乎参与了信号转导。与其他扩散调节的蛋白质不同，我们有鉴定出，OP18在蛋白质和RNA水平上均过表达相对于非白血病增殖的淋巴样细胞。也是急性白血病细胞的磷酸化程度要小得多。在这个应用，我们建议确定OP18在淋巴机中的作用扩散并更准确地定义差异的基础 OP18在正常淋巴样细胞和急性之间观察到的磷酸化白血病，使用明确定义的正常淋巴样细胞种群来自胸腺和骨髓。完成OP18的基因组测序后，我们还建议研究OP18基因表达的调节使用功能分析识别顺式作用元件；通过识别涉及OP18基因激活的转录因子；和确定哪个是否可能负责其过表达白血病。三个多肽（L2，L3，L4）在pre-b all，a中表达成熟定义的亚型，其中大多数情况是被鉴定为热的磷酸化和未磷酸化形式休克蛋白HSP27，以前尚不知道是组成型表达的在热休克反应外的淋巴样细胞中。在pre-b all中， HSP27的磷酸化在患者之间发生了可变的程度。我们通过随访确定，磷酸化的磷酸化 HSP27与预后不良有关。我们建议研究机制 Hsp27的磷酸化；鉴定磷酸化位点；然后生成对HSP27磷酸肽的单克隆抗体，以允许研究骨髓B淋巴前体中的Hsp27，更精确地确定pre-b全部HSP27磷酸化的变异性程度。所有人的临床和实验室特征都是我们开发的白血病数据库将进行调查以识别哪些特征可能与OP18和HSP27磷酸化相关。这提出的研究旨在更好地了解在全部和生化基础上取消管细胞增殖 pre-b all的患者之间观察到异质性。