THE ROLE OF STATS IN TRANSFORMATION BY BCR/ABL

统计数据在 BCR/ABL 转型中的作用

• 批准号: 6604264
• 负责人: ROBERT L ILARIA
• 金额: $ 27.3万
• 依托单位: UT SOUTHWESTERN MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-07-01 至 2005-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6604264
• 关键词: Retroviridae; apoptosis; biological signal transduction; bone marrow; carcinogenesis; cell differentiation; cell proliferation; chimeric proteins; chromosome translocation; gene expression; gene targeting; genetic transcription; genetically modified animals; hematopoietic growth factor; interleukin 3; laboratory mouse; leukemia; neoplastic transformation; oncoproteins; protein structure function; provirus; tissue /cell culture; transcription factor; transfection /expression vector; virus protein

The chimeric fusion protein Bcr/Abl has been implicated in a variety of human hematologic malignancies, including the vast majority of cases of chronic myelogenous leukemia (CML), 20-30 percent of acute lymphocytic leukemia (ALL) in adults, and rare cases of acute myelogenous leukemia (AML). Recently it has been demonstrated that P210BCR/ABL activates members of the signal transducers and activators of transcription (STAT ) family members, implicated in cytokine and growth factor signaling pathways. STAT5 is the major STAT activated by p210BCR/ABL and STAT5 activation is a common feature in Philadelphia chromosome positive (Ph+) cell lines. P190BCR/ABL and v-AB1, which share the propensity for lymphoid transformation in vivo, differ from P210 in that they also STAT6, implicated in IL-4-dependent lymphoid signaling. This proposed work has two broad purposes (1) to determine the role of STAT5 activation in P210 transformation. This will be investigated by introducing dominant negative forms of STAT5 into hematopoietic factor- dependent cell lines and determining whether they interfere with the ability of P210 to render these cells cytokine independent. Also, murine bone marrow cells, co-expressing both P210 and dominant negative STAT5, will be used to reconstitute lethally- irradiated mice to determine whether dominant negative STAT5 impairs P210-induced leukemia in vivo. In a complementary experiment, wild-type mice will be reconstituted with P210- infected bone marrow from STAT5A and STAT5A/5B knockout mice to determine whether recipient animals show resistance to P210- induced leukemia. P210-infected STAT5 knockout bone marrow will also analyzed for defects in hematopoietic transformation in vitro by a myeloid colony assay (2) to determine the role of STAT6 activation in transformation by P190 and v-Abl This will be accomplished by introducing either P 190 or v-Abl into bone marrow cells from mice with homozygous deficiency of STAT6 by retroviral gene transfer, and assessing transformation in Whitlock-Witte and soft agar colony assays in vitro, and for the ability of these cells to induce leukemia in vivo when used to reconstitute lethally-irradiated STAT6 wild-type animals. Insight into the role of STAT activation by Bcr/Abl and v-Abl may lead to novel targeted therapies for patients afflicted with Philadelphia chromosome positive leukemias.

Bcr/abl融合蛋白与多种人类血液系统恶性肿瘤有关，包括绝大多数慢性粒细胞白血病(CML)，20-30%的成人急性淋巴细胞白血病(ALL)，以及罕见的急性髓系白血病(AML)。最近研究表明，P210BCR/ABL可以激活信号转导和转录激活因子(STAT)家族成员，参与细胞因子和生长因子信号转导通路。STAT5是p210BCR/ABL激活的主要STAT，STAT5激活是Ph+细胞系的共同特征。P190BCR/ABL和v-AB1在体内具有相同的淋巴转化倾向，与P210的不同之处在于它们也参与了IL-4依赖的淋巴信号转导。这项拟议的工作有两个广泛的目的：(1)确定STAT5激活在P210转化中的作用。这将通过将STAT5的显性阴性形式引入造血因子依赖的细胞系，并确定它们是否干扰P210使这些细胞独立于细胞因子的能力来进行研究。此外，同时表达P210和显性阴性STAT5的小鼠骨髓细胞将被用来重建致死性照射的小鼠，以确定显性阴性STAT5是否在体内损害了P210诱导的白血病。在一个补充实验中，野生型小鼠将用来自STAT5A和STAT5A/5B基因敲除小鼠的感染了P210的骨髓重建，以确定受体动物是否对P210诱导的白血病表现出抵抗力。(2)为了确定STAT6激活在P190和v-Abl转化中的作用，这将通过逆转录病毒基因转移将P190或v-Abl导入STAT6纯合缺陷小鼠的骨髓细胞，并在体外Whitlock-Witte和软琼脂集落试验中评估转化，以及这些细胞用于重建致死照射的STAT6野生型动物时在体内诱发白血病的能力。深入了解bcr/abl和v-abl激活STAT的作用可能会为患有费城染色体阳性白血病的患者带来新的靶向治疗。