Nuclear Translocation of I-kappaB-alpha as a Therapeutic Target

I-κB-α 的核转位作为治疗靶点

• 批准号: 7184005
• 负责人: Ivana Vancurova
• 金额: $ 24.53万
• 依托单位: ST. JOHN'S UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-01-09 至 2010-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7184005
• 关键词: Affinity Chromatography; Anti-Inflammatory Agents; Anti-inflammatory; Apoptosis; Apoptotic; Binding; Biochemical; Cell Nucleus; Cells; Class; Confocal Microscopy; Data; Development; Disease; Drug Delivery Systems; Event; Fractionation; Gene Expression; Genes; Genetic Transcription; Goals; HL-60 Cells; HL60; Hela Cells; Human; Immunoprecipitation; Inflammatory; Laboratories; Leukocytes; MG115; MG132; Malignant Neoplasms; Mass Spectrum Analysis; Measures; Mediating; Messenger RNA; Molecular; Nuclear; Nuclear Matrix; Nuclear Protein; Nuclear Proteins; Nuclear Translocation; Post-Translational Protein Processing; Proteasome Inhibition; Proteasome Inhibitor; Proteins; RNA; Rate; Rest; Role; Testing; Transfection; base; cell type; chromatin immunoprecipitation; human disease; inhibitor/antagonist; leukemia; monocyte; multicatalytic endopeptidase complex; neutrophil; novel; promoter; protein expression; therapeutic target; transcription factor

DESCRIPTION (provided by applicant): NFkB is a critical transcription factor regulating expression of pro-inflammatory and anti- apoptotic genes. Previous studies from our laboratory demonstrated that as opposed to other cell types, resting human neutrophils contain predominant amount of NFkB inhibitor, IkBa, in the nucleus, and this increased nuclear accumulation of IkBa results in the inhibition of NFkB activity and increased rate of neutrophil apoptosis. Our recent data have shown that proteasome inhibition induces translocation of IkBa to the nucleus in leukemia HL-60 and U- 937 cells, and in cancer HeLa cells; however, the mechanisms are currently unknown. The central hypothesis of this proposal is that induction of nuclear accumulation of IkBa inhibits NFkB activity and expression of NFkB-regulated anti-apoptotic and pro-inflammatory genes, and could thus provide a basis for novel anti-cancer and anti-inflammatory therapies aimed at the inhibition of NFkB activity by the nuclear IkBa. The specific aims focus on analyzing the mechanisms by which the nuclear IkBa inhibits NFkB activity and expression of NFkB-regulated genes in leukemia HL-60 and U-937 cells. In Aim 1, we will test the hypothesis that the proteasome inhibition-induced nuclear translocation of IkBa results in the inhibition of NFkB activity and decreased expression of NFkB-regulated anti-apoptotic genes, by using transfection of HL-60 and U-937 cells with inhibitory IkBa RNA. In Aim 2, we will use chromatin immunoprecipitation to test the hypothesis that the nuclear IkBa inhibits NFkB activity by associating with the promoters of NFkB-regulated genes. In Aim 3, we will investigate the mechanisms that regulate the proteasome inhibition-induced nuclear translocation of IkBa. Identification of the key molecular events that control NFkB activity by the nuclear IkBa will broaden our understanding of the mechanisms regulating NFkB activity, and might provide a new class of drug targets to regulate the NFkB driven pro-inflammatory and anti-apoptotic gene expression. The focus of this proposal is to identify the mechanisms by which the nuclear translocation of IkBa regulates activity of the transcription factor NFkB. Since NFkB activity is increased in many human diseases including inflammatory disorders, cancer, and leukemia, identification of the mechanisms by which the nuclear IkBa inhibits NFkB activity will contribute to the development of novel anti-cancer and anti-inflammatory therapies.

描述（由申请人提供）：NFkB是调节促炎和抗凋亡基因表达的关键转录因子。我们实验室之前的研究表明，与其他细胞类型不同，静息的人中性粒细胞的细胞核中含有大量的 NFkB 抑制剂 IkBa，而 IkBa 的核积累增加会导致 NFkB 活性的抑制和中性粒细胞凋亡率的增加。我们最近的数据表明，在白血病 HL-60 和 U-937 细胞以及癌症 HeLa 细胞中，蛋白酶体抑制会诱导 IkBa 易位至细胞核；然而，其机制目前尚不清楚。该提议的中心假设是，诱导 IkBa 核积聚会抑制 NFkB 活性以及 NFkB 调节的抗凋亡和促炎基因的表达，因此可以为旨在通过核 IkBa 抑制 NFkB 活性的新型抗癌和抗炎疗法提供基础。具体目标是分析白血病HL-60和U-937细胞中核IkBa抑制NFkB活性和NFkB调控基因表达的机制。在目标 1 中，我们将通过使用抑制性 IkBa RNA 转染 HL-60 和 U-937 细胞来检验以下假设：蛋白酶体抑制诱导的 IkBa 核易位会导致 NFkB 活性受到抑制并降低 NFkB 调节的抗凋亡基因的表达。在目标 2 中，我们将使用染色质免疫沉淀来检验核 IkBa 通过与 NFkB 调节基因的启动子结合来抑制 NFkB 活性的假设。在目标 3 中，我们将研究调节蛋白酶体抑制诱导的 IkBa 核转位的机制。鉴定核 IkBa 控制 NFkB 活性的关键分子事件将拓宽我们对调节 NFkB 活性机制的理解，并可能提供一类新的药物靶点来调节 NFkB 驱动的促炎和抗凋亡基因表达。该提案的重点是确定 IkBa 核易位调节转录因子 NFkB 活性的机制。由于 NFkB 活性在许多人类疾病（包括炎症性疾病、癌症和白血病）中增加，因此鉴定核 IkBa 抑制 NFkB 活性的机制将有助于开发新型抗癌和抗炎疗法。

项目成果

Bortezomib induces nuclear translocation of IκBα resulting in gene-specific suppression of NF-κB--dependent transcription and induction of apoptosis in CTCL.

• DOI: 10.1158/1541-7786.mcr-10-0368
• 发表时间: 2011-02
• 期刊: Molecular cancer research : MCR
• 作者: Juvekar A;Manna S;Ramaswami S;Chang TP;Vu HY;Ghosh CC;Celiker MY;Vancurova I
• 通讯作者: Vancurova I