Novel Proapoptotic BH3-only Proteins in Cancer Apoptosis

癌症细胞凋亡中的新型促凋亡 BH3 蛋白

• 批准号: 6922748
• 负责人: Chien-An Andy Hu
• 金额: $ 22.11万
• 依托单位: UNIVERSITY OF NEW MEXICO
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-05-16 至 2010-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6922748
• 关键词: BCL2 gene /protein; Internet; RNA interference; antibody; apolipoproteins; apoptosis; bioinformatics; biotechnology; cell line; electrospray ionization mass spectrometry; flow cytometry; gas chromatography mass spectrometry; gene expression; immunofluorescence technique; immunoprecipitation; molecular site; neoplasm /cancer genetics; protein localization; protein protein interaction; protein sequence; proteomics; western blottings

DESCRIPTION (provided by applicant): Many kinds of cancer cells possess defects in the pathways of apoptosis. Members of the Bcl-2 family of proteins play pivotal roles in regulating apoptosis and possess at least 1 of 4 conserved Bcl-2-Homology (BH) domains, designated, BH1, BH2, BH3, and BH4. The BH3 domain is the only one (1) present in pro-apoptotic "BH3-only" molecules and plays important roles in protein-protein interactions and apoptosis by regulating dimerization and multimerization of the Bcl-2 family members. To date, approximately 21 human genes have been found that encode proteins belonging to the Bcl-2 family, 14 of which are BH3-only pro-apoptotic proteins. This shows that the BH3-only proteins are important and possess overlapping, complementary and/or specific roles in different types of cells in apoptosis. Therefore, the overall goals of this study are to identify and characterize novel BH3-only proteins from the human proteome and to delineate functions of the newly identified proteins in cancer cell death. We hypothesized that there are additional genes encoding BH3-only proteins in the human genome that interact with other members of the Bcl-2 family and/or other molecules in regulating apoptosis in cell type and/or signaling-specific manners. We further hypothesize that some of the newly identified BH3-only proteins possess additional (i.e., non-apoptogenic) functions in normal physiology. In the preliminary studies, we utilized the bioinformatic data-mining approach to identify 3 novel BH3-only proteins. The candidate genes, apolipoprotein L6 (ApoL6), ApoL.1 and BH3- Only Member B (BOMB), were cloned and functionally expressed in cancer models. By transient expression analysis, we showed that ApoL6, ApoL1 and BOMB promoted cell death in p53-null HCT116 cells. Furthermore, by constructing and characterizing an inducible ApoL6 gene in another p53-null cancer model, DLD-1, we found that expression of ApoL6 induced a mitochondria-mediated apoptosis in DLD-1 cells. These hypotheses will be tested further with 5 specific aims. Deciphering functions of the novel BH3-only proteins and their interacting molecules should enhance our understanding, and potential utilization, of BH3-only proteins and lipid-mediated apoptosis in treatment of cancer.

描述（由申请人提供）：多种癌细胞在凋亡途径中存在缺陷。 Bcl-2蛋白质家族的成员在调节细胞凋亡中起关键作用，并且至少有4个保守的Bcl-2总体学（BH）结构域中的1个，指定为BH1，BH2，BH3和BH4。 BH3结构域是促凋亡“仅BH3”分子中唯一的一个（1），并且通过调节Bcl-2家族成员的二聚化和多种化，在蛋白质 - 蛋白质相互作用和凋亡中起重要作用。迄今为止，已经发现大约21个人类基因编码属于Bcl-2家族的蛋白质，其中14个是仅BH3蛋白。这表明仅BH3蛋白很重要，并且在凋亡中不同类型的细胞中具有重叠，互补和/或特定的作用。因此，这项研究的总体目标是鉴定和表征来自人类蛋白质组的新型BH3蛋白质，并描绘新鉴定的蛋白质在癌细胞死亡中的功能。我们假设人类基因组中编码仅BH3蛋白的其他基因与Bcl-2家族的其他成员和/或其他分子相互作用，以调节细胞类型和/或信号特异性界的细胞凋亡。我们进一步假设，一些新鉴定的仅BH3蛋白在正常生理学中具有额外的（即非凋亡）功能。在初步研究中，我们利用生物信息学数据挖掘方法来识别3种新的仅BH3蛋白。候选基因，载脂蛋白L6（Apol6），Apol.1和BH3-仅成员B（炸弹）被克隆并在癌症模型中功能表达。通过瞬态表达分析，我们表明apol6，apol1和炸弹促进了p53-null HCT116细胞中的细胞死亡。此外，通过在另一个p53-null癌症模型DLD-1中构建和表征可诱导的apol6基因，我们发现APOL6的表达诱导了线粒体介导的DLD-1细胞中的细胞凋亡。这些假设将通过5个特定目标进一步检验。新型BH3蛋白及其相互作用的分子的解密功能应增强我们对仅BH3蛋白的理解和潜在利用，以及脂质介导的癌症治疗中的凋亡。