Genetic Interaction Between the pRB and Warts Tumor Suppressor Pathways

pRB 和疣肿瘤抑制途径之间的遗传相互作用

• 批准号: 7697115
• 负责人: Brandon Nicolay
• 金额: $ 3.91万
• 依托单位: UNIVERSITY OF ILLINOIS AT CHICAGO
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-09-19 至 2013-09-18
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7697115
• 关键词: Address; Alleles; Apoptosis; Apoptotic; Biochemistry; Biological Models; Bypass; Cancerous; Cell Count; Cell Cycle; Cell Proliferation; Cell division; Cells; Cellular biology; Complex; Cues; DNA Binding; Development; Drosophila genome; Drosophila genus; Drosophila melanogaster; E2F transcription factors; Exhibits; Failure; Family; Family member; Gene Targeting; Genes; Genetic; Genetic Transcription; Goals; Growth; Homeostasis; Homologous Gene; Human; Immunohistochemistry; In Vitro; Incidence; Inhibition of Apoptosis; Knock-out; Malignant Neoplasms; Mitotic; Modeling; Molecular Biology; Mutate; Mutation; Normal Cell; Organ Size; Orthologous Gene; Outcome Study; Pathway interactions; Phenotype; Process; Proliferating; Proteins; Regulation; Relative (related person); Resistance; Response Elements; Retinoblastoma Protein; Role; Scallop; Signal Transduction; Stress; System; Techniques; Testing; Time; Tissues; Transcription Coactivator; Transgenic Animals; Tumor Suppressor Proteins; Work; anti-cancer therapeutic; cancer therapy; cyclin G1; fly; in vivo; insight; member; mutant; neoplastic cell; overexpression; promoter; trait; tumor

DESCRIPTION (provided by applicant): The retinoblastoma protein (pRB) is very important tumor suppressor that is often mutated or inactivated during the formation of cancer. As a tumor suppressor pRB regulates the activity of the E2F transcription factor family. The E2F family is characterized by "activators" and "repressors", both of which traditionally form a heterodimer with the DP protein at the promoters of target genes. The activator E2Fs, in the absence of pRB, can drive the cell into the cell cycle by activating the transcription of the G1 cyclins. Thus, in cancers in which pRB function is lost, E2F activity is high, and therefore, the tumor continues to grow and divide. Due to the high incidence in which pRB function is lost during tumor formation it has been suggested that targeted inhibition of the E2F family could be a promising anti-cancer therapeutic. However, to carry out these studies in the mammalian model system has proven challenging due to the overwhelming number of E2F, pRB, and Dp, family members. Fortunately, the fruit fly, Drosophila melanogaster, has less complexity between the E2F, pRB, and DP families. There is one activator E2F(dE2F1) and one repressor E2F(dE2F2), and when the activator E2F is lost due to mutation or targeted inhibition it results in a severe proliferation block. Thus, reinforcing the idea that loss of E2F activity could help slow cancerous growths. However, when all E2F activity is lost, both in vivo and in vitro, cells can proliferate with relative normality. Recently, a new tumor suppressor pathway referred to'as the Hippo pathway has been delineated in Drosophila. All members of this pathway have orthologs or homologs in humans, and are found to be mutated in human cancers. When this pathway becomes inactive, cells gain a proliferative advantage over neighboring wildtype tissue and are resistant to apoptotic stresses. This study aims to test what effects the loss of the E2Fs, in all combinations, has in tissue that has an inactive Hippo tumor suppressor pathway. This study will use a combination of new and classical Drosophila genetics, molecular biology, and cell biology to address this issue. Immunohistochemistry analysis will be used to determine in vivo effects upon proliferation and apoptosis Hippo mutant tissue in the absence of the E2Fs. Furthermore, any requirement for dE2F dependent transcription will be confirmed via ChIP analysis. Due to the evolutionary conservation between both of these pathways (pRB/E2F and SWH) in Drosophila and humans, this study will provide insight into the functional relationship between two important tumor suppressor pathways. Thus, the outcome of this study could demonstrate that targeted inhibition of activator E2Fs could prove to be a productive anticancer therapy.

描述（由申请人提供）：视网膜母细胞瘤蛋白（pRB）是非常重要的肿瘤抑制因子，在癌症形成过程中经常发生突变或失活。作为一种肿瘤抑制因子，pRB调节E2 F转录因子家族的活性。E2 F家族的特征在于“激活子”和“阻遏子”，这两者传统上在靶基因的启动子处与DP蛋白形成异源二聚体。在pRB不存在的情况下，激活剂E2 Fs可以通过激活G1期细胞周期蛋白的转录来驱动细胞进入细胞周期。因此，在pRB功能丧失的癌症中，E2 F活性高，因此，肿瘤继续生长和分裂。由于在肿瘤形成期间pRB功能丧失的高发生率，已经表明E2 F家族的靶向抑制可能是有希望的抗癌治疗剂。然而，在哺乳动物模型系统中进行这些研究已被证明具有挑战性，因为E2 F、pRB和Dp家族成员的数量巨大。幸运的是，果蝇（Drosophila melanogaster）在E2 F、pRB和DP家族之间的复杂性较小。有一个激活因子E2 F（dE 2F 1）和一个阻遏因子E2 F（dE 2F 2），当激活因子E2 F由于突变或靶向抑制而丢失时，会导致严重的增殖阻滞。因此，加强E2 F活性的丧失可以帮助减缓癌症生长的想法。然而，当体内和体外的所有E2 F活性丧失时，细胞可以相对正常地增殖。最近，一个新的肿瘤抑制途径被称为"河马途径已划定在果蝇。该途径的所有成员在人类中都有直系同源物或同源物，并且发现在人类癌症中发生突变。当该途径变得不活跃时，细胞获得相对于邻近野生型组织的增殖优势，并且对凋亡应激具有抗性。这项研究的目的是测试在所有组合中，E2 Fs的损失对具有非活性Hippo肿瘤抑制途径的组织有什么影响。本研究将结合新的和经典的果蝇遗传学，分子生物学和细胞生物学来解决这个问题。免疫组织化学分析将用于确定在不存在E2 F的情况下对Hippo突变体组织增殖和凋亡的体内影响。此外，将通过ChIP分析确认对dE 2F依赖性转录的任何要求。由于这两个途径（pRB/E2 F和SWH）在果蝇和人类之间的进化保守性，这项研究将提供深入了解两个重要的肿瘤抑制途径之间的功能关系。因此，本研究的结果可以证明，靶向抑制激活剂E2 Fs可以证明是一种有效的抗癌疗法。