Role of the Y-Located TSPY Gene in Human Oncogenesis

Y 定位的 TSPY 基因在人类肿瘤发生中的作用

• 批准号: 8391614
• 负责人: YUN-FAI CHRIS LAU
• 金额: --
• 依托单位: VETERANS AFFAIRS MED CTR SAN FRANCISCO
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-10-01 至 2014-09-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8391614
• 关键词: 12p; Affect; Androgen Receptor; Androgens; Animal Model; Animals; Apoptotic; Binding; Binding Sites; Biological Assay; Biological Markers; CDC2 Protein Kinase; Cell Cycle; Cell Cycle Regulation; Cell Proliferation; Cells; ChIP-on-chip; Chromosomes; Chromosomes, Human, Y; Complex; CpG Islands; Cultured Cells; Cyclin B; DNA; DNA Binding Domain; DNA Methylation; Development; Diagnostic; Ectopic Expression; Epigenetic Process; Etiology; Exons; Gene Expression; Gene Expression Profile; Gene Expression Regulation; Gene Proteins; Gene Structure; Gene Targeting; Genes; Genetic Polymorphism; Genetic Transcription; Genomic Instability; Gonadoblastoma; Growth; Homologous Gene; Hormones; Hot Spot; Human; Human Genome; Ligands; M cell; Malignant Neoplasms; Malignant neoplasm of prostate; Mediating; Methylation; Microarray Analysis; Molecular; Nodular Neoplasm; Normal tissue morphology; Nude Mice; Oncogenes; Oncogenic; Ovary; Pathogenesis; Pathway interactions; Phosphotransferases; Physiology; Play; Primary carcinoma of the liver cells; Process; Property; Prostatic; Prostatic Tissue; Protein Binding; Proteins; Proto-Oncogenes; Regulation; Reporter; Research; Resources; Reverse Transcriptase Polymerase Chain Reaction; Role; Sex Chromosomes; Staging; Stretching; Structural Genes; Structure; Structure-Activity Relationship; Testicular Germ Cell Tumor; Testosterone; Time; Tissue Recombination; Transactivation; Transcription Repressor/Corepressor; Transfection; Transgenes; Transgenic Mice; Tumor Suppressor Genes; Tumor Suppressor Proteins; Tumor Tissue; Veterans; X Chromosome; Y Chromosome; arm; bisulfite; cell growth; chromatin immunoprecipitation; demethylation; domain mapping; early onset; human TSPY protein; inhibitor/antagonist; insight; male; man; melanoma; programs; promoter; prostate cancer model; protein structure; public health relevance; pyrosequencing; receptor function; therapeutic target; transcription factor; transgene expression; tumor; tumor growth; tumorigenesis

DESCRIPTION (provided by applicant): The testis-specific protein Y-encoded (TSPY) gene is a tandemly repeated gene on the short arm of the human Y chromosome. Its 2.8-kb structural gene is embedded within a 20-kb highly homologous unit that is tandemly repeated up to 64 times, constituting the largest tandem array of functional sequences in the human genome. The TSPY repeats are hot spots for both genomic instability and epigenetic dysregulation on the Y chromosome. TSPY is the proto-oncogene for the gonadoblastoma locus on the Y chromosome (GBY), the only oncogenic locus on this male-specific chromosome. Our research shows that TSPY harbors a conserved protein interacting domain, termed SET/NAP. TSPX is a single-copy TSPY homologue on the X chromosome. Both TSPY and TSPX share significant homologies at both gene organization and protein structure. When ectopically expressed, TSPY and TSPX show contrasting properties in cell cycle regulation. TSPY is ectopically expressed and plays key roles in the initiation and/or progression of gonadoblastoma, testicular germ cell tumors, prostate cancer, and sexual dimorphic cancers, such as hepatocellular carcinoma. TSPY potentiates cell proliferation, accelerates the transition and disrupts the G2/M checkpoints, binds cyclin B and enhances cyclin B-CDK1 kinase activities, and promotes tumor growth in athymic mice. TSPY induces gonadoblastoma-like structure in the ovaries of transgenic mice. TSPX is a tumor suppressor. It binds cyclin B, but represses the cyclin B-CDK1 kinase activity. Ectopic expression of TSPX arrests cells at G2/M stage, and represses tumor growth in athymic mice. We postulate that TSPX serve a normal function in maintaining an orderly cell proliferation and growth while TSPY, when ectopically expressed, counteracts such function(s) and promotes tumorigenesis in susceptible cells. Recently, we have showed that TSPY interacts with androgen receptor (AR) and exacerbates its ligand-dependent transactivation of responsive genes while TSPX interacts but represses AR functions. Hence, TSPY and TSPX could participate in the transcriptional programs mediated by androgen-dependent prostatic oncogenesis. When a TSPY transgene is introduced into the transgenic mouse (LADY) model of prostate cancer, it is ectopically activated at the onset of prostatic oncogenesis in the bi-transgenic mice, resulting in qualitatively more nodular tumors than those from animals without TSPY. These results have provided some important clues and excellent resources for investigating the mechanisms by which TSPY could contribute to prostatic oncogenesis. We will study these problems under three specific aims. First, we plan to elucidate the epigenetic changes associated with TSPY transgene activation during prostatic oncogenesis in the TSPY-LADY bi-transgenic mice, in terms of tumor pathogenesis, transgene expression, DNA methylation status of the TSPY promoter and exon 1, and identification of transcription factors and repressors affected by such epigenetic changes. Second, we will determine the domains responsible for the contrasting functions of TSPY and TSPX on AR transactivation and elucidate the structure-function relationship with a prostatic tissue recombination strategy. Third, we plan to identify and confirm the target genes of a TSPY-AR transcription complex using advanced chromatin immunoprecipitation and promoter tiling microarray (ChIP-Chip) approach. We will determine the transcriptomes of tumors from TSPY-LADY and LADY transgenic mice under normal and hormone-ablated conditions, thereby deducing the genes and pathways mostly affected by an ectopically expressed TSPY transgene in prostatic oncogenesis. We will characterize in details those differentially expressed genes whose promoters are also bound by a TSPY-AR transcriptional complex. The proposed research will provide critical insights on the roles of TSPY and TSPX on prostatic oncogenesis, and translational opportunities in developing diagnostic biomarkers and targets for therapeutic strategies for prostate cancer.

描述（由申请人提供）： 睾丸特异性蛋白Y编码（TSPY）基因是人Y染色体短臂上的一个串联重复基因。它的2.8-kb结构基因嵌入了20 kb高度同源的单元中，该单元的串联重复高达64次，构成了人类基因组中功能序列的最大串联阵列。 TSPY重复序列是Y染色体上基因组不稳定性和表观遗传失调的热点。 TSPY是Y染色体（GBY）上性腺母细胞瘤基因座的原始癌基因，这是该男性特异性染色体上唯一的致癌基因座。我们的研究表明，TSPY拥有一个保守的蛋白质相互作用结构域，称为set/nap。 TSPX是X染色体上的单拷贝TSPY同源物。 TSPY和TSPX在基因组织和蛋白质结构上均具有重要的同源性。当异位表达时，TSPY和TSPX在细胞周期调节中显示出对比的特性。 TSPY在异位表达，并在性腺母细胞瘤，睾丸生殖细胞肿瘤，前列腺癌和性二态性癌（例如肝细胞癌）的起始和/或进展中起关键作用。 TSPY增强细胞增殖，加速过渡并破坏G2/M检查点，结合细胞周期蛋白B并增强细胞周期蛋白B-CDK1激酶活性，并促进胸膜小鼠的肿瘤生长。 TSPY在转基因小鼠的卵巢中诱导类腺母细胞样结构。 TSPX是肿瘤抑制剂。它结合细胞周期蛋白B，但抑制细胞周期蛋白B-CDK1激酶活性。 TSPX的异位表达在G2/M阶段阻止细胞，并抑制无胸腺小鼠的肿瘤生长。我们假设TSPX在维持有序的细胞增殖和生长时起着正常的功能，而TSPY则在异位表达时，应对这种功能并促进易感细胞的肿瘤发生。 最近，我们表明TSPY与雄激素受体（AR）相互作用，并加剧了其配体依赖性反应基因的反式化基因的反式激活，而TSPX相互作用，但抑制了AR功能。因此，TSPY和TSPX可以参与由依赖雄激素依赖性前列腺肿瘤发生的转录程序。当将TSPY转基因引入前列腺癌的转基因小鼠（LADY）模型时，在双重转基因小鼠的前列腺肿瘤发生时，它会被异位地激活，从而导致质性肿瘤比没有TSPY的动物的肿瘤更大。这些结果为研究TSPY可以促进前列腺肿瘤发生的机制提供了一些重要的线索和出色的资源。我们将根据三个具体目标研究这些问题。首先，我们计划在肿瘤发病机理，转基因表达，TSPY促进剂和外显子1的DNA甲基化状态以及对转录因子和抑制因素的鉴定方面，在TSPY-Lady双胞胎转基因小鼠中前列腺肿瘤发生过程中与TSPY转基因激活相关的表观遗传变化。其次，我们将确定负责TSPY和TSPX对AR反式激活的对比功能的域，并阐明与前列腺组织重组策略的结构功能关系。第三，我们计划使用晚期染色质免疫沉淀和启动子瓷砖微阵列（CHIP-CHIP）方法来识别和确认TSPY-AR转录复合物的靶基因。我们将在正常和激素驱动的条件下确定来自TSPY-荷兰和LADY转基因小鼠的肿瘤的转录组，从而推断出前列腺肿瘤中主要受到异位表达的TSPY转基因影响的基因和途径。我们将详细介绍那些差异表达的基因，其启动子也受TSPY-AR转录复合物的约束。拟议的研究将提供有关TSPY和TSPX在前列腺肿瘤发生的作用的关键见解，以及在开发诊断生物标志物和靶标的前列腺癌治疗策略方面的转化机会。