Cisplatin-induced epigenomic modifications in male germ cells

顺铂诱导的雄性生殖细胞表观基因组修饰

• 批准号: 9002272
• 负责人: MILES Frome WILKINSON
• 金额: $ 33.29万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN DIEGO
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-12-01 至 2017-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9002272
• 关键词: Address; Adverse effects; Affect; Age; Bioinformatics; Cancer Patient; Categories; Cell Maturation; Child; Chronic; Cisplatin; Code; DNA; DNA Methylation; Data; Data Analyses; Defect; Deposition; Development; Disease; Drug usage; Embryonic Development; Environmental Exposure; Epigenetic Process; Event; Exhibits; Exposure to; Fathers; Fertilization; Future; Future Generations; Gene Expression; Gene Expression Profiling; Generations; Genes; Genetic Transcription; Genome; Genomic Segment; Germ Cells; Health; Histones; Lead; Litter Size; Malignant Neoplasms; Malignant neoplasm of testis; Methodology; Methylation; Modeling; Modification; Mus; Obesity; Paternal Exposure; Patients; Physical condensation; Physicians; Population; Post-Transcriptional Regulation; Principal Investigator; Protamines; Reporting; Reproductive Biology; Research Personnel; Risk; Rodent; Solid Neoplasm; Spermatids; Spermatogenesis; Staging; Stem cells; Structure of primordial sex cell; Testis; Untranslated RNA; base; cancer therapy; cell type; chemotherapeutic agent; chemotherapy; demethylation; epigenomics; genome-wide; innovation; male; men; methylation pattern; methylome; natural Blastocyst Implantation; next generation; offspring; preimplantation; public health relevance; reproductive; reproductive tract; research study; sperm cell; theories; toxicant; transcriptome; tumor; young man

 DESCRIPTION (provided by applicant): Testicular cancer is the most common malignancy in men between the ages of 15 and 34. Chemotherapy approaches provide a ~90% cure rate and many of these men will often go on to father children. A critical concern is whether chemotherapy will negatively impact the offspring of these men. In support of this possibility, a number of studies have documented that chemotherapeutic agents used to treat testicular cancer have adverse effects on the subsequent generation. An epigenetic basis for these defects is suggested by chemotherapy-induced changes in the DNA methylation status and expression of specific genes, as well as histone/protamine ratio changes. However, genome-wide analyses of the epigenetic modifications that occur in male germ cells as a result of exposure of the paternal genome to chemotherapy have not yet been performed. This is a critical gap in the field that greatly limits our understanding of the underlying mechanisms by which adverse exposures to the germline lead to disease in the offspring. In this application, we propose to address the epigenetic effects of cisplatin, a drug used in testicular cancer therapy, as well as many other solid tumors. We will determine the effects of cisplatin on the DNA methylome and transcriptome of both transcriptionally active and inactive male germ cells. We will examine round spermatids (RSPs) since these male germ cells are at the last developmental stage that still undergoes active transcription. We will examine mature sperm since they are transcriptionally quiescent but harbor stable RNAs that may be important for fertilization and early embryogenesis. To specifically identify stable alterations that remain afte the affected germ cells are cleared and replaced from the pool of spermatogonial stem cells (SSCs), we will assay gene expression and methylation after 3 cycles of spermatogenesis. In the F1 generation, we will examine male primordial germ cells (PGCs), a unique cell type that undergoes global DNA demethylation. This will allow us to determine whether cisplatin treatment triggers epigenetic changes that allow specific genes to escape this genome-wide epigenetic reprogramming event. We will also define the methyomes and transcriptomes of RSPs and mature sperm from the F1 generation. Given that genome-wide epigenetic effects of cisplatin treatment have not previously been reported, we regard the innovation quotient of this proposal as high. We will also provide new genome-wide epigenetic and transcriptome information on normal germ cell subsets. The experiments proposed here represent a critical first step towards defining the specific mechanisms by which epigenetic marks-deposited as a result of environmental exposure to toxicants-are maintained throughout germ cell development and lead to specific anomalies in future generations. This information may allow physicians to better inform their patients of the reproductive risks associated with chemotherapy treatment.

 描述（由申请人提供）：睾丸癌是15至34岁男性中最常见的恶性肿瘤。化疗方法提供了~90%的治愈率，其中许多人往往会继续生育。一个关键的问题是化疗是否会对这些男性的后代产生负面影响。为了支持这种可能性，一些研究已经证明，用于治疗睾丸癌的化疗药物对后代有不良影响。化疗诱导的DNA甲基化状态和特定基因表达的变化以及组蛋白/鱼精蛋白比例的变化提示了这些缺陷的表观遗传学基础。然而，尚未进行全基因组分析的表观遗传修饰，发生在男性生殖细胞作为一个结果，暴露于化疗的父亲的基因组。这是该领域的一个关键空白，极大地限制了我们对生殖系不良暴露导致后代疾病的潜在机制的理解。在本申请中，我们建议解决顺铂（一种用于睾丸癌治疗的药物）以及许多其他实体瘤的表观遗传效应。我们将确定顺铂对转录活跃和不活跃的雄性生殖细胞的DNA甲基化组和转录组的影响。我们将研究圆形精子细胞（RSPs），因为这些雄性生殖细胞处于最后的发育阶段，仍然经历活跃的转录。我们将研究成熟精子，因为它们在转录上是静止的，但含有稳定的RNA，这可能对受精和早期胚胎发生很重要。为了特异性鉴定受影响的生殖细胞从精原干细胞（SSC）库中清除和替换后仍然存在的稳定改变，我们将在3个精子发生周期后测定基因表达和甲基化。在F1代中，我们将研究雄性原始生殖细胞（PGCs），这是一种独特的细胞类型，会发生整体DNA去甲基化。这将使我们能够确定顺铂治疗是否会引发表观遗传变化，从而使特定基因逃脱这种全基因组表观遗传重编程事件。我们还将定义RSPs和F1代成熟精子的甲基化组和转录组。鉴于顺铂治疗的全基因组表观遗传效应以前没有报道过，我们认为这一建议的创新商数很高。我们还将提供新的全基因组表观遗传和转录组信息的正常生殖细胞亚群。这里提出的实验代表了关键的第一步，以确定特定的机制，表观遗传标记-沉积作为环境暴露于有毒物质的结果-保持整个生殖细胞的发展，并导致后代的特定异常。这些信息可以让医生更好地告知患者与化疗相关的生殖风险。