Robust assays to define telomere maintenance mechanisms as cancer biomarkers.

将端粒维持机制定义为癌症生物标志物的稳健测定。

• 批准号: 10693944
• 负责人: CHARLES Patrick REYNOLDS
• 金额: $ 35.83万
• 依托单位: TEXAS TECH UNIVERSITY HEALTH SCIS CENTER
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-09-16 至 2026-08-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10693944
• 关键词: ATM activation; ATRX gene; Adult; Affect; Anticoagulants; Biological; Biological Assay; Biological Markers; Biology; Biopsy; Blood; Blood specimen; Bone Marrow; Bone Marrow Aspiration; CLIA certified; Catalytic Domain; Cells; Child; Chromosomes; Classification; Clinical; Clinical Trials; Code; Collection; DAXX gene; DNA; DNA Damage; Data; Detection; Drug Targeting; Enzymes; Fixatives; Genetic Recombination; Heparin; Human; Laboratories; Malignant Childhood Neoplasm; Malignant Neoplasms; Marrow; Messenger RNA; Modeling; Mutation; Neoplasm Metastasis; Neuroblastoma; Nucleic Acids; Nucleoproteins; Outcome; Patient risk; Patients; Pediatric Oncology Group; Phase III Clinical Trials; Phenotype; Plasma; Prevalence; Process; Prognosis; Prognostic Marker; Proliferating; Protocols documentation; Quality Control; Quantitative Reverse Transcriptase PCR; RNA; Research; Resistance; Reverse Transcriptase Polymerase Chain Reaction; Ribonucleoproteins; Sampling; Selection for Treatments; Sensitivity and Specificity; Solid Neoplasm; Source; TERC gene; TERT gene; TP53 gene; Telomerase; Telomere Maintenance; Temperature; Therapeutic Clinical Trial; Time; Tissues; Translating; Tube; Tumor Burden; Tumor Tissue; ataxia telangiectasia mutated protein; cancer biomarkers; cancer cell; cancer classification; cancer type; cell free DNA; chemotherapy; clinical application; clinical implementation; clinical risk; cohort; companion diagnostics; diagnostic assay; improved; inhibitor; mRNA Expression; molecular pathology; neoplastic cell; new therapeutic target; novel; novel strategies; novel therapeutics; participant enrollment; peripheral blood; prognostic; risk stratification; sample collection; success; targeted treatment; telomere; tumor; tumor DNA

Abstract Telomeres are nucleoproteins with TTAGGG DNA repeats at the ends of chromosomes that protect coding DNA from erosion and detection as DNA damage. Telomere maintenance is necessary for cancer cells to have unlimited proliferation capacity. Most cancers maintain their telomeres via activation of the ribonucleoprotein telomerase containing a catalytic subunit encoded by the TERT gene and an RNA template encoded by the TERC gene. Cancers with low or no telomerase activity often use another mechanism to extend their telomeres, the Alternative Lengthening of Telomeres (ALT) in which telomeres are maintained via homologous telomeric-DNA recombination, but the mechanism is still poorly understood. ALT tumors contain extra-chromosomal telomeric DNA C-circles, which (detected with a unique PCR assay) provides a specific and sensitive ALT biomarker. We have shown that quantifying TERT mRNA expression together with telomeric DNA C-circles enables classifying cancers into 3 groups based on telomere maintenance mechanism (TMM); telomerase- positive (high TERT), ALT-positive (C-circle+), and TMM-negative. Classifying the childhood cancer neuroblastoma by TMM provides prognostic information that overrides currently employed clinical and biological prognostic markers, and our preliminary data suggest this is possible for other cancer types. ALT cancers are consistently difficult to treat but have dysfunctional telomeres, creating unique vulnerabilities that can provide novel therapeutic targets. For example, we have recently demonstrated high ATM kinase activation at telomeres in ALT neuroblastoma leads to resistance to DNA damaging chemotherapy that can be reversed with a clinical-stage ATM inhibitor AZD0156. Biomarkers of TMM provide both prognostic information and the C-circle assay can potentially serve as a companion diagnostic assay to identify patients with tumors that are likely to be more responsive to novel ALT-targeted therapies. Thus, it is important to define parameters that impact accurate TMM assessment of cancers, i.e. accurate quantitation of TERT mRNA and DNA C-circles. We will define the impact of collection and storage conditions and the minimum amounts of tissue and amounts, and quality of nucleic acids needed for the assays. Identifying ALT patients from a blood sample would have clinical utility, and our preliminary data suggest that C-circles can be detected in plasma containing circulating tumor DNA. Thus, we also propose to develop and validate a plasma C-circle assay as a novel approach to identifying patients with ALT cancers. Finally, to ensure that these assays can be used for clinical risk stratification, and as companion diagnostics for selection of therapy, we propose to carry out studies necessary for CAP/CLIA certification of TERT mRNA qPCR and the telomeric DNA C- circle assay. To accomplish our aims, we are integrating sample collection from adult and pediatric cancers together with a team of experts in telomere biology and molecular pathology. This project will provide important information on analyzing cancer TMM phenotype that will be of value to both research and clinical labs and will enable completion of regulatory requirements necessary for clinical implementation of the assays.

抽象的 端粒是核蛋白，在染色体的末端具有TTAGGG DNA重复序列，可保护编码DNA免受 侵蚀和检测为DNA损伤。端粒维持对于癌细胞具有无限的增殖所必需 容量。大多数癌症通过激活含有催化的核糖核蛋白端粒酶维护其端粒 亚基由TERT基因和TERC基因编码的RNA模板编码。低或没有端粒酶的癌症 活动通常使用另一种机制扩展其端粒，端粒的替代延长（ALT），其中 端粒是通过同源端粒DNA重组来维持的，但是该机制仍然很少了解。 Alt肿瘤包含染色体外端粒DNA C-Circles（用独特的PCR分析检测）提供了一个 特异性和敏感的Alt生物标志物。我们已经表明，将TERT mRNA表达与端粒一起定量 DNA C圆使癌症基于端粒维护机制（TMM）将癌症分为3组；端粒酶 阳性（高度），Alt阳性（C-Circle+）和TMM阴性。通过 TMM提供了预后信息，这些信息覆盖了当前采用临床和生物学预后标记，以及 我们的初步数据表明，对于其他癌症类型来说，这是可能的。 Alt Cancer一直很难治疗，但 功能失调的端粒，创造了独特的漏洞，可以提供新颖的治疗靶标。例如，我们有 最近在ALT神经母细胞瘤中端粒的高ATM激酶激活高导致对DNA损害的抗性 可以用临床阶段ATM抑制剂AZD0156逆转的化学疗法。 TMM的生物标志物都提供 预后信息和c-circle分析可能有可能用作伴侣诊断测定法，以识别患者 可能对新型的Alt靶向疗法反应更敏感的肿瘤。因此，定义参数很重要 这会影响癌症的精确TMM评估，即对TERT mRNA和DNA C圆的准确定量。我们将 定义收集和存储条件的影响以及组织和量的最低量以及质量 测定所需的核酸。从血液样本中识别出ALT患者将具有临床实用性，我们的 初步数据表明，可以在含有循环肿瘤DNA的血浆中检测到C圆。因此，我们也提出 为了开发和验证等离子体C-CIRCLE分析，作为一种识别ALT癌症患者的新方法。最后，到 确保这些测定方法可用于临床风险分层，并作为选择治疗的伴侣诊断， 我们建议进行TERT mRNA qPCR和端粒DNA C-的CAP/CLIA认证所需的研究。 圆形测定。为了实现我们的目标，我们正在将成人和儿科癌的样本收集与 端粒生物学和分子病理学专家团队。该项目将提供有关分析的重要信息 癌症TMM表型对研究和临床实验室都有价值，并将完成调节 临床实施测定所需的要求。