BRCA2 Hereditary Ovarian Cancer Tissue Truncation Test

BRCA2 遗传性卵巢癌组织截断试验

• 批准号: 7404496
• 负责人: Jeffrey T Holt
• 金额: $ 16.17万
• 依托单位: TISSUE GENETICS, INC.
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-09-28 至 2008-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7404496
• 关键词: Address; Affect; Animals; Antibodies; BRCA1 gene; BRCA2 Mutation; BRCA2 gene; Benchmarking; Biological Assay; Blood Glucose; Blood specimen; Breast; C-terminal; Cancer Patient; Chemistry; Cholesterol; Clinical Research; Clinical Trials; Colon; Communities; DNA Sequence; Data; Depth; Diagnosis; Diagnostic; Family; Family member; Funding; Genes; Genetic; Genetic Counseling; Genetic Screening; Genetic screening method; Genus Cola; Goals; Hereditary Breast and Ovarian Cancer Syndrome; Hereditary Malignant Neoplasm; Hospitals; Human; Immunohistochemistry; Individual; Inherited; Knowledge; Lead; Length; Malignant Neoplasms; Malignant neoplasm of ovary; Marketing; Medical; Methods; Mutation; N-terminal; Oral Contraceptives; Ovarian; Ovarian Tissue; Ovary; Patients; Phase; Phase II Clinical Trials; Polymerase Chain Reaction; Population; Prevention strategy; Process; Protein Truncation; Proteins; Protocols documentation; Relative (related person); Reporting; Research; Resolution; Risk; Roentgen Rays; Sample Size; Sampling; Score; Screening procedure; Sensitivity and Specificity; Serum; Small Business Technology Transfer Research; Societies; System; Tamoxifen; Technology; Testing; Time; Tissue Sample; Tissues; United States Food and Drug Administration; base; cancer genetics; cancer risk; concept; cost; diet and exercise; inhibitor/antagonist; malignant breast neoplasm; mutant; mutation carrier; prevent; research and development; size; tissue preparation

DESCRIPTION (provided by applicant): This is a second revision of a Phase I STTR proposal that received a score of 177, to develop a tissue-based genetic test for BRCA2 hereditary ovarian cancer. Six percent of unselected US ovarian cancers are BRCA2 hereditary cancers with truncating mutations in the BRCA2 gene. It is important to know which ovarian cancer patients have BRCA2 hereditary ovarian cancer because BRCA2 patients have an increased risk of breast cancer and their relatives with mutations have an increased risk of breast and ovarian cancer. These subsequent cancers would be discovered early or prevented if widespread genetic screening was available. We have developed an antibody-based tissue truncation method to identify BRCA2 hereditary cancers and have demonstrated the proof of concept for this technology. This approach visualizes protein truncation by showing with immunohistochemistry (IHC) that the N-terminus is present but the C-terminus is absent. Preliminary Data shows that 3 breast cancers with BRCA2 truncating mutations have truncated proteins by IHC while 20 sporadic breast cancers have full-length proteins detected by both N- and C-terminal antibodies. This project will fund research and development which will ultimately lead to a Phase II large clinical study of appropriate size to convince the FDA and the medical community that this test can efficiently and effectively identify patients with hereditary BRCA2 ovarian cancer. The product (test) will be an antibody-based IHC diagnostic kit for cancer tissue samples which hospital labs will use to identify hereditary cancers. The milestones for the Phase I proposal are: 1) Determine optimal tissue preparation protocols for IHC with both N- terminal and C-terminal BRCA2 antibodies. 2) Develop a quantitative scoring system for N-terminal and C- Terminal BRCA2 immunostaining on ovarian tissues with intra-assay variability of 15% and inter-assay variability of 20% or less. 3) Demonstrate that a C-terminal to N-terminal ratio for protein truncation (BRCA2 Truncation Ratio) can distinguish 20 hereditary BRCA2 ovarian cancers from 50 sporadic ovarian cases with greater than 90% sensitivity and specificity (comparing different scoring systems). 4) Develop tissue based methods for PCR-sequencing to validate results of IHC studies using the sequencing benchmark. The goal of this Phase I proposal is to develop technology for a Phase II proposal to determine if the BRCA2 truncation test can achieve 90% sensitivity and specificity in a clinical trial of 500 ovarian cancer samples (sample size to provide 30 BRCA2 hereditary cancers).Ovarian Cancer relevance: Successful completion of this Phase I research would lead to a Phase II clinical trial which could establish a new tissue-based genetic test for BRCA2 hereditary ovarian cancer based on an IHC method to visualize protein truncation. This simpler more widely applicable approach will identify many more families with hereditary breast and ovarian cancer and consequently help patients and their relatives by identifying individuals likely to develop subsequent breast or ovarian cancer which might be prevented by tamoxifen and/or screening exams and X-rays.

描述（由申请人提供）：这是I期STTR提案的第二次修订，该提案获得了177分，以开发BRCA 2遗传性卵巢癌的基于组织的基因检测。6%的卵巢癌是BRCA 2基因截短突变的BRCA 2遗传性癌症。重要的是要知道哪些卵巢癌患者患有BRCA 2遗传性卵巢癌，因为BRCA 2患者患乳腺癌的风险增加，而其携带突变的亲属患乳腺癌和卵巢癌的风险增加。如果能够进行广泛的基因筛查，这些后续癌症将被早期发现或预防。我们开发了一种基于抗体的组织截断方法来识别BRCA 2遗传性癌症，并证明了这项技术的概念证明。这种方法通过用免疫组织化学（IHC）显示存在N-末端但不存在C-末端来可视化蛋白质截短。初步数据显示，3例BRCA 2截短突变的乳腺癌通过IHC检测到截短蛋白，而20例散发性乳腺癌通过N端和C端抗体检测到全长蛋白。该项目将资助研究和开发，最终将导致适当规模的II期大型临床研究，以说服FDA和医学界，该测试可以有效地识别遗传性BRCA 2卵巢癌患者。该产品（测试）将是一种基于抗体的癌症组织样本IHC诊断试剂盒，医院实验室将使用该试剂盒来识别遗传性癌症。I期提案的里程碑是：1）确定使用N-末端和C-末端BRCA 2抗体进行IHC的最佳组织制备方案。2)开发卵巢组织N-末端和C-末端BRCA 2免疫染色的定量评分系统，测定内变异性为15%，测定间变异性为20%或更低。BRCA 2截断比（BRCA 2 Truncation Ratio）可以区分20例遗传性BRCA 2卵巢癌和50例散发性卵巢癌，敏感性和特异性均大于90（比较不同的评分系统）。4)开发基于组织的PCR测序方法，以验证使用测序基准的IHC研究结果。该I期提案的目标是为II期提案开发技术，以确定BRCA 2截短试验是否可以在500个卵巢癌样本的临床试验中达到90%的灵敏度和特异性（样本量提供30例BRCA 2遗传性癌症）。卵巢癌相关性：成功完成第一阶段的研究将导致第二阶段的临床试验，这可能会建立一个新的组织-BRCA 2遗传性卵巢癌的基因检测基于IHC方法，以可视化蛋白质截短。这种更简单、更广泛适用的方法将识别出更多的遗传性乳腺癌和卵巢癌家族，从而帮助患者及其亲属识别出可能发生后续乳腺癌或卵巢癌的个体，这些个体可以通过他莫昔芬和/或筛查检查和X射线来预防。