Validation of an Antibody Test for Early Diagnosis of Ovarian Cancer

描述（由申请人提供）：如果在I期发现卵巢癌，90%的病例可以通过手术和化疗治愈。每年有21000例卵巢癌新病例但是其中75%的病例是在III期或IV期被诊断出来的他们的5年生存率约为20%。这导致美国每年约有14000人死亡。在北美，大约每200名女性中就有1名携带BRCA1或BRCA2突变，500万女性有一级或二级亲属有卵巢癌家族史。这些类别中卵巢癌风险较高的妇女显然会从筛查测试中受益，因此代表了将从该项目中受益的社区。卵巢癌的筛查试验将通过减少卵巢癌在诊断时的阶段到更有可能治愈的阶段来改变医疗保健服务的方法。我们开发了一种高通量蛋白质组学技术，我们称之为“Epitomics”（表位组学），我们从卵巢癌组织和细胞的RNA cDNA文库中免疫选择数千种噬菌体显示的抗原。我们使用蛋白质微阵列作为大规模平行免疫分析系统来鉴定由T7噬菌体cDNA文库编码的蛋白质，这些蛋白质与卵巢癌患者血清中的抗体特异性结合，而不是与良性妇科疾病女性血清中的抗体结合。我们建议在Luminex头阵列上使用免疫测定法，利用体外合成的蛋白质来验证这些生物标志物。我们的假设是，它需要一组生物标志物来准确区分卵巢癌患者和妇科良性疾病患者。生物标志物领域的大多数人都会同意这一假设。我们将在体外使用PCR模板合成蛋白质，这些模板来自我们选择的生物标志物噬菌体克隆，我们已经证明这些克隆是肿瘤抗原，与卵巢癌患者血清中的抗体特异性反应。我们将使用早期和晚期卵巢癌的血清验证这些生物标志物。此外，为了确保我们正在开发的诊断测试的特异性，我们将在患有良性妇科疾病、自身免疫性疾病和其他癌症的女性血清中检测这些生物标志物。然而，如果一小部分患者仍然使用这些生物标志物进行错误分类，我们将使用其他方法，如肿瘤抗原的全长重组蛋白。如有必要，将寻求针对肿瘤细胞过度表达或突变的肿瘤抗原形成的自身抗体的替代方法。这些方法应该为我们提供一个足够强大的抗原生物标志物分析小组，用于早期检测卵巢癌的头阵列分析。该项目的重点是将我们的肿瘤相关抗原的大规模免疫蛋白质组学发现转化为Luminex头阵列检测血清自身抗体，用于检测高危妇女和有卵巢癌家族史的妇女的早期卵巢癌。

DESCRIPTION (provided by applicant): When discovered at stage I ovarian cancer is curable in 90% of the cases using surgery and chemotherapy. There are 21,000 new cases per year of ovarian cancer however 75% of those cases are diagnosed at stage III or IV and their 5-year survival is about 20%. This results in about 14,000 deaths per year in the US. About 1 in 200 women in North America carries BRCA1 or BRCA2 mutations and 5 million women with a family history of ovarian cancer in a first or second degree relative. Women in these categories who are at higher risk of ovarian cancer would clearly benefit from a screening test and therefore represent the communities that would benefit from this project. A screening test for ovarian cancer will change the approach to healthcare delivery by reducing stage of ovarian cancer at diagnosis to stage at which it is more likely to be curable. We developed a high-throughput proteomics technology we call "Epitomics" for (epitope-omics) in which we immunoselect thousands of phage displayed antigens from cDNA libraries made from RNA from ovarian cancer tissue and cells. We used protein microarrays as a massively parallel immunoassay system to identify the proteins coded by the T7 bacteriophage cDNA libraries that bind to antibodies specifically in the serum of ovarian cancer patients and not to antibodies present in women with benign gynecological diseases. We propose to validate these biomarkers using in vitro synthesized proteins using immunoassays on Luminex bead arrays. Our hypothesis is that it requires panels of biomarkers to accurately distinguish patients with ovarian cancer from those with gynecological benign diseases. Most people in the biomarker field would agree with this hypothesis. We will synthesize proteins in vitro using PCR templates from our selected biomarker bacteriophage clones that we have shown are tumor antigens reacting with antibodies specifically in the serum of ovarian cancer patients. We will validate these biomarkers using sera from early and late stage ovarian cancer. In addition, to ensure the specificity of the diagnostic test we are developing we will assay these biomarkers against sera from women with benign gynecological diseases, autoimmune diseases, and women with other cancers. However, if a fraction of patients are still misclassified using these biomarkers we will use additional approaches such as full length recombinant proteins of the tumor antigens. If necessary alternative approaches will be pursued targeting autoantibodies that are formed against tumor antigens that are overexpressed or mutated by tumor cells. These approaches should provide us with a sufficiently robust panel of antigen biomarker analytes for a bead array assay for the early detection of ovarian cancer. The focus of this project is to translate our large scale immuno-proteomics discoveries of tumor associated antigens into Luminex bead array assays to detect serum autoantibodies for the detection of early stage cancer of the ovary in high risk women and women with a family history of ovarian cancer. PUBLIC HEALTH RELEVANCE: The goal of this project is the final refinement of antigen biomarkers from a large scale proteomic screen so as to employ peptide antigens for the detection of ovarian cancer at an early stage. We are focusing on the most dangerous form of ovarian cancer serous adenocarcinoma, which is often diagnosed at a late stage that is difficult to treat successfully. A blood test to detect antibodies against cancer antigens is a laboratory format for a diagnostic test that can readily be implemented in a clinical setting in order to identify this disease at an early and 95% curable stage.