MicroRNA in Blood as an Early Biomarker of Breast Cancer

描述（由申请人提供）：乳腺癌是美国妇女最常诊断的癌症，不包括非黑色素瘤皮肤癌。虽然乳房X光检查的使用提高了乳腺癌的生存率，但需要更好的方法进行早期检测，特别是在年轻女性中。分析血液中的循环肿瘤标志物可能有助于乳腺癌筛查。微小RNA（microRNA，miR）是一类长度为22-25个核苷酸的非编码小RNA，通过与靶信使RNA的3'非翻译区（UTR）结合，有效地减少靶信使RNA的翻译。已经提出miR有助于肿瘤发生，因为它们可以作为肿瘤抑制因子或癌基因发挥作用。与相应的正常组织相比，已经观察到成熟和/或前体miR序列的异常表达水平。其他研究表明，miR可以在血液中发现，并且非常稳定。这些结果导致了miR的血浆水平可能对癌症的早期诊断有用的假设。该提案旨在获得试点资金，以鉴定与对照相比在乳腺癌病例血浆中过表达的候选生物标志物miR，并建立用于血浆中定量的实验室测定。乳腺肿瘤、邻近组织和相应的血液可从哥伦比亚大学医学中心新诊断的乳腺癌病例中获得。这些资源将使我们能够识别血浆miR作为有前途的新型生物标志物，用于早期检测乳腺癌。有两个具体目标。目的1将比较来自乳腺癌病例的20个血浆样本和20个年龄和种族匹配的对照的全基因组miR表达谱。然后使用真实的时间定量PCR（RT-qPCR）测定来测定病例中过表达的前5-10个miR，以确认阵列数据，然后分析石蜡切片乳腺肿瘤/配对的相邻组织，以确定与相邻组织相比，它们是否也在肿瘤中过表达。在目标2中，将使用RT-qPCR确认病例/对照血浆差异，使用100例病例和匹配对照的独立组。这项试点研究将提供资源，以选择乳腺癌特异性miR，建立定量血浆中miR的实验室测定，并证明我们可以在诊断时检测乳腺癌。我们的长期目标是使用从乳腺癌家庭登记处的参与者中收集的血液，这是一个国际登记处，用于乳腺癌高风险家庭，其中血液在诊断前可用。在高危人群中早期发现乳腺癌的筛查方法的发展将导致更好的治疗和生存。 公共卫生相关性：这项初步研究将确定与对照组相比乳腺癌病例血浆中上调的miR，这些miR可能用于筛查乳腺癌的早期诊断。开发真实的时间测定方法，用于在乳腺癌病例和对照的血浆和试点数据中进行测量，对于未来大型前瞻性研究的资助至关重要。

DESCRIPTION (provided by applicant): Breast cancer is the most frequently diagnosed cancer in U.S. women, excluding nonmelanoma skin cancers. While mammography use has enhanced breast cancer survival, better methods are needed for screening for early detection, especially in younger women. Analysis of blood for circulating tumor markers may be useful in breast cancer screening. MicroRNAs (miR) are small (22-25 nucleotides in length) noncoding RNAs that can effectively reduce the translation of target messenger RNAs by binding to their 3' untranslated region (UTR). miRs have been proposed to contribute to oncogenesis because they can function either as tumor suppressors or oncogenes. Abnormal levels of expression for mature and/or precursor miR sequences compared with the corresponding normal tissues have been observed. Other studies have demonstrated that miRs can be found in the blood and are highly stable. These results have lead to the hypothesis that plasma levels of miRs might be useful for early diagnosis of cancer. This proposal seeks to obtain pilot funding to identify candidate biomarker miRs overexpressed in plasma of breast cancer cases compared to controls and to establish the laboratory assays for their quantitation in plasma. Breast tumor, adjacent tissues, and the corresponding bloods are available from consenting, newly-diagnosed breast cancer cases seen at Columbia University Medical Center. These resources will enable us to identify plasma miRs as promising novel biomarkers for early detection of breast cancer. There are two specific aims. Aim 1 will compare whole genome miR expression profiles in 20 plasma samples from breast cancer cases and 20 age- and ethnicity-matched controls. The top 5-10 miRs overexpressed in cases will then be assayed using a real time quantitative PCR (RT-qPCR) assay to confirm the array data and then paraffin section breast tumor/paired adjacent tissues will be analyzed to determine if they are also overexpressed in tumor compared with adjacent tissues. In Aim 2 the RT-qPCRs will be used to confirm case/control plasma differences using an independent set of 100 cases and matched controls. This pilot study will provide the resources to select breast cancer-specific miRs, establish the laboratory assays for quantitation of miRs in plasma, and demonstrate that we can detect breast cancer at the time of diagnosis. Our long term goal is to use bloods collected from participants in the Breast Cancer Family Registry, an international registry of families at high risk for breast cancer in which bloods are available prior to diagnosis. The development of screening methods for the early detection of breast cancer in high risk populations will lead to better treatment and survival. PUBLIC HEALTH RELEVANCE: This pilot study will identify miRs upregulated in plasma of breast cancer cases compared to controls that can potentially be used to screen for early diagnosis of breast cancer. The development of real time assays for their measurement in plasma and pilot data on breast cancer cases and controls will be essential for future funding of a large prospective study.