Multifunctional nanoparticles for multiplex detection of breast cancer biomarkers

描述（由申请人提供）：Her-2、雌激素受体（ER）或孕激素受体(P)在乳腺癌细胞上的存在是一个非常重要的生物标志物，有助于医生制定治疗方案和提出疾病预后。目前ER、PR和Her2/neu的诊断和预后分类方法是基于免疫组织化学（IHC）的，这是一种在临床医学中使用了80多年的技术。然而，免疫酶（基于hrp）的免疫组化方法具有单色性质，无法进行多路分子分析。此外，免疫组化仍然是半定量和主观的，导致观察者之间的结果有相当大的差异。半导体纳米晶体也被称为量子点（QDs），是一类新型的生物检测标记，在生物医学领域有着广泛的应用，包括多色标记、单分子生物物理学、生物分子谱分析、光学条形码、体外和体内成像等。目前研究表明，量子点可用于乳腺肿瘤组织中ER、PR和Her2的多重检测。在I期工作中，我们已经证明基因工程蛋白G片段可以作为纳米颗粒与抗体结合的通用连接体，这使得探针具有小尺寸和抗体取向。在II期，我们将首先分离循环癌细胞，然后定量分析ER， PR和Her2/neu生物标志物的多路复用表达水平。我们的总体目标是开发一种能够分离循环癌细胞的检测方法，同时量化一组癌症生物标志物的表达水平，为癌症治疗提供指导。公共卫生相关性：乳腺癌是美国第二大死亡原因。2007年，预计约有1,444,920例新的癌症病例被诊断出来，约559,650名美国人预计将死于癌症——每天超过1,500人。乳腺癌细胞中几种重要的生物标志物的存在是一个非常重要的诊断标准，它有助于医生制定治疗方案和提出疾病的预后。然而，准确、同时测量这些受体的表达水平一直很困难。纳米技术的发展，特别是生物共轭纳米粒子的发展提供了必要的解决方案。本课题的成功开展将极大地推动多种肿瘤受体表达水平的多重定量技术的发展，并为更有效的治疗提供有价值的指导。

DESCRIPTION (provided by applicant): The presence of Her-2, estrogen receptor (ER) or progesterone receptor (P) on breast cancer cells is a very important biomarker which facilitates physicians in making decisions on treatment schemes and in proposing prognosis of the disease. Current methods for diagnostic and prognostic classifications of ER, PR and Her2/neu are based on immunohistochemistry (IHC), a technique that has been used in clinical medicine for over 80 years. However, the immunoenzyme (HRP-based) IHC method has a single color nature and is unable to perform multiplexed molecular profiling. Moreover, IHC remains semi-quantitative and subjective, resulting in considerable inter-observer variations of results. Semiconductor nanocrystals also known as quantum dots (QDs) are a new class of biological detection labels, which present a broad range of biomedical applications including multicolor labeling, single molecule biophysics, biomolecular profiling, optical barcoding, and in vitro and in vivo imaging. Current studies have indicated that QDs can be used for multiplex detection of ER, PR and Her2 in breast tumor tissue. In Phase I work, we have demonstrated that genetic engineered protein G fragment can serve as universal linker to conjugate nanoparticles with antibodies, which presented the probes with small size and antibody orientation. In phase II, we will first separate the circulating cancer cells and then quantitatively analyze the expression levels of ER, PR and Her2/neu biomarkers in a multiplexed fashion. Our overall goal is to develop an assay that is capable of isolating circulating cancer cells while quantifing the expression levels of a panel of cancer biomarkers to provide guidance for cancer treatment. 1 PUBLIC HEALTH RELEVANCE: Breast cancer is the second leading cause of death in the United States. In 2007, about 1,444,920 new cancer cases were expected to be diagnosed, and about 559,650 Americans were expected to die of cancer-more than 1,500 people per day. The presence of several important biomarkers on breast cancer cells is a very important diagnostic criterion, which facilitates physicians in making decisions on treatment schemes and in proposing prognosis of the disease. However it has been difficult to accurately, simultaneously measure the expression levels of these receptors. The development of nanotechnology, especially the development of bioconjugated nanoparticles provides an essential solution. Successful development of this project will significantly advance the technique of multiplex quantification of expression levels of various cancer receptors and provide valuable guidance for more effective treatments.