SELECTIVELY IMAGING CANCER STEM CELLS

描述（由申请人提供）：越来越多的证据表明肿瘤生长是由癌症干细胞（CSCs）驱动的。这些细胞被认为是肿瘤生长的驱动力，因为它们对治疗有抵抗力，并且能够自我更新。在CSCs发现之前，肿瘤进展的克隆模型获得了大多数支持。该模型假设肿瘤中的每个细胞都有自我更新的能力，因此，如果在治疗过程中没有被杀死，就可以用亚克隆重新填充肿瘤，对治疗产生抗性。CSC模型认为肿瘤由细胞层次结构组成。肿瘤内的csc是能够自我再生并共同产生非csc后代的细胞，它们构成了剩余肿瘤体积的很大一部分。由于csc是一组肿瘤细胞中的一个亚群，因此它们被标记为附着在细胞外部的两种不同分子。我们提出了一种基于抗体的成像系统，该抗体对这两种标记具有高亲和力，我们将开发。我们还将开发第三种抗体，用于用染料标记的小报告分子。该抗体将被分成两半，每一半将与两个细胞表面标记的抗体融合。当细胞表面标记物被抗体结合时，这两半将被拉近，形成一个小报告分子的结合袋。我们将通过在显微镜下观察人类肿瘤细胞的过程来观察小报告分子是否结合，从而证明该系统是有效的。小的报告分子将携带一种染料，使其可视化。目标1-3概述了这个过程。目的1。制备和测试针对细胞表面标记物和小报告分子的抗体。目的2将半抗体与全抗体融合，并重新检测其结合能力是否受到阻碍。目的3将融合抗体和染料标记的小报告分子加入人癌细胞中，在显微镜下观察这一过程，以确定该系统是否有效。如果我们能够使这个成像系统工作，它就可以在人类癌症的动物模型中进行测试。如果成功，它也可以用于观察治疗期间和治疗后的人类csc水平。当开发出抗csc疗法时，这将特别有用。

DESCRIPTION (provided by applicant): Evidence is mounting that tumor growth is driven by cancer stem cells (CSCs).These cells are believed to act as the driving force for tumor growth because they are resistant to therapy and are able to self renew. Prior to the discovery of CSCs, the clonal model of tumor progression held the majority of support. This model posits that every cell within a tumor has the capacity for self-renewal and therefore, if not killed during therapy, can repopulate the tumor with subclones resistance to the therapy. The CSC model maintains that a tumor consists of a hierarchy of cells. The CSCs within the tumor are the cells that are able to regenerate themselves and co-produce non-CSC progeny which make up a good deal of the remaining tumor bulk. Because CSCs are a sub population within a group of tumor cells, they are marked with two different molecules that are attached to the outside of the cell. We propose an imaging system based on antibodies that have high affinity for two of these markers which we will develop. We will also develop a third antibody for a small reporting molecule that will be labeled with a dye. This antibody will be divided in half and each half will be fused to the antibodies for the two cell surface markers. When the cell surface markers are bound by the antibodies the two halves will be brought in close proximity and form a binding pocket for the small reporting molecule. We will prove this system works by visualizing whether the small reporting molecule binds by viewing the process on human tumor cells in a microscope. The small reporting molecule will bear a dye that will enable its visualization. The process is outlined below in Aims 1-3. Aim 1. Prepare and test antibodies to the cell surface markers and the small reporting molecule. Aim 2 Fuse the half-antibodies to the whole antibodies and retest to show that binding ability has not been hampered. Aim 3 Add the fused antibodies and dye-labeled small reporting molecule to the human cancer cells and view the process under the microscope to determine whether the system can work. If we are able to make this imaging system work, it can then be tested in animal models of human cancer. If successful, it also be used in humans to view the levels of CSCs during and after therapy. This will be particularly useful when anti-CSC therapies are developed.