SELECTIVELY IMAGING CANCER STEM CELLS

描述（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，因为它们对治疗具有抗性，并且能够自我更新。在发现CSC之前，肿瘤进展的克隆模型获得了大多数支持。该模型假定肿瘤内的每个细胞都具有自我更新的能力，因此，如果在治疗期间没有被杀死，则可以用对治疗具有抗性的亚克隆重新填充肿瘤。CSC模型认为肿瘤是由一系列细胞组成的。肿瘤内的CSC是能够自我再生并共同产生非CSC后代的细胞，这些后代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，它们被标记有两种不同的分子，附着在细胞外部。我们提出了一种基于抗体的成像系统，这些抗体对我们将开发的其中两种标记物具有高亲和力。我们还将开发第三种抗体，用于标记染料的小报告分子。将该抗体分成两半，每一半将与两种细胞表面标志物的抗体融合。当细胞表面标记物被抗体结合时，两个半部分将被紧密靠近并形成小报告分子的结合口袋。我们将通过在显微镜下观察人类肿瘤细胞的过程来可视化小报告分子是否结合，从而证明该系统的工作原理。小的报告分子将带有染料，这将使其可视化。这一进程在下文目标1-3中概述。目标1。制备并检测细胞表面标志物和小报告分子的抗体。目的2将半抗体与全抗体杂交，并重新检测，以显示结合能力没有受到阻碍。目的3将融合抗体与染料标记的小报告分子（small reporting molecule，smL）一起作用于人癌细胞，并在显微镜下观察其作用过程，以确定该系统是否能够发挥作用。如果我们能够使这种成像系统工作，那么它就可以在人类癌症的动物模型中进行测试。如果成功，它也可以用于人类，以查看治疗期间和治疗后的CSC水平。当开发抗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.