Elucidating cellular heterogeneity among cancer stem cells by Raman Spectroscopy

描述（由申请人提供）：乳腺癌细胞通常表现出功能和表型的异质性。细胞异质性可能是促进癌症复发的耐药和休眠的来源。肿瘤细胞异质性的一个来源可能是肿瘤干细胞的存在。基于这一假设，致瘤性CSCs（此处称为肿瘤起始细胞（tic））“分化”为非致瘤性癌细胞，形成层次结构和肿瘤细胞异质性。乳腺tic通过表达独特的细胞外表面标记物如CD44hi/CD24lo来鉴定。现在认为，即使是tic也可能通过克隆进化表现出细胞异质性。为了研究乳腺tic的异质性，我们使用了拉曼光谱（RS）。RS能够表征活tic的细胞内分子组成。通过进行RS，我们证明了基于独特的细胞内分子成分的表达，活的tic表现出肿瘤间和肿瘤内的异质性。基于这些数据，我们假设tic是异质的，拉曼镊子光谱（RTS）可能是一种分类和功能评估具有独特细胞内分子谱（imp）的tic群的致瘤潜力的方法。我们的长期目标是识别和根除

DESCRIPTION (provided by applicant): Breast cancer cells often exhibit functional and phenotypic heterogeneity. Cellular heterogeneity may be the source of drug resistance and dormancy promoting cancer relapse. One source of tumor cell heterogeneity may be the existence of cancer stem cells. Based on this hypothesis, the tumorigenic CSCs, herein referred to as tumor initiating cells (TICs), "differentiate" into non-tumorigenic cancer cells creating a hierarchical organization and tumor cell heterogeneity. Breast TICs have been identified by the expression of unique extracellular surface markers such as CD44hi/CD24lo. It is now believed that even TICs may exhibit cellular heterogeneity through clonal evolution. In order to study heterogeneity among breast TICs, we utilized Raman Spectroscopy (RS). RS enables the characterization of intracellular molecular composition of live TICs. By performing RS, we demonstrated that live TICs exhibited both inter- and intra-tumoral heterogeneity based on the expression of a unique intracellular molecular component. Based on these data, we hypothesize that TICs are heterogeneous and Raman Tweezer Spectroscopy (RTS) may be a method by which to sort and functionally evaluate the tumorigenic potential of TICs groups that exhibit unique intracellular molecular profiles (IMPs). Our long-term goal is to identify and eradicate the most resistant, dormant, and aggressive breast TICs in order to prevent cancer relapse. Our objective is to characterize heterogeneity among TICs by IMP using RTS. Our Rationale is that so far, TICs have been isolated and characterized by the expression of unique surface markers. However, a methodology for isolation and characterization of TICs based on combined extracellular and IMP has not been evaluated. RS is a vibrational spectroscopy. Photons of the laser light are absorbed by live cells and then reemitted, providing spectral profiles (wavelengths) that represent the intracellular biochemical signatures of living cells. RTS will be combined with advanced mathematical tools to quantify characteristic IMPs of TICs non-invasively, with high specificity and rapidly. RTS permits sorting cells according to their IMPs. The trapped cells will then be functionally evaluated for their tumorigenic potential by limiting dilution transplantation assays. These studies will provide the basis for future molecular characterization of the most aggressive and indolent breast TICs and design of therapeutic strategies for their eradiation.