Multicellular tumour spheroids are an ideal in vitro tumour model to study clonal heterogeneity and drug resistance in cancer research because different cell types can be mixed at will. However, measuring the individual response of each cell population over time is challenging: current methods are either destructive, such as flow cytometry, or cannot image throughout a spheroid, such as confocal microscopy. Our group previously developed a wide-field fluorescence hyperspectral imaging system to study spheroids formed and cultured in microfluidic chips. In the present study, two subclones of a single parental ovarian cancer cell line transfected to express different fluorophores were produced and co-culture spheroids were formed on-chip using ratios forming highly asymmetric subpopulations. We performed a 3D proliferation assay on each cell population forming the spheroids that matched the 2D growth behaviour. Response assays to PARP inhibitors and platinum-based drugs were also performed to follow the clonal evolution of mixed populations. Our experiments show that hyperspectral imaging can detect spheroid response before observing a decrease in spheroid diameter. Hyperspectral imaging and microfluidic-based spheroid assays provide a versatile solution to study clonal heterogeneity, able to measure response in subpopulations presenting as little as 10% of the initial spheroid.

中文翻译：

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对芯片上处理的共培养肿瘤球体进行长期荧光高光谱成像，以跟踪克隆进化。


多细胞肿瘤球体是癌症研究中研究克隆异质性和耐药性的理想体外肿瘤模型，因为不同的细胞类型可以随意混合。然而，随着时间的推移测量每个细胞群的个体反应具有挑战性：当前的方法要么具有破坏性，例如流式细胞术，要么无法对整个球体进行成像，例如共焦显微镜。我们的小组之前开发了一种宽视场荧光高光谱成像系统，用于研究微流控芯片中形成和培养的球体。在本研究中，产生了单个亲本卵巢癌细胞系的两个亚克隆，转染以表达不同的荧光团，并使用形成高度不对称亚群的比例在芯片上形成共培养球体。我们对形成与 2D 生长行为相匹配的球体的每个细胞群进行 3D 增殖测定。还进行了对 PARP 抑制剂和铂类药物的反应测定，以跟踪混合群体的克隆进化。我们的实验表明，高光谱成像可以在观察球体直径减小之前检测球体响应。高光谱成像和基于微流体的球体测定为研究克隆异质性提供了一种通用的解决方案，能够测量仅占初始球体 10% 的亚群的反应。