Institute of Analytical Chemistry, University of Vienna , Waehringer Strasse 38, 1090 Vienna, Austria.
Department of Analytical Chemistry, Ghent University , Campus Sterre, Krijgslaan 281-S12, 9000 Ghent, Belgium.
Anal Chem. 2017 Dec 5;89(23):12641-12645. doi: 10.1021/acs.analchem.7b02681. Epub 2017 Nov 15.
Multicellular tumor spheroid models serve as an important three-dimensional in vitro cell model system as they mimic the complex tumor microenvironment and thus have contributed to valuable assays in drug discovery studies. In this study, we present a state-of-the-art laser ablation-inductively coupled plasma mass spectrometry (LA-ICPMS) setup for high spatial resolution elemental imaging of multicellular tumor spheroids and an approach to account for variations in cell density. A low dispersion LA-ICPMS setup was employed, providing accelerated throughput and high sensitivity and permitting a lateral image resolution down to ∼2.5 μm for phosphorus and platinum in HCT116 colon cancer spheroids upon treatment with the clinically used anticancer drug oxaliplatin. Phosphorus was introduced as scalar to compensate for differences in cell density and tissue thickness and the Pt/P ratios together with the high resolution adopted in our approach allows the differentiation of platinum accumulation within each part of the morphology of the tumor spheroids (layers of proliferating, quiescent, and necrotic cells).
多细胞肿瘤球体模型作为一种重要的三维体外细胞模型系统，模拟了复杂的肿瘤微环境，因此有助于药物发现研究中的有价值的测定。在本研究中，我们提出了一种最先进的激光烧蚀-电感耦合等离子体质谱（LA-ICPMS）装置，用于多细胞肿瘤球体的高空间分辨率元素成像，并提出了一种考虑细胞密度变化的方法。采用低分散度的 LA-ICPMS 装置，提供了加速的吞吐量和高灵敏度，并允许在 HCT116 结肠癌细胞球体用临床使用的抗癌药物奥沙利铂处理后，对磷和铂的横向图像分辨率达到约 2.5 μm。引入磷作为标量来补偿细胞密度和组织厚度的差异，并且我们的方法中采用的 Pt/P 比值和高分辨率允许区分肿瘤球体形态的每个部分内的铂积累（增殖、静止和坏死细胞层）。
