Ministry of Education Key Laboratory of Analytical Science for Food Safety and Biology, Fujian Provincial Key Laboratory of Analysis and Detection Technology for Food Safety, College of Chemistry, Fuzhou University, Fuzhou, Fujian, 350116, China.
State Key Laboratory of Environmental and Biological Analysis, Department of Chemistry, Hong Kong Baptist University, Hong Kong SAR, China.
Talanta. 2023 Dec 1;265:124795. doi: 10.1016/j.talanta.2023.124795. Epub 2023 Jun 20.
Lipids and metabolites are small biological molecules that act major roles in cellular functions. Multicellular tumor spheroids (MCTS) are a highly beneficial three-dimensional cellular model for cancer research due to their ability to imitate numerous characteristics of tumor tissues. Increasing studies have performed spatial lipidomics and metabolomics in MCTS using matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI). However, these approaches often lack the sensitivity and specificity to offer a comprehensive characterization of lipids and metabolites within MCTS. In this study, we addressed this challenge by utilizing MALDI combined with laser-induced postionization (MALDI-2) and trapped ion mobility spectrometry (TIMS) imaging in H295R adrenocortical MCTS. Our results showed that MALDI-2 could detect more lipids and metabolites in MCTS than the traditional MALDI. TIMS data revealed a successful separation of many isomeric and isobaric ions of lipids and metabolites with different locations (e.g., proliferative region and necrotic region) within MCTS, suggesting an enhanced peak capacity for spatial lipidomics and metabolomics. To further identify these isomeric and isobaric ions, we performed MS/MS imaging experiments to compare the differences in signal intensities and spatial distributions of product ions. Our data highlight the strong potential of MALDI-2 and TIMS imaging for analyzing lipids and metabolites in MCTS, which may serve as valuable tools for numerous fields of biological and medical research.
脂质和代谢物是在细胞功能中起主要作用的小分子生物。多细胞肿瘤球体（MCTS）是一种非常有益的三维细胞模型，用于癌症研究，因为它们能够模拟肿瘤组织的许多特征。越来越多的研究使用基质辅助激光解吸/电离质谱成像（MALDI-MSI）在 MCTS 中进行空间脂质组学和代谢组学研究。然而，这些方法通常缺乏灵敏度和特异性，无法全面描述 MCTS 内的脂质和代谢物。在本研究中，我们通过在 H295R 肾上腺皮质 MCTS 中使用 MALDI 与激光诱导后电离（MALDI-2）和离子阱迁移谱（TIMS）成像相结合来解决这一挑战。我们的结果表明，MALDI-2 可以在 MCTS 中检测到比传统 MALDI 更多的脂质和代谢物。TIMS 数据显示，MCTS 内不同位置（例如增殖区和坏死区）的脂质和代谢物的许多同分异构体和等质异位离子得到了成功分离，表明空间脂质组学和代谢组学的峰容量得到了增强。为了进一步鉴定这些同分异构体和等质异位离子，我们进行了 MS/MS 成像实验，以比较产物离子的信号强度和空间分布的差异。我们的数据突出了 MALDI-2 和 TIMS 成像在分析 MCTS 中的脂质和代谢物方面的强大潜力，这可能成为生物和医学研究众多领域的有价值的工具。
