University of Notre Dame, 251 Nieuwland Science Hall, Notre Dame, Indiana 46556, USA.
Anal Chem. 2013 Jul 2;85(13):6295-302. doi: 10.1021/ac400519c. Epub 2013 Jun 11.
Drug penetration into solid tumors is critical for the effectiveness of clinical chemotherapy. Failing to consider the efficiency of drug penetration can lead to fatal recurrence in many cancers. Three-dimensional (3D) cell cultures have served as an important model system and have contributed to valuable assays in drug discovery studies. However, limited methodologies result in incomplete evaluation of the distribution of many anticancer drugs. As a proof-of-concept study, we have applied matrix-assisted laser desorption/ionization (MALDI) imaging mass spectrometry (IMS) in HCT 116 colon carcinoma multicellular spheroids to assess the distribution of the anticancer drug, irinotecan. The time-dependent penetration of irinotecan was visualized and the localization of three metabolites as well as the parent drug in treated spheroids was mapped. To validate the identities of the metabolites, we analyzed extracts from drug-treated spheroids using nanoflow liquid chromatography-tandem mass spectrometry (nLC-MS/MS). Ten metabolites were identified with nLC-MS/MS, including those detected by MALDI IMS. This novel approach allows the measurement of drug penetration and distribution in 3D culture mimics and provides a more cost and time-effective approach for the testing of new pharmaceuticals compared to animal models.
药物渗透进入实体肿瘤对于临床化学疗法的效果至关重要。如果不考虑药物渗透的效率，许多癌症都会导致致命的复发。三维（3D）细胞培养已成为一个重要的模型系统，并为药物发现研究中的有价值的检测方法做出了贡献。然而，有限的方法导致许多抗癌药物的分布无法得到完整评估。作为概念验证研究，我们已经将基质辅助激光解吸/电离（MALDI）成像质谱（IMS）应用于 HCT 116 结肠癌细胞球，以评估抗癌药物伊立替康的分布。可视化了伊立替康的时间依赖性渗透，并绘制了处理后的球体中三种代谢物以及母体药物的定位。为了验证代谢物的身份，我们使用纳流液相色谱-串联质谱（nLC-MS/MS）分析了来自药物处理的球体的提取物。使用 nLC-MS/MS 鉴定了 10 种代谢物，包括 MALDI IMS 检测到的代谢物。与动物模型相比，这种新方法可以测量 3D 培养模拟物中的药物渗透和分布，并为新药物的测试提供更具成本效益和更有效的方法。
