Riken Biodynamics Research Center (BDR) , 6-2-3 Furuedai , Suita , Osaka 565-0874 , Japan.
Research Center , Misr International University , Cairo 19648 , Egypt.
Anal Chem. 2019 Feb 19;91(4):2710-2718. doi: 10.1021/acs.analchem.8b04393. Epub 2019 Feb 5.
Monitoring drug uptake, its metabolism, and response on the single-cell level is invaluable for sustaining drug discovery efforts. In this study, we show the possibility of accessing the information about the aforementioned processes at the single-cell level by monitoring the anticancer drug tamoxifen using live single-cell mass spectrometry (LSC-MS) and Raman spectroscopy. First, we explored whether Raman spectroscopy could be used as a label-free and nondestructive screening technique to identify and predict the drug response at the single-cell level. Then, a subset of the screened cells was isolated and analyzed by LSC-MS to measure tamoxifen and its metabolite, 4-Hydroxytamoxifen (4-OHT) in a highly selective, sensitive, and semiquantitative manner. Our results show the Raman spectral signature changed in response to tamoxifen treatment which allowed us to identify and predict the drug response. Tamoxifen and 4-OHT abundances quantified by LSC-MS suggested some heterogeneity among single-cells. A similar phenomenon was observed in the ratio of metabolized to unmetabolized tamoxifen across single-cells. Moreover, a correlation was found between tamoxifen and its metabolite, suggesting that the drug was up taken and metabolized by the cell. Finally, we found some potential correlations between Raman spectral intensities and tamoxifen abundance, or its metabolism, suggesting a possible relationship between the two signals. This study demonstrates for the first time the potential of using Raman spectroscopy and LSC-MS to investigate pharmacokinetics at the single-cell level.
监测药物摄取、代谢和单个细胞水平的反应对于维持药物发现工作至关重要。在本研究中，我们展示了通过使用活单细胞质谱（LSC-MS）和拉曼光谱监测抗癌药物他莫昔芬，在单细胞水平上获取上述过程信息的可能性。首先，我们探索了拉曼光谱是否可以用作无标记和非破坏性的筛选技术，以识别和预测单细胞水平的药物反应。然后，对筛选出的细胞子集进行分离，并通过 LSC-MS 进行分析，以高度选择性、灵敏和半定量的方式测量他莫昔芬及其代谢物 4-羟基他莫昔芬（4-OHT）。我们的结果表明，拉曼光谱特征在他莫昔芬处理后发生变化，这使我们能够识别和预测药物反应。LSC-MS 定量的他莫昔芬和 4-OHT 丰度表明单细胞之间存在一些异质性。在单个细胞中，代谢和未代谢的他莫昔芬的比例也观察到了类似的现象。此外，还发现了他莫昔芬与其代谢物之间的相关性，表明细胞摄取和代谢了该药物。最后，我们发现拉曼光谱强度与他莫昔芬丰度或其代谢之间存在一些潜在相关性，表明这两个信号之间存在可能的关系。本研究首次证明了使用拉曼光谱和 LSC-MS 研究单个细胞水平的药代动力学的潜力。
