School of Cancer and Pharmaceutical Science, King's College London, SE1 9NH, UK.
Analyst. 2019 Apr 8;144(8):2725-2735. doi: 10.1039/c8an02218f.
Fourier transform infrared spectroscopy (FTIR) has been shown to be a promising tool for identifying the mode of action of drugs. However, most previous studies have focused on the analysis of fixed or dried cells. The measurement of living cells has the advantage of obtaining time series data, and the in situ approach eliminates the need for fixing or drying the cells. In this study, the potential of live-cell FTIR method for the identification of the mode of action of drugs was demonstrated. Four different drugs were tested, with two of the drugs having the same mode of action (tamoxifen and toremifene) and the other two having different modes of action (imatinib and doxorubicin). Live cells were treated in the four drugs at and below the IC50 level (i.e. the concentration of drug required to inhibit the growth of cells by 50%), and the changes to their spectra after the addition of drugs were monitored over a 24-hour period. Principal component analysis (PCA) of the spectral data shows that drugs with different modes of action are well-separated, while the drugs with the same mode of action are grouped together. The results also show that at IC50, the separation appears to be the clearest at 2 hours for imatinib and tamoxifen/toremifene and 6 hours for doxorubicin. However, at 50% of the IC50 drug concentration, the separation appears to be the best at longer incubation time, i.e. 24 hours, for all four drugs. In conclusion, live-cell FTIR has shown to be able to distinguish and group spectral signatures of cells treated with drugs of known modes of action after a relatively short time of exposure. Further collection of live-cell data would enable an algorithm to be developed for the prediction of the modes of action of novel drugs, which can help in the preclinical drug screening process.
傅里叶变换红外光谱（FTIR）已被证明是一种有前途的工具，可以用于识别药物的作用模式。然而，大多数先前的研究都集中在固定或干燥细胞的分析上。活细胞的测量具有获得时间序列数据的优势，而原位方法则无需固定或干燥细胞。在这项研究中，证明了活细胞 FTIR 方法用于识别药物作用模式的潜力。测试了四种不同的药物，其中两种药物具有相同的作用模式（他莫昔芬和托瑞米芬），另外两种药物具有不同的作用模式（伊马替尼和阿霉素）。在低于 IC50 水平（即抑制细胞生长 50%所需的药物浓度）下用四种药物处理活细胞，并在 24 小时内监测添加药物后其光谱的变化。对光谱数据进行主成分分析（PCA）表明，作用模式不同的药物分离良好，而作用模式相同的药物聚集在一起。结果还表明，在 IC50 下，伊马替尼和他莫昔芬/托瑞米芬的分离似乎在 2 小时和阿霉素的 6 小时时最清晰。然而，在 IC50 的 50%药物浓度下，所有四种药物的分离似乎在更长的孵育时间（即 24 小时）时最佳。总之，活细胞 FTIR 已经证明能够在相对较短的暴露时间后区分和分组已知作用模式的药物处理后的细胞的光谱特征。进一步收集活细胞数据将能够开发用于预测新型药物作用模式的算法，这有助于临床前药物筛选过程。
