Infrared spectroscopy as a tool for discrimination between sensitive and multiresistant K562 cells

Fourier transform infrared spectroscopy was performed on human leukemic daunorubicin-sensitive K562 cells and their multiresistant counterpart derived by selection. Statistical analysis, including variable reduction and linear discriminant analysis was performed on sensitive and multiresistant cells spectra in order to establish a diagnostic tool for multiresistant pattern. For each of the two methods of data reduction tested [genetic algorithm or principal component analysis (PCA)] discrimination between the two cell lines was found to be possible. The best results, obtained with PCA-reduction, showed an accuracy of 93% on a distinct test set of spectra. These results demonstrate the efficiency of Fourier transform infrared spectroscopy for classification. Further analysis of the spectral differences indicated that discrimination between resistant and sensitive cells was based on variations in all cellular contents. Lipid and nucleic acid decreased, relatively, while the protein content increased.