Monitoring all-trans-retinoic acid-induced differentiation of HL-60 cells by Fourier-transform infrared spectroscopy

This study reports a new in vitro analytical method, based on Fourier-transform infrared (FTIR) spectroscopy, to monitor the myeloid differentiation process in human myeloblast leukemia HL-60 cells induced by all-trans-retinoic acid (ATRA). The alteration of characteristic bands was identified in the differentiated cells, arising from proteins, lipids, carbohydrates and nucleic acids. Besides the changes in lipid content and plasma membrane fluidity, the most striking changes were observed in the region of nucleic acids and carbohydrates. The authors speculate that the glycosylation and phosphorylation of proteins and the hydrogen-bonding of nucleic acids were involved in differentiation. The spectral parameters were correlated with the differentiation index, as determined by NBT reduction assay. These results suggest that FTIR spectroscopy can be used to monitor the differentiation process of HL-60 cells.