A rapid method for detecting conformational changes during differentiation and apoptosis of HL60 cells by Fourier-transform infrared spectroscopy.

The conformational changes of HL60 cells during differentiation and apoptosis are still not clearly understood. This study uses a new method, Fourier-transform infrared (FT-IR) spectroscopy, to analyse the changes of HL60 cells. We detected several differences among normal HL60 cells, differentiated cells induced by all-trans retinoic acid (ATRA) and PMA, and apoptotic cells induced by vincristine (VCR). The results suggest that the alpha-helix content of the membrane protein of differentiated HL60 cells induced by ATRA and PMA increased,and that the beta-sheet content of membrane proteins of apoptotic cells induced by VCR also increased. Also, C-O(H)-stretching modes of serine, threonine and tyrosine residues of cell proteins were shown to be distinctly different, but no significant differences were detected between cells differentiated along different lineages by ATRA and PMA.