Apoptosis of K562 cell induced by N-phosphoryl dipeptide methyl ester

Abstract

BACKGROUND & OBJECTIVE: Phosphorus plays a crucial role in metabolism. Some N-phosphoryl amino acids and N-phosphopeptides have important biological activities and medicinal value. The current study was designed to investigate the apoptosis of K562 cells induced by N-phosphoryl dipeptide methyl ester. METHOD: Cell growth inhibition of K562 cells induced by 15 kinds of N-phosphoryl dipeptide methyl esters was analyzed by using MTT assay. The nuclei were stained by Hoechst 33,258 and the morphologic changes were observed. DNA agarose gel electrophoresis, double-staining, and flow cytomery were used to detect early apoptosis of K562 cells. RESULT: (DIPP-L-Leu)2-L-Lys-OCH3 was the compound screened with MTT method that had better growth inhibiting activity with the IC50 of 22.66 mumol/L. Chromatin condensation and nuclear fragmentation were seen under fluorescence microscope in the cells treated with Hoechst 33,258. DNA agarose gel electrophoresis showed nuclear fragmentation (DNA ladder). Early apoptotic cells were also detected by flow cytometry. CONCLUSION: These results suggest that(DIPP-L-Leu)2-L-Lys-OCH3 could induce the apoptosis of K562 cells.