OBJECTIVETo explore the molecular mechanisms of apoptotic NB4 cells induced by the histone deacetylase inhibitor, sodium butyrate(SB).

METHODSSB was exposed to NB4 cells at a final concentration of 1.0 mmol/L. The untreated and treated cells were analysed with FACS and 2-dimensional electrophoresis (2-DE) at 0, 12, 24, 48 and 72 h. The changed protein spots were identified with MALDI-TOF-MS and ESI-TOF-MS/MS.

RESULTSSB induced apoptosis of NB4 cells. Twenty-one changed proteins involving apoptotic signal transduction, immunological regulation, transcriptional control, cellular metabolism, molecular transport and so on were identified. Thirteen of them had been reported to be related to apoptosis.

CONCLUSIONSB can induce apoptosis and many functional protein changes in tumor cells. These results pave the way to further explore the anti-tumor mechanism of SB.