OBJECTIVETo investigate the effects of tributyrin (TB), a histone deacetylase inhibitor, on the growth, differentiation and apoptosis of SHI-1 leukemia cells and explore its possible mechanism.

METHODCell proliferation and viability were determined by cell counting, trypan blue dye exclusion. Cell morphological analysis, Annexin binding, DNA electrophoresis, expression of CD11b and CD14, NBT reduction were performed to evaluate differentiation and apoptosis of SHI-1 cells. The level of acetylated histone H3 was detected by Western blot and p21(WAF1/CIP1) expression by semi-quantitative RT-PCR.

RESULTSTB inhibited the proliferation and viability of SHI-1 cells in a time-dose dependent manner. The morphology of SHI-1 cells cultured in the presence of 0.1 mmol/L TB for 72 hs was more mature with higher NBT positivity and up-regulated expressions of CD11b and CD14 than that of control group. Exposed to 0.5 - 1.0 mmol/L TB for 48 hs, SHI-1 cells exhibited the morphological hallmarks of apoptosis, the increasing of Annexin binding and the DNA ladder on gel electrophoresis. The level of acetylated histone H3 and p21(WAF1) mRNA extracted from SHI-1 cells were increased by the treatment of TB.

CONCLUSIONTB can inhibit proliferation, induce differentiation and apoptosis of SHI-1 cells. The mechanism may associate with its up-regulation of acetylated histone and the expression of p21(WAF1).