Role of Histone Acetylation in the Differentiation Induced byDiallyl Disulfide in Gastric Cancer MGC803 Cells

Abstract: We previously reported that diallyl disulfide (DADS) could significantly induce the differentiation in human gastric cancer MGC803 cells. In this study， we further investigated the change of histone acetylation level and the expression of p21^WAF1 in the differentiation induced by DADS in MGC803 cells in vitro. Experiment were divided into six groups: untreated group， treated group with 5 mmol/L sodium butyrate， treated groups with 15， 30， 60 mg/L DADS and treated group with 5 mmol/L SB+30 mg/L DADS. After treated with 30 mg/L DADS for 24h in vitro， 0.2 ml including 1×10⁷ MGC803 cells were implanted into subcutaneous side in BALB/C nude mice. Morphological changes were examined under light microscopy. Expression of acetylated histone H3， H4 and p21^WAF1 were detected by Western blot. The results showed that MGC803 cells after 24 h treated with 30 mg/L DADS were fusiform multiplication， volume shrink， enlarged cytoplasm， diminished nucleus， descend karyoplasmic ratio， karyotin thinningz， decreased nucleoli and atypia reduced. The formation of xenograft tumor was not found. The acetylation level of histone H3 in MGC803 cells was elevated after treated by 30 mg/L DADS for 12 h， and the effect was higher 38 % than untreated cells (P<0.05)， and acetylation H4 did not changed. At the same time， the expression of p21^WAF1 also was increaser after treated by 15， 30， 60 mg/L DADS， and treated by 30 mg/L DADS was higher 34.6% and 60.8% than untreated at 12 h and 24 h， respectively. It is suggested that the differentiation of MGC803 cells induced by DADS possibly involved in increase of histone acetylation and expression of p21^WAF1.

CSTR: 32200.14.cjcb.2006.06.0018