OBJECTIVETo investigate the effect of embryonic stem cells on the proliferation and apoptosis in human acute myeloid leukemia cell line KG-1a and to explore its potential mechanism.

METHODSThe direct co-culture system between human embryonic stem cells H9 and human acute myeloid leukemia cell line KG-1a was established, and CCK8 assay was used to detect the proliferation of KG-1a cells. The changes of cell cycle and apoptosis were detected by flow cytometry (FCM). The mRNA expressions of BCL-2, BAX, Caspase-3 were assessed by RT-PCR. Meanwhile, the protein-expressions of BCL-2, BAX, Caspase-3 were detected by Western blot.

RESULTSThe proliferation level of KG-1a cells was significantly inhibited by H9, and the apoptotic rate increased, and the cell cycle was blocked at G/M phase. The mRNA-expression and the protein-expression of BAX and Caspase-3 increased, the mRNA and protein-expression of BCL-2 decreased.

CONCLUSIONEmbryonic stem cells can inhibit the proliferation of KG-1a and induce the apoptosis that maybe relate with the down-regulation of BCL-2 expression and up-regulation of BAX and caspase-3 expression.