OBJECTIVESTo investigate the expression status of IER3IP1 gene during matrine induced K562 cell differentiation, and to figure out the function of IER3IP1 gene in K562 cell line.

METHODSTrypan-blue staining was used to analyze the growth inhibitory effect of matrine on K562 cells. Semi-quantitative RT-PCR was employed to investigate the expression status of IER3IP1 gene treated with different time and dosage of matrine. The alteration of cellular morphology, cellular proliferation and ultra-microstructure were observed and the cell cycle was detected on the recombinant IER3IP1 gene eukaryotic expression vector eYFP-IER3IP1 plasmid transfected K562 cells (K562/eYFP-IER3IPl).

RESULTSMatrine inhibited the growth of K562 cells and reduced the expression of IER3IP1 gene. The expression level of IER3IP1 gene was transiently increased to three-to-four times in a dose-dependent manner after treated with matrine for 2 - 3 hours. Then, in 6-48 hours it maintained at a low level as compared with the control group. The proliferation rate of the K562/eYFP-IER3IP1 cells significantly slowed down with more cells blocked in G0-G1 phase (P < 0.05). The number of erythroid blast cells began to increase after 24 hours of matrine treatment. At the same time, differentiated erythroid cells could be observed.

CONCLUSIONSMatrine can inhibit the growth of K562 cells, and transiently increase the expression level of IER3IP1 gene in a dose-dependent manner. The sensitivity of K562 cells to matrine maybe increased after being transfected by the eYFP-IER3IP1 plasmid, indicating a possible involvement of the IER3IP1 gene in the early response of the cells to matrine and its possible role in the erythroid cell differentiation.