OBJECTIVETo study the effects of hermap gene on kinases in erythroid signal transduction pathway and investigate the mechanism of hermap on erythroid differentiation.

METHODSThe K562 cells expressing hermap and hermap-siRNA respectively were established for up- and down-regulating the expression of hermap gene. These K562 cells were then induced by Ara-C to erythroid differentiation and analyzed at 0, 24, 48, 72 and 96 h, respectively, for cell morphology and biphenylamine staining positive cells, determination of CD235a, CD36, kinases p-STAT5, p-Akt, p-MAPK and p-c-JUN by FCM; and quantification of hermap gene and γ (Aγ,Gγ) globin gene by FQ-PCR.

RESULTSWith up-regulating hermap gene and inducing by Ara-C, K562 cells were changing to low ratio of nucleus to cytoplasm, cytoplasm colour from basophilic to pinkish or amethyst tinge, increase of number of biphenylamine positive cells and expression of CD235a, CD36, γ (Aγ,Gγ) globin gene, hermap gene and p-STAT5 from 0 to 96 h. At 0, 24, 48, 72 and 96 h of culture, the positive rates of p-STAT5 cells were detected of 0.46%, 4.54%, 20.01%, 23.65% and 33.08%, respectively. This results demonstrated that there was a positive correlation between expression of p-STAT5 and hermap gene expression (P < 0.05).

CONCLUSIONhermap gene can stimulate erythroid differentiation of Ara-C induced K562 cells mainly through JAK/STAT5 signal transduction pathway.