[The effect of ATRA-induced leukemic cell differentiation on Brd7 gene expression in leukemia cell lines]

This study was purposed to investigate the relationship between brd7 gene and differentiation of leukemia cells and the role of brd7 gene in differentiation of leukemia cells. The HL-60 and K562 cell lines were induced by all-trans retinoic acid (ATRA) for 7 days, then the cell morphologic change was observed under inverted microscope with Wright-Giema staining, the expression level of CD11b was detected by flow cytometry for evaluating cell differentiation level, the expression changes of BRD7 protein before inducing differentiation and in process of cell differentiation were determined by Western blot. The results showed that ATRA could inhibit the proliferation and induce differentiation of HL-60 cells, but no differentiation in K562 cells was induced by ATRA. The level of CD11b expression in HL-60 cells was up-regulated gradually during ATRA-induced cell differentiation. The expression of BRD7 protein increased markedly along with differentiation of HL-60 cells towards granulocytes. However, BRD7 protein did not significantly alter in K562 cells in which inducing differentiation was not found. It is concluded that brd7 gene expression enhances as the HL-60 cells differentiate, underlying which the mechanism remains to clarify.