Inhibitory effects of Hes1 on acute myeloid leukemia cells

To elucidate the impact of Hes1 on the proliferation and apoptosis of acute myeloid leukemia (AML) cells. The expression levels of Hes1 and p21 in AML patient samples and myeloid leukemia cell lines were analyzed by real-time PCR. Hes1 was up-regulated by retrovirus transfection in AML cell lines and the proliferation capacity were assayed by MTT, cell cycle by Hoechst/PY, apoptosis by AnnexinV. The expression of Hes1 in primary AML cells and HL-60, U937, KG1a cell lines were 0.67 ± 0.24, 0.59 ± 0.43, 0.42 ± 0.03, and 0.32 ± 0.26, respectively, and p21 were 0.54 ± 0.01, 0.44 ± 0.12, 0.36 ± 0.12, and 0.59 ± 0.43, respectively. Hes1 expression levels after transduction in HL-60, U937, KG1a were 4.9 ± 0.2, 5.2 ± 0.4, 5.8 ± 0.5, respectively. Induced activation of Hes1 led to AML cells growth arrest and apoptosis, which was associated with an enhanced p21 expression. Besides, activated Hes1 led to AML cells growth inhibition in vivo. Hes1 could mediate growth arrest and apoptosis in AML cells, which may be a nove