Abstract:OBJECTIVE: ATRA can restrain proliferation and promote differentiation in various tumor cells. The aim of the study is to investigate the differentiation characteristics of K562 induced by ATRA. METHODS: Morphology (Benzidine staining, Wright's staining, NSE staining and NBT recovery test) and flow cytometry were used to observe the differentiation characteristics of K562 after co-incubation with 1 μmol/L and 2.5 pmol/L ATRA for 1 d, 4 ds, and 5 ds. RESULTS: Co-incubated for 4 ds, 61.5% K562 cells in the 1 μmol/L ATRA group and 39% K562 cells in the 2.5 μmol/L ATRA group showed some evidence of myeloid maturation, but no evidence of erythroid or monocytoid maturation. Cb-incubated for 5 ds, the percentage of differentiated K562 cells was much higher than that in the control group. One day after induction by 1 μmol/L ATRA or 2.5 μmol/L ATRA, the expression of CD13 was 8.0% and 6.7%, respectively, which was higher than that in the control group (2.1%). Five days after induction by 1 μmol/L ATRA or 2.5 μmol/L ATRA, the expression of CD13 increased to 28.1 % and 37.8 % , respectively, while the expression of CD71 decreased to 1.2 % and 0.9 % respectively. The differences between the ATRA groups and the control group were significant ( P < 0.05). CD71 decreased from 9.7% and 10.8% in the 1 μmol/L and 2.5 μmol/L ATRA groups on day 1 to 1.2% and 0.9% on day 5, while the CD13 expression level increased from 8.0% and 6.7% to 28.1% and 37.8% , respectively. CONCLUSIONS: ATRA can induce K562 to differentiate into myeloid linage. [Chin J Contemp Pediatr, 2003, 5(1): 8-11]
