RESUMO
Objective To study the effect of acute lymphoblastic leukemia (ALL) children bone marrow mesenchymal stem cells (MSCs) on the resistance of K562cell atd mechanism in vitro.Method MSCs were obtained from AL children bone marrow after derivation, cultivation and identification.The coculture of MSCs and K562 and K562 suspension were established.Effects of MSCs on the growth of K562 cells were investigated in vivo.The two kinds of cells treated with different concentration of adriamycin (ADM) and the rate of apoptosis was evaluated by flow cytometry.Cell cycle was determined by flow cytometry.RT-PCR was used to detect Bcl-2 and Bax in K562 cells.Result Compared with the cell growth curve of K562 alone, the K562 cell co-cultured with MSCs grew slower and the exponential phase of growth was not obvious.The apoptosis index of the K562 cells co- clutured with MSCs was (9.19 ±0.53)% examined by flow cytometry, and that of the K562 cells alone was 4.00 ± 0.37% respectively( P ＜ 0.05 ).The percentage of cells at G0/G1 phase was (50.2 ± 2.26) % and that at S phase was (37.03 ± 3.50) % in the group of K562 alone, but those of the K562 cells co - cultured with MSCs were (80.95 ± 3.83) % and ( 17.40 ± 1.50)% respectively( P ＜0.05).The result of RT-PCR suggested expression of Bcl-2/Bax of the K562 cell co-cultured with MSCs was higher than K562 alone.Conclusion ALL children MSCs suppressed the growth of K562 cell in vitro.Adhesion made K562 depress sensitive to ADM.The mechanism was perhaps caused by adhesion with MSCs, K562 cell cycle was changed and related to Bcl-2 gene high level expression.