ABSTRACT
The aim of study was to investigate the effect of acute lymphoblastic leukemia (ALL) children bone marrow mesenchymal stem cells (MSC) on resistance of K562/A02 cells and its mechanism. MSC obtained from bone marrow of AL children were cultured and identified. The co-culture of MSC and K562/A02 and the culture of K562/A02 cell suspension alone was performed, of which 2 kinds of cells were treated with same concentration of adriamycin (ADM), and the rate of apoptosis was detected by flow cytometry, bcl-2 and bax of K562/A02 were detected by RT-PCR, while mdr1 gene level was detected by FQ-PCR. The results indicated that the MSC separation and proliferation were viable and steady. The apoptosis rate of the K562/A02 cells co-cultured with MSC was 1.97 ± 0.11%, while apoptosis rate of the K562/A02 cells cultured alone was 8.38 ± 0.29%, there was significant difference (p < 0.05). As compared with the K562/A02 cells cultured alone, the bcl-2 gene expression in K562/A02 cells co-cultured with MSC obviously increased; ratio of bcl-2/bax was obviously enhanced. The mdr1 gene level in K562/A02 co-cultured with MSC was no statistical different from K562/A02 cultured alone (p > 0.05), which suggested that adhesion co-cultured with MSC did not induce mdr1 expression higher than the culture of suspension. It is concluded that the MSC of ALL children can escape the leukemia cells from proapoptotic effect of drugs, the resistance of K562/A02 to ADM may be involved in enhancement of bcl-2 gene expression of K562/A02 cells co-cultured with MSC, but not in relation to mdr1 gene in K562/A02 cells themselves.