Mechanism of ouabain inducing the apoptosis of T lymphoblastic leukemia Jurkat cells / 医学研究生学报

ABSTRACT

Objective Ouabain is a cardiotonic steroid that can induce the apoptosis of many tumorous cells .This study was to investigate the anti-tumor mechanisms of ouabain by observing its effects on the apoptosis of T lymphoblastic leukemia Jurkat cells and the expressions of hTERT and c-myc mRNA and protein . Methods Jurkat cells were treated with ouabain at the concentrations of 50 and 100 nmol/L for 24 and 48 hours, and those treated with 1 ×PBS served as the control .Then the apoptosis rate of the cells was detected by flow cytometry after Annexin V/PI staining, the expressions of hTERT and c-myc mRNA determined by RT-PCR, and those of hTERT and c-myc protein by Western blot . Results The apoptosis rates of the Jurkat cells in the 50 and 100 nmol/L oua-bain groups were (5.67 ±3.71)%and (9.63 ±4.83)%respectively at 24 hours, and (19.67 ±4.55)%and (37.60 ±11.89)%at 48 hours, significantly higher than (4.23 ±1.01)%in the PBS control group at 48 hours (P<0.05).Compared with the control, the expressions of hTERT and c-myc mRNA were decreased by 200%and those of hTERT and c-myc protein by 224%and 400%, re-spectively, at 48 hours (P<0.05).There was a positive correlation between the reduction of the mRNA levels and that of the protein levels of hTERT and c-myc (P<0.05). Conclusion Ouabain can down-regulate the mRNA and protein expressions of hTERT and c-myc, which may be one of the mechanisms of its induction of the apoptosis of Jurkat T lymphocyte leukemia cells .