The Experimental Research On Effects Of Ouabain At Low Concentrations On The Leukemia Cells Growth

Objective:To determine the therapeutic potential of ouabain in leukemia, we examined the effects of ouabain at low concentrations on growth regulation in various primary leukemia Cells and leukemia cell lines. To observe the basic expression of Na~+/K~+-ATPase and the regulation of ouabain on the expression of Na~+/K~+-ATPase in leukemia cells.Methods:By using MTT method, changes in cell growth of various leukemia cells were observed after cells were exposed to increasing concentrations (0.1, 1, 10nmol/L), during a 24 hours period. After the cells were treated with ouabain in low concentrations (≤10nmol/L), the cell cycles of leukemia cells were assayed by flow cytometry (FCM) technique. The expressions of Na~+/K~+-ATPaseα1 Subunit in various leukemia cells were evaluated by western-blot, before and after the cells were treated with low concentrations of ouabain.Results:We found that low concentrations of ouabain (≤10nmol/L) inhibited the cell growth of megakaryocytic leukemia cell lines, M07e and Meg-01; while it induced the proliferation of lymphoid leukemia cell lines, B95 and Jhhan as well as primary leukemia cells, in a dose dependent manner by MTT method.The data of FCM(flow cytometry) further indicated that ouabain in low concentrations during a 24 hours period could block the cell cycles at G1 phase in two megakaryocytic leukemia cell lines, while increase the percent of cells of S phase as well as G2/M phase in two lymphoid leukemia cell lines.The results of Western-blot show that the basic expression of Na~+/K~+-ATPaseα1 Subunit in megakaryocytic leukemia cell lines , M07e and Meg-01 were lower than that in the other leukemia cells from our significant experiment (P<0.01) . After treated with ouabain in low concentrations, the expression of Na~+/K~+-ATPaseα1 Subunit in two megakaryocytic leukemia cell lines were decreased, while which in lymphoid leukemia cell lines were increased.Conclusion:There are difference in the influence of ouabain on the growth in different leukemia cells, which might relate to the differential expression and regulation of Na~+/K~+-ATPaseα1 Subunit by ouabain.