| Human leukemia is a common hematological malignant disease and current treatment choices are not very satisfactory. So, searching for some new effective antileukemia drugs is an important way to improve the cure rate. Berbamine(BER) is a kind of bis-benzylisoquinoline alkaloids that was extracted from Chinese herb. Recently berbamine and its derivatives have been proven to be calmodulin antagonist which could obviously inhibit the proliferation of different kinds of cell lines, such as hepatoma, HeLa cells and so on. Dong Y and Ji ZN had reported that berbamine could induce both growth inhibition and apoptotic cell death in HLeo cells and the effects may be associated with inhibition of the telomerase activity and down-regulation of bcl-2 gene expression. But the details about the mechanism of berbamine-induced apoptosis of other leukemic cell lines have not been reported yet. In this research, we tried to elucidate the antileukemia effects of berbamine and the possible molecular mechanisms in vitro and in vivo in order to provide a theoretical and experimental basis for berbamine as a new drug for hematopoitic maligancies.MTT method was used to examine the effect of berbamine on cell growth in K.562, Jurkat , NB4 , HLeo cells and normal bone marrow cells as well. A significant time-and-concentration-dependent inhibition of cell growth was found in all the cells treated with berbamine. After the cells were exposed to 8.0礸/ml berbamine for 24,48 and72 h, the percentage of growth inhibition in K562 cells progressively increased by 26.63% ?.57%, 61.84%?.74%, 75.32%?.95% respectively. While in Jurkat cells the figures were 26.77%?.30%, 44.48%?.05%, 70.31%?.63%, respectively. Berbamine also inhibited the cell proliferation in both NB4 and HLeo cells. The percentage of growth inhibition were 46.07%?.72%, 85.21%?.78%, 92.26%+1.73% in NB4 cells and 43.67%+1.94%, 56.77%+4.45%, 79.26%+2.28% in HL60 cells when NB4 and HL60 cells were treated with 4.(K 8.0 and 16.0礸/ml berbamine for 72 h (vs control, PO.01). The ICso(72 h) value of K562, Jurkat, NB4 and HLeo cells were 5.227?1.307 ng/ml, 3.893 ?1.207jig/ml, 3.769 + 1.319礸/ml and 5.926 + 1.031 ng/ml, respectively. Incontrast, berbamine had slight effect on normal bone marrow cells and its ICso value was 103.650+ 10.257礸/ml which was 17.5-27.5 times higher than those of leukemic cells.Berbamine elicited typical apoptosis morphologic changes and the DNA ladder was clearly observed. Through flow cytometry assay, the apoptotic pick was detected, the apoptosis rate of K562 cells treated with 8.0礸/ml berbamine for 24 and 72 h increased from 29.20%+3.82% to 61.77%?.35% (PO.01) .In addition, when K562 cells were treated with berbamine ranging from 2.0礸/ml to 8.0礸/ml for 24 h, the percentage of the apoptotic cells also increased, they were 4.27%?.58% and 29.20%?.82%, respectively. Similarly, Jurkat and NB4 cells underwent apoptosis, and the apoptotosis rate of the berbamine-treated cells(8.0礸/ml for 72 h) increased to 64.80%+5.87% and 67.53%+ 3.79% respectively (vs control, PO.01). So, berbamine could significantly induce apoptosis in those four kinds of leukemic cells in a time-and-concentration-dependent manner in vitro.The expression levels of appoptosis-related genes including bcl-2, bax, survivin, and bcr/abl gene (semiquantity value) were determined by RT-PCR and the BCR/ABL protein level was detected by Western blotting. The results suggested that berbamine up-regulated bax gene of Jurkat cells significantly and down-regulate bcl-2 gene relatively weakly, resulting in an enhancement of the ratio of bax/bcl-2. When the cells were treated with 8.0礸/ml berbamine for 72 h, the expression of bax became higher than control(1.60±0.01 vs 0.93 ?.01,P<0.01). Treatment with 16.0|ig/ml berbamine for 24 h decreased the bcl-2 level more than control did (1.20 ?.01 vs 1.50+0.05, P<0.01) .The expression of survivin gene decreased in the berbamine-treated cells. When K562 cells were treated with S.Ofig/ml berbamine for 72 h , the level...
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