Abstract:
Objective To observe pro-apoptotic effect of flavone from
Galium verum L (FGVL) on acute promyelocytic leukemia cells (NB4) and to explore the mechanism of the effect.
Methods NB4 cells in culture medium
in vitro were treated with different concentrations of FGVL (50,100,and 200 μg/mL).Changes in cell morphological were observed with Hoechst staining and the changes in cell cycle and apoptosis rate were analyzed with flow cytometry.The expression levels of Mel-18,Sall4,and Bmi-1mRNA were assessed with reverse transcriptase PCR(RT-PCR).
Results Morphological observations revealed that the percentages of apoptotic cells were significantly enhanced in NB4 cells treated with FGVL for 48 hours,with the percentages of 9.3%,13%,and 20.4% (
P<0.05 for all) for the dosages of 50,100,and 200 μg/mL groups,compared with that of in the control group (2.3%);typical apoptotic morphological changes (karyopyknosis,karyorrhexis,and apoptosis bodies) were observed in the NB4 cells.Cell cycle analysis indicated that compared with the control group,the cell ratios in G0/G1 phase (43.92%,37.26%,ans 29.15%) decreased significantly,while the ratios in S phase (54.16%,62.23%,and 70.46%) increased obviously for the NB4 cells treated with 50,100,and 200 μg/mL FGVL.Compared with the control group,the expression level of Mel-18 mRNA increased and Sall4 and Bmi-1mRNA decreased obviously for the NB4 cells treated with 100 and 200 μg/mL FGVL.
Conclusion FGVL could inhibit cell proliferation,induce cell apoptosis,and arrest cells in S phase in NB4 cells;the mechanism of the effects is probably through regulating the expressions of Mel-18,Sall4,and Bmi-1 gene.