ABSTRACT
[Objective] To investigate the anti-proliferative and apoptosis effect induced by Honokiol (HNK) on human myeloid leukemia cell line U937 cells in vitro.[Methods] After treated with different concentration of HNK,Hoechst33342 fluorescent staining was used to detect cell apoptosis;the growth inhibition ration of U937 cells and PBMCs were analyzed by MTT assay;the apoptosis ration was detected by flow cytometry;mitochondrial membrane potential was explored by rhodamine 123 stain;Caspase3/7 protein activity kit was used to test the Caspase3/7 activity;the Caspase-3 and Caspase-7 mRNA levels were detected by real-time fluorescent relative-quantification reverse transcriptional PCR (FQ-PCR).[Results] Honokiol could significantly inhibit the proliferation of U937 cells in terms of the indexes of IC50/U937 11.8 μg/mL and IC50/PBMCs 40.3 μg/mL,and the anti-proliferative effect was in a time and concentration dependent manner;Flow cytometry analysis manifested that Honokiol could induce U937cells apoptosis by Annexin V/PI double Annexin V/PI fluorescein stain;Honokiol significantly inhibited the mitochondrial membrane potential of U937 cells and enhanced the ability of Caspase3/7 and the mRNA expression levels,but not the PBMCs.[Conclusion] HNK can inhibit U937 cells proliferation and induce cells apoptosis via activating Caspase 3/7.
ABSTRACT
In this study, several physiological factors were studied for their effects on the growth and differentiation of U937 cells in vitro .The results showed that (1)rhTNF-?,PHA-LCM and c-RA exerted a dose and time-dependent suppression of proliferation of U937 cells; (2) the synergistic effect oc-cured when rhTNF-? was combined with c-RA in the cell culture; and (3)rhIL-1-? augmented the differentiation of U937 cells induced by c-RA though it had no effect on the cell line by itself. According to the [3H]-TdR incorporation, it can be concluded that the reduction of DNA synthesis of U917 cells by rhTNF-? ,PHA-LCM,and c-RA is attributed to the inhibition of the growth. The results might have clinical significance in the induction of differentiation of leukemia cells.