The Effect Of Honokioi Combined With Cytarbine On Human Acute Myeloid Leukemia And The Tudy Of Its Mechanism

Objective:The aim of this study was to investigate the Synergistical effect of honokiol combined with cytarbine on human acute myeloid leukemia cell line THP-1cells proliferation and apoptosis,and to explore its potential anti-acute myeloid leukemia mechanism. Then may proide a new idea for the treatment of AML.Methods:Cell morphology was used to observed how honokiol or cytarabine alone or combined affect THP-1cell morphology; CCK-8assay and flow cytometry (cell apoptosis and cell cycle) were used to detect the effect of different concentrations of honokiol alone or combined with1μmol/1cytarabine on THP-1cells cell proliferation and apoptosis; The effect of monotherapy or combined therapy treatment on THP-1cells viability and caspase3/7were detected by Apolive-GloTM muti-assay; MicroRNA analysis was conducted to analyze the effect of different concentrations of honokiol alone or combined with cytarabine on the MicroRNA expression in THP-1cells, and the potential target genes prediction, screening and identification; Statistical significance was defined as p<0.05, one way ANOVA was used for analysis.Results:(1) Cell morphology indicated that honokiol or cytarabine alone or combined had an impact on THP-1cell morphology, and this effect in combined groups was more obvious;(2) CCK-8results showed that:6μmol/1and8μmol/1honokiol alone induced THP-1cells proliferation inhibition; while1μmol/1cytarabine alone had no obvious inhibition effect; however, compared with honokiol or cytarbine alone and normal group,2μmol/1,4μmol/1and6μmol/1honokiol joint with1μmol/1cytarabine could markedly inhibit THP-1cells growth (P<0.05);(3) Flow cytometry analysis showed:Treated with honokiol of different concentrations alone for36hours, the total apoptosis rates in THP-1cells (Early apoptosis rate+Late apoptosis rate) were as follows, respectively:8.37±0.61%,11.78±0.82%,46.67±0.69%; cytarabine alone was12.81±0.35%, while the control group was6.64±0.87%, only the higher concentration of honokiol (8μmol/1) could induce a significant apoptosis in THP-1cells; however, when honokiol combined with1μmol/1cytarabine, the total apoptosis rates of THP-1cells were24.8±0.73%,26.49±1.85%and48.77±1.55%, respectively. Compared with the monotherapy group and the normal control group, the combined treatment induces more obvious cell apoptosis;(4) Cell cycle results were as shown below:the role of honokiol alone in THP-1cells for12hours was cell cycle arrest in G0/G1phase, and which was positively correlative with the concentration of honokiol; This G0/G1phase arrest effect was more significant in combined groups;(5) Apolive-GloTM muti-assay results showed:Honokiol alone could inhibite THP-1cells viability and activate caspase3/7expression, thus resulted in cell apoptosis; Neverthelss, these results also showed that honokiol and cytarbine exerted a synergistic effect in the inhibition of cell viability and induction cell apoptosis;(6) MicroRNA analysis showed that honokiol or cytarabine monotherapy or their combination could lead to an obvious upregulation or downregulation of over100kinds of microRNA. The MAPKs pathway and pathway in cancer were maily involved in THP-1cells proliferation and apoptosis.Conclusion:Honokiol or cytarabine alone played an important role in THP-1cells proliferation and apoptosis. Moreover, the two agents exerted a significant synergistic effect, which indicated that honokiol alone or combined with cytarbine could be potential novel treatments for acute myeloid leukemia.