Kaempferol in reversing drug resistance of chronic myelogenous leukemia K562/ADM cells and its related mechanism / 白血病·淋巴瘤

Objective@#To investigate the drug resistance of kaempferol reversed adriamycin (ADM)-resistant K562/ADM cells in chronic myelogenous leukemia (CML) and its related mechanism.@*Methods@#Methyl thiazolyl tetrazolium (MTT) method was used to detect the toxicity of ADM on K562 and K562/ADM cells for 24 h. The half inhibitory concentration (IC50) of ADM and the drug resistance multiple for 24 h were calculated. MTT method was used to detect the toxicity of kaempferol on K562/ADM cells for 24 h. The 5% inhibitory concentration (IC5) and 10% inhibitory concentration (IC10) of kaempferol for 24 h were calculated to determine the concentration of kaempferol in the subsequent experiments. And the cells untreated by the kaempferol were selected as the control group. The cell inhibition after the treatment of ADM for 24 h of the blank control group and kaempferol intervention group was detected by using MTT method. And then the cell inhibition for 24 h and ADM IC50 for 24 h in the above groups were calculated. The ratio of IC50 in the blank control group and kaempferol group was the reversal drug resistance multiple of kaempferol. The fluorescence intensity of ADM in K562/ADM cells treated by kaempferol was detected by using flow cytometry. Western blotting was used to detect the expressions of P-glycoprotein (P-gp), multidrug resistance-associated protein 1 (MRP1), phosphorylated p38 (p-p38), and total p38 (t-p38) protein in K562/ADM cells after the treatment of kaempferol, the specific inhibitor of p38-MAPK signaling pathway SB202190, and the combination of kaempferol and SB202190.@*Results@#After the treatment of ADM for 24 h, the IC50 value of K562 and K562/ADM cells was (0.9±0.6), (28.1 ±3.5) μg/ml, respectively. The drug resistance multiple of K562/ADM cells on the treatment of ADM for 24 h was 31.16 compared with the K562 cells. MTT method showed that kaempferol inhibited the proliferation of K562/ADM cells in a dose-dependent manner. According to the IC5 and IC10, 0.5 μmol/L and 1.0 μmol/L kaempferol were determined to do the subsequent experiments. After the combined interaction of kaempferol and ADM for 24 h, the ADM IC50 of K562/ADM cells in the blank control group, 0.5 μmol/L kaempferol group and 1.0 μmol/L kaempferol group was (33.7±5.7), (21.4±0.6), (15.9±1.8) μg/ml, respectively (F = 30.85, P < 0.05), and there was a statistical difference of pairwise comparison (both P < 0.05). The reversal drug resistance multiple of K562/ADM cells for 24 h in 0.5 μmol/L kaempferol group and 1.0 μmol/L kaempferol group was 1.58 and 2.12, respectively. Flow cytometry results showed that the mean fluorescence intensity (MFI) of ADM in the blank control group, 0.5 μmol/L kaempferol group and 1.0 μmol/L kaempferol group was 138.4±8.9, 154.3±2.2, 165.7±4.8, respectively, and the difference was statistically significant (F = 161.48, P < 0.05). Compared with the blank control group, after treatment of K562/ADM cells with 0.5 μmol/L and 1.0 μmol/L kaempferol for 24 h, the relative expressions of P-gp, MRP1 and p-p38 protein were decreased in K562/ADM cells (all P < 0.05), but there was no statistical difference in the expression of t-p38 protein (P > 0.05); SB202190 could reduce the relative expressions of P-gp, MRP1 and p-p38 protein (all P < 0.05); after the treatment of SB202190 combined with different concentration of kaempferol, the relative expressions of P-gp, MRP1 and p-p38 protein in K562/ADM cells did not decrease (P > 0.05).@*Conclusions@#Kaempferol can decrease the relative expressions of P-gp and MRP1 in K562/ADM cells by inhibiting p38-MAPK pathway, so as to increase the concentrations of ADM and to reverse the drug resistance of K562/ADM cells.

Inhibitory effect of PI3Kδ inhibitor idelalisib on proliferation of human myeloid leukemia cells and the reversal effect on drug resistance to adriamycin / 中南大学学报(医学版)

OBJECTIVES@#To investigate the effect of adriamycin (ADM), idelalisib or ADM and their combination on cell proliferation and intracellular concentration of ADM, and to explore the reversal effect of idelalisib on drug resistance to ADM.@*METHODS@#The K562 and K562/ADM cells were respectively treated with ADM and idelalisib at different concentrations. The 50% inhibitory concentration (IC@*RESULTS@#The cell survival rates were significantly decreased in a dose-dependent manner when the cells were treated with different doses of ADM (0.001-10.000 mg/L ). The IC@*CONCLUSIONS@#Idelalisib exerts effect on inhibition of the proliferation in myeloid leukemia K562 and K562/ADM cells, which may partially reverse the drug resistance of K562/ADM cells to ADM. The mechanisms for the effect of idelalisib may be related to increasing the accumulation of ADM and inducing the cell apoptosis in the K562 and K562/ADM cells.

Effect of Artesunate on Transferrin Receptor in K562/ADM Cells / 现代生物医学进展

Objective:To investigate the effect of Artesunate (Art) on the expression of transferrin receptor (TtR)in K562/ADM cells.Methods:The drug-resistant K562/ADM cells were cultured with 1000 ng/mL doxorubicin for two weeks followed by Artesunate treatment with different concentrations (12.5 μg/mL,25μg/mL and 50 μg/mL) or different time (12 h,24 h,36 h,and 48 h).The content of transferrin receptor in K562/ADM cells was determined by flow cytometry.The effect of Artesunate on the expression of transferrin receptor protein in K562/ADM cells was measured by Westem blot.Cell counting kit-8 (CCK-8) assay was used to evaluate inhibitory effect of Art combined with doxorubicin (ADM) in K562/ADM cells.The reversal index was defined as the IC50 of the experimental group divided by the IC50 of the control group in K562/ADM cells.Results:Art effectively decreased the content of transferrin receptor and the expression of transferrin receptor protein in K562/ADM cells in a dose-dependent manner.Moreover,Art also inhibited transferrin receptor protein expression in K562/ADM cells in a time-dependent manner.The different concentrations of Art(12.5 μg/mL,25μg/mL and 50 μg/mL) could induce reversal of drug-resistance with the reversal index being 1.38,2.12 and 2.95 times (P＜0.05).Art inhibited cell proliferation of K562/ADM cells,and the IC50 werel9.7 μmol/L.Conclusions:Art effectively down-regulated the transferrin receptor content as well as transferrin receptor protein expression in K562/ADM cells,which resulted in reversal of drug resistance of K562/ADM cells.Art also inhibited K562/ADM cells proliferation,which has great value in clinical treatment of leukemia.