Study on relationship between autophagy and drug resistance of leukemia K562/ADM cells / 中国药理学通报

Aim To set up leukemic K562/ADM cells with stable tolerance to 15 fimol • L_1 ADM induced in vitro by long-term and continuous stepwise increment of adriamycin (ADM) concentration, to observe the sensitivity to other chemotherapy drugs and the relationship between autophagy and drug resistance.Methods MTT assay was used to detect the sensitivity of cells to chemotherapy drugs.The morphological changes of autophagy were observed by transmission electron microscope and fluorescence microscopy.Cell apoptosis analysis was performed using Annexin-V/PI double staining and flow cytometry ( FCM ).The expressions of autophagy and drug resistance associated proteins were tested by Western blot.Results K562/ADM cells were cross-resistance to the other chemotherapeu-tics besides adriamyciri, such as pirarubicin, daunoru- bicin, 5-flurouracil, vincristine but not arsenic triox- ide.The number of autophagosomes, the fluorescence intensity of monodansylcadaverine (MDC) and the expression of LC3-H ,Beclin-l in K562/ADM cells were significantly higher than those in K562 cells.The inhibition of autophagy by 3-MA significantly increased the sensitivity of K562/ADM cells to ADM, and 3-MA also effectively inhibited the expressions of drug resistance related proteins P-gp, MRP1 and BCRP in K562/ADM cells.Conclusions The K562/ADM cells resistant to adriamycin occur multidrug resistance, and the drug resistanceis closely related to the level of autophagy.

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.

Enhancing effect of chidamide on the sensibility of human chronic myeloid leukemia K562/ADM cells to daunorubicin / 解剖学报

Objective: To investigate whether chidamide (CDM) could influence the sensibility of human chronic myeloid leukemia K562/ADM cells to daunorubicin (DNR) and its possible mechanism. Methods: The K562 and K562/ADM cells were cultured in vitro and treated with CDM and(or) DNR for 48 hous, and then the cell viability was measured by cell counting kit-8(CCK-8) assay. The proliferation, cell cycle and apoptosis were analyzed by flow cytometry. Western blotting was performed to measure the protein levels of histon 2AX (H2AX), γH2AX (Serl39), ataxia telangiectasia mutated gene (ATM), p-ATM (Serl981), breast cancer susceptibility protein 1(BRCAl), and p-BRCAl (Serl524). Results: DNR remarkably inhibited the cell activity of K562/ADM cells in dose-dependent manner with a half maximal inhibitory concentration(IC50) value of 11.76 μmol/L, and the resistant factor was 18.09. Co-treatment with CMD and DNR produced a synergistic effect confidence interval(GI) (CI<1) with a reversal fold of 8.11. DNR remarkably inhibited proliferation (P<0.05), induced G2/M phase arrest and apoptosis (P<0.05), these effects were enhanced under non-toxic concentration of CMD (P<0.05). K562/ADM cells had a significantly higher protein levels of ATM and BRCA1 than K562 cells (P<0.05). DNR significantly up-regulated the protein levels of γH2AX, p-ATM and p-BRCAl (P<0.05), and the protein level of γH2AX appeared higher in the combination group compared to DNR alone (P<0.05); however, the co-treatment with CMD and DNR induced a decreased expression of p-ATM and p-BRCAl than the DNR alone (P< 0.05). Conclusion: CDM may enhance the sensibility of K562/ADM cells to DNR by up-regulating the protein level of γH2AX, and down-regulating the protein levels of p-ATM and p-BRCAl.

Reverse Effect of Interferon-α Combined with All-Trans Retinoic Acid on Multidrug Resistance of Human Leukemic Cell Line K562/ADM / 中国药学杂志

OBJECTIVE: To investigate the effects of interferon-α(IFN-α) and all-trans retinoic acid(ATRA) on multidrug resistance reversal effect and mechanism of human leukemia K562/ADM cells. METHODS: The cytotoxicity and reversal times of IFN-α and ATRA were detected by CCK-8 method. Apoptosis rate and cell cycle were detected by flow cytometry. PI3K, Akt and Bad mRNA were detected by RT-PCR method. Western blot method was used to detect the expression of PI3K, AKt, P-AKt and Bad protein.RESULTS: The drug resistance of K562/ADM cells to adriamycin(ADM) was 54 times. ADM, respectively, with IFN-α, ATRA or combined application, the drug resistance of K562/ADM cells to ADM was 1.24, 2.34 and 8.14, respectively. The apoptosis rate of K562/ADM cells was significantly increased by using ADM 4 mg·L-1alone or in combination with IFN-α 2.5×106 U·L-1, ATRA 7.5 μmol·L-1, and the cell cycle was blocked in G0/G1 phase. PI3K mRNA and protein expression were significantly lowered, Akt mRNA and protein has no obvious change, Bad mRNA and protein expression are raised, phosphorylated Akt protein expression decreased, the expression is more obvious when the two drug combination. CONCLUSION: IFN-α and ATRA can reverse the multidrug resistance of K562/ADM cells, its mechanism may be the inhibition of the PI3K/Akt pathway.

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.

Anti-cancer Effects of Deguelin on Human Leukemia K562 and K562/ADM Cells In Vitro / 华中科技大学学报（医学）（英德文版）

In order to investigate the anti-cancer effects of deguelin and on K562 and K562/ADM cells in vitro and the underlying molecular mechanism and compare the cytotoxicity of deguelin on K562, K562/ADM cells and human peripheral blood mononuclear cells (PBMCs). The effects of deguelin on cell proliferation were assessed by MTT assay. Apoptosis were detected by AnnexinV/PI double-labeled cytometry. The effects of deguelin on the cell cycle were studied by a propidium iodide method. Our study showed that deguelin inhibited the proliferation of K562 cell and K562/ADM cell in a time- and dose-dependent manner and had minimal effects on normal human peripheral blood mononuclear cells. The ratio of IC50 value of deguelin of 24 h on K562/ADM cells to K562 cells was only 1.27, which was significantly lower than the ratio of IC50 value of ADM (higher than 20). Deguelin could induce apoptosis of K562 cells and K562/ADM cells. K562 cells were arrested at G2/M phase while K562/ADM cells were arrested at G0/G1 phase. Our results suggested that deguelin was a novel anti-leukemia agents with high efficacy and low toxicity and it is also a promising agent for reversing drug resistance.

Influence of arsenic bisulfide on the expression of HSP70 in K_(562)/ADM cell / 中国癌症杂志

Purpose:To study the expression of membrane protein HSP70 of K 562 /ADM cell using arsenic bisulfide(As 2S 2) treatment Methods:Membrane HSP70 and apoptosis of K 562 and multidrug resistant K 562 /ADM cell were studied by flow cytometry assay and RT PCR Results:Membrane HSP70 of K 562 and K 562 /ADM cell gradually increased from 12 to 24 hours with arsenic bisulfide treatment, and had higher expression at the level of HSP70mRNA Expression of membrane HSP70 and apoptosis of K 562 /ADM was higher than that of K 562 Conclusions:Arsenic bisulfide treatment can increase expression of membrane HSP70 of K 562 /ADM and K 562 cells.The change of membrane HSP70 is probably related to K 562 /ADM cell apoptosis