Effect and Mechanism of Atorvastatin on Reversing Drug Resistance in Leukemia by Regulating Glycolysis through PTEN/mTOR Pathway / 中国实验血液学杂志

OBJECTIVE@#To investigate the influence and mechanism of atorvastatin on glycolysis of adriamycin resistant acute promyelocytic leukemia (APL) cell line HL-60/ADM.@*METHODS@#HL-60/ADM cells in logarithmic growth phase were treated with different concentrations of atorvastatin, then the cell proliferation activity was measured by CCK-8 assay, the apoptosis was detected by flow cytometry, the glycolytic activity was checked by glucose consumption test, and the protein expressions of PTEN, p-mTOR, PKM2, HK2, P-gp and MRP1 were detected by Western blot. After transfection of PTEN-siRNA into HL-60/ADM cells, the effects of low expression of PTEN on atorvastatin regulating the behaviors of apoptosis and glycolytic metabolism in HL-60/ADM cells were further detected.@*RESULTS@#CCK-8 results showed that atorvastatin could inhibit the proliferation of HL-60/ADM cells in a concentration-dependent and time-dependent manner (r=0.872, r=0.936), and the proliferation activity was inhibited most significantly when treated with 10 μmol/L atorvastatin for 24 h, which was decreased to (32.3±2.18)%. Flow cytometry results showed that atorvastatin induced the apoptosis of HL-60/ADM cells in a concentration-dependent manner (r=0.796), and the apoptosis was induced most notably when treated with 10 μmol/L atorvastatin for 24 h, which reached to (48.78±2.95)%. The results of glucose consumption test showed that atorvastatin significantly inhibited the glycolytic activity of HL-60/ADM cells in a concentration-dependent and time-dependent manner (r=0.915, r=0.748), and this inhibition was most strikingly when treated with 10 μmol/L atorvastatin for 24 h, reducing the relative glucose consumption to (46.53±1.71)%. Western blot indicated that the expressions of p-mTOR, PKM2, HK2, P-gp and MRP1 protein were decreased in a concentration-dependent manner (r=0.737, r=0.695, r=0.829, r=0.781, r=0.632), while the expression of PTEN protein was increased in a concentration-dependent manner (r=0.531), when treated with different concentrations of atorvastatin for 24 h. After PTEN-siRNA transfected into HL-60/ADM cells, it showed that low expression of PTEN had weakened the promoting effect of atorvastatin on apoptosis and inhibitory effect on glycolysis and multidrug resistance.@*CONCLUSION@#Atorvastatin can inhibit the proliferation, glycolysis, and induce apoptosis of HL-60/ADM cells. It may be related to the mechanism of increasing the expression of PTEN, inhibiting mTOR activation, and decreasing the expressions of PKM2 and HK2, thus reverse drug resistance.

Effects of RNA Targeting mPGES-1 on Proliferation and Apoptosis of K562/A Cells / 中山大学学报(医学科学版)

@#【Objective】 To explore the effects and the possible mechanism of RNA targeting membrane-bound prostaglandin E2 synthase l（mPGES- 1）on proliferation，apoptosis and drug resistance of leukemia cell line K562/A.【Methods】RNA interference was used to inhibit the expression of mPGES-1 of K562/A cells. Four groups were set up as follows：untreated group（K562/A），negative control group after interference（K562/A-NC），group after interference（K562/ A-KD），and group after interference with exogenous PGE2（K562/A-KD+PGE2）.Cell viability was assessed by CCK-8 assay. Cell apoptosis was analyzed by flow cytometry. Concentration of PGE2 was detected by ELISA. Proteins expression was detected by western blot.【Results】The expression of mPGES- 1 in K562/A cells was significantly down- regulated and the synthesis of PGE2 decreased（P < 0.000 1）after RNA interference. After RNA interference，the proliferation of K562/A cells was inhibited and apoptosis increased，and the sensitivity to chemotherapy drugs was enhanced（P < 0.05）. Meanwhile，the expression of β-catenin and MDR1 was decreased（P < 0.01）. Exogenous PGE2 could reverse the effect of RNA interference on proliferation ，apoptosis and drug sensitivity in K562/A cells（P < 0.05），and up-regulate the expression of β-catenin and MDR1（P < 0.01）. XAV939，an inhibitor of β-catenin，could down-regulate the expression of β- catenin and MDR1 in an dose- dependent pattern in K562/A cells（P < 0.05）.【Conclusions】RNA interference of mPGES- 1 could inhibit proliferation，induce apoptosis and reverse drug resistance in K562/A cells. The mechanism was related to reducing the synthesis of PGE2 and thus down- regulating the expression of β- catenin and MDR1. Wnt/β- catenin signal pathway may participate in the regulation of MDR1 by mPGES-1/PGE2.