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ObjectiveTo investigate the impact of PI3K-AKT pathway inhibitor (AKTi ) on the acute crisis of chronic myeloid leukemia (CML) and its regulatory effect on PI3K-AKT pathway in Wnt/β-catenin signal pathway. Methods K562 cells were cultured to logarithmic growth phase, and they were treated with 0, 2.5, 5, 10μmol/L AKTi respectiv ely. Cell growth was determined with MTT test. The ability of cell colonization was assessed by colony-forming assay. The protein expression of pAKT (Thr308) and pGSK-3β(Ser9) was determined by Western blotting. The protein expression and mRNA levels of β-catenin and its down-stream targets c-myc and cyclin D1 were analyzed by Western blotting and realtime fluorescence quantitative polymerse chain reaction (Q-PCR), respectively. ResultsCell growth and colony-forming ability of K562 cells were inhibited significantly after treatment with AKTi for 6, 10, 16h, and the best exposure time for K562 cells was 10h. PI3K-AKT pathway was inhibited obviously and the protein level of pAKT (Thr308) was lowered apparently after 2.5, 5, 10μmol/L AKTi treatment. When K562 cells were treated by 5μmol/L AKTi for 10h, pGSK-3β (Ser9) and β-catenin protein levels were lowered significantly, while the mRNA of β-catenin was not affected. The mRNA and protein levels of c-myc and cyclin D1 in the downstream of β-catenin were also decreased obviously after treatment with 5μmol/L AKTi for 10h. ConclusionAKTi can inhibit the proliferation and colony-forming ability of K562 cells in critical stage of CML. The mechanism may be related to down-regulation of expression of Wnt/β-catenin pathway by blocking the signal transduction of cell growth.
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<p><b>OBJECTIVE</b>To investigate the inhibitory effect of indomethacin combined with imatinib on proliferation of KCL22 and K562/G01 cells, and to elucidate the molecular mechanism of antiproliferative effect by Wnt/β-Catenin signaling way.</p><p><b>METHODS</b>Indomethacin was used in KCL22 and K562/G01 cells. The cell growth was detected by MTT assay to explore the optimal concentration and time. The effect of drugs on proliferation capacity was assessed by MTT assay and colony-forming assay. Flow cytometry was used to identify the cell cycle and apoptosis changes. The protein expression of pβ-catenin (S33/37/T41), pGSK-3β (Ser9) and C-MYC were analyzed by Western blot.</p><p><b>RESULTS</b>The optimal concentration and time of indomethacin on KCL22 and K562/G01 were 80 µmol/L for 48 h. The inhibitory effect of 80 µmol/L indomethacin combined 2 µmol/L imatinib on cell proliferation was significantly better than a single drug treatment. Flow cytometry results showed that cell cycle was arrested in the G0/G1 phase in both combined treatment groups. The number of apoptosis cells in combined treatment groups was significantly higher than that in single drug treatment groups. Compared with the control group or single drug treatment groups, the protein level of pβ-catenin, β-catenin, pGSK-3β (Ser9) and C-MYC decreased significantly.</p><p><b>CONCLUSION</b>Indomethacin significantly enhances inhibitory effect of imatinib on proliferation of KCL22 and K562/G01 cells and regulate cell proliferation through Wnt/β-Catenin signaling way.</p>
