Abstract
Objective: To investigate the effect of Quercetin (Qu) on cell proliferation, apoptosis and cell cycle, as well as the expression changes of Wnt/β-catenin signaling pathway, apoptosis and cell cycle regulators and BCR-ABL in CML susceptible cells K562 and imatinib-resistant cells (IM) K562R.
Methods: The trypan blue staining was used to detect the all proliferation. The cell cycle and apoptosis were detected by flow cytometry. The fluorescence quantitative PCR and Western blot were used to detect the expression of mRNA and protein respectively.
Results: After administration with 5, 10, 20, 40, 80, 160, 320 μmol/L Qu, the inhibition ratio in K562 cells was 5.07%, 5.98%, 11.09%, 31.88%, 56.89%, 70.44%, 86.63%; and that in K562R cells were 4.99%, 9.75%, 10.54%, 8.93%, 25.13%, 46.89%, 68.60%; IC50 of K562 and K562R was 76.4 μmol/L and 230.2 μmol/L, respectively. Flow cytometry showed that Qu (50, 100 and 200 μmol/L) could induce cell apoptosis and cell cycle arrest in a dose-dependent manner (r=0.9914, r=0.9871 respectively). After treatment with Qu (100 μmol/L)，the expressions of mRNA (P＜0.05) and protein(except Caspase-9) expression of Caspase-3, 8 and 9, p21 and p27 increased in K562 cells as compared with control, but the protein expression of p27 and Caspase-3 not changed in K562R. Qu (100 μmol/L) could decrease the mRNA(P＜0.05) and protein levels of Wnt/β-catenin signaling pathway members GSK-3β, β-catenin, Lef-1 and the downstream targets PPAR-δ and Cyclin D1 compared with control. The PCR results showed that Qu could reduce the BCR-ABL mRNA expression in CML cells, but the protein expression of BCR-ABL and p-BCR-ABL not obviouly changed.
Conclusion: Qu can inhibit the proliferation K562 and K562R cells, and decrease the drug resistance and increase the sensitivity, that relate with inhibiting Wnt/β-catenin signaling pathway, activating apoptosis pathway and cyclins.
