RESUMO
Objective To investigate the effect of cytarabine (Ara-C) on proliferation and apoptosis of human erythroleukemia K562 cell linethrough autophagy pathway and its possible mechanism.Methods The cellular proliferation inhibiting rate after different concentrations of Ara-C acting for 24,48 h was detected by CCK-8;the cell cycle and apoptosis were detected by flow cy tometry(FCM);the chromatin morphological changes in nucleus were observed by Hoechst staining;the cell acidic autophagy vesicles were detected by acridine orange staining;the expression changes of p38 and p-p38 proteins were detected by Western blot.The expressions of autophagy apoptosis related gene and protein were examined by RT-PCR and immunofluorescence.Results The CCK-8 results found that different concentrations of Ara-C could inhibit the proliferation of K562 cells with dose-and time-dependent manners.FCM detecting indicated that Ara-C could increase apoptosis and could arrest the cell cycle at S phase;Hoechest staining showed that K562cells had typical apoptotic morphological changes after Ara-C treating;the Acridine orange staining revealed that Ara-C caused the inclease of the green fluorescene in cells of the Ara-C group,and the cells appeared a great number of acidic autophagy vesicles;RT-PCR results showed that Ara-C up-regulated the expression of autophagy key genes Beclin-1,LC3A and LC3B;Western blot results showed that Ara-C increased the expression of phosphorylated p-p38.Immunofluorescence results showed the expression of LC3B was significantly enhanced.Conclusion Ara-C canactivate p-p38 mediated K562 cells to generate autophagy,then inhibit the cell proliferation and promotes apoptosis.