RESUMEN
Aim To investigate the effect of ribonucleic acidⅡon apoptosis in human leukemia cell lines K562 and KG1 a.Methods Cell counting kit-8(CCK-8)as-say was performed to detect proliferation activity of K562 and KG1 a cells treated with ribonucleic acidⅡ. Apoptosis index was assessed by flow cytometry(FCM) and fluorescent Hoechst 33258 staining was used for observing morphologic changes of apoptosis.Expres-sion levels of p53,Bax,Bcl-2 and cleaved caspase-3 were analyzed by Western blot.Results The prolifera-tion of K562 and KG1 a cells was significantly inhibited by ribonucleic acid Ⅱ treatment for 12 h,24 h,48 h at concentrations of 100~300 mg·L-1 ,which indica-ted the inhibitory effect of ribonucleic acid Ⅱ was in dose-dependent and time-dependent manners.FCM re-sults displayed a dose-dependent increase in cell apop-totic rate.Hoechst 33258 staining showed the typical apoptotic morphology in some leukemic cells treated with ribonucleic acid Ⅱ,including increased nuclear chromatin concentration and edge accumulation.West-ern blot analysis showed the increased expression of p53,Bax,cleaved caspase-3 and decreased expression of Bcl-2 in K562 and KG1 a cells treated with ribonu-cleic acid Ⅱ.Conclusions Ribonucleic acid Ⅱ can induce apoptosis of leukemia K562 and KG1 a cells by up-regulating p53,which mediates Bcl-2/Bax balance and activates caspase-3 .
RESUMEN
Objective To investigate the effects of curcumin on proliferation and apoptosis of CD34+CD38-KG1a cells and its synergetic effect with busulfan on CD34+CD38-KG1a cells.Methods The expressions of CD34 and CD38 on the surface of KG1a cells and the effect of curcumin on the cell cycle and apoptosis in CD34+CD38-KG1a cells were detected by flow cytometry.MTT assay was used to analyze curcumin’s inhibitory effects on proliferation and synergistic effect with busulfan on CD34+CD38-KG1a.Clone formation rate was measured by methylcellulose colony-formation assay.Morphological changes of apoptotic cells were observed with the inverted optical microscope.The expression of Bcl-2 at the protein level was detected by Western blot.Results The percentage of CD34+CD38-KG1a was (98.2±3.2)% in KG1a cells.Curcumin could inhibit the proliferation in time-and dose-dependent manners and reduce the colony-formation ability of CD34+CD38-KG1a.The coefficient of drug interaction between curcumin and busulfan was less than 1.CD34+CD38-KG1a cells were arrested in the G0/G1 phase by decreasing S phase cells.Meanwhile,curcumin induced the apoptosis of CD34+CD38-KG1a cells. Apoptotic cells became bigger than normal ones,with unclear cell structure and rough edge of cell membrane.The expression of Bcl-2 at the protein level was down-regulated by curcumin.Conclusion Curcumin inhibited the proliferation of CD34+CD38-KG1a cells by reducing colony-formation ability,arresting cells in the G0/G1 phase and inducing apoptosis.Besides,there was a synergistic effect between curcumin and busulfan in CD34+CD38-KG1a cells.The down-regulated expression of Bcl-2 at the protein level may be associated with curcumin-induced apoptosis of CD34+CD38-KG1a cells.