抑制白血病K562细胞FoxM1表达可增强细胞对高三尖杉酯碱的敏感性

目的:探讨抑制白血病K562细胞叉头框蛋白M1(Fox M1)是否增强细胞对高三尖杉酯碱(HHT)的敏感性。方法:HHT以不同浓度(0、0.015、0.030和0.045μmol/L)和最低起效浓度不同时间(0.015μmol/L,0、24、48和72 h)作用于K562细胞,real-time PCR和Western blot检测Fox M1 mRNA和蛋白表达;以0.015μmol/L HHT作用K562细胞后转染Fox M1 siRNA,观察沉默K562细胞Fox M1后细胞对HHT的敏感性、细胞增殖和凋亡效应以及Fox M1相关靶分子c-Myc和Sp1表达状况。结果:随着HHT浓度增加和时间延长Fox M1表达逐渐降低,说明HHT抑制K562细胞Fox M1表达;HHT处理K562细胞后转染Fox M1 siRNA,细胞生长和克隆形成显著下降,细胞凋亡增加,因此抑制Fox M1可增加K562细胞对HHT的敏感性;Fox M1 siRNA组c-Myc和Sp1表达显著降低,表明Fox M1可正性调控c-Myc和Sp1表达。结论:HHT可以抑制白血病K562细胞Fox M1表达,干扰Fox M1可增强细胞对HHT的敏感性。

Inhibition of FoxM1 sensitizes leukemia K562 cells to homoharringtonine

AIM: To study whether inhibition of forkhead box protein M1(FoxM1) sensitizes leukemia K562 cells to homoharringtonine (HHT). METHODS: K562 cells were incubated with HHT at different concentrations (0μmol/L, 0.015μmol/L, 0.030μmol/L and 0.045μmol/L) for different time (0 h, 24 h, 48 h and 72 h). The mRNA and protein levels of FoxM1 were detected by real-time PCR and Western blot. FoxM1 siRNA was transfected into K562 cells with 0.015μmol/L HHT after 6 h. After 72 h incubation, the cell proliferation was detected by cell counting and soft agar assay, and the proportion of apoptotic K562 cells was determined by flow cytometry. The expression of c-Myc and Sp1 were detected by real-time PCR and Western blot. RESULTS: FoxM1 expression was reduced time-dependently and dose-dependently, suggesting that HHT mediated the downregulation of FoxM1 in K562 cells. In K562 cells, treatment with FoxM1 siRNA and HHT inhibited the cell proliferation and promoted the apoptosis significantly. Therefore, inhibition of FoxM1 sensitized leukemia K562 cells to HHT. The expression of c-Myc and Sp1 was positively regulated by FoxM1. CONCLUSION: HHT inhibits Forkhead box protein M1 expression in K562 cells. Inhibition of FoxM1 sensitizes K562 cells to HHT.