姜黄素对人髓母细胞瘤DOAY细胞增殖的影响及其机制

Effect of curcumin on proliferation of human medulloblastoma DAOY cells and relevant mechanism

目的探讨姜黄素对髓母细胞瘤(medulloblastoma,MB)DAOY细胞增殖的影响及其机制。方法用20、40、60、80、100μmol/L的姜黄素(curcumin)处理DAOY细胞24、48和72 h,采用MTT法检测姜黄素对细胞增殖活性的影响;用30μmol/L姜黄素处理DAOY细胞48 h,设未处理细胞为对照组,免疫细胞化学法检测姜黄素对细胞中β-catenin蛋白表达的影响,Western blot法检测β-catenin及cylinD1蛋白的表达水平。结果不同浓度及作用不同时间姜黄素均可明显抑制DAOY细胞的增殖(P<0.05),且在姜黄素浓度≤60μmol/L时,呈时间、剂量依赖性。对照组细胞中,β-catenin蛋白在胞浆和胞核中均有表达,且以胞核为主,经30μmol/L姜黄素处理48 h后,胞核蛋白β-catenin及总蛋白cyclinD1的表达均明显低于对照组(P<0.05),胞浆蛋白β-catenin的表达无明显降低(P>0.05)。结论姜黄素可通过抑制β-catenin的表达和核转位,阻断Wnt/β-catenin信号通路转导,进而抑制其下游靶基因cyclinD1的表达,从而抑制MB的增殖。

Objective To investigate the effect of curcumin on proliferation of human medulloblastoma （MB） DAOY cells as well as the relevant mechanism. Methods DAOY cells were treated with 20, 40, 60, 80 and 100 p.mol/L curcumin for 24, 48 and 72 h separately, and determined for proliferative activity by MTY assay. DAOY cells were treated with 30 μmol/L curcumin for 48 h, using those untreated as control, then determined for expression of β-catenin by immunocytochemical assay, and for expression levels of β-catenin and cylinD1 by Western blot. Results The treatment with curcumin at various concentrations for various hours inhibited the proliferation of DAOY cells significantly （P 〈 0. 05 ）. However, the curcumin at a concentration of not more than 60 μmol / L showed does- and time-dependent inhibitory effect. β-catenin was in expressed in both cytoplasm and nucleus, especially in nucleus of DAOY cells in control group. After treatment with 30 p, mol/ L curcumin for 48 h, the both the expression levels of β-catenin and cyelinD1 in nucleus were significantly lower than those in control group （P 〈 0. 05 ）, whereas the expression level of β-catenin in cytoplasm showed no significant decrease （P 〉 0. 05 ）. Conclusion Curcumin inhibited the proliferation of MB cells by inhibiting the expression and nuclear translocation of β-catenin, blocking the Wnt/β-catenin signaling pathway and suppressing the expression of target gene cyclinD1.