褐藻糖胶通过抑制Wnt/β-catenin通路诱导多发性骨髓瘤细胞PRMI8226凋亡

Fucoidan induces apoptosis of PRMI8226 cells via inhibiting Wnt/β-catenin signaling pathway

目的探讨褐藻糖胶诱导多发性骨髓瘤细胞PRMI8226凋亡时Wnt/β-catenin通路的变化。方法褐藻糖胶不同浓度(25、50、100、200、400μg·mL-1)分别作用于PRMI8226细胞24、48、72 h,采用MTT法检测PRMI8226细胞增殖情况并求得半数抑制浓度(IC50);以1/2 IC50浓度的褐藻糖胶作用于PRMI8226细胞72 h后,采用流式细胞术检测细胞凋亡率。将细胞分为空白对照组、Wnt通路抑制剂(DKK-1)组(100 ng·mL-1)及褐藻糖胶(25μg·mL-1)组,采用Western blot检测β-catenin、c-myc、bax及caspase 3蛋白表达水平。结果褐藻糖胶对PRMI8226细胞增殖抑制作用呈时间-剂量依赖性增强。PRMI8226细胞经褐藻糖胶25μg·mL-1处理72 h后,其凋亡率(12.22%)明显高于对照组(4.82%)(P<0.05)。Western blot结果显示,与空白对照组比较,两组β-catenin和c-myc表达水平均有显著差异(P<0.05),褐藻糖胶组β-catenin和c-myc表达水平与DKK-1组比较无显著差异(P>0.05);褐藻糖胶组caspase3和bax蛋白表达水平较DKK-1组增加(P<0.05),两组与空白对照组比较表达亦增加,均有显著差异(P<0.05)。结论褐藻糖胶通过抑制Wnt/β-catenin通路的活化,能诱导多发性骨髓瘤PRMI8226细胞凋亡。

AIM To investigate the effect of fucoidan on the apoptosis of PRMI8226 cells and its possiblemechanism. METHODS The MTT assay was used to evaluate the effect of fucoidan on the growth of PRMI8226 cells and calculate the IC50 after the cells were treated with 25, 50, 100, 200, 400 μg· mL-1 fucoidan each for 24, 48, 72 h. Treating cells with the half IC50 fucoidan （25μg·mL-~） for 72 h, they tested the apoptosis of PRMI8226 by FITC-annexin V/PI assay. And then, the PRMI8226 cells were divided into blank control group, DKK-1 group （100 ng·mL^-1） and fucoidan group （25 μg· mL^-1）. According to the groups processing PRM18226 cells for 72 h, they analyzed the cells protein levels of [3-catenin, c-myc, bax and caspase 3 respectively by western blotting. RESULTS The results showed that the proliferation of PRMI8226 cells was inhibited by fucoidan in a time- and dose-dependent manner. Compared with the blank control group, the apoptosis rate of PRMI8226 cells increased in 1/2 IC50 fucoidan group （4,82% vs. 12.22% , P 〈 0.05）. There was no difference between the fucoidan and DKK-1 group in the western blotting expression of β- catenin and c- myc protein （P 〉 0.05）, but they had magnificent difference with the blank control group （P 〈 0.05）. Compared with the DKK-1 group, the expression of caspase3 and bax protein increased in the fucoidan group （P 〈 0.05）. Further compared with the blank control group, the expression of caspase3 and bax protein increased in the fucoidan and DKK- 1 group （P 〈 0.05）. CONCLUSION Fucoidan can induce apoptosis of PRMI8226 ceils via inhibiting Wnt/β-catenin signaling pathway.