Beclin 1 基因对恶性胶质瘤细胞 U87 自噬活性和增殖的影响简

目的研究BeclinJ基因对U87胶质瘤细胞自噬和增殖的影响。方法实验分5组：空白对照组．pSUPER—Bec组（表达BeclinsiRNA）与其阴性对照组（pSUPER—non组），pcDNA3．1-Bec组（表达BeclinJ基因质粒）与其阴性对照组（pcDNA3．1-non组）。分别转染U87细胞，采用免疫印迹检测Beclin1、LC3和p62蛋白在各组的表达；用氚标胸腺嘧啶脱氧核苷（3H-TdR）检测各组细胞增殖率。结果转染后48h，pSUPER—Bec组Beclin1、LC3B—11蛋白表达下降，p62蛋白表达升高。pcDNA3．1-Bec组Beclin1、LC3B-Ⅱ蛋白表达升高，p62蛋白表达下降。与空白对照组或pcDNA3．1-non组相比．pcDNA3．1-Bec组细胞增殖速度降低（P〈0．05），其他各组细胞增殖速度无明显差异。结论恶性胶质瘤细胞中自噬相关基因Beclinj表达下降，过表达Beclinl蛋白能增强细胞的自噬活性，抑制细胞的增殖活性。

Influence of Beclin 1 on autophagy and cell proliferation in U87 glioma cells

Objective To explore influence ofBeclin 1 on autophagy and proliferation of U87 glioma cells. Methods The experiments were divided into 5 groups： blank control group （untreated U87 cells）, pSUPER-Bec group （expression ofBeclin 1 siRNA） and its negative control group （pSUPER-non group）, peDNA3.1-Bec group （over-expression of Beclin 1 gene plasmid） and its negative control group （pcDNA3.1-non group）. U87 cells were transfected using liposome-based method. The expression levels of Beclin 1, LC3 and p62 protein were measured by Western blotting. Cell proliferative activity was assessed by 3H-TdR assay. Results Forty-eight hours after transfection, the lanes of Western blotting showed that expressions of Beelin 1 and LC3B- II were slightly increased in pcDNA3.1-Bec group compared with pcDNA3.1-non group or blank control group, whereas Beelin 1 and LC3B- I1 expressions were decreased in pSUPER-Bec group. Conversely, the level of p62 was lower in pcDNA3.1-Bee group but higher in pSUPER-Bec group. The cell proliferation in pcDNA3.1-Bec group was lower than that in pcDNA3.1-non group or blank control group （P 〈 0.05）, but there was no significant difference among pcDNA3.1-non group, pSUPER-Bec group, pSUPER-non group or blank control group. Conclusion Expression of Beclin 1 （autophagy associated gene） is down-regulated in U87 glioma cells. Over-expression ofBeclin 1 protein in U87 cells could augment autophagie capacity but reduce cell proliferation.