MEG3抑制视网膜母细胞瘤细胞增殖

MEG3 inhibits the proliferation of retinoblastoma cells

目的 :探讨母系表达基因3(maternally expressed gene 3,MEG3)对视网膜母细胞瘤(retinoblastoma,RB)细胞增殖的影响。方法 :应用实时荧光定量PCR法检测RB细胞SO-RB50和HXO-RB44及正常视网膜色素上皮h TERT RPE-1细胞中MEG3的表达水平。将pc DNAMEG3或si RNA-MEG3分别转染SO-RB50或HXO-RB44细胞后,应用实时荧光定量PCR法检测细胞中MEG3的表达水平,CCK-8法检测细胞的增殖能力,蛋白质印迹法检测细胞中RB蛋白的表达水平。用不同浓度的5-氮杂-2’-脱氧胞苷(5-Aza-2’-deoxycytidine,5-Aza-Cd R)处理SO-RB50和HXO-RB44细胞后,应用实时荧光定量PCR法检测细胞中MEG3的表达水平。CCK-8法检测si RNA-MEG3转染10μmol/L 5-Aza-Cd R处理组SO-RB50和HXO-RB44细胞的增殖能力。结果:RB细胞SO-RB50和HXO-RB44中MEG3的表达水平均显著低于正常视网膜色素上皮h TERT RPE-1细胞(P值均<0.01)。pc DNA-MEG3转染后,SO-RB50细胞中MEG3和RB蛋白的表达水平上调(P<0.01和P<0.05),细胞增殖受到抑制(P<0.05);si RNA-MEG3转染后,HXO-RB44细胞中MEG3和RB蛋白的表达水平下调(P<0.01和P<0.05),并促进细胞增殖(P<0.05)。5和10μmol/L 5-Aza-Cd R处理后,SO-RB50细胞(P<0.05和P<0.01)和HXO-RB44细胞(P<0.05和P<0.01)中MEG3的表达水平上调。si RNA-MEG3转染10μmol/L 5-Aza-Cd R处理组SO-RB50和HXORB44细胞的增殖受到抑制(P值均<0.05)。结论 :RB细胞中MEG3表达下调,这可能与DNA甲基化有关。MEG3可能通过促进RB蛋白的表达而抑制RB细胞的增殖。

Objective：To investigate the effect of maternally expressed gene 3（MEC3） on the proliferation of retinoblastoma cells.Methods：The expression of MEC3 in retinoblastoma SO-RB50 and HXO-RB44 cells and normal retinal pigment epithelial hTERT RPE-1 cells was detected by real-time fluorescent quantitative-PCR.After transfection with pcDNA-MEC3 or siRNA-MEC3,the expression of MEC3 in retinoblastoma SO-RB50 and HXO-RB44 cells was detected by real-time fluorescent quantitative-PCR,the cell proliferation was examined by CCK-8 method,and the expression level of RB protein in cells was detected by Western blotting.After treatment with different concentrations of 5-Aza-2’-deoxycytidine（5-Aza-CdR）,the expression of MEC3 in S0-RB50 and HXO-RB44 cells was detected by real-time fluorescent quantitative-PCR.The proliferation of SO-RB50 and HXO-RB44 cells-treated with 10 μmol/L 5-Aza-CdR then transfected with siRNA-MEC3 was examined by CCK-8 method.Results：The expression level of MEC3 in retinoblastoma SO-RB50 or HXO-RB44 cells was lower than that in normal retinal pigment epithelial hTERT RPE-1 cells（both P 〈 0.01）.After transfection with pcDNA-MEC3,the expression levels of MEC3 and RB protein in SO-RB50 cells were significantly up-regulated（P 〈 0.01,P 〈 0.05）,and the cell proliferation was inhibited（P 〈 0.05）.After transfection with siRNA-MEC3,the expression levels of MEC3 and RB protein in HXO-RB44 cells were down-regulated（both P 〈 0.05）,and the cell proliferation was promoted（P 〈 0.05）.After treatment with 5 and 10 μmol/L 5-Aza-CdR,the expression level of MEC3 in SO-RB50 and HXO-RB44 cells was up-regulated（SO-RB50 cells：P 〈 0.05,P 〈 0.01;HXO-RB44 cells：P 〈 0.05,P 〈 0.01）.The proliferation of SO-RB50 and HXO-RB44cells-treated with 10 μmol/L 5-Aza-CdR then transfected with siRNA-MEC3 was inhibited（all P 〈 0.05）.Conclusion：The expression of MEC3 is down-regulated in retinoblastoma cells,which may be related to DNA methylation.It is suggested that MEC3 might inhibit the proliferation of retinoblastoma cells via promoting the expression of Rb protein.