中文摘要：

目的观察N—myc下游调节基因-2（NDRG2）对肾癌细胞株786—0增殖及细胞周期素（Cyclin）D1、p21表达的影响。方法以携带人NDRG2基因的慢病毒载体感染体外培养的肾癌细胞株786-O。采用间接免疫荧光实验检测慢病毒感染后细胞中NDRG2的过表达。Westernblot检测CyclinD1、p21的表达变化，通过细胞生长实验、平板克隆实验检测NDRG2对786一O细胞增殖能力的影响。流式细胞仪检测感染前后细胞的凋亡。结果786一O细胞经慢病毒感染后NDRG2蛋白表达水平明显增加。Westernblot实验显示慢病毒感染后细胞中CyclinD1表达明显降低；而p21表达明显增加。噻唑蓝（MTT）比色（抑制率12h为3．96％，24h为4．78％，36h为9．32％，48h为20．27％，60h为22．85％，72h为30．86％）显示NDRG2对786—0细胞的生长有明显抑制作用。平板克隆实验（3组分别为67．1％、65．5％和41．7％）显示lenti—NDRG2组786—0细胞的克隆形成能力明显降低。流式细胞术显示lenti-NDRG2组细胞凋亡率为（17．20±1．44）％，明显高于对照组[（6．30±0．46）％，t=12．49，P〈0．01]和lenti—mCherry组[（6．00±0．31）％，t=13．17，P〈0．01]。结论通过慢病毒载体使786-O细胞表达NDRG2基因，可以明显抑制细胞的增殖，并可降低CyelinD1表达，同时增加p2l的表达。

英文摘要：

Objective To investigate the effect of N-myc downstream regulated gene 2 （NDRG2） gene on the renal cancer 786-0 cells＇ proliferation and expressions of Cyclin D1 and p21. Methods The lentiviral vector were infected into renal cancer cell line 786-0 in vitro. The up-regulation of NDRG2 pro- tein was determined by indirect immunofluorescence assay. The protein expressions of Cyclin D1 and p21 in the cells infected with Lenti-NDRG2 and Lenti-mCherry were determined by Westernblot respectively. Methyl thiazol tetrazolium （MTT） assay and plate colony formation were used to determine the effect of pro- liferation of cells. The variation of cell apoptosis was detected by flow cytometry. Results After infected by lentivirus, it had been verified that the protein expression of NDRG2 in the cells by indirect immunofluo-rescence assay. The expression of Cyclin D1 became low, moreover the expression of p21 became high. With the MTT assay（inhibition ratio 12 h 3.96%, 24 h 4. 78%, 36 h 9. 32%, 48 h 20. 27%, 60 h 22. 85% and 72 h 43.7% ） and plate colony formation （ 56.3% , 55.2% and 36. 7% respectively ） , NDRG2 exhibited significant inhibiting the growth and proliferation of 786-0 ceils. The apoptosis rate of cells transfected with Lenti-NDRG2 （17.20±1.44）% was significantly higher than coutrol group （6. 30±0.46）%, （t=12.49, P〈0.01） and Lenti-mCherry group （6.00±0.31）%, （t=13.17, P〈0.01）. Conclusion The lentiviral vector expressing NDRG2 could inhibit the proliferation of 786-0, furthermore it could down regulate the expression of Cyclin D1 and up-regulate the expression of p21.