中文摘要：

构建特异性抑制白血病病毒致癌基因同源体2（ErbB2）的小干扰RNA（siRNA）表达载体，并检测联合^60Coγ照射对U251细胞增殖抑制及促进凋亡作用。设计、合成ErbB2特异性的19bp短链寡核苷酸，经退火形成双链DNA片段，克隆到Psflence2．1-U6-H1载体中，构建ErbB2特异siRNA的表达载体，HindⅢ和BamHⅠ双酶切及测序鉴定重组体，并转染U251细胞，四甲基偶氮唑盐法（Methylthiazolyl tetrazolium assay，MTT）检测细胞增殖活性，Hoechst33258染色，Annexin—V检测细胞凋亡情况。经双酶切与测序鉴定成功构建ErbB2一siRNA表达载体，转染星型胶质瘤细胞株U251细胞可显著抑制细胞增殖活性（p〈0．05），并诱导细胞产生时间依赖性凋亡，24h凋亡细胞百分比增加10．52％，48h凋亡细胞百分比增加50．65％。联合^60Coγ照射U251细胞增殖活性较单独转染进一步显著降低（p〈0．05）。运用Psflence2．1-U6-H1载体构建的ErbB2-siRNA表达载体可有效抑制U251细胞增殖并促进时间依赖性细胞凋亡；联合^60Coγ照射可增加增殖抑制效果。

英文摘要：

To construct erythroblastic leukemia viral oncogene homolog 2 （ErbB2） small interference RNA （siRNA） expression vector and to study its effect on U251 cell line proliferation and apoptosis combining with ^60Coγ-iradiation. ErbB2 specific 19bp oligonucleotides were designed and synthesized. These oligonucleotides were annealed to form the double strand DNA fragments,which was cloned into pSilence2.1-U6-H1 vector. The recombinant pSilence2.1-ErbB2 expression construct was confirmed by Hind Ⅲ and BamH Ⅰ double digestion and sequencing. The pSilence 2.1-ErbB2 was transfected into U251 cell. Cellular proliferation activities were assayed by tetrazolium bromide （MTT） colorimetry. The apoptosis of transfected U251 cell was examined with Hoechst 33258 staining and Annexin-V kit. Psilence 2.1-ErbB2 expression vector was successfully constructed and it can effectively inhibit proliferation（p〈0.05） and induced time dependent apoptosis（the percentage of apoptosis cell increase 10.52% after 24h transfection, the percentage of apoptotic cell increase 50.65% after 48h transfection） in transfected U251 cell line compared with non-transfected and pSilence2.1-GFP U251 cells, After combination with ^60Coγ-irradiation, the effect of inhibiting proliferation was more significant compared with non-irradiated U251 cells（p〈0.05）. The pSilence 2.1-ErbB2 expression vector can effectively inhibit proliferation and induced U251 cells time dependent apoptosis; combination of ^60Coγ-irradiation can enhance the inhibitory efficiency in U251 cell line.