中文摘要：

目的 探讨人视网膜母细胞瘤Rb94基因重组腺病毒载体（Ad-Rb94）联合γ射线照射对体外人大肠癌细胞生长的联合抑瘤作用及其机制.方法 将Ad-Rb94于体外转染大肠癌HT29细胞,转染后12h进行4Gy ^137Csγ射线照射.实验分组为5组：对照组、β-半乳糖苷酶基因重组腺病毒载体组（Ad-lacZ组）、Ad-Rb94组、照射组和Ad-Rb94联合照射组.用噻唑蓝法检测HT29细胞的生长,用流式细胞术检测HT29细胞的细胞周期和细胞凋亡的变化.结果 当Ad-Rb94有效转染HT29细胞后,从转染第4日开始,照射组和联合照射组细胞生长速率较对照组和Ad-lacZ组缓慢;与Ad-Rb94组和照射组相比,Ad-Rb94联合照射组细胞的生长表现出更强的抑制效应（t=15.02、17.30,P＜0.01）.细胞周期结果表明,与对照组、Ad-lacZ组和Ad-Rb94组相比,照射组大量细胞停留在G2期,各组间差异有统计学意义（t=18.65、15.23、16.38,P＜0.01）;但Ad-Rb94联合照射组停留在G2期细胞更多（约40％）,远高于照射组（t=7.78,P＜0.05）.细胞凋亡结果表明,与对照组相比,Ad-Rb94组和照射组细胞凋亡率明显增加（t=16.19、10.72,P＜0.01）;Ad-Rb94联合照射组细胞凋亡率最高（21％）,与Ad-Rb94组和照射组相比,差异有统计学意义（t=6.17、9.25,P＜0.05）.结论 腺病毒介导的Rb94基因联合照射对大肠癌细胞的抑瘤作用具有协同效应,其机制可能是促进细胞G2期阻滞和凋亡.

英文摘要：

Objective To evaluate the mechanism of combined effects of recombinant adenovirus-mediated retinoblastoma gene 94（Ad-Rb94）with γ-ray radiation on inhibiting the growth of human colorectal cancer cells in vitro.Methods HT29 cells were transfected by Ad-Rb94 and irradiated by 4 Gy ^137Cs γ-ray 12 h after transfection.The cohorts were divided into five groups：blank control,Ad-LacZ,Ad-Rb94,radiation and Ad-Rb94 combined with radiation.The cells growth curve of HT29 cells was detected by MTT assay.Changes of cell cycle and cell apoptosis in HT29 cells were detected by flow cytometry.Results The growth of cells treated with Ad-Rb94 or radiation alone was all inhibited when AdRb94 was transfected effectively into HT29 cells.The growth of HT29 cells treated with radiation or combination of Ad-Rb94 and radiation was slower than that of blank control and Ad-lacZ at 4 d after transfection.The growth of HT29 cells treated with combination of Ad-Rb94 and radiation resulted in greater inhibition compared with that of Ad-Rb94 or radiation alone （t=15.02 and 17.30,P〈0.01）.Cell cycle data showed that HT29 cells treated with radiation were arrested at G2 phase,and there were significant differences compared with that of blank control,Ad-lacZ and Ad-Rb94 （t=18.65,15.23 and 16.38,P〈0.01）.Cells treated with combination of Ad-Rb94 and radiation arrested at G2 phases increasingly,reached 40%,significantly higher than that of radiation alone （t=7.78,P〈0.05）.Cells apoptosis data showed that the apoptosis ratio of HT29 cells treated with Ad-Rb94 or radiation was markedly increased compared with that of blank control （t=1 6.19 and 10.72,P〈0.01）.Cells apoptosis ratio of HT29 cells treated with combination of Ad-Rb94 and radiation was the highest,reached 21%,and there were significant differences compared with that of Ad-Rb94 or radiation alone （t=6.17 and 9.25,P〈0.05）.Conclusion The recombinant Ad-Rb94 transfection combined with radiation shows synergism for the suppression of colorectal cancer cells gr