【摘要】 目的探讨XRCC2基因沉默对人结肠癌细胞放射敏感性的影响。方法实验分组为control组(结肠癌T84细胞)、shRNA-SC组(T84/shRNA-SC细胞)和shRNA-XRCC2组(T84/XRCC2-shRNA细胞)。经X-射线照射后,采用碱性"彗星"电泳法测定结肠癌细胞的DNA损伤修复,采用流式细胞术检测结肠癌细胞的细胞周期和细胞凋亡率。结果照射前shRNA-XRCC2组细胞显示出拖尾彗星;照射后shRNA-XRCC2组细胞尾长、尾矩或Olive尾矩均明显高于control组细胞,差异有统计学意义(t=6.95、5.34、9.43,P<0.01)。照射前shRNA-XRCC2组细胞与control组细胞相比,停留在G2/M期较多(14.36%±1.32%),差异有统计学意义(t=10.46,P<0.01);照射后shRNA-XRCC2组滞留在G2/M期的细胞显著增加(38.51%±4.15%),与control组细胞相比差异有统计学意义(t=3.92,P<0.05)。照射前shRNA-XRCC2组细胞凋亡率(17.40%±4.81%)明显高于control组细胞(t=8.59,P<0.01);照射后shRNA-XRCC2细胞的凋亡率显著增加(33.16%±2.69%),与control组细胞相比差异有统计学意义(t=15.31,P<0.01)。结论 XRCC2基因沉寂提高了结肠癌细胞的放射敏感性,XRCC2有望在结肠癌的临床放射治疗敏感性中作为一重要的靶向基因。更多还原

【Abstract】 Objective To study the effect of XRCC2 gene silencing on the radiosensitivity of colon cancer cells. Methods The cohorts were divided into three groups: control( colon cancer T84 cells),shRNA-SC( T84 / shRNA-SC cells) and shRNA-XRCC2( T84 / XRCC2-shRNA cells) and exposed to X-ray radiation. DNA damage’s repair of colon cancer cells was determined by alkaline comet assay. The cell cycle distribution or cell apoptosis of colon cancer cells was detected by flow cytometric analysis. Results Cells of shRNA-XRCC2 group before radiation treatment showed comet image with tail. The value of TDNA% 、TM and OTM of shRNA-XRCC2 group cells after exposure to radiation were significantly higher than that of control group( t = 6. 95、5. 34、9. 43,P < 0. 01). Cells of shRNA-XRCC2 group before radiation treat-ment were arrested in G2/ M phase( 14. 36 ± 1. 32%),and there were significant differences compared with that of control( t = 10. 46,P < 0. 01). Cells of shRNA-XRCC2 group after exposure to radiation arrested at G2/ M phase were increased,reached( 38. 51 ± 4. 15) %,significantly higher than that of control( t = 3. 92,P < 0. 05). The apoptosis ratio of shRNAXRCC2 group cells before radiation was significantly higher( 17. 40% ± 4. 81%) than that of control( t = 8. 59,P < 0. 01). Cells apoptosis ratio of shRNA-XRCC2 group cells after radiation treatment was markedly increased,reached( 33. 16 ± 2. 69) %,and there were significant differences compared with that of control( t = 15. 31,P < 0. 01). Conclusion The radiosensitivity is increased in colon cancer cells of silencing XRCC2 gene,and XRCC2 may be further developed as a promising therapeutic target for the treatment of colon cancer.更多还原