辐射诱导p53腺病毒重组体转染对结直肠癌细胞周期的影响

Effects of AdCMV-p53 gene transfer induced by irradiation on cycle of human colorectal adenocarcinoma cells

以复制缺陷型重组腺病毒载体(AdCMV-GFP)为对照,用复制缺陷型p53重组腺病毒载体 (AdCMV-p53)转染经0．5、1．0、2．0Gyγ射线照射的HT-29细胞,克隆形成法检测对细胞的抑制作用,流式细胞分析法检测细胞周期和细胞凋亡,探讨辐射诱导对AdCMV-p53转染p53突变型结直肠癌细胞(HT-29细胞系)细胞周期的影响。结果显示,0．5-1．0Gy辐射诱导明显增强40 MOI AdCMV-p53转染对HT-29细胞的抑制。与AdCMV-p53转染对照相比,1 d后,辐射诱导转染组G0／G1期细胞减少5%-15％,S期细胞增加 2%-19％,2．0Gy辐射诱导80 MOI AdCMV-p53转染组G2/M期细胞增加12％;3d后,0．5、1．0Gy辐射诱导40 MOI AdCMV-p53转染组G2／M期细胞分别增加10%-13％。辐射诱导AdCMV-p53转染组细胞凋亡与辐射诱导剂量和AdCMV-p53转染剂量相关。以上结果表明,辐射诱导加速AdCMV-p53转染细胞由G0／G1期到S期的进程,促进S期阻滞和G2/M期阻滞发生。

The work is to investigate effects of AdCMV-p53 gene transfer induced by ^60Co γ-rays on cell cycles of human colorectal adenocarcinoma cells. HT-29 cells exposed to 0.5, 1.0 and 2.0Gy were infected with AdCMV-GFP, a replication deficient recombinant adenoviral vector containing a CMV promoter and green fluorescent protein, or AdCMV-p53, a replication deficient recombinant adenoviral vector containing a CMV promoter and carrying human wild-type p53 gene. Survival rate of the cells was determined by clonogenic assay. Cell cycle and cell apoptosis were determined by flow cytometry. The results showed that, 0.5-1.0 Gy irradiation significantly enhanced the inhibition of AdCMV-p53 infection on HT-29. Compared with the control, lday after the infection, the cells in G0/G1 phase decreased by 5 %--15 %, the cells in S phase increased by 2 %-19 %. The 0.5 and 1.0Gy irradiation made the cells in the in G2/M phase increase by 12 %, infected with 80 MOI AdCMV-p5. Three days later, the proportion of cells in G2/M phase in groups of 0.5 and 1.0 Gy irradiation ＋ 40 MOI AdCMV-p53 infection increased by 10%--13 %. There was a relation between cell apoptosis and irradiation dose, or AdCMV-p53 dose. Therefore, the irradiation-induction could quicken the progression from G0/G1 phase to S phase, and promote S and G2/M phase arrest.