【摘要】 目的观察人PIF1解旋酶敲低对电离辐射致细胞生长及细胞周期阻滞的影响,以探讨人PIF1在电离辐射致DNA损伤应答中的作用。方法采用慢病毒系统建立PIF1敲低稳转细胞系,实时荧光定量PCR及Western印迹检测PIF1敲低效果。细胞计数法观察PIF1敲低对4 Gyγ射线照射下细胞增殖的影响,流式细胞术观察PIF1敲低对8 Gyγ射线照射下细胞周期阻滞的影响。结果建立了PIF1敲低的稳转细胞系,4 Gyγ射线照射后,PIF1敲低细胞系的生长受到明显抑制,在照后第2⁴天几乎无任何增殖,直到第5天才开始缓慢增殖。8 Gyγ射线照射后,PIF1敲低细胞系的S期阻滞与G₂/M期阻滞相对于对照细胞发生明显延迟。结论 PIF1敲低后显著增加了细胞的辐射敏感性以及电离辐射所致的S期阻滞与G₂/M期阻滞延迟。更多还原

【Abstract】 Objective To observe the effect of PIF1 knockdown on cell growth and cell cycle arrest induced by ionizing radiation. Methods He La cell lines that consistently down-regulated PIF1 were prepared by the lentivirus granules interfering technology and confirmed by real-time PCR and Western blotting. The effect of down-regulation of PIF1 on cell growth and cell cycle arrest induced by ionizing radiation was evaluated by cell counting and flow cytometry. Results He La cell lines consistently down-regulating PIF1 were established. The growth of He La that down-regulated PIF1 was inhibited greatly after 4 Gy of γ-ray irradiation. There was little cell proliferation until the 5thday post 4 Gy γ-ray. Moreover,the S phase block and G2/M phase block of PIF1 knock-downed cell lines were significantly delayed after 8 Gy γ-ray irradiation.Conclusion Knockdown of PIF1 can significantly enhance the radiation sensitivity and delayes the S phase block and G2/M phase block induced by ionizing radiation.更多还原