【摘要】 目的:探讨蚯蚓纤溶酶(EFE)对食管癌细胞的放射增敏作用及机制。方法:选取人食管癌细胞株ECA109,采用MTT法观察EFE对细胞的生长抑制作用,克隆形成实验观察EFE对细胞的放射增敏作用,流式细胞术观察EFE对细胞周期分布的影响,RT-PCR法检测EFE对细胞内硒谷胱甘肽过氧化物酶(SeGPx)mRNA表达的影响。结果:EFE对ECA109有生长抑制作用,其作用呈剂量依赖性,IC50为3.8 ukU.ml-1;EFE0.1、0.3 ukU.ml-1的放射增敏比分别为1.37和1.59;EFE作用24 h后,食管癌细胞G2与M期比例明显下降,细胞内SeGPx基因表达明显下调。结论:EFE在体外可抑制ECA109的生长,同时可增加其对放射线的敏感性;放射增敏机制可能与EFE清除细胞G/M期阻滞及下调细胞内抗氧化酶SeGPx mRNA表达有关。更多还原

【Abstract】 Objective To study the radiosensitivity-enchancing effect of earthworm fibrinolytic enzyme(EFE) on human esophageal carcinoma cell line and its related mechanism.Methods The esophageal carcinoma cell line EC A109 was used in the experiment.MTT assay was performed to analyze the inhibitory ratio of the cell line,the clonogenic assay was used to determine cell survival fraction,the flow cytometer was used to check cell cycle distribution and the RT-PCR was used to determine the gene expression of selenium dependent glutathione peroxidase(SeGPx).Results The proliferation of cell line ECA 109 was suppressed by EFE in vitro.The inhibitory concentration of 50%(IC50) was 3.8 ukU·ml-1.EFE could definitely enhance radiosensitivity of ECA 109 cells.The sensitivity-enchancement-ratio was 1.37 for 0.1 ukU·ml-1EFE and 1.59 for 0.3 ukU·ml-1 of EFE respectively.EFE abrogated the G2/M arrest induced by γ-ray.Meanwhile,the expression of SeGPx mRNA decreased after the EFE or(and) γ-ray treatment.Conclusion EFE might be a potential radiosensitizer for esophageal carcinoma.In addition,the abrogation of G2/M arrest and the downregulated expression of SeGPx mRNA may be related with EFE’s radiosensitizing effect.更多还原