抑制MRN复合体功能对喉鳞状细胞癌放射敏感性的影响

Influences of Functional Inhibition of MRN Complex on Radiosensitivity of Laryngeal Squamous Cell

目的:探讨抑制Nbs1基因的表达对喉鳞癌细胞放射敏感性的影响。方法:用ADV1包装的干扰质粒(ADV1-Nbs1)和空载腺病毒(ADV1-NC)转染Hep-2细胞,将细胞分为正常对照组、ADV1-Nbs1转染组、ADV1-NC转染组,上述各组又分为X射线照射组和未照射组。RT-PCR和Western Blot检测Nbs1基因的表达水平,MTT法描绘出各组增殖曲线,流式细胞仪检测细胞周期,RT-PCR法测定各组相对端粒长度。结果:RT-PCR和Western Blot结果显示ADV1-Nbs1转染组的Nbs1基因的表达水平明显低于正常对照组和ADV1-NC转染组。ADV1-Nbs1转染联合X射线放射组抑制增殖最显著(P<0.05)。对比正常对照组(11.8%),ADV1-Nbs1转染组和ADV1-Nbs1转染联合放射组G_2/M期百分比均有增高,分别为34.2%(P<0.05)、25%(P<0.05)。ADV1-Nbs1转染组端粒长度较正常组缩短约57%(P<0.05),ADV1-Nbs1转染组同ADV1-Nbs1转染联合放射组端粒长度无差异(P>0.05)。结论:干扰MRN复合体功能可有效使Hep-2细胞的放射敏感性提高。

Objective:To investigate the effect of inhibition of Nbs1 gene expression on radiosensitivity of laryngeal squamous cell carcinoma.Methods:A interference plasmid of Nbs1 gene was packaged with ADV1(ADV1-Nbs1).Blank control group,and ADV1-Nbs1 transfection group,and ADV1-NC transfection group were grouped according to the treatment of Hep-2cells by ADV1-Nbs1 or ADV1-NC transfection,and then the groups were divided into X-ray irradiation group and non-irradiation group by 2Gy X-ray irradiation.RT-PCR and Western blot were used to determine the interference effect of the target gene.MTT was used to determine the growth curve.Flow cytomery was used to analyze the cell cycle distribution.RT-PCR was used to determine the relative telomere length.Results:The transfection of ADV 1-Nbs1 could significantly inhibit the expression of Nbs1 mRNA in Hep-2cells.The ADV1-Nbs1 treatment demonstrated a significant decrease in cell growth compared with other groups(P<0.05).Compared with that in blankcontrd group(11.8),the percentage of G_2/M phase in ADV1-Nbs1 transfection group(34.2%)and ADV1-Nbs1 transfection combined irradiation group(25%)both increased significantly(P<0.05).The telomere length of ADV 1-Nbs1 transfection group was shorter than that of blank control group by 57%(P<0.05),but the telomere length of ADV1-Nbs1 transfection group had no difference from that of ADV1-Nbs1 transfection combined irradiation group(P >0.05).Conclusion:Interfering with MRN complex function can effectively increase the radiosensitivity of Hep-2 cells.