电离辐射对人肺非小细胞癌细胞株H446 nm23-H1基因表达的影响

Effect of ionizing radiation on expression of nm23-H1 gene in human non-small cell lung carcinoma cell line H446

目的：探讨电离辐射对人肺非小细胞癌细胞株H446 nm23-H1基因表达的影响。方法：取对数生长期的H446细胞置^60Co放射治疗机上单次照射，照射剂量分别为0、1、2．3、4和5Gy，继续培养至0、6、24和48h后收集细胞，提取细胞总RNA和总蛋白。分别用RT-PCR和Western Not检测nm23-H1基因mRNA和蛋白的表达水平。结果：照射后各剂量组nm23-H1 mRNA和蛋白的表达量均明显降低（P〈0．01），与剂量之间呈负相关（P〈0．05），相关系数r分别≥0．785和≥0．66；mRNA的表达水平在0～24h内随培养时间延长逐渐增加，48h时有所降低。蛋白表达在0～6h内没有明显变化，24h达到高点，48h有所降低。结论：电离辐射对H446细胞nm23-H1基因表达有一定的影响，随着辐射剂量的增大该基因mRNA和蛋白表达水平逐渐降低，并且在所有观察时间点均显示出一定的剂量效应关系。

Objective ：To investigate the effect of ionizing radiation on expression of nm23 - H1 gene in human non - small cell lung carcinoma cell line H446. Methods：The cells at logarithmic phase were exposed to ^60Co γ ray at single dose irradiation （0, 1, 2, 3,4 and 5Gy）, and then these cells were cultured in the same medium for 0, 6, 24 and 48 hours after exposure. The nm23 - H1 mRNA levels of the cells were determined by RT - PCR, and expression of the nm23 - H1 gene protein was detected by Western blotting. Results：The levels of the nm23 -H1 mRNA and protein expression were obviously declined, respectively, at the range of dose from 0 -5Gy after exposure （P 〈0. 01 ）, and showed the negative correlation with dosages （P 〈0. 05 ,r≥0. 785 and r≥0. 66, respectively）. The levels of mRNA were to increase gradually at the period from 0 to 24 h, and decrease a little at 48 h after the irradiation. No significant changes on expression of nm23 - H1 protein were observed in the period from 0 to 6h, and the expression reached to peak value at 24h after irradiation and decreased to some extent at 48 h. Conclusion： Levels of nm23 - H1 mRNA and protein expression decreased gradually with increase of the radiation doses, and both between the levels of the expressions and radiation doses showed a dose -effect response at different time after irradiation.