不同放射敏感性肺腺癌细胞株中DNA-PKcs蛋白的表达情况比较

目的 通过检测DNA-PKcs在肺腺癌细胞中的表达情况,探讨其与放射敏感性的关系.方法 成克隆实验分别测定肺腺癌细胞株A549、H1299照射后的剂量.存活曲线,Western blotting及DNA-PK活性分析法检测两株细胞中DNA-Pkcs的含量与活性.分析放射敏感性与DNA-PKcs的关系.结果 成克隆实验结果显示:肺腺癌细胞H1299较A549放射更敏感,SF2分别为A549:0.7412,H1299:0.2473.Western-blot显示A549和H1299积分光密度比值分别为:3.29±0.44、0.50±0.17,A549中DNA-PKcs的表达更高(t=10.37,P<0.001).DNA-PKcs活性检测结果为A549:8.29±1.37.H1299:2.47±1.09(t=5.76,P=0.005).结论 放射敏感性不同的肺腺癌细胞株中DNA-Pkcs的表达不同.提示DNA-PKcs可能是影响肺腺癌细胞放射敏感性的重要因素.

Abstract：

Objective To investigate DNA-dependent protein kinase catalytic subunit (DNA-PKcs) content and activity in lung adenocarcinoma cell lines and its correlation with radiosensitivity. Methods The content and activity of DNA-PKcs were analyzed in two lung adenocarcinoma cell lines A549 and H1299 by Western blotting and the Signa TECT DNA-PK assay kit. The dose-survival relationship for two cell lines was analyzed using clonogenic formation assay. Results A549 was more radiosensitive than H1299. The survival fractions at 2 Gy (SF2) were 0.7412 in A549 cell line and 0.2473 in H1299 cell line. The content of DNA-PKcs was significantly higher in A549 cells than in H1299 cells (t=10.37, P<0.001). The integrated optical densities were 3.29±0.44 in A549 cells and 0.50±0.17 in H1299 cells. DNA-PKcs activities in A549 and H1299 cells were 8.29±1.37 and 2.47±1.09, respectively, showing a significant difference between them (t=5.76, P=0.005). Conclusion DNA-PKcs is an important factor to affect the radiosensitivity of lung adenocarcinoma cell lines.

Comparison of DNA-dependent protein kinase catalytic subunit expression in two lung adenocarcinoma cell lines with different radiosensitivity

Objective To investigate DNA-dependent protein kinase catalytic subunit (DNA-PKcs) content and activity in lung adenocarcinoma cell lines and its correlation with radiosensitivity. Methods The content and activity of DNA-PKcs were analyzed in two lung adenocarcinoma cell lines A549 and H1299 by Western blotting and the Signa TECT DNA-PK assay kit. The dose-survival relationship for two cell lines was analyzed using clonogenic formation assay. Results A549 was more radiosensitive than H1299. The survival fractions at 2 Gy (SF2) were 0.7412 in A549 cell line and 0.2473 in H1299 cell line. The content of DNA-PKcs was significantly higher in A549 cells than in H1299 cells (t=10.37, P<0.001). The integrated optical densities were 3.29±0.44 in A549 cells and 0.50±0.17 in H1299 cells. DNA-PKcs activities in A549 and H1299 cells were 8.29±1.37 and 2.47±1.09, respectively, showing a significant difference between them (t=5.76, P=0.005). Conclusion DNA-PKcs is an important factor to affect the radiosensitivity of lung adenocarcinoma cell lines.