食管癌细胞照射后细胞周期及相关蛋白表达的变化

目的：探讨食管癌细胞照射后细胞周期、细胞凋亡及其相关蛋白表达的变化。方法：食管癌细胞株TE-1和TE-13照射2、5、10、15Gy后，应用流武细胞仪分别检测照射后6、24和48h细胞周期和凋亡指数变化、Western blot检测细胞周期相关蛋白的表达。结果：2、5、10、15Gy照射0～48h，TE-1和TE-13细胞均出现明显剂量依赖性的G2／M期阻滞和解除变化；5～15Gy照射后48h，TE-13细胞在G2／M期阻滞逐渐解除时伴随着细胞凋亡的明显增加，而TE-1细胞凋亡不增加。2株细胞胞浆CHK2-p68磷酸化水平均呈随照射后时间延长而出现时相性变化，但与照射剂量无关；而CHK1、CHK2、CHK1-p345和CDK1蛋白表达均无明显变化。15Gy照射后24h，TE-13细胞胞浆中eyelin B1表达下降而TE1细胞中无明显变化。结论：病理不同分化的食管癌细胞照射后细胞周期、细胞凋亡以及细胞周期相关蛋白表达变化不尽相同。

Changes of cell cycle and its correlated protein expressions in esophageal carcinoma cells after irradiation

Objective:To study the changes of cell cycle, apoptosis and protein expression in esophageal carcinoma cells after irradiation. WTHZ]Metheds: Esophageal carcinoma cell lines well-differentiated TE-1 cells and poor-differentiated TE-13 cells were irradiated at 2, 5, 10, and 15 Gy. The changes of cell cycle and apoptotic index were measured at 6, 24, and 48 h after irradiation by flow cytometry. The expression of cell cycle related protein was detected by Western blotting. Results:After being irradiated at 2, 5, 10, and 15 Gy for 0-48 h, both TE-1 and TE-13 cells showed apparent dose-dependent G_2/M-phase arrest and release. After being irradiated at 5-15 Gy for 48 h, TE-13 cells showed gradual release of G_2/M arrest coupled with increase in apoptosis but the apoptotic rate of TE-1 cells did not increase. After irradiation, only phosphated level of Csk homologous kinase (CHK)2-p68 protein in cytoplasm of TE-1 and TE-13 cells changed in a time-dependent but irradiation dosage-independent manner. The protein expressions of CHK1, CHK2, CHK1-p345 and cyclin-dependent kinase (CDK)1 were not affected in both TE-1 and TE-13 cells. After 15 Gy irradiation, expression of cyclin B1 protein decreased in cytoplasm of TE-13 cells but not in TE-1 cells. Conclusion:Changes of cell cycle, apoptosis and expression of cell cycle related protein may be not simultaneous in poor-and well-differentiated esophageal carcinoma cells.