内质网应激通路抑制剂Salburinal增加射线诱导人头颈部鳞癌细胞凋亡机理研究

Mechanism of endoplasmic reticulum stress pathway inhibitor salubrinal enhancing the apoptosis ofhead and neck squamous carcinoma cells

目的 探讨内质网应激通路抑制剂Salburinal增加射线诱导人头颈鳞癌细胞凋亡的作用机制。方法 将3种头颈部鳞癌细胞系（KB、Fadu、Detroit562）分别设立对照组、sal组、单纯照射组（IR组）和sal联合照射组（IR＋sal组）,检测头颈部鳞癌细胞DNA损伤修复相关蛋白p-ATM/ATM、DNA-PK及凋亡相关蛋白Cleaved Caspase-3的表达;检测对照组、sal组、 IR组和IR＋sal组细胞凋亡分数;MTT法检测Salburinal对细胞存活率的影响。结果 与IR组相比,IR＋sal组增加DNA损伤相关蛋白ATM磷酸化水平增加（t=3.5、8.43、9.42,P均〈0.05）,DNA双链修复蛋白DNA-PK的表达较IR组相比下调（t=9.19、17.44、16.67,P均〈0.05）。放射联合Salubrinal增加凋亡相关蛋白Cleaved Caspase-3表达（t=6.79、9.76、9.78,P均〈0.05）。此外,与IR组相比,Salubrinal增加射线诱导的人头颈部鳞癌细胞凋亡（t=5.67、6.95、7.28,P均〈0.05）。Salburinal对3种头颈部鳞癌细胞具有浓度依赖性和时间依赖性。结论 内质网应激通路抑制剂Salburinal上调射线诱导人头颈部鳞癌细胞的凋亡,其作用机制可能与射线诱导DNA双链的损伤,抑制其损伤的修复,进而增加肿瘤细胞的凋亡。

Objective To explore the mechanism underlying the effect of endoplasmic reticulum stress pathway inhibitor Salubrinal on enhancing the apoptosis of head and neck squamous carcinoma cells. Methods Three types of head and neck squamous carcinoma cell lines （KB,Fadu,Detroit562） were divided into the control,Salburinal （sal）, irradiation （IR） and sal combined with IR （IR＋sal） groups. The expression levels of p-ATM/ATM,DNA-PK and cleaved Caspase-3 were quantitatively measured. The cell apoptosis rate was detected among four groups. The effect of Salburinal on cell viability was evaluated by MTT assay. Results Compared with the IR group, the expression level of p-ATM/ATM （t=3.5,8.43 and 9.42,all P〈0.05） was significantly up-regulated, whereas that of DNA-PK （t=9.19,17.44,16.67,all P〈0.05） was considerably down-regulated in the IR＋sal group. The expression level of cleaved Caspase-3 in the IR＋sal group was significantly higher compared with those in the other three groups （t=6.79,9.76 and 9.78,all P〈0.05）.Compared with the IR group, the cell apoptosis rate was significantly enhanced in the IR＋sal group （t=5.67,6.95 and 7.28,all P〈0.05）.Salubrinal exerted an effect upon the apoptosis of three cell lines in a concentration-and time-dependent manner. Conclusions As an endoplasmic reticulum stress pathway inhibitor, Salubrinal can enhance the apoptosis rate of head and neck squamous carcinoma cells. The underlying mechanism is probably correlated with irradiation-induced DNA double strand injury, suppressing the repairing of DNA damage and thereby increasing the apoptosis of tumor cells.