ATM蛋白在不同肺癌细胞株中表达差异与放射敏感性关系的研究

Relationship between expression of ATM protein and radiosensitivity in lung cancer cell lines

目的 通过对ATM蛋白在不同肺癌细胞株中表达差异与放射敏感性关系的研究，为下一步研究打下基础。方法利用细胞集落形成实验研究肺癌细胞株A549、NCI—H446的放射敏感性差异，并结合免疫荧光实验和激光共聚焦扫描（LSCM）技术来探讨两细胞株中ATM蛋白的表达差异与放射敏感性之间的关系。结果集落形成实验中，在接受2、4、6、8Gy剂量照射时，A549和NCI—H446两肺癌细胞株的存活分数分别为81．0％、32．4％、12．0％、3．5％和52．4％、17．0％、3．2％、0．7％。ATM蛋白定位于细胞浆和胞核；利用LSCM分析两细胞株中ATM蛋白的表达差异，A549细胞ATM蛋白荧光强度（71．188＋13．379）较NCI-H446细胞（47．478±19．032）明显增强（P〈0．0001），有统计学意义。结论两肺癌细胞株A549和NCI-H446具有放射敏感性差异，ATM蛋白在两细胞株中的表达亦有差异显著性，表明其表达量可能与放射敏感性呈负相关。

Objective To investigate the relationship between radiosensitivity and expression levels of ATM protein in different lung cancer cell lines, and maybe as a foundation for our future research. Methods The radiosensitive difference between two lung cancer cell lines, A549 and NCI-H446, was observed by clonogenic survival assay. The localization and expression of ATM protein were analyzed by fluorescence immunohistochemical method and laser scanning confocal microscope （LSCM）. The relation between expression of ATM protein and radionsensitivity in two lung cancer cell lines was observed. Results Each cell lines was divided five groups, and was received radiation at dose of 0, 2, 4, 6, and 8Gy, respectively. With＂ regard to A549 and NCI-H446, the survival fraction in clonogenic survival assay were 81.0%, 32.4%, 12.0% and 3.5%, and 52.4%, 17.0%, 3.2% and 0.7% in 2, 4, 6 and 8Gy. ATM protein was located in nuclei and cytoplasm; The fluorescence intensity of ATM protein was stronger in A549 （71.188±13.379） than that in NCI-H446 （47.478±19.032） sighificantly（p 〈 0.0001）. Conclusions Both radionsensitivity and expression of ATM protein may be different typically for two lung cancer cell lines as A549 and NCI-H446, which indicate the negative correlation between expression of ATM protein and radiosensitivity.