摘要
目的观察曲妥珠单抗对乳腺癌SKBR3细胞中Her-2的入核过程和核内DNA损伤修复的影响，探讨曲妥珠单抗的放疗增敏机制。方法克隆形成实验检测曲妥珠单抗对辐射后细胞存活分数（SF）的影响，荧光共聚焦观察曲妥珠单抗对DNA双链断裂（DSB）损伤标志物γH2AX表达和Her-2核转运过程的影响，免疫印迹法检测曲妥珠单抗对辐射诱导细胞的胞核内Her-2蛋白、DNA依赖蛋白激酶（DNA—PK）功能亚单位DNA-PKcs的表达量的改变。结果细胞克隆形成实验中，曲妥珠单抗干预组接受2Gy时SF（SF2）为0．321±0．022，单纯照射组为0．547±0．046（P=0．000）；辐射后γH2AX的荧光灰度表达提高，曲妥珠单抗干预组为85．40±25．63，单纯照射组为18．53±44．32（P=0．000）；Her-2蛋白入核灰度表达降低，单纯照射组为52．80±19．74，曲妥珠单抗组为21．41±10．55（P=0．000）；免疫印迹实验表明曲妥珠单抗干预组辐射后早期核内DNA—PKcs及Her-2的表达下降。结论曲妥珠单抗能够抑制辐射诱导的Her-2入核过程，并减少核内Her-2和DNA—PKcs的表达，从而可能提高辐射后早期的DSB损伤。
Objective To observe the influence of trastuzumab on DNA break repair and Her-2 nuclear import after radiation in breast cancer cell line SKBR3, and discuss the radiosensitivity mechanism of trastuzumab. Methods Clone formation assay was used to analyze the difference of survival fractions between radiation group and radiation plus trastuzumab group. Confocal microscopy was applied to observe the influence of trastuzumab in the nuclear import process of Her-2 and the expression of γH2AX after radiation, which is considered as the marker of DNA double strand break. Western blotting was used to detect the expression of Her-2 and DNA-PKcs in nuclei after radiation. Results The result of clone formation assay showed that the SF2 in radiation group was 0.547±0.046 and 0.321±0.022 in the radiation plus trastuzumab group were significantly decreased, the results of confocal microscopy showed that trastuzumab postponed the nuclear import process of Her-2 （52.80±19.74 in radiation group, 21.41±10.55 in the radiation group）, and increased expression of γH2AX after radiation （85.40±25.63 in radiation group, 18.53±44.32 in the radiation group）, and western blotting revealed trastuzumab reduced the expression of Her-2, DNA-PKcs in nuclei. Conclusion Trastuzumab can inhibit the radiation induced nuclear import of Her-2, and decrease Her-2, DNA-PKcs in nuclei to increase the DSB on early stage after radiation.
出处
《肿瘤研究与临床》
CAS
2011年第11期729-732,共4页
Cancer Research and Clinic
基金
基金项目：国家自然科学基金（30672426,30801351）
