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目的:探讨EGFR核转位抑制肽对鼻咽癌细胞辐射耐受相关分子DNA-PK表达的作用及其潜在的分子关联机制。方法:采用EGFR核转位抑制肽(pT654)及对照肽(5μM)预处理人鼻咽癌CNE-1细胞16h,细胞再暴露于60Coγ射线,辐射4Gy后采用Western blot方法分别测定细胞质和细胞核EGFR和pEGFRThr654,以及非同源末端连接(NHEJ)修复作用相关的DNA-PK和p DNA-PKThr2609在不同时间点的表达,分析pEGFRThr654与p DNAPKThr2609表达的相互关联。结果:辐射后CNE-1细胞的核EGFR和pEGFRThr654表达呈时间依赖性的增加,且与pDNA-PKThr2609的表达呈正相关(R~2=0.935);EGFR核转位抑制肽p T654显著降低核pEGFRThr654和pDNA-PKThr2609的表达(R~2=0.962)。结论:EGFR核转位抑制肽可阻遏辐射诱导的鼻咽癌细胞EGFR核转位及其介导的NHEJ修复通路相关分子DNA-PK的活化。
Objective: To investigate the effect of EGFR nuclear translocation inhibitor on the expression of DNA-PK in radiation-tolerant NPC cells and its potential molecular mechanisms. Methods: Human nasopharyngeal carcinoma CNE-1 cells were pretreated with EGFR nuclear translocation inhibitor (pT654) and control peptide (5μM) for 16h. The cells were exposed to 60Coγ-rays for further 4 days. Western blotting was used to detect the expression of EGFR The expression of pEGFRThr654 and pDNAPKThr2609 was analyzed at different time points by the expression of pEGFRThr654 and DNA-PK and pDNA-PKThr2609 related to the repair of non-homologous terminal (NHEJ). Results: The expression of nuclear EGFR and pEGFRThr654 in CNE-1 cells after irradiation increased in a time-dependent manner, and positively correlated with the expression of pDNA-PKThr2609 (R ~ 2 = 0.935). The EGFR nuclear translocation inhibitor pT654 significantly decreased the expression of nuclear pEGFRThr654 And pDNA-PKThr2609 expression (R ~ 2 = 0.962). CONCLUSION: EGFR nuclear translocation inhibitory peptide can suppress radiation-induced nuclear translocation of EGFR and activation of DNA-PK mediated by NHEJ repair pathway in nasopharyngeal carcinoma cells.