放射诱导的EGFR核转位阻断可增加人宫颈癌细胞放射敏感度

李璐; 黄建鸣; 冯梅; 漆云翔; 马士淇; 谭明宇; 郎锦义

doi:10.3971/j.issn.1000-8578.2020.19.0807

放射诱导的EGFR核转位阻断可增加人宫颈癌细胞放射敏感度

Blockade of Radiation-induced EGFR Nuclear Transport Enhances Radiosensitivity of Human Cervical Cancer

摘要

摘要:
目的探讨抑制EGFR核转位是否会降低人宫颈癌细胞的放射抵抗。
方法 Western blot测定pEGFR-T654多肽、pEGFR-T654对照多肽、西妥昔单抗或吉非替尼预处理后X线照射的人宫颈鳞癌CaSki和腺癌HeLa细胞pEGFR-T654和pDNA-PK-T2609的表达; 克隆形成法测定存活分数(SF₂), 单击多靶模型拟合剂量-存活曲线, 计算放射增敏比(SER)。
结果 4 Gy照射后, CaSki和HeLa细胞核EGFR表达呈时间依赖性增加; 与对照多肽比较, pEGFR-T654多肽显著降低了CaSki和HeLa细胞核内pEGFR-T654、DNA-PK和pDNA-PK-T2609的表达; 与单独放射比较, 西妥昔单抗联合放射明显降低了CaSki细胞核EGFR、pEGFR-T654和pDNA-PK-T2609的表达以及克隆形成率和存活分数(SF₂=31.030), 增加CaSki细胞的放射敏感度(SER=2.34)。
结论放射诱导pEGFR-T654核转位介导pDNAPK-T2609的活化, 西妥昔单抗抑制pEGFR-T654核转运, 降低了DNAPK介导的宫颈鳞癌放射抵抗。

Abstract:
Objective To investigate whether the inhibition of EGFR nuclear transport could reduce the radioresistance of human cervical cancer cells.
Methods Human cervical cancer CaSki and HeLa cells were exposed to radiation treated with or without Thr654 inhibitory peptide, cetuximab and gefitinib. The expression levels of pEGFR-T654 and pDNA-PK-T2609 were determined using Western blot. The survival fraction (SF₂) was determined by colony formation and the dose-survival curve was fitted with a singlehit multi-target model to calculate the radiosensitization ratio (SER).
Results After 4 Gy irradiation, EGFR expression in the nuclear of CaSki and HeLa cells were up-regulated in a time-dependent manner. Compared with the control peptide, Thr654 inhibitory peptide significantly reduced the expression levels of pEGFR-T654, DNA-PK and pDNA-PK-T2609 in the nucleus of CaSki and HeLa cells; compared with irradiation alone, cetuximab combined with irradiation significantly reduced the expression levels of EGFR, pEGFR-T654 and DNA-PK-T2609 in the nucleus of CaSki cells, as well as clone formation rate and survival fraction (SF₂=31.030), and increased the radiosensitivity (SER=2.34).
Conclusion Radiationinduced pEGFR-T654 nuclear translocation mediates the activation of pDNA-PK-T2609, and the inhibition of pEGFR-T654 nuclear transport by cetuximab reduces DNA-PK-mediated radiation resistance of cervical squamous cell carcinoma.

HTML全文

参考文献(35)

施引文献

资源附件(0)