【摘要】 目的:探讨鼻咽癌细胞放疗后肿瘤细胞加速衰老及辐射抗拒机制。方法:采用免疫印迹,流式细胞术,SA-β-gal及H-E染色,BrdU细胞标记及细胞计数的方法,检测鼻咽癌CNE2细胞株5 Gy间断照射后,细胞周期时相与cdc2/cdk1和survivin蛋白表达的关系。结果:鼻咽癌细胞株射线5 Gy间断照射期间及照射后的2~6 d内,细胞BrdU标记率大于90%,SA-β-gal阳性细胞小于3%,流式显示G2/M期细胞比例增多,cdk1和survivin表达无明显变化,PCNA表达稍有增加,此期即加速增殖期;细胞处理后第7天~25天,流式显示G1/S期细胞比例增多,BrdU标记率小于10%,SA-β-gal染色阳性细胞达55%以上,H-E染色可见四倍体细胞,cdk1和survivin表达明显下降,PCNA下调不明显,此期即细胞增殖阻滞期;照射细胞后第26天以后,细胞BrdU标记率恢复大于90%,SA-β-gal阳性细胞小于3%,流式检测G2/M期细胞比例增多,cdk1和survivin表达明显上调,此期即再增殖期,结论:细胞衰老可能是人鼻咽癌细胞放射后的反应,衰老细胞中cdk1和survivin表达上调可能是鼻咽癌衰老细胞再增殖机制,也可能是鼻咽癌局部复发和进展的根源。更多还原

【Abstract】 Objective:To investigate the mechanism of accelerated cellular senescence(ACS) and radioresistant in nasopharyngeal carcinoma cell line CNE2 treated-ray.Methods:Western blot,flow cytometry by propidium iodide(PI)staining,BrdU staining,SAβ-gal,hematoxylin and eosin(HE) staining and cell counting detected,respectively,expression of cdc2/cdk1 and survivin,cell cycle stages and proliferation and change in cell senescence and morphology.Results:Following exposure to ionizing radiation(IR) with incontinuous 5 Gy for 3 times,CNE2 cell showed a BrdU-labeling index of 90%and the positive for SA-β-Gal of 3%,as well as concomitant cell cycle arrest in G2/M,and no significant change was detected for the cdkl and survivin from 1- 15 days.CNE2 cell showed a BrdU-labeling index of 3%and the positive stain for SA-β-Gal of55%,as well as concomitant cell cycle arrest in G0/G1,and significant decrease was detected for the cdkl and survivin from15 to 26 days after IR.CNE2 cell again showed a BrdU-labeling index of 90%and the positive for SAβ-Gal of 3%,as well as concomitant cell cycle arrest in G2/M,and significant increase was detected for the cdkl and survivin from 27 to any days after IR.Conclusion:We propose that ACS is one of the mechanism of in vivo tumor response to irradiation and that mechanisms aberrantly up-regulate Cdk1 and survivin promotes escape from the senescence pathway may be involved in a subset of tumors and likely accounts for tumor recurrence/progression.更多还原