放射后鼻咽癌细胞株C666-1存活亚克隆高表达miR-181a

High Expression of miR-181a in the Radiated Survival Subclones of C666-1 Cell Line from Nasopharyngeal Carcinoma

目的:初步分析miR-181a与鼻咽癌细胞系C666-1放射敏感的相关性。方法:首先使用大剂量8Gy的X射线照射C666-1,挑选三个大的存活亚克隆并命名为C666-1-R1,C666-1-R2和C666-1-R3,然后应用MTT等技术分析亚克隆及对照母本C666-1细胞系放射敏感性的差异,最后采用实时荧光定量PCR法,分析三个存活亚克隆及对照C666-1的miR-181a表达水平。结果:通过MTT比色法检测细胞增殖:6Gy照射后,三个亚克隆C666-1-R1,C666-1-R2和C666-1-R3的细胞存活率均高于对照细胞C666-1,尤其C666-1-R2在48、72和96h的存活率增高均有显著性差异(P<0.05),提示C666-1-R2具有放射抗拒性。另一方面,各亚克隆及对照细胞的miR-181a的2-△△Ct值如下:C666-1-R1=0.693,C666-1-R2=0.486,C666-1-R3=0.762,C666-1=1。提示放射后存活的三个亚克隆均高表达miR-181a,尤其放射抗拒亚克隆C666-1-R2的miR-181a表达更高。结论:miR-181a与鼻咽癌存活亚克隆的放射抗拒性密切相关。miR-181a可能是评估鼻咽癌放射敏感性的一个新分子,miR-181a与鼻咽癌放射抗拒的相关性值得深入研究。

Objective：To investigate the correlation of miR-181a and the radiosensitive of C666-1 cell line from nasopharyngeal carcinoma.Methods：First,C666-1 was irradiated by using high dose 8 Gy X-ray.Three survival subclones were selected and named for C666-1-R1,C666-1-R2 and C666-1-R3;Then,the difference of cell radiosensitivity between survival subclonedand the control sample was analyzed by MTT assay;Finally,the expression of miR-181a between three survival subclones and control sample was analyzed by fluorescence quantitative PCR.Results：Cell proliferation was detected by MTT colorimetric assay.As compared with the control C666-1,the cell survival rate of C666-1-R1,C666-1-R2 and C666-1-R3 was higher by using 6 Gy X-ray,especially for C666-1-R2.The cell survival rate of C666-1-R2 differed significantly by X-ray in 48 h,72 h and 96 h（P〈0.05）.These results suggested that C666-1-R2 was radioresistance.On the other hand,the relative values of miR-181a （2^-△△Ct ）for each subclone and the control cells were showed as following：C666-1-R1=0.693,C666-1-R2=0.486,C666-1-R3=0.762,C666-1=1.These results suggested that miR-181 a of three survival subclones had high expression level, especially the radioresistance C666-1-R2.Conclusion：miR-181a and the radioresistance of survival subclones in nasopharyngeal carcinoma are closely related.miR-181a may be used as a new marker for assessing the radiosensitivity of nasopharyngeal carcinoma.The relation of miR-181a and the radioresistance of nasopharyngeal carcinoma are worthy of further study.