放射敏感性、X线辐射剂量对鼻咽癌细胞miR-7表达的影响  

Effects of radiosensitivity and X-ray dose on miR-7 expression in nasopharyngeal carcinoma

作　　者：陈智贤[1] 孙爱民[1] 陈勇[1] 刘英[1] 詹军芳[1] 陈龙华[1] 袁亚维[1] 

机构地区：[1]南方医科大学南方医院放疗科,广东广州510515

出　　处：《南方医科大学学报》2010年第8期1810-1812,1816,共4页Journal of Southern Medical University

基　　金：国家自然科学基金(30670633;30973846)

摘　　要：目的探讨放射敏感性、X线辐射剂量对鼻咽癌细胞miR-7表达的影响。方法以低放射敏感性鼻咽癌细胞株CNE-1、高放射敏感性鼻咽癌细胞株CNE-2为研究对象,采用析因设计的方法,分别给予CNE-1、CNE-2假照(0Gy)、低剂量照射(2Gy)、高剂量照射(8Gy)。Trizol法提取总RNA,设计特异性茎环引物逆转录miR-7,随机六引物逆转录18srRNA,所得cDNA进行染料法荧光定量PCR,以0Gy照射的CNE-1细胞为参照样本,ΔΔCt法计算各组细胞miR-7的相对表达值,SPSS13.0行析因设计资料方差分析。结果 CNE-1和CNE-2的miR-7表达量有显著差异(F=135.483,P<0.001),CNE-1的miR-7表达量(χ=4.49±3.62)高于CNE-2(χ=1.29±1.10),不同剂量照射后,鼻咽癌细胞株miR-7表达量也有显著性差异(F=39.565,P<0.001),CNE-1接受2GyX线照射后miR-7表达最高,8Gy照射组次之,0Gy照射组最低。CNE-2接受2GyX线照射后miR-7表达最低,8Gy照射组次之,0Gy照射组最高。结论放射敏感性不同导致细胞受X线辐射后,miR-7表达调整方向不同,即低放射敏感细胞上调,而高放射敏感性细胞下调;X线辐射剂量将影响miR-7的表达调整幅度,即低剂量照射后miR-7调整幅度大,高剂量照射后调整幅度小。抑制miR-7表达可能会提高鼻咽癌细胞的放射敏感性。Objective To investigate the effects of radiosensitivity and X-ray dose on the expression of miR-7 in nasopharyngeal carcinoma （NPC） cells. Methods Low radiosensitive NPC cells CNE-1 and high radiosensitive NPC cells CNE-2 were exposed to 0, 2 and 8 Gy X-ray. The total RNAs of the cell lines were extracted 10 h after radiation for reverse transcription of miR-7 and 18S rRNA by stem-loop primer and random hexamers, respectively. The non-irradiated CNE-1 cells served as the control sample and the relative quantity of the expression level was calculated after real-time PCR using SyBR green. Results miR-7 expression differed significantly between CNE-1 and CNE-2 cells （4.49±3.62 vs 1.29±1.10, F=135.483, P〈0.001）. The radiation dose also significantly affected the expression of miR-7 in NPC cells （F=39.565, P〈0.001）. CNE-1 cells with a 2 Gy exposure had the highest expression level of miR-7, while the non-irradiated CNE-1 cells had the lowest expression. CNE-2 cells exposed to 2 Gy X-ray had the lowest expression level of miR-7 and the non-irradiated CNE-2 cells had the highest. Conclusions Radiosensitivity and radiation dose of X-ray have significant effect on the expression of miR-7 in NPC cells, indicating that miR-7 plays an important role in radioresistance of NPC cells to X-ray, and suppressed miR-7 expression may elevate the radiosensitivity of NPC cells.

关 键 词：放射敏感性 辐射剂量 鼻咽癌 MICRORNA 

分 类 号：R739.63[医药卫生—肿瘤]