中文摘要：

目的探讨姜黄素对放射诱导产生的鼻咽癌抗拒株CNE-2R的放射增敏作用及其机制。方法通过MTT实验筛选姜黄素的最佳浓度;对克隆生存实验结果进行L-Q拟合和单机多靶拟合,计算相关放射生物学参数;再通过流式细胞术检测细胞周期的改变;最后通过RT-qPCR实验检测细胞周期及DNA损伤修复相关基因的表达情况。结果浓度在10μmol·L-1的姜黄素对CNE-2R细胞无明显抑制作用。给药后抗拒株CNE-2R的α/β值从6.56增加到1 596;SF2从1.93 Gy减少到0.361 Gy;N值从1.60减少到1.06;D0值从3.27减少到2.12;Dq值从1.53减少到0.12。细胞周期G2期明显增多,G1期稍微减少,S期明显减少。CDK4基因的表达明显上调,GADD45 g、BRCA1基因的表达明显下调。结论姜黄素通过调控GADD45 g、CDK4、BRCA1基因的表达,改变CNE-2R的细胞周期和影响DNA损伤修复,发生G2期阻滞,从而增加了抗拒株的放射敏感性。

英文摘要：

Aim To investigate the effect of curcumin on radiosensitivity of radioresistant nasopharyngeal carcinoma cell line CNE-2R and its mechanism. Methods The concentration of curcumin was screened by MTT assay. Dose-survival curves were obtained according to the colony forming test for L-Q matching and multitarget-single hitting matching,while SF2 and the correla-tion parameters of radiation biology were calculated.The changes of cell cycle in CNE-2R cells caused by curcumin were also tested by flow cytometry（ FCM）.The differential expression of genes related to cell cycle and DNA damage repair were detected by RT-q PCR.Results CNE-2R cells could not be inhibited by 10 μmol·L-1curcumin. Dealt with 10 μmol·L-1curcumin for 24 h, the value of α/β increased to1 596 from 6. 56; the value of SF2 decreased to 0. 361 Gy from 1. 93 Gy; the value of N decreased to 1. 06 from 1. 60; the value of D0 decreased to 2. 12 from 3. 27; the value of Dqdecreased to 0. 12 from 1. 53.FCM showed that the cells in G2 phase had a significant increase and the cells in S phase had a significant decrease after dealt with 10 μmol · L-1curcumin for 24 h. The expression of CDK4 was significantly up-regulated and GADD45 g, BRCA1 were significantly down-regulated. Conclusion Curcumin radiosensitizes nasopharyngeal carcinoma cell line CNE-2R by changing cell cycle and affecting DNA damage repair through regulating the expression of CDK4,GADD45 g and BRCA1.