枇杷叶三萜酸提高神经胶质瘤C6细胞和骨肉瘤MG63细胞放射敏感性  

Increased radiosensitivity of gliomas C6 cell and osteosarcoma MG63 cells by triterpene acids of Ioquat leaf

作　　者：金问森[1] 肖林林[2] 王娟[2] 黄艳[1] 徐师国[2] 李俊[1] 

机构地区：[1]安徽医科大学药学院,合肥230032 [2]安徽医科大学药学院核医学教研室,合肥230032

出　　处：《中华放射医学与防护杂志》2012年第6期597-601,共5页Chinese Journal of Radiological Medicine and Protection

基　　金：安徽省自然科学基金（11040606M210）;安徽省教育厅重点项目（kj2010A189）;中国博士后基金面上项目（20100470822）

摘　　要：目的研究枇杷叶三萜酸对肿瘤细胞放射敏感性的影响及其作用机制。方法采用枇杷叶三萜酸（TAL）预处理大鼠神经胶质瘤c6细胞和人骨肉瘤MG63细胞，经1、2、3、5和7Gy的x射线照射后，通过细胞集落形成实验，计算TAL的放射增敏比（SER）。采用细胞微核测定法，检测细胞微核率，观察DNA损伤情况。通过RT—PCR和Westernblot观察细胞中Rad51和XRCC4的表达变化。结果TAL作用后c6和MG63细胞的仇值分别降低至1．31和2．85Gy，对c6和MG63细胞的SER值分别为1．73和2．04。与单纯照射组比较，当吸收剂量达到2Gy以上时，TAL可导致两种肿瘤细胞的微核形成率增加（C6：t=-8．372～-2．476，P〈0．05；MG63：t=-4．03- -2．557，P〈0．05）。TAL并未显著抑制Rad51基因的表达水平，但可降低XRCC4在转录和翻译水平上的表达。结论TAL可明显增加肿瘤细胞的放射敏感性，提高x射线对肿瘤细胞的杀伤效应，其作用机制可能与抑制照射后肿瘤细胞的非同源末端连接（NHEJ）修复有关。Objective To study the increased radiosensitivity of tumor cells by triterpene acids of loquat leaf （TAL） and mechanism. Methods C6 and MG63 cells were pretreated by TAL, and then were exposed to X-rays at 1, 2, 3, 5, 7 Gy. Clonogenic assay was used to evaluate those tumor ceils survival fraction （SF） to calculate the sensitization enhancement ratios （SER） of TAL. The cellular micronuclei ratios of tumor cells were analyzed by mieronuclei assay. Additionally, the changes of Rad51 and XRCC4 levels were observed by RT-PCR and Western blot. Results DO values were decreased to 1.31 and 2. 85 Gy in C6 and MG63 cells by TAL pretreatment respectively. The SER value of the effect of TAL on C6 and MG63 cells was 1.73 and 2.04, respectively. There was a statistical difference in the cellular mieronuclei ratios between tumor cells with TAL above 2 Gy and those without TAL （ C6 ：t = - 8. 372 - - 2. 476, P 〈 0.05; MG63 ：t = -4. 03 - -2. 557, P 〈 0.05 ）. TAL attenuated the expression of XRCC4 at transcriptional and translational level, but not for Rad51, a key gene in homologous recombination repair （HRR）. Conclusions TAL pretreatment could increase the lethal effect of X-rays on tumor ceils in vitro. The mechanism might be involved in the inhibition of non-homologous end joining （NHEJ）.

关 键 词：枇杷叶三萜酸 放射敏感性 肿瘤 

分 类 号：R739.4[医药卫生—肿瘤]