2015 年第 1 期 第 13 卷

单次、分次照射与125I粒子低剂量率照射对人喉鳞癌Hep2细胞抑制作用

作者：

单位：

关键词：125I粒子低剂量率照射Hep2细胞DNA损伤细胞周期

• 摘要：
• 【摘要】目的　探讨125I粒子持续低剂量率照射与分次照射、单次照射对人喉鳞癌细胞Hep2抑制作用及其作用机制。方法　实验分四组：空白照射组（Ctrl组）、单次照射组（SDR组）、分次照射组（FDR组）和125I粒子持续低剂量率照射组（125I -CLDR组）。通过细胞克隆形成实验检测Hep2细胞在不同照射条件下细胞克隆形成能力；用流式细胞仪检测细胞凋亡和细胞周期阻滞；Western blot检测不同照射条件后Hep2细胞总γ-H2AX、CyclinB1、Caspase3蛋白表达的变化。结果 经2Gy、4Gy、6Gy照射，125I-CLDR组Hep2细胞克隆形成率均低于SDR组和FDR组。4Gy照射后，125I –CLDR可诱导Hep2细胞G2/M期阻滞，且效应较SDR组及FDR组强；125I –CLDR组Hep2细胞凋亡比例明显高于SDR组及FDR组；4Gy照射后三组γ-H2AX、CyclinB1、Caspase3、NF-κB、p21、 Cdk1的表达量上调， 125I –CLDR 组p-Cdc25c蛋白量表达比SDR组、FDR组低。结论 在本实验条件下，125I-CLDR较单次照射、分次照射能够诱发更多Hep2细胞DNA损伤、引起持续G2/M期阻滞、诱导细胞凋亡，抑制细胞再增殖。
• Objective To investigate the inhibition effects of different irradiation methods on human laryngeal squamous carcinoma cell line Hep2 proliferation and the corresponding mechanisms. Methods We had four groups in our experiment，that was，no radiation control group (Ctrl), high dose rate single dose radiation group (SDR), high dose rate fractionated dose radiation group(FDR), and iodine-125 seeds continuous low dose rate radiation group (125I -CLDR). Colony formation assay was used to determine the radiosensitivity of Hep2 cells to SDR, FDR and 125I-CLDR. Flow cytometry was used for detecting cell apoptosis and cell cycle arrest. Western blot was used to detect the protein expression levels ofγ-H2AX,CyclinB1 and Caspase3. Results The capability of clone formation of Hep2 cells declined after 2Gy、4Gy 、6Gy irradiation. Compare to SDR and FDR，125I-CLDR was lower. 125I -CLDR induced Hep2 cells most significant G2/M arrest among three irradiation groups. 125I -CLDR significantly induced cell apoptosis than SDR and FDR did. The expression levels ofγ-H2AX, CyclinB1, Caspase3, NF-κB, p21 and Cdk1 increased mostly in 125I –CLDR group among three treatment groups. The expression levels of p-Cdc25c is lowest in 125I –CLDR group among three treatment groups. Conclusions It seemed that125I-CLDR can obviously reduced cellular DNA repair capacity, induced cell apoptosis and G2/M arrest, and inhibited cell growth.