丙戊酸对乳腺癌细胞放射敏感性的影响

发布时间：2019-01-30 14:12

【摘要】：目的探讨丙戊酸(VPA)对乳腺癌细胞MCF7放射敏感性的影响。方法 MCF7细胞用VPA临床安全剂量0.5 mmol·L-1和临界剂量1 mmol·L-1分别预处理0,24,48和72 h,8Gy电离辐射后6 h,免疫荧光染色法观察磷酸化组蛋白H2AX(γ-H2AX)焦点形成。对数生长期的MCF7细胞分别以VPA 0.5和1 mmol·L-1预处理72 h,4 Gy电离辐射后48 h,MTT法检测细胞存活率。MCF7细胞用VPA 0.5 mmol·L-1预处理24 h后,按照每皿接种细胞数分别给予电离辐射2 Gy(每皿500和1000),4 Gy(每皿2000和4000)和6 Gy(每皿8000和16000),计算克隆形成率。MCF7细胞分别用VPA 0.5和1 mmol·L-1预处理0,24,48和72 h,流式细胞仪检测细胞周期。结果与正常对照组相比,单独VPA 0.5 mmol·L-1处理0,24,48和72 h后,γ-H2AX焦点阳性率分别为(5.3±0.6)%,(10.8±1.0)%,(12.6±0.9)%和(17.8±1.1)%(r=0.985,P0.05);VPA 1 mmol·L-1对γ-H2AX焦点形成有相同的影响趋势。单独照射组细胞核内γ-H2AX焦点阳性率为100%,其中表示DNA损伤较重的焦点较大且明亮的B类细胞所占比例为(16.5±1.8)%;与单独照射组相比,VPA 0.5 mmol·L-1预处理0,24,48和72 h后,B类细胞所占比例分别为(16.5±1.8)%,(28.9±1.0)%,(58.0±2.0)%和(70.8±0.9)%(r=0.986,P0.05);VPA 1 mmol·L-1对辐射诱导的γ-H2AX焦点形成的影响有相同趋势。MTT和细胞克隆形成实验结果显示,与正常对照组相比,单独给予VPA0.5 mmol·L-1可显著降低细胞克隆形成率(P0.05);与单独照射组相比,VPA预处理后接受电离辐射能显著降低细胞存活率(P0.05)和细胞克隆形成率(P0.05);VPA 0.5和1 mmol·L-1对细胞周期影响均无统计学差异。结论临床安全剂量和临界剂量VPA对肿瘤细胞具有放射增敏作用,且对肿瘤细胞生长具有抑制作用,其机制与增加电离辐射所致的DNA双链断裂损伤的蓄积有关。
[Abstract]:Objective to investigate the effect of valproate (VPA) on radiosensitivity of breast cancer cell line MCF7. Methods MCF7 cells were pretreated with 0.5 mmol L ~ (-1) VPA safe dose and 1 mmol L ~ (-1) critical dose for 6 h after 0 ~ (24) h ~ (48) and 72 h ~ 8 Gy ionizing radiation respectively. The focal formation of phosphorylated histone H2AX (纬 -H2AX) was observed by immunofluorescence staining. In logarithmic growth phase, MCF7 cells were pretreated with VPA 0.5 and 1 mmol L-1 for 72 h, 4 Gy and 48 h, respectively. MCF7 cells were pretreated with VPA 0.5 mmol L-1 for 24 h. According to the number of cells inoculated in each dish, ionizing radiation was given for 2 Gy (500 and 1000 per dish), 4 Gy (2000 and 4000 per dish) and 6 Gy (8000 and 16000 per dish), respectively. MCF7 cells were pretreated with VPA 0.5 and 1 mmol L-1 for 48 and 72 hours, respectively, and the cell cycle was detected by flow cytometry. Results compared with the normal control group, the positive rates of 纬-H2AX focus were (5.3 卤0.6)% and (10.8 卤1.0)%, respectively, after treatment with VPA 0.5 mmol L-1 for 48 h and 72 h, respectively. (12.6 卤0.9)% and (17.8 卤1.1)%; VPA 1 mmol L -1 had the same effect on 纬-H2AX focus formation. In the single irradiation group, the positive rate of 纬-H2AX focus was 100%, and the percentage of group B cells with severe DNA damage was (16.5 卤1.8)%. Compared with the irradiation group alone, the percentage of B cells pretreated with VPA 0.5 mmol L-1 for 48 h and 72 h were (16.5 卤1.8)% and (28.9 卤1.0)%, respectively. (58.0 卤2.0)% and (70.8 卤0.9)%; The effects of VPA 1 mmol L-1 on 纬-H2AX focal point formation induced by radiation have the same trend. The results of MTT and cell clone formation experiments showed that, compared with the normal control group, the effect of VPA 1 mmol L -1 on 纬-H2AX focus formation was similar. VPA0.5 mmol L-1 alone could significantly reduce the cell clone formation rate (P0.05). Compared with the single irradiation group, the cell survival rate (P0.05) and the cell clone formation rate (P0.05); VPA 0.5 and 1 mmol L-1) were significantly decreased by ionizing radiation after pretreatment with VPA (P0.05); VPA and 1 mmol L-1 respectively). Conclusion Clinical safe dose and critical dose of VPA have radiosensitizing effect on tumor cells and inhibit the growth of tumor cells. The mechanism is related to the accumulation of DNA double strand break damage induced by increased ionizing radiation.
【作者单位】：山东大学公共卫生学院环境与健康系;
【基金】：国家自然科学基金(81172527);国家自然科学基金项目(81472800) 山东省科技发展计划(2013GGE27052)~~
【分类号】：R96

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