| 陈霞,刘晓丹,王豫,周平坤.DNA依赖蛋白激酶催化亚基抑制剂NU7026对结肠癌HCT116癌干细胞的放射增敏作用[J].中华放射医学与防护杂志,2016,36(5):395-400 |
| DNA依赖蛋白激酶催化亚基抑制剂NU7026对结肠癌HCT116癌干细胞的放射增敏作用 |
| Radiosensitization of DNA-dependent protein kinase catalytic subunit inhibitor NU7026 on HCT116 colorectal cancer stem cells |
| 投稿时间：2015-11-17 |
| DOI：10.3760/cma.j.issn.0254-5098.2016.05.020 |
| 中文关键词: DNA依赖蛋白激酶催化亚基 结肠癌细胞HCT116 放射增敏 癌干细胞 |
| 英文关键词:DNA-PKcs HCT116 Radiosensitization Cancer stem cells |
| 基金项目:国家自然科学基金大科学装置联合基金(U1432248) |
|
| 摘要点击次数: 3043 |
| 全文下载次数: 2156 |
| 中文摘要: |
| 目的 以结肠癌细胞HCT116为研究对象,评价DNA依赖蛋白激酶催化亚基(DNA-PKcs)抑制剂NU7026对癌干细胞的放射增敏作用及其机制。方法 以CD133+/CD44+为标志物,流式细胞术检测癌干细胞亚群。将HCT116细胞分为对照组、单纯药物(20 μmol/L NU7026)组、单纯照射(2 Gy γ射线)组和药物+照射(20 μmol/L NU7026联合2 Gy γ射线)组,照射前2 h加入NU7026。细胞集落形成实验检测HCT116细胞增殖,流式细胞术检测细胞周期和凋亡, γ-H2AX foci的免疫荧光激光共聚焦分析DNA双链断裂损伤修复。结果 体外培养HCT116细胞中CD133+/CD44+癌干细胞亚群比例高达(88.14±0.47)%,HCT116细胞低密度接种无血清培养基中集落形成率为(84.75±1.35)%。与单纯照射组比较,药物+照射组细胞存活率显著降低(t=7.22,P<0.01)。受照后48 h,药物+照射组的癌干细胞亚群比例较单纯照射组显著降低(t=9.55,P<0.01)。受照后24 h,NU7026明显增加G2/M期阻滞(t=7.67,P<0.01),48 h细胞早期凋亡发生率也明显增加(t=8.24,P<0.05)。药物+照射组在照后2、4、8和24 h DNA双链断裂(γ-H2AX foci)残留比单纯照射组明显增多(t=19.58、11.95、7.01和9.45,P<0.01)。结论 NU7026对癌干细胞为优势亚群的结肠癌HCT116细胞具有明显的放射增敏作用,显著增加对癌干细胞的杀伤效应,增敏机制包括抑制DNA修复,诱发不可逆G2/M期阻滞和增加细胞凋亡。 |
| 英文摘要: |
| Objective To evaluate the radiosensitization and mechanism of DNA-dependent protein kinase catalytic subunit inhibitor NU7026 on HCT116 colorectal cancer stem cells.Methods The flow cytometry was used to determine the sub-population of cancer stem cells with the markers CD133/CD44. The cells were divided into four groups: control group, 20 μmol/L NU7926 group, 2 Gy irradiation group, and 20 μmol/L NU7026 combined with 2 Gy irradiation group. Cell proliferation and survival were evaluated by colony-formation experiment. Flow cytometry was used to analyze the cell cycle distribution and apoptosis induction. γ-H2AX foci were detected with immune-fluorescence staining analysis by a laser confocal microscopy for investiating the DNA double-strand break repair. Results The flow cytometric data of CD133+/CD44+ positive cells indicated that the sub-population of cancer stem cell (CSC) took the ratio of (88.14±0.47)% of the cultured HCT116 cells. The colony-formation efficiency of HCT116 cells was (84.75±1.35)% in serum-free mediums in vitro culture. Compared to 2 Gy irradiation alone group, the NU7026 combined with 2 Gy irradiation group had a lower cell colony-forming ratio (t=7.21, P<0.01) and a lower survival ratio (t=7.22, P<0.01). The proportion of CSCs sub-population increased at 48 h post-2 Gy irradiation, suggesting that HCT116 CSCs was more resistant to ionizing radiation. Importantly, NU7026 largely decreased the proportion of CSCs sub-population in 2 Gy-irradiated cells. The difference of CSC proportion between 2 Gy irradiation alone group and 2 Gy combined with NU7026 treatment group was statistically significant (t=9.55, P<0.01). In addition, the group of NU7026 combined with 2 Gy irradiation had a higher ratio of G2/M arrest 24 h post-irradiation (t=7.67, P< 0.01) and an increased induction of cell early apoptosis (t=8.24, P< 0.05). 48 h post irradiation as compared to 2 Gy irradiation alone group. NU7026 treatment significantly inhibited the cellular capacity of repairing DNA double-strand breaks induced by γ-ray irradiation. The γ-H2AX foci of the combined treatments group were much higher than that of 2 Gy irradiation alone group at 2, 4, 8, 24 h post-irradiation (t=19.58, 11.95, 7.01, 9.45, P<0.01). Conclusions DNA-dependent protein kinase catalytic subunit inhibitor NU7026 can significantly sensitize the cancer stem cells of colorectal carcinoma HCT116 cells to γ-ray irradiation. Multiple mechanisms are involved in the radiosensitization effect of NU7026, including DNA repair inhibition, elongation of G2/M arrest, and increase of radiation-induced apoptosis. |
| HTML 查看全文 查看/发表评论 下载PDF阅读器 |
| 关闭 |
|
|
|