吲哚-3-甲醇酸性代谢产物辐射防护作用的研究

目的 探讨吲哚-3-甲醇(I3C)酸性代谢产物的辐射损伤防护作用.方法 采用细胞克隆形成实验检测细胞的存活分数;采用Western Blot方法检测蛋白表达水平.结果 采用正常纤维上皮细胞184A1,发现7种I3C酸性代谢产物表现出不同的辐射损伤防护效果,其中CTET(1μmol/L)、LTET(1μmol/L)、HI-IM(1 μmol/L)和3,3'-二吲哚甲烷(DIM)(0.3 μmol/L)4种代谢产物在细胞γ-射线照射前24 h预处理细胞均不同程度地提高了辐照细胞的存活分数,差异均有统计学意义(P＜0.05,P＜0.01),而CT(1μmol/L)、LTr-1(1 μmol/L)和ICZ(1μmol/L)3种代谢产物则对辐照细胞存活分数无影响(P＞0.05).进一步研究发现CTET、LTET、HI-IM和DIM可导致ATM、BRCA1和NBS1蛋白磷酸化水平的改变.同样,CT、LTr-1和ICZ对这些蛋白的磷酸化水平不产生影响.另外,HI-IM可明显降低辐射损伤诱导的细胞坏死和细胞凋亡.结论 CTET、LTET、HI-IM和DIM 4种I3C酸性代谢产物可明显降低184A1细胞的辐射敏感性,即具有辐射防护作用,其机制可能与其调节DNA损伤与修复蛋白磷酸化和细胞凋亡有关.

Study on radioprotection of indole-3-carbinol acid condensation products

Objective To study the radioprotective effect of indole-3-carbinol (I3C) acid condensation products.Methods Cell colony formation assay was used to determine cell survival rate,and Western Blot assay was employed to measure protein expression.Results Seven kinds of the I3C acid condensation products showed different radioprotective effect on normal fibrous epithelial cells 184A1,among which 24 h pre-treatment of CTET (1 μmol/L),LTET (1 μmol/L),HI-IM (1 μmol/L) and 3,3'-diindoly methane (DIM) (0.3 μmol/L) showed significant increase of cell survival rate following irradiation with γ-ray,and the difficence was statistically significant (P＜0.05,P＜0.01).However,CT (1 μmol/L),LTr-1 (1 μmol/L) and ICZ (1 μmol/L) showed no effect on cell survival rate caused by radiation (P＞0.05).Furthermore,CTET,LTET,HI-IM and DIM activated the phosphorylation of ATM,BRCA1 and NBS1 proteins.HI-IM significantly decreased radiation-caused cell death and apoptosis.Conclusions CTET,LTET,HI-IM,and DIM can significantly reduce the radiosensitivity in 184A1 cells,and the mechanism may be related to the regulation of DNA damage and the repair of protein phosphorylation.