目的 使用L5178Y細(xì)胞分別開展tk基因突變試驗和hprt基因突變試驗評價納米氧化鐵顆粒（iron oxidenanoparticle， IONP）的潛在基因突變風(fēng)險，比較兩種方法的靈敏性。方法 不同質(zhì)量濃度的PEG-IONP（31.25、62.5、125、250、500 μg/mL）分別與細(xì)胞作用3 h，于給藥后第0、2、6天將細(xì)胞接種于96孔板繼續(xù)培養(yǎng)9～10 d，用于計算平板接種效率。分別在給藥后第2天或第6天加入三氟胸苷（TFT）和6-硫鳥嘌呤（6-TG）作為tk基因和hprt基因選擇劑，繼續(xù)培養(yǎng)14 d后分析基因突變頻率。試驗平行設(shè)置滅菌注射用水溶媒對照組和甲基甲烷磺酸酯（MMS，10 μg/mL）陽性對照組。結(jié)果 溶媒對照組和陽性對照組的hprt基因突變率均低于tk基因突變率，且統(tǒng)計學(xué)結(jié)果提示hprt基因突變試驗數(shù)據(jù)獲得顯著性差異的起始濃度（250 μg/mL）高于tk基因突變試驗（125 μg/mL）。但整體而言兩種試驗方法對PEG-IONP的評價結(jié)果一致。結(jié)論 PEG-IONP可引起小鼠淋巴瘤L5178Y細(xì)胞tk基因及hprt基因突變率顯著性升高。該研究結(jié)果可為納米材料基因突變風(fēng)險評價的選擇提供借鑒與參考。

Objective To perform tk gene mutation assay and hprt gene mutation assay using L5178Y cells for evaluating the gene mutation risk of IONP, and comparing the sensitivity of both assays. Methods Cells were treated with different concentrations of PEG-IONP (31.25, 62.5, 125, 250, 500 μg/mL) for 3 h. Cells were seeded in 96-well plates on 0, 2 and 6 days after treatment and cultured for 9 to 10 days for calculating the plating efficiency. TFT and 6-TG were adopt as the tk gene and hprt gene selection agents on 2 or 6 days after treatment respectively, and the gene mutation frequencies were analyzed after a 14 days incubation. Sterile water and MMS (10 μg/mL) were included in parallel as vehicle control and positive control groups. Results The mutation rates of hprt gene in vehicle control group and the positive control group were lower than that of the tk gene, and the statsistical results indicated that the initial concentration for positive result in the hprt gene mutation assay (250 μg/mL) was higher than the tk gene mutation (125 μg/mL). However, the results for PEG-IONP are generally consistent in both assays. Conclusion PEG-IONP could significantly increase the mutation rates of both tk gene and hprt gene in mouse lymphoma L5178Y cells. This data provided reference for the methods selection on the gene mutation risk assessment of nanomaterials.

國家十三五“重大新藥創(chuàng)制”專項課題（2018ZX09201017）；國家自然科學(xué)基金（81503347）#共同