PCB153对人肾上皮细胞中LINE-1表达及转座的影响

Effects of PCB153 on LINE-1 expression and translocation in human renal tubular epithelial cells

[目的]探究2,2',4,4',5,5'-六氯联苯(PCB153)对人肾上皮细胞系(293T)细胞中长散在重复序列-1(LINE-1)基因表达和转座的影响。[方法]293T细胞每2 d传代一次,传代后立即使用5μmol/L PCB153进行染毒。染毒后的细胞置于37℃、体积分数5%CO2培养箱中继续培养,连续染毒10 d。同时设置二甲基亚砜(DMSO)对照组。采用实时荧光定量PCR技术检测LINE-1开放阅读框1(ORF-1)和开放阅读框2(ORF-2)基因的m RNA表达水平及拷贝数,LINE-1拷贝数增加反映其发生转座。Western blot检测LINE-1 ORF-1和ORF-2蛋白表达水平。[结果]与对照组比较,从第4天开始PCB153染毒组细胞中LINE-1 ORF-1 m RNA表达水平增加(P<0.05),从第6天开始PCB153染毒组细胞中LINE-1 ORF-2 m RNA表达水平增加(P<0.05)。染毒第10天时,与对照组(LINE-1 ORF-1:2.74±0.51;LINE-1 ORF-2:0.57±0.10)相比,PCB153染毒组的LINE-1 ORF-1蛋白表达水平(4.39±0.85)和LINE-1 ORF-2蛋白表达水平(0.78±0.10)均明显增加(P<0.05)。染毒第10天时,PCB153染毒组与对照组的LINE-1 ORF-1拷贝数分别为1.43±0.64和0.83±0.37,LINE-1 ORF-2拷贝数分别为1.11±0.52和0.81±0.12,差异均具有统计学意义(P<0.05)。[结论]PCB153暴露可增加LINE-1的表达和拷贝数,诱导其转座。

[Objective] To assess the effects of 2, 2＇, 4, 4＇, 5, 5＇-hexachlorobiphenyl （PCB153） on long interspersed nuclear element-1 （LINE-1） gene expression and transposition in human renal tubular epithelial 293T cells.[Methods] The 293T cells were transmitted every two days and exposed to PCB153 （5 μmol/L） in vitro after transmitting. The exposed cells were cultured in a 5% CO2 incubator at 37℃ and the exposure lasted for 10 days, with the 293T cells treated with dimethyl sulfoxide （DMSO） as control group. LINE-1 open read framework 1 （ORF-1） and open read framework 2 （ORF-2） gene mRNA expression levels and copy numbers （increasing copy number indicates transposition） were detected by real-time fluorescence quantitative PCR. LINE-1 ORF-1 and ORF-2 protein expression levels were measured by Western blot.[Results] Compared with the control group, the mRNA expression level of LINE-1 ORF-1 in the PCB153 exposed group was increased from day 4 （P 〈 0.05）, and the mRNA expression level of LINE-1 ORF-2 in the PCB153 exposed group was increased from day 6 （P 〈 0.05）. On day 10, compared with the control group （LINE-1 ORF-1：2.74±0.51; LINE-1 ORF-2：0.57±0.10）, the protein expression levels of LINE-1 ORF-1 （4.39±0.85） and LINE-1 ORF-2 （0.78±0.10） in the PCB153 exposed group were both increased （P 〈 0.05）. In addition, on day 10, the copy numbers of LINE-1 ORF-1 were 1.43±0.64 and 0.83±0.37, and the copy numbers of LINE-1 ORF-2 were 1.11±0.52 and 0.81±0.12 in the PCB153 exposed group and the control group, respectively, with significant differences （P 〈 0.05）.[Conclusion] Exposure to PCB153 can increase the expression and copy number of LINE-1 and induce its transposition in 293T cells.