三氧化二砷对鼻咽癌细胞系表达DNA甲基转移酶的抑制作用

Effects of arsenic trioxide on DNA methyltransferases expression of nasopharyngeal carcinoma cell lines

目的探讨三氧化二砷(As2O3)对鼻咽癌细胞系DNA甲基转移酶(DNA methyltransferase,DNMT)(DNMT1、DNMT3A及DNMT3B)表达水平的影响。方法应用8μmol/L As2O3与鼻咽癌细胞系C666-1、CNE1、CNE2和鼻咽上皮永生细胞系NP69细胞分别共同孵育48h,基于细胞计数试剂盒8测定鼻咽癌细胞的增殖情况。应用定量反转录聚合酶链反应和蛋白质印迹检测药物处理前后鼻咽癌细胞及NP69细胞中DNMT mRNA及蛋白表达水平的变化。结果NP69细胞相对鼻咽癌细胞表达DNMT1和DNMT3A水平最低。经As2O3作用后,鼻咽癌细胞活力下降,形态改变明显;各种细胞表达DNMT的水平变化不完全一致,其中C666-1细胞对3种DNMT的表达水平均显著降低;而CNE1和CNE2细胞中DNMT1及DNMT3B表达下调,CNE1细胞中DNMT3A的表达显著上调。结论As2O3可抑制鼻咽癌细胞中DNMT的表达,表明其在一定程度上对鼻咽癌细胞具有去甲基化作用,存在治疗鼻咽癌的潜在价值。

Objective To investigate the effect of arsenic trioxide(As2O3)on the expression levels of DNA methyltransferases(DNMT)(DNMT1,DNMT3A and DNMT3B)in nasopharyngeal carcinoma cell lines.Methods Incubation of 8μmol/L As2O3 with nasopharyngeal carcinoma cell line C666-1,CNE1,CNE2 and nasopharyngeal epithelial immortal cell line NP69 cells for 48h,cell counting kit-8 was measured the proliferation of nasopharyngeal carcinoma cells.Moreover,quantitative reverse transcriptase-mediated polymerase chain reaction and Western blot were used to determine the levels of DNMT mRNA and protein expression in nasopharyngeal carcinoma cells and NP69 cells before and after As2O3 treatment.Results Compared with nasopharyngeal carcinoma cells,the expression of DNMT1 and DNMT3A in NP69 cells were the lowest.After being incabation with the As2O3,NPC cell viability decreased with obvious morphological changes.It is observed that levels of DNMT expressed in various cells were not completely consistent,with C666-1 cells showing significantly lower expression levels for all three DNMT.However,DNMT1 and DNMT3B were downregulated in CNE1 and CNE2 cells,DNMT3A expression was significantly upregulated in CNE1 cells.Conclusion It is suggested that As2O3 has potential therapeutic value for nasopharyngeal carcinoma through which could inhibite the expression of DNMT.