De Oliveira Sabrina Rocha Luna, Da Silva Isabelle Cristina Borba, Mariz Bruno Augusto Linhares Almeida, Pereira Ana Maria Barros Chaves, De Oliveira Naila Francis Paulo
Programa de Pós Graduação em Odontologia, Centro de Ciências da Saúde, Universidade Federal da Paraíba, João Pessoa, PB, Brazil.
Departamento de Biologia Molecular, Centro de Ciências Exatas e da Natureza, Universidade Federal da Paraíba, João Pessoa, PB, Brazil.
Arch Oral Biol. 2015 Jun;60(6):825-33. doi: 10.1016/j.archoralbio.2015.02.022. Epub 2015 Mar 3.
The aim of this study was to investigate the smoking habit influence on DNA methylation status in the promoters of the cancer related-genes MLH1, hTERT and TP53 in oral epithelial cells of healthy subjects.
DNA methylation analysis was performed using methylation-sensitive restriction enzymes (MSRE) in oral epithelial cells from non-smokers, smokers and ex-smokers.
The investigated CpG dinucleotides located at HhaI and HpaII sites in the MLH1 gene promoter were observed to be fully methylated in the majority of DNA samples from the smoker group and statistical differences were found between non-smokers and smokers and between smokers and ex-smokers (p<0.05). The same was observed in the hTERT gene promoter at HhaI sites (p<0.05) and for HpaII sites the unmethylated condition was more frequent in smokers in comparison to non-smokers (p<0.05). For TP53, no differences were found among groups (p>0.05), with the fully methylated condition found to be a common event in healthy oral epithelial cells.
We conclude that smoking may induce changes in DNA methylation status in cancer-related genes of oral epithelial cells and that the cessation of smoking is capable of reversing this process. Based on our data, we suggest that DNA methylation status of the hTERT and MLH1 gene promoters are promising markers for screening a set of smoking-related alterations in oral cells.
本研究旨在调查吸烟习惯对健康受试者口腔上皮细胞中癌症相关基因MLH1、hTERT和TP53启动子区DNA甲基化状态的影响。
使用甲基化敏感限制性内切酶（MSRE）对非吸烟者、吸烟者和戒烟者的口腔上皮细胞进行DNA甲基化分析。
在吸烟者组的大多数DNA样本中，观察到位于MLH1基因启动子区HhaI和HpaII位点的被研究CpG二核苷酸完全甲基化，且在非吸烟者与吸烟者之间以及吸烟者与戒烟者之间发现了统计学差异（p<0.05）。在hTERT基因启动子的HhaI位点也观察到同样情况（p<0.05），对于HpaII位点，与非吸烟者相比，吸烟者中未甲基化状态更为常见（p<0.05）。对于TP53，各组之间未发现差异（p>0.05），在健康口腔上皮细胞中完全甲基化状态是常见情况。
我们得出结论，吸烟可能诱导口腔上皮细胞癌症相关基因的DNA甲基化状态发生变化，且戒烟能够逆转这一过程。基于我们的数据，我们认为hTERT和MLH1基因启动子的DNA甲基化状态是筛选口腔细胞中一系列吸烟相关改变的有前景的标志物。
