MRC Integrative Epidemiology Unit at the University of Bristol, Bristol, UK.
Population Health Sciences, Bristol Medical School, University of Bristol, Oakfield House, Oakfield Grove, Bristol, BS8 2BN, UK.
Clin Epigenetics. 2021 Sep 28;13(1):183. doi: 10.1186/s13148-021-01174-7.
Little evidence exists on the health effects of e-cigarette use. DNA methylation may serve as a biomarker for exposure and could be predictive of future health risk. We aimed to investigate the DNA methylation profile of e-cigarette use.
Among 117 smokers, 117 non-smokers and 116 non-smoking vapers, we evaluated associations between e-cigarette use and epigenome-wide methylation from saliva. DNA methylation at 7 cytosine-phosphate-guanine sites (CpGs) was associated with e-cigarette use at p < 1 × 10 and none at p < 5.91 × 10. 13 CpGs were associated with smoking at p < 1 × 10 and one at p < 5.91 × 10. CpGs associated with e-cigarette use were largely distinct from those associated with smoking. There was strong enrichment of known smoking-related CpGs in the smokers but not the vapers. We also tested associations between e-cigarette use and methylation scores known to predict smoking and biological ageing. Methylation scores for smoking and biological ageing were similar between vapers and non-smokers. Higher levels of all smoking scores and a biological ageing score (GrimAge) were observed in smokers. A methylation score for e-cigarette use showed poor prediction internally (AUC 0.55, 0.41-0.69) and externally (AUC 0.57, 0.36-0.74) compared with a smoking score (AUCs 0.80) and was less able to discriminate lung squamous cell carcinoma from adjacent normal tissue (AUC 0.64, 0.52-0.76 versus AUC 0.73, 0.61-0.85).
The DNA methylation profile for e-cigarette use is largely distinct from that of cigarette smoking, did not replicate in independent samples, and was unable to discriminate lung cancer from normal tissue. The extent to which methylation related to long-term e-cigarette use translates into chronic effects requires further investigation.
目前关于电子烟使用对健康影响的证据有限。DNA 甲基化可能作为暴露的生物标志物，并可预测未来的健康风险。我们旨在研究电子烟使用的 DNA 甲基化谱。
在 117 名吸烟者、117 名非吸烟者和 116 名非吸烟电子烟使用者中，我们评估了电子烟使用与唾液中全基因组甲基化之间的关联。在 p<1×10-1 和 p<5.91×10-7 处，有 7 个胞嘧啶-磷酸-鸟嘌呤位点 (CpG) 的 DNA 甲基化与电子烟使用相关。在 p<1×10-1 和 p<5.91×10-7 处，有 13 个 CpG 与吸烟相关。与电子烟使用相关的 CpG 主要与吸烟无关。在吸烟者中，已知与吸烟相关的 CpG 存在强烈富集，但在电子烟使用者中没有富集。我们还测试了电子烟使用与预测吸烟和生物老化的甲基化评分之间的关联。在电子烟使用者和非吸烟者中，吸烟和生物老化的甲基化评分相似。吸烟者的所有吸烟评分和生物老化评分（GrimAge）都较高。电子烟使用的甲基化评分在内部（AUC 0.55，0.41-0.69）和外部（AUC 0.57，0.36-0.74）预测效果均较差，并且在区分肺鳞状细胞癌与相邻正常组织方面的能力也较差（AUC 0.64，0.52-0.76 与 AUC 0.73，0.61-0.85）。
电子烟使用的 DNA 甲基化谱与吸烟的甲基化谱有很大的不同，在独立样本中未得到复制，并且无法区分肺癌与正常组织。长期电子烟使用与甲基化相关的程度转化为慢性影响还需要进一步研究。
