Nwanaji-Enwerem Jamaji C, Colicino Elena
Belfer Center for Science and International Affairs, Harvard Kennedy School of Government, Cambridge, MA, USA.
Harvard Medical School, Boston, MA, USA.
Curr Environ Health Rep. 2020 Jun;7(2):121-128. doi: 10.1007/s40572-020-00269-2.
This manuscript orients the reader to the underlying motivations of environmental biomarker development for human population studies and provides the foundation for applying these novel biomarkers in future research. In this review, we focus our attention on the DNA methylation-based biomarkers of (i) smoking, among adults and pregnant women, (ii) lifetime cannabis use, (iii) alcohol consumption, and (iv) cumulative exposure to lead.
Prior environmental exposures and lifestyle modulate DNA methylation levels. Exposure-related DNA methylation changes can either be persistent or reversible once the exposure is no longer present, and this combination of both persistent and reversible changes has essential value for biomarker development. Here, we present available biomarkers representing past and cumulative exposures using individual DNA methylation profiles. In the present work, we describe how the field of environmental epigenetics can leverage machine learning algorithms to develop exposure biomarkers and reduce problems of misreporting exposures or limited access technology. We emphasize the crucial role of the individual DNA methylation profiles in those predictions, providing a summary of each biomarker, and highlighting their advantages, and limitations. Future research can cautiously leverage these DNA methylation-based biomarkers to understand the onset and progression of diseases.
本手稿旨在引导读者了解环境生物标志物在人群研究中开发的潜在动机,并为在未来研究中应用这些新型生物标志物奠定基础。在本综述中,我们将注意力集中在基于DNA甲基化的生物标志物上,这些生物标志物涉及:(i)成年人和孕妇的吸烟情况;(ii)终生大麻使用情况;(iii)酒精消费情况;以及(iv)铅的累积暴露情况。
既往环境暴露和生活方式会调节DNA甲基化水平。与暴露相关的DNA甲基化变化在暴露不再存在时既可以是持久的,也可以是可逆的,而这种持久和可逆变化的组合对生物标志物的开发具有重要价值。在此,我们展示了利用个体DNA甲基化谱来代表过去和累积暴露的现有生物标志物。在当前工作中,我们描述了环境表观遗传学领域如何利用机器学习算法来开发暴露生物标志物,并减少暴露误报或技术获取受限的问题。我们强调个体DNA甲基化谱在这些预测中的关键作用,总结了每种生物标志物,并突出了它们的优势和局限性。未来的研究可以谨慎地利用这些基于DNA甲基化的生物标志物来了解疾病的发生和发展。