Centro de Investigaciones Científicas Avanzadas (CICA), Departamento de Psicología, Facultad de Ciencias de la Educación, Universidade da Coruña, Grupo DICOMOSA, Campus Elviña s/n, 15071, A Coruña, Spain.
Instituto de Investigación Biomédica de A Coruña (INIBIC), AE CICA-INIBIC, Oza, 15071, A Coruña, Spain.
Arch Toxicol. 2021 Jun;95(6):2179-2187. doi: 10.1007/s00204-021-03038-8. Epub 2021 Mar 31.
Peripheral blood leucocytes (PBL) have been traditionally used to investigate DNA damage by the comet assay in population studies, but validating alternative non-invasive samples would expand the application of this assay in human biomonitoring. The objectives of this study were (i) to test the validity of salivary leucocytes as a proper biomatrix for the comet assay, (ii) to evaluate the ability of this approach to detect different types of primary and oxidative DNA damage, and (iii) to determine whether frozen salivary leucocytes are still suitable for displaying those types of DNA damage. Fresh and frozen leucocytes isolated from saliva samples (six healthy non-smoking volunteers), were exposed to four genotoxic agents inducing different types of DNA damage, both primary (methyl methanesulfonate, actinomycin-D, ultraviolet radiation) and oxidative (potassium bromate), and standard or enzyme-modified comet assay was conducted. Results were compared with those obtained from PBL. Cells exposed to the four genotoxic agents showed dose-dependent increases of primary and oxidative DNA damage, demonstrating the suitability of all these samples to detect genetic damage from different origin. When comparing baseline levels of DNA damage, just a slight significant increase in primary DNA damage was observed in frozen salivary leucocytes regarding the other biomatrices, but similar results were obtained regarding sensitivity to DNA damage induction by all agents tested. This study demonstrates that salivary leucocytes can be employed in comet assay as an alternative or complement to blood samples. Frozen salivary leucocytes were proved to be a very convenient sample in large biomonitoring studies.
外周血白细胞（PBL）传统上被用于通过彗星试验在人群研究中研究 DNA 损伤，但验证替代的非侵入性样本将扩大该试验在人体生物监测中的应用。本研究的目的是：（i）测试唾液白细胞作为彗星试验合适的生物基质的有效性；（ii）评估该方法检测不同类型原发性和氧化 DNA 损伤的能力；（iii）确定冷冻唾液白细胞是否仍适合显示这些类型的 DNA 损伤。从唾液样本（六位健康不吸烟志愿者）中分离出新鲜和冷冻白细胞，暴露于四种诱导不同类型 DNA 损伤的遗传毒性剂，包括原发性（甲磺酸甲酯、放线菌素-D、紫外线辐射）和氧化（溴酸钾），并进行标准或酶修饰的彗星试验。结果与 PBL 获得的结果进行比较。结果表明，四种遗传毒性剂处理的细胞显示出原发性和氧化 DNA 损伤的剂量依赖性增加，证明所有这些样本都适用于检测不同来源的遗传损伤。当比较 DNA 损伤的基线水平时，与其他生物基质相比，冷冻唾液白细胞中仅观察到原发性 DNA 损伤略有显著增加，但对于所有测试的遗传毒性剂诱导 DNA 损伤的敏感性，获得了类似的结果。本研究表明，唾液白细胞可以在彗星试验中作为血液样本的替代或补充来使用。冷冻唾液白细胞被证明是大型生物监测研究中非常方便的样本。
