γH2AX, pChk1, and Wip1 as Potential Markers of Persistent DNA Damage Derived from Dibenzo[a,l]pyrene and PAH-Containing Extracts from Contaminated Soils
2012 (English)In: Chemical Research in Toxicology, ISSN 0893-228X, E-ISSN 1520-5010, Vol. 25, no 4, 862-872 p.Article in journal (Refereed) Published
Polycyclic aromatic hydrocarbons (PAHs) are formed during incomplete combustion of organic material and are ubiquitous environmental contaminants. High levels of PAHs are commonly found in soils at industrial sites, thereby constituting a risk for humans and the environment. However, this risk is often difficult to estimate due to the complexity of the contamination. In the present study we investigated the cellular DNA damage response induced by extracts of PAH-contaminated soils collected at various industrial sites in Sweden. The results show that interactions of PAHs in the soil extracts caused activation of DNA damage signaling consistent with persistent DNA damage. Signaling in HepG2 cells exposed to soil PAH extracts corresponding to 1 µM benzo[a]pyrene was similar to that of 0.1 µM dibenzo[a,l]pyrene, a highly carcinogenic PAH known to produce persistent DNA damage. The response involved prolonged activation of DNA damage marker (H2AX), check point kinase (Chk1), and phosphatases (Wip1). Furthermore, blocking DNA damage signaling using specific inhibitors and siRNA showed the important role of signaling through Chk1 for the level of DNA damage. We conclude that the combination of prolonged Chk1 phosphorylation and induced expression of Wip1 might serve as potential markers for persistent DNA damage induced by complex mixtures of environmental PAHs. Discrepancies between mRNA and protein levels of Wip1 in response to soil extracts, in parallel with increased microRNA (miR)-16 levels, suggest a role of miR-16 in the regulation of DNA damage signaling in response to PAHs. Taken together, our data indicate that PAH extracts induce irreparable DNA-damage and that this is consistent with the prolonged activation of DNA-damage signaling.
Place, publisher, year, edition, pages
2012. Vol. 25, no 4, 862-872 p.
Medicinal Chemistry Pharmacology and Toxicology
IdentifiersURN: urn:nbn:se:umu:diva-53230DOI: 10.1021/tx200436nISI: 000302826000008PubMedID: 22409540OAI: oai:DiVA.org:umu-53230DiVA: diva2:510838
Publication Date (Web): March 12, 20122012-03-192012-03-192013-02-12Bibliographically approved