Analysis of Crotonaldehyde- and Acetaldehyde-Derived 1,N²-Propanodeoxyguanosine Adducts in DNA from Human Tissues Using Liquid Chromatography Electrospray Ionization Tandem Mass Spectrometry

Abstract

Crotonaldehyde, a mutagen and carcinogen, reacts with deoxyguanosine (dGuo) in DNA to generate a pair of diastereomeric 1,N 2 -propanodeoxyguanosine adducts (Cro-dGuo, 2), which occur in (6S, 8S) and (6R, 8R) configurations. They can also be formed through the consecutive reaction of two acetaldehyde molecules with dGuo. Cro-dGuo adducts inhibit DNA synthesis and induce miscoding in human cells. Considering their potential role in carcinogenesis, we have developed a sensitive and specific liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/ MS) method to explore the presence of Cro-dGuo adducts in DNA from various human tissues, such as liver, lung, and blood. DNA was isolated from human tissues and enzymatically hydrolyzed to deoxyribonucleosides. [ 15 N 5 ]Cro-dGuo was synthesized and used as an internal standard. The CrodGuo adducts were enriched from the hydrolysate by solid phase extraction and analyzed by LC-ESI-MS/MS, using selected reaction monitoring (SRM). This method allows the quantitation of the Cro-dGuo adducts at a concentration of 4 fmol/μmol dGuo, corresponding to about 1 adduct per 10 9 normal nucleosides starting with 1 mg of DNA, with high accuracy and precision. DNA from human liver, lung and blood were analyzed. The Cro-dGuo adducts were detected more frequently in human lung DNA than in liver DNA, but were not detected in DNA from blood. The results of this study provide quantified data on Cro-dGuo adducts in human tissues. The higher frequency of Cro-dGuo in lung DNA than in the other tissues investigated is potentially important and deserves further study.

Exposure to Nicotine and Selected Toxicants in Cigarette Smokers Who Switched to Electronic Cigarettes: A Longitudinal Within-Subjects Observational Study

“…The characteristics and significance of measured biomarkers and their precursors are presented in Supplementary Table 1. [16][17][18][19][20][21][22][23][24][25][26][27] Urine total (free plus conjugated) concentrations of nicotine, cotinine, trans-3′-hydroxycotinine, and free nicotine N-oxide and cotinine N-oxide were measured by LC-MS/MS as described previously. 28,29 Urine nicotine equivalents (Nic Eq) was determined as the molar sum of nicotine, cotinine, trans-3′-hydroxycotinine and their respective glucuronides, and free nicotine N-oxide and cotinine N-oxide corrected for creatinine concentration.…”

Comprehensive Assessment of Oxidatively Induced Modifications of DNA in a Rat Model of Human Wilson's Disease

“…Byproducts of LPO could react with DNA to generate exocyclic adducts, including 1,N 6 -etheno-2Ј-deoxyadenosine (dA) and 1,N 2 -etheno-2Ј-deoxyguanosine (dG) (5,6). Multiple lines of evidence showed that these DNA lesions in mammalian cells, tissues and blood may serve as potential biomarkers of oxidative stress (7)(8)(9)(10)(11)(12)(13)(14).…”

Metabolism in Vitro and in Vivo of the DNA Base Adduct, M1G

“…Evaluating genomic exposure to oxidative damage may have an impact in risk assessment (2). It has been suggested that monitoring DNA adduct formation is a useful diagnostic tool in human populations (3) and is commonly employed by multiple laboratories (4)(5)(6)(7).…”