Development of an Optimized Two-Step Solid-Phase Extraction Method for Urinary Nucleic Acid Adductomics

Area of Science:

• Environmental Health Sciences
• Toxicology
• Analytical Chemistry

Background:

• The exposome encompasses all exposures influencing health.
• Nucleic acid adducts, formed by exposures, are implicated in diseases like cancer.
• Urine analysis offers a non-invasive method to study the body's adductome.

Purpose of the Study:

• To develop an optimized solid-phase extraction (SPE) method for maximal recovery of diverse nucleic acid adducts from urine.
• To demonstrate the method's efficacy in identifying endogenous urinary adducts using untargeted high-resolution mass spectrometry.

Main Methods:

• Evaluation of various SPE sorbent combinations for nucleic acid adduct extraction from urine.
• Utilizing an ENV+ and PHE SPE column combination for enhanced adduct retention.
• Employing untargeted high-resolution mass spectrometry with FeatureHunter 1.3 software for adduct identification.

Main Results:

• The ENV+ and PHE SPE combination demonstrated superior recovery of a 20-adduct standard cocktail.
• The method successfully recovered endogenous nucleic acid adducts from mouse and human urine.
• Approximately 500 adducts were identified in both species, with isotopically labeled standards aiding in endogenous adduct characterization.

Conclusions:

• An optimized SPE method coupled with high-resolution mass spectrometry enables comprehensive analysis of the urinary nucleic acid adductome.
• This approach facilitates the study of exposome-related health effects and disease mechanisms.
• The characterized adductome provides a foundation for understanding individual susceptibility and disease risk.