DNA damage measurements within tissue samples with Repair Assisted Damage Detection (RADD)

Abstract

Exposures to genotoxic carcinogens and reactive species result in strand breaks and a spectrum of covalent modifications to DNA that can induce mutations and contribute to the initiation and progression of cancer. Measurements of DNA damage within tissue or tumor samples can serve as a biomarker for exposures or assess changes in DNA repair capacity relevant in cancer development and treatment. Numerous methods to characterize DNA damage exist. However, these methods are primarily applicable to isolated DNA or cultured cells, often require a substantial amount of material, and may be limited to the detection and quantification of only a handful of DNA adducts. Here, we used the Repair Assisted Damage Detection (RADD) assay to detect and excise DNA adducts using a cocktail of DNA repair enzymes, then the damage site within the genome are tagged for detection using a modified nucleotide. We previously demonstrated the RADD assay can detect lesions within isolated DNA and fixed cell, and now RADD can be used to detect DNA adducts and DNA strand breaks in formalin-fixed paraffin-embedded (FFPE) tissue samples. We verified the ability of the RADD assay to detect DNA damage in tissue by exogenously inducing DNA damage with X-rays and restriction enzymes. We also showed that RADD damage detection can be multiplexed with antibodies to detect cell cycle markers or other proteins of interest. Finally, we showed that RADD can detect DNA damage within clinically relevant ovarian tumor samples. RADD is a flexible and easy-to-use assay that allows relative damage levels to be determined within FFPE samples and allows the heterogeneity of DNA adducts and strand breaks within clinically relevant samples to be measured.

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Reference:

Kevin J. Lee, Elise Mann, Luciana Madeira da Silva, Jennifer Scalici, Natalie R. Gassman, DNA damage measurements within tissue samples with Repair Assisted Damage Detection (RADD), Current Research in Biotechnology, Volume 1, 2019, Pages 78-86, ISSN 2590-2628, https://doi.org/10.1016/j.crbiot.2019.11.001

Keywords: DNA damage measurements, tissue samples, Repair Assisted Damage Detection (RADD), DNA damage, DNA adducts, Tissue, Ovarian cancer, DNA strand breaks, Glycosylases, Fluorescent microscopy, formalin-fixed paraffin-embedded (FFPE) tissue samples, covalent modifications to DNA, Exposures to genotoxic carcinogens, #DNA, #DNAdamage.

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