Shining light on single-strand lesions caused by the chemotherapy drug bleomycin
Journal article, 2021

Quantification of the DNA damage induced by chemotherapy in patient cells may aid in personalization of the dose used. However, assays to evaluate individual patient response to chemotherapy are not available today. Here, we present an assay that quantifies single-stranded lesions caused by the chemotherapeutic drug Bleomycin (BLM) in peripheral blood mononuclear cells (PBMCs) isolated from healthy individuals. We use base excision repair (BER) enzymes to process the DNA damage induced by BLM and then extend the processed sites with fluorescent nucleotides using a DNA polymerase. The fluorescent patches are quantified on single DNA molecules using fluorescence microscopy. Using the assay, we observe a significant variation in the in vitro induced BLM damage and its repair for different individuals. Treatment of the cells with the BER inhibitor CRT0044876 leads to a lower level of repair of BLM-induced damage, indicating the ability of the assay to detect a compromised DNA repair in patients. Overall, the data suggest that our assay could be used to sensitively detect the variation in BLM-induced DNA damage and repair in patients and can potentially be able to aid in personalizing patient doses.

Single-strand breaks

DNA damage

Fluorescence microscopy

Personalizing chemotherapy

Single molecule imaging

Damage mechanism of drugs

BER inhibition

Author

Vandana Singh

Sahlgrenska University Hospital

Chalmers, Biology and Biological Engineering, Chemical Biology

Pegah Johansson

Sahlgrenska University Hospital

University of Gothenburg

Yii Lih Lin

Chalmers, Biology and Biological Engineering, Chemical Biology

Ola Hammarsten

Sahlgrenska University Hospital

University of Gothenburg

Fredrik Westerlund

Chalmers, Biology and Biological Engineering, Chemical Biology

DNA Repair

1568-7864 (ISSN)

Vol. 105 103153

Genomic diagnostics beyond the sequence (BeyondSeq)

European Commission (EC) (EC/H2020/634890), 2015-06-01 -- 2019-12-31.

Subject Categories

Clinical Laboratory Medicine

Pharmacology and Toxicology

Hematology

DOI

10.1016/j.dnarep.2021.103153

PubMed

34119948

More information

Latest update

6/23/2021