DNA Probes for Analysis the Activity of Key Enzymes of the Base Excision DNA Repair Pathway in Human Cells

Abstract

The important role of DNA damage in the occurrence of various diseases, including cancer, stimulates studies of the mechanisms of genetic information stability, carried out since the discovery of DNA repair systems. The question of the relationship between the accumulation of DNA damage, disorders in DNA repair pathways, and an increased risk of diseases developing still remains relevant. Over the past few years, significant efforts have been made to develop methods for analyzing the activity of DNA repair enzymes in human cells. In this work, we developed fluorescent DNA probes that allow us to determine the activity of key enzymes of base excision DNA repair in cell extracts, namely DNA glycosylases UNG2, SMUG1, MBD4, TDG, AAG, NEIL1, NTHL1, and OGG1 and AP endonuclease APE1. The sensitivity of DNA probes was determined on purified enzyme preparations. Determination of the activity of repair enzymes in cell extracts of the human ovarian tumor lines TOV112, 79, OVCAR3, MESOV, SCOV3, and TOV21 revealed a significant variability in the level of enzyme activity in these cell lines. Obtained results can become the test system platform for analyzing the activity of the base excision DNA repair system in the human body.