Investigating the efficacy of UVSE protein at repairing CPD and 6-4 pp DNA damages in human cells

Abstract

UV exposure could induce carcinogenic mutation in human cells, including CPD (Cyclobutane pyrimidine dimer), and 6-4 pp (6-4 photoproduct) DNA damages. Spiting the active BER (Base Excision Repair) system of human cells, it lacks initiator glycosylase, rendering these damages to be only repaired through NER (Nucleotide Excision Repair) system. Some microorganisms such as Deinococcus radiodurans bacteria have a BER system for repairing these damages with an enzyme coded by the uvsE gene. This study evaluated the efficacy of the recombinant UVSE protein for repairing the CPD and 6-4 pp DNA damages in human cells. At the current study, the optimized sequence of the uvsE gene was synthesized and expressed in Hek293T cell line. The identity of protein was ascertained through ELISA assay and the stability of expression was measured via qPCR. The human Hek293T cells with the recombinant protein and without it were exposed to the UV light, and the repair of DNA damages was analyzed in both conditions using CPD and 6-4PP ELISA Combo Kit. The results indicated that uvsE gene was successfully colonized and expressed and expression showed to be stable. Hek293T cells with recombinant uvsE gene showed efficacy at repairing 80% of CPD and 85% of 6-4 photoproducts during one hour, and more than 95% of damages over 4 h' repair time. Considering the outcome of this study, it could be concluded that the uvsE recombinant product is highly effective at repairing both CPD and 6-4 pp damages and could be considered as a preventive agent for UV-induced skin cancers.

Keywords: DNA repair; Deinococcus radiodurans; Mutation; Skin cancer; UVSE protein.