Simulating the Role of RAD51 Over-Expression on DNA Repair and its Potential Impact on Tumor Prognosis via Targeted Gene Therapy

ROS-induced DNA damage is particularly detrimental in the context of cancers as the tumor microenvironment (TME) is often characterized by oxidative stress. Cells in the TME play a vital role in cancer pathogenesis, and by understanding the therapeutic strategies for cancer, ROS-induced damage can be mitigated to improve tumor prognosis. ROS can cause single-strand DNA breaks (SSBs) and double-strand breaks (DSBs); accumulating these breaks can lead to genomic instability and cancer progression. The study focuses on the pathway and effects of introducing DNA repair proteins (RAD51 in this study) via adenoviral vectors into the TME to reduce ROS-induced DNA damage. RAD51 is a repair protein involved with homologous recombination to anneal DSBs. Adenoviruses are double-stranded DNA viruses ubiquitous in common diseases like rhinitis; however, they are commonly used in clinical gene therapies. A gene therapy methodology that simulates adenoviral gene insertion without involving the actual virus focuses instead on engineered vectors designed for therapy. The DNA damage response efficacy can be measured by analyzing phosphorylated H2AX (γH2AX), a histone that regulates DNA damage response. γH2AX also plays a vital role in accumulating DNA repair proteins at the site of the break. During DSB induction, kinase enzymes phosphorylate many H2AX molecules that flank the break region–DSBs and γH2AX increase analogously. If future preclinical studies confirm the effectiveness of this research, it could lead to significant benefits for patients, such as reducing their resistance to radiotherapy.