Tampering of Viruses and Bacteria with Host DNA Repair: Implications for Cellular Transformation

SIMPLE SUMMARY: A large number of DNA damages occur per cell every day due to several causes, including viral and bacterial infections. The majority of them are repaired, but in some cases the repair processes are not totally efficient due to viral and bacterial proteins interferences with the host cellular machineries. Not repaired damages increase mutations, that ultimately cause genomic instability that increases the risk of cancer. The increased consideration of the role of DNA damage and repair in tumorigenesis has implications for the prevention and treatment of cancer. Our review provides a framework to better understand the common role played by some viruses and bacteria in cellular transformation. ABSTRACT: A reduced ability to properly repair DNA is linked to a variety of human diseases, which in almost all cases is associated with an increased probability of the development of cellular transformation and cancer. DNA damage, that ultimately can lead to mutations and genomic instability, is due to many factors, such as oxidative stress, metabolic disorders, viral and microbial pathogens, excess cellular proliferation and chemical factors. In this review, we examine the evidence connecting DNA damage and the mechanisms that viruses and bacteria have evolved to hamper the pathways dedicated to maintaining the integrity of genetic information, thus affecting the ability of their hosts to repair the damage(s). Uncovering new links between these important aspects of cancer biology might lead to the development of new targeted therapies in DNA-repair deficient cancers and improving the efficacy of existing therapies. Here we provide a comprehensive summary detailing the major mechanisms that viruses and bacteria associated with cancer employ to interfere with mechanisms of DNA repair. Comparing these mechanisms could ultimately help provide a common framework to better understand how certain microorganisms are involved in cellular transformation.