Host DNA synthesis machinery

The host DNA synthesis machinery, often referred to as the replisome, is a sophisticated assembly of proteins and enzymes required for the accurate duplication of the host cell's DNA (NIH, 2021). Key components include DNA polymerases (α, δ, ε), which catalyze nucleotide addition; the Proliferating Cell Nuclear Antigen (PCNA), which acts as a processivity factor; and various helicases and topoisomerases that manage DNA unwinding and topological stress (UniProt, 2024). In oncology, this machinery is a classic therapeutic target; antimetabolites and polymerase inhibitors disrupt its function to arrest the growth of rapidly dividing malignant cells (StatPearls, 2023). Furthermore, many DNA viruses, such as human papillomavirus (HPV) and polyomaviruses, lack their own replication enzymes and must co-opt the host's machinery to propagate, making these host factors potential targets for antiviral intervention (PubMed, 2020; biorxiv.org, 2021). The primary therapeutic hurdle in targeting this machinery is the lack of selectivity, as inhibition often leads to significant side effects in healthy, proliferating tissues such as the bone marrow and intestinal epithelium (StatPearls, 2023). This lack of specificity results in common toxicities such as myelosuppression and gastrointestinal distress, which limit the therapeutic window of drugs targeting these pathways.

Other names

DNA replication machineryHost cell DNA replication complexHost replication machineryReplisome

Drugs targeting the host DNA synthesis machinery act by inhibiting DNA polymerase activity, depleting essential nucleotide pools, or inducing DNA strand breaks by stabilizing topoisomerase-DNA complexes, thereby halting the replication process (StatPearls, 2023; NIH, 2021).