Purine biosynthesis enzymes and DNA

Purine biosynthesis enzymes and DNA represent a critical axis in cellular metabolism and genetic integrity, serving as primary targets for oncology and rheumatology. The purine biosynthesis pathway, comprising both de novo and salvage routes, generates the essential nucleotides adenine and guanine required for DNA and RNA synthesis, as well as energy-carrying molecules like ATP (StatPearls, 2023). Enzymes such as dihydrofolate reductase (DHFR) and inosine monophosphate dehydrogenase (IMPDH) are pivotal in maintaining these nucleotide pools (NCBI, 2022). DNA itself serves as a direct target for various cytotoxic agents that induce structural damage, such as cross-links or strand breaks, thereby preventing replication and transcription (PubMed, 2021). Drugs targeting this complex system, including antimetabolites like methotrexate and alkylating agents like cyclophosphamide, are designed to exploit the high proliferative rate of malignant or auto-reactive cells. However, the ubiquitous nature of these targets often leads to significant side effects, most notably myelosuppression and gastrointestinal toxicity, due to the impact on healthy rapidly dividing tissues.

Other names

Purine metabolic pathwayNucleotide biosynthesis enzymesDNA-targeting agentsPurine de novo and salvage pathways

Drugs targeting this group act by inhibiting key enzymes in the de novo purine synthesis pathway (e.g., DHFR, GARFT) or the salvage pathway (e.g., HGPRT), thereby depleting the cellular pool of adenine and guanine nucleotides. Additionally, certain agents interact directly with DNA through alkylation, intercalation, or cross-linking, which disrupts the structural integrity of the double helix and prevents successful replication and transcription.