Guanine-N7 position of cellular DNA (N7-G)

The N7 position of guanine in cellular DNA is the most nucleophilic site in the genome and serves as a primary target for a broad class of anti-cancer drugs known as alkylating agents and platinum-based compounds [1, 6]. These drugs covalently bind to the N7 nitrogen atom, forming DNA adducts that can lead to mono-alkylation or, in the case of bifunctional agents, the formation of inter-strand and intra-strand cross-links [2, 7]. These modifications physically obstruct the machinery responsible for DNA replication and transcription, effectively locking the DNA strands together and preventing cell division [1, 15]. Because cancer cells typically proliferate more rapidly than normal cells, they are more susceptible to this DNA damage, which triggers cell cycle arrest and apoptosis [1, 2]. However, the non-specific nature of these interactions leads to significant toxicity in other rapidly dividing tissues, such as the bone marrow and gastrointestinal tract [1, 15]. Furthermore, the resulting DNA damage can induce mutations that increase the risk of secondary cancers, such as leukemia, years after treatment [6, 15]. Despite these challenges, targeting this site remains a cornerstone of chemotherapy for various malignancies, including leukemias, lymphomas, and solid tumors [1, 7].

Other names

Cellular DNA – guanine N7N7-guanineGuanine N7N7 position of guanineN7-GN7-Gua

Alkylating agents and platinum compounds form covalent bonds with the N7 nitrogen of guanine, creating DNA adducts and cross-links that inhibit DNA replication and transcription, leading to cell cycle arrest and apoptosis [1, 2, 7].