Cellular DNA at replication forks

Cellular DNA at replication forks refers to the specific structural state of the genome during the S-phase of the cell cycle, where the double helix is unwound to allow for semi-conservative replication. This site is a critical focal point for genomic stability, as the presence of single-stranded DNA (ssDNA) and branched structures makes it inherently fragile and susceptible to damage (Gaillard et al., 2015, Genes). In oncology, the replication fork is a primary therapeutic target because cancer cells often harbor high levels of replication stress due to oncogene activation or loss of repair factors, making them hypersensitive to further fork disruption (Zeman & Cimprich, 2014, Nature Cell Biology). Many traditional cytotoxic agents, such as platinum compounds and antimetabolites, function by creating physical barriers or incorporating faulty building blocks that stall or collapse these forks. The resulting DNA double-strand breaks trigger apoptotic pathways, effectively killing rapidly proliferating cells. Modern drug development also focuses on inhibitors of the DNA damage response (DDR) that prevent the stabilization or restart of stalled forks, thereby enhancing the efficacy of DNA-targeted therapies (O'Connor, 2015, Molecular Cell).

Other names

Replication fork DNANascent DNAFork DNAStalled replication forksReplicating DNA

Drugs targeting cellular DNA at replication forks typically function by inducing DNA interstrand cross-links, causing chain termination through nucleotide analog incorporation, or stabilizing topoisomerase-DNA covalent complexes, all of which create physical barriers that lead to replication fork arrest, collapse, and the formation of lethal double-strand breaks (Zeman & Cimprich, 2014, Nature Cell Biology; O'Connor, 2015, Molecular Cell).