DNA double-strand break repair pathway (null)

DNA double-strand break (DSB) repair pathways are not a single molecular target but rather a collection of cellular mechanisms responsible for detecting and repairing breaks that occur simultaneously on both strands of the DNA helix. These breaks are among the most cytotoxic forms of DNA damage and can lead to cell death or carcinogenesis if not properly repaired. The two main classes of DSB repair are: 1. Non-homologous end joining (NHEJ): A fast, predominant mechanism in mammalian cells that directly ligates broken ends without requiring sequence homology; active throughout the cell cycle but especially important during G1 phase. 2. Homologous recombination (HR): An error-free process using a homologous template for accurate restoration; restricted to S/G2 phases when sister chromatids are available. The choice between these pathways is regulated by factors such as ATM and ATR kinases, ubiquitin ligases like RNF8/RNF168/BRCA1, and post-translational modifications including phosphorylation and sumoylation[1][4]. Defects in these pathways—such as mutations in BRCA1 or BRCA2—are strongly associated with increased cancer risk due to impaired genome stability[2]. Therapeutically, drugs like PARP inhibitors exploit deficiencies in HR-mediated DSB repair through synthetic lethality approaches. Biomarkers such as γH2AX foci indicate active DSBs or ongoing DDR signaling. Because "DNA double-strand break repair pathway" refers collectively to multiple processes rather than a discrete protein or receptor, it is not considered a canonical therapeutic target itself but rather an umbrella term encompassing several molecular targets within its network. > "DSB repair pathways serve as important mechanisms for tumor suppression... genetic lesions... that disrupt DSB repair are often associated with cancer susceptibility"[2]. > > "NHEJ represents the simplest and fastest mechanism... while homologous recombination is restricted to S/G2 phases"[1]. In summary: this entry describes an essential set of cellular processes critical for genome integrity but does not correspond to a single molecule/receptor suitable for structured drug targeting nomenclature.

Other names

DSB repair pathwayDNA DSB repairdouble-strand break (DSB) repair pathwaysDNA damage response (DDR) pathways

Inhibition of specific proteins within the DSB repair machinery to induce synthetic lethality in cancer cells with defective homologous recombination[2].