Rescue from DNA injury: arise and routes of damage repair Double strand breaks (DSBs) are considered to be some of the most harmful genomic DSB type. Non-Homologous End Joining (NHEJ) and Homologous Recombination (HR).Cells have evolved two main pathways to repair the breaks.
Mechanisms of Repair
Non-Homologous End Joining (NHEJ):
NHEJ is a fast process where the two broken ends of DNA are directly ligated, and it does not require homology to mediate repair. This is especially so in the G1 phase of the cell cycle when a sister chromatid not available for repair. A bit sloppy, NHEJ introduces a lot of mistakes (InDels) but even these small InDel mutations may change the configuration of how genes are arranged in the genome12.
HR (Homologous Recombination)
HR, by on the other hand is mainly a mistake free repair pathway that uses homologous sequence as a template for accurate reparation. This process becomes especially active during S and G2 phases when sister chromatids are present. HR is important for genomic stability and achieves a very faithful restoration of the original sequence34.
Importance of DNA Repair
The ability of cells to repair DNA damage efficiently is an essential mechanism for preventing genomic instability, which can cause a variety of diseases including cancer. Failure of these repair mechanisms results in an increase in mutations and may lead to cancer among other pathologies. Furthermore, the cross-talk between these repair pathways and cell cycle checkpoints prevents trans-lesional synthesis of DNA from spreading during piggyback division processes to maintain genetic integrity56.
Conclusion
Thus, one will get an understanding from this paper about how the dynamics of DNA repair mechanisms — such as NHEJ (non-homologous end joining) and HR(homologous recombination) give insights into cellular responses to DNA damage which could assist in generating therapeutic strategies for diseases with genomic instability. Deeper understanding in that realm alone could pave the way for cancer and other genetic disease treatments to greatly improve.DNA Repair (ad)