Decoding DNA repair processes in Human Cells Our body houses flexible mechanisms that help to regulate the normal functioning of cells and tissue as well.DNA repair (ad) DNA damage is one among these forces, and it can be caused by both endogenous factors (byproducts generated during metabolism) or exogenous agents (UV light exposure). It is essential to have this capability in order to secure the integrity of genomes and avoid diseases like cancer.
Mechanisms of DNA Repair
Base Excision Repair (BER): BER is used to repair small, non-helix-distorting lesions. This process consists of the excision of damaged bases by glycosylases that are specifically recognizing these modified sites, and progressive action with polymerase and ligase activities to reconstitute the DNA strand18.
Nucleotide Excision Repair (NER): This pathway is necessary for the removal of bulgy DNA adducts, and damage caused by UV radiation. This involves damage recognition, removal of the offending section of DNA and resynthesis using an undamaged template24.
Mismatch Repair (MMR): This pathway is involved in repairing errors occurring during DNA replication, like base mismatches and insertion-deletion loops. Error in replication is corrected by MMR, which selectively replaces wrong bases with correct ones 35.
How DNA Damage Affects Cancer Cells
Mutant cancer cells frequently present problems in the pathways that repair these defects, causing genomic instability as a result. The mutation accumulation because of this instability is an important step in the development of cancer. As an example, defects in the NER-related genes can result in diseases such as xeroderma pigmentosum where UV-induced skin cancer is frequent due to inefficient repair of DNA damage by UV47.
Conclusion
The process by which human cells are able to repair damage in our DNA, is a very dynamic and basic principle of cellular health. Nevertheless, if these mechanisms are faulted or weakened then it can lead to devastating repercussions such as the formation of cancer.