What kind of DNA damage is caused by ionizing radiation?
DNA double-strand breaks constitute the most dangerous type of DNA damage induced by ionising radiation (IR). Accordingly, the resistance of cells to IR is modulated by three intimately related cellular processes: DNA repair, recombination, and replication.
How is ionizing radiation repaired?
DNA double-strand breaks (DSBs) generated by IR are the most lethal form of damage, and are mainly repaired via either homologous recombination (HR) or nonhomologous end-joining (NHEJ) pathways.
What DNA repair mechanisms can repair DNA damage?
At least five major DNA repair pathways—base excision repair (BER), nucleotide excision repair (NER), mismatch repair (MMR), homologous recombination (HR) and non-homologous end joining (NHEJ)—are active throughout different stages of the cell cycle, allowing the cells to repair the DNA damage.
What repair mechanism is most likely involved in repairing DNA damage caused by ionizing radiation?
DSB repair pathways NHEJ is the most common mechanism of DSB repair in eukaryotic cells. In this mechanism, the DNA strands at the DSB are cut or modified, and the ends are ligated together regardless of homology, generating deletions or insertions.
How is damaged DNA repaired?
Most damage to DNA is repaired by removal of the damaged bases followed by resynthesis of the excised region. Some lesions in DNA, however, can be repaired by direct reversal of the damage, which may be a more efficient way of dealing with specific types of DNA damage that occur frequently.
How damaged DNA is repaired?
What is DNA explain the DNA damage and repair?
DNA repair is a collection of processes by which a cell identifies and corrects damage to the DNA molecules that encode its genome.
As mentioned above, mutations in the ATM gene are associated with extreme hypersensitivity to ionizing radiation (Masuda and Kamiya, 2012), and polymorphisms in genes like XRCC3 and RAD51 increase the risk of radiosensitivity (Vral et al., 2011). These genes are also implicated in breast cancer.
How is DNA damage related to cancer treatment?
Abstract. Significance: Ionizing radiation (IR) is an effective and commonly employed treatment in the management of more than half of human malignancies. Because IR’s ability to control tumors mainly relies on DNA damage, the cell’s DNA damage response and repair (DRR) processes may hold the key to determining tumor responses.
How is ionizing radiation used to treat cancer?
Significance: Ionizing radiation (IR) is an effective and commonly employed treatment in the management of more than half of human malignancies. Because IR’s ability to control tumors mainly relies on DNA damage, the cell’s DNA damage response and repair (DRR) processes may hold the key to determining tumor responses.
What are genes involved in DNA damage repair?
The BRCA-1 and BRCA-2 proteins are involved in DSB damage repair, and several mutations in these genes increase the risk for developing breast and other neoplasias (Roy et al., 2012). Ionizing Radiation-Associated DNA Damage, Radiotherapy and Mechanisms of DNA Repair