Oxidative DNA damage: A new mechanism linking telomere instability, inflammation, and cellular senescence has been discovered
Oxidative DNA damage: A new mechanism linking telomere instability, inflammation, and cellular senescence has been discovered
Encouraging prospects for understanding the molecular processes involved in tumor progression. The study, led by Professor Stefano Amente, was published in the international journal *Redox Biology*
A new study, coordinated by Professor Stefano Amente, full professor of Genetics in the Department of Molecular Medicine and Medical Biotechnology at Federico II, and to which researchers Francesca Gorini (RTDA), Anna Piscone (postdoc) and Susanna Ambrosio (RTDB), has identified a mechanism through which defects in the DNA oxidative damage repair process can promote telomere instability, the activation of inflammatory responses, and the entry of cancer cells into a state of senescence. The research, published in the international journal *Redox Biology*, opens up new avenues for the development of innovative therapeutic strategies.
Every day, the DNA in our cells is subjected to thousands of lesions, many of which are oxidative damages caused by reactive oxygen species (ROS)—highly reactive molecules generated during normal cellular metabolism or produced in response to environmental factors such as ultraviolet radiation, pollution, smoking, and poor diet. If not properly recognized and repaired, these alterations can compromise genomic stability and promote the accumulation of cellular abnormalities. To counteract this process, cells possess sophisticated DNA repair systems, including those specialized in removing oxidative damage, which operate continuously to preserve the integrity of the genetic material. When these mechanisms are compromised, the risk of genomic instability and the development of pathological conditions—including cancer—increases.
Researchers have identified a crucial role for XRCC1, a protein involved in the mechanisms that repair oxidative DNA damage. The loss or impairment of its function leads to an accumulation of improperly repaired lesions, affecting the stability of telomeres—structures located at the ends of chromosomes that play an essential role in protecting the genome and maintaining chromosomal integrity.
The study demonstrates that defects in XRCC1 protein function—induced via CRISPR-Cas9 gene-editing techniques in cellular models— lead to the accumulation of unrepaired damage, compromising telomere structure and promoting the occurrence of telomere breaks. As a result of these events, fragments of telomeric DNA can escape from the nucleus and reach the cytoplasm, where they are mistakenly recognized by cellular surveillance systems as foreign DNA—similar to that produced during an infection— triggering an inflammatory response.
The result is the activation, in the analyzed cancer cells, of a cellular senescence program , characterized by the permanent arrest of proliferation. Senescence represents a protective response that prevents cells with significant genomic damage from continuing to replicate; however, the accumulation of senescent cells can contribute to the maintenance of a persistent inflammatory state and alter the tumor microenvironment, influencing the progression of the disease.
This discovery provides new insights into the link between oxidative DNA damage repair, telomere instability, inflammation, and tumor progression. Although further studies are needed to evaluate potential clinical applications, the findings could contribute to the development of more selective therapeutic approaches capable of exploiting specific vulnerabilities of cancer cells and enhancing the efficacy of innovative treatments, including immunotherapy.
Understanding how the mechanisms of oxidative DNA damage repair influence the fate of cells therefore represents a fundamental step toward increasingly targeted and personalized cancer medicine, with the goal of developing new strategies to combat the disease and improve patients’ quality of life.