Cigarette smoke and air pollution damage our DNA!

Experts state that our DNA, which carries genetic information, can be damaged for various reasons, saying that the most common causes of this damage include radiation (UV, X, and gamma rays), chemicals (cigarette smoke, toxins), viral infections, and metabolic processes naturally occurring in the body.

Noting that structural damage to DNA can harm genetic information and threaten the health of cells, Molecular Biologist RA Ayşegül Yanık said, "Methods that directly correct mutations in DNA involve genetic engineering techniques, including gene therapy or gene editing technologies. CRISPR-Cas9 is one of the most powerful gene editing tools developed in recent years. With this technology, a specific gene can be targeted, cut out, a healthy gene can be inserted, or the gene's function can be modified."

Üsküdar University Faculty of Engineering and Natural Sciences, Department of Molecular Biology and Genetics RA Ayşegül Yanık shared important information about DNA damage, repair, and treatment methods at the genetic level on the occasion of April 25th, World DNA Day.

Our DNA can be damaged by environmental factors

Noting that DNA is one of the most important molecules in our body carrying genetic information, RA Ayşegül Yanık said, “However, it is not always stable. It can be damaged due to environmental factors and natural events occurring in our body or cells. Factors that damage DNA include radiation (UV, X-rays, gamma rays), cigarette smoke, toxic chemicals, environmental toxins, air pollution, and viral infections. These factors can cause breaks in the DNA structure and lead to changes in the base structures that make up genetic information. Besides this, some viruses bind to our DNA and can disrupt our genetic structure. This situation can cause cells to multiply uncontrollably. Some substances formed as a result of metabolic events occurring in our body, and errors that can occur during DNA self-replication, can also disrupt the structure of DNA. These errors are mostly repaired by our body.”

How do the naturally occurring DNA repair mechanisms in our cells work?

Stating that cells are programmed to ensure the correct storage, protection, and transmission of genetic information from generation to generation, Yanık explained, “For this reason, our cells contain highly sophisticated repair mechanisms that can recognize and correct damage in DNA. This is a naturally occurring, inherent process. Thanks to this, genetic information is preserved, and cells continue their lives healthily. The cell recognizes structural defects on the DNA with special proteins. The damaged part of the DNA is cut out by special enzymes. A new piece is synthesized using the intact DNA template for the empty region, and the synthesized piece is ligated (connected) to the old DNA by enzymes present in the cell, thus completing the chain.”

What problems does unrepaired DNA cause?

Yanık also stated that if the damage occurring in DNA is not repaired properly, permanent mutations form in the cells. “These mutations can occur anywhere in the DNA, including in genes responsible for controlling cell growth, proliferation, and cell death. If this situation leads to uncontrolled cell proliferation, the risk of cancer increases. For example, when genes like BRCA1 and BRCA2 are damaged, the risk of breast and ovarian cancer increases. If DNA repair is insufficient, dysfunction and cell death can develop in nerve cells. This situation can cause neurological diseases. DNA repair is also important during the development of immune cells. Defects can lead to immune deficiencies. Additionally, DNA damage accumulates in cells over time. This situation slows down tissue regeneration, thereby increasing signs of aging,” she stated.

Intervening in DNA with CRISPR technology…

Saying that the concept of DNA repair or improvement means correcting errors in DNA or fixing genetic mutations, RA Ayşegül Yanık continued:

“It aims to support natural repair processes or treat diseases by making direct genetic corrections. DNA repair or improvement occurs through drugs that activate DNA repair enzymes or through direct genetic interventions. Methods that directly correct mutations in DNA involve genetic engineering techniques, including gene therapy or gene editing technologies (like cutting out a faulty gene with CRISPR and inserting a healthy one). CRISPR-Cas9 is one of the most powerful gene editing tools developed in recent years. With this technology, a specific gene can be targeted, cut out, a healthy gene can be inserted, or the gene's function can be modified.”

For which diseases does it hold promise?

Stating that DNA improvement approaches are particularly important for genetic-based diseases because they can directly intervene in problems at the genetic level, Yanık said, “Treatment approaches targeting DNA repair; CRISPR and gene therapy hold promise for genetic diseases such as sickle cell anemia, cystic fibrosis, Duchenne muscular dystrophy, rare genetic diseases like Spinal Muscular Atrophy (SMA), aging-related diseases like Alzheimer's; immune system diseases like SCID (Severe Combined Immunodeficiency), and some cancers.”

At what stage are the drugs and gene therapies?

Also stating that some drugs targeting DNA repair mechanisms are currently in clinical use today, RA Ayşegül Yanık concluded her words as follows:

“Some others are in the trial phase. Some drugs (e.g., PARP inhibitors) are already used in cancer treatment; these treatments aim to selectively kill cells with defective DNA repair by targeting them. Gene therapies, while having passed clinical trials for some rare diseases, are still undergoing trials for more common diseases. FDA-approved gene therapies exist for spinal muscular atrophy and some eye diseases. Some CRISPR-based therapies are currently in early clinical trial stages. Sickle cell anemia treatment has been successfully applied and received FDA approval in 2024.”

Üsküdar News Agency (ÜNA)