A combination of smoking and genetic characteristics causes head and neck cancer. This is what Weizmann Institute scientists discovered
A new genetic risk factor indicates an increased risk of getting head and neck cancer, as a result of smoking. This is according to a new study by Prof. Zvi Livna, head of the biological chemistry department at the Weizmann Institute of Science, Dr. Tamar Paz-Elitzur from the same department, and members of their research group. The research was done in collaboration with Dr. Rami Ben-Yosef from the Sourasky Medical Center, Prof. Lawrence Friedman from the Sheba Medical Center, and Prof. Edna Shechtman from Ben-Gurion University.
Prof. Livna focuses on researching the mechanisms that repair damage caused to the genetic material, DNA. To avoid the formation of unwanted mutations, the cells activate enzyme systems to repair these damages. These repair systems scan the DNA and locate defects in it using a sophisticated system of molecular sensors. When the system detects damage, it performs a kind of local analysis on the DNA: the repair enzymes cut and remove the damaged area, and replace it with a new DNA segment, similar to removing a damaged component in a computer, and replacing it with a new component.
In a study recently published in the scientific journal Cancer Research, the researchers examined whether a low personal (non-hereditary) ability to repair DNA damage increases the risk of developing head and neck cancer. This disease, of which smoking is one of the main causes, includes cancer of the throat, oral cavity, and pharynx. The researchers focused on one of the DNA-repairing enzymes, called OGG1, who previously developed a unique blood test that allows measuring its activity. They compared the level of activity of this enzyme in the bodies of healthy people to the level of activity of the same enzyme in the bodies of patients with head and neck cancer. It was found that indeed, this relatively simple blood test, which reveals the level of OGG activity, may indicate a relatively high level of risk for head and neck cancer. A person with weak OGG activity has a relatively high risk of getting this cancerous disease, compared to the risk level of a person with normal OGG activity. Prof. Livna says that smokers, who also have low OGG activity, are at a much greater risk level - 70 times - compared to non-smokers with normal OGG activity.
This study joins a previous study by the researchers, in which they showed that low activity of OGG indicates a relatively high risk of getting lung cancer (as you know, smoking is also considered a major risk factor for getting this disease). These studies show that a low personal level of OGG activity is a major risk factor for the development of lung cancer and head and neck cancers, and that the combination of smoking and low OGG activity causes a very large increase in the risk of these diseases. Dalia Elinger from the Department of Biological Chemistry, Dr. Akiva Wechsler from the Sourasky Medical Center, Dr. Adi Shani and Dr. Alan Barbie from the Kaplan Medical Center, and Dr. Meir Krupsky from the Sheba Medical Center also participated in the study.
Early identification of the level of risk of contracting lung cancer, and head and neck cancer, may help identify population groups at risk, and serve as an effective tool for preventing these diseases, among other things through increasing the motivation to quit smoking, as well as through the future development of medicinal and other measures to reduce the risk, as is done in diseases heart.
