Scientists have discovered the almost magical abilities of the human lung that enable it to repair itself and counteract the cancerous mutations caused by smoking. According to previous information, mutations that lead to lung cancer were considered permanent and persisted even after smoking cessation. But the surprising results, published in the journal Nature, reveal that the few cells that survive the mutations of cancerous cells can repair the lungs. This effect was observed even in patients who smoked an entire pack of cigarettes per day for a full 40 years before stopping completely.

Scientists have discovered the almost -magical- abilities of the human lung that enables it to repair itself and counteract the cancerous mutations caused by smoking. According to previous information, mutations that lead to lung cancer were considered permanent and persisted even after smoking cessation. But the surprising results, published in the journal Nature, reveal that the few cells that survive the mutations of cancerous cells can repair the lungs. This effect was observed even in patients who smoked an entire pack of cigarettes per day for a full 40 years before stopping completely. Thousands of chemicals in tobacco denature and transform DNA in lung cells, then slowly transform from healthy cells to cancerous ones. The vast majority of cells taken from a smokers airways were mutated by tobacco smoking, as the cells contain up to 10,000 genetic changes. These can be thought of as little time bombs, waiting for the next hit that causes them to turn into cancerous cells, said Dr. Kate Gowers, a researcher at the University of California, Los Angeles. But a small percentage of the cells remain healthy. It is not currently known how healthy cells avoid infection and the genetic change caused by smoking, and the researchers believe that they are present in a nuclear repository. However, after a person stops smoking, it is these cells (present in the lungs nuclear reservoir) that grow and replace the damaged cells in the lungs. And for people who quit smoking, they had a large number of healthy cells, up to 40 percent of healthy cells in people who did not smoke. Dr Peter Campbell, from the Sanger Institute, told BBC News: We never expected this result. He added: There are a number of cells that, sort of, magically work to regenerate the lining of the airways. Motivation to quit smoking Researchers still need to assess how much the lungs are repaired. The study focused on the major air passages rather than the small structures called alveoli, where oxygen from the air we breathe crosses into our lungs. There are around 47,000 cases of lung cancer in Britain each year. Nearly three-quarters of it is caused by smoking. Studies have already shown that people reduce their risk of developing lung cancer once they stop smoking. The assumption was that this result came about simply because any further mutations caused by smoking were avoided. Dr Rachel Orrett, from Cancer Research UK, said: Its a really stimulating idea that people who stop smoking are doing twice as well, by preventing further tobacco-related damage to their lung cells, and giving their lungs a chance to balance out some of the damage to healthy cells . Source: BBC Arabic