Latest news with #DNAmutations
Bloomberg
2 days ago
- Health
- Bloomberg
Why Non-Smokers Can Still Develop Lung Cancer
Why do some people get lung cancer even if they've never smoked? In this conversation, David Rubenstein speaks with Dr. Benjamin L. Ebert, CEO and President of Dana-Farber Cancer Institute, about the surprising role of DNA mutations in cancer, the impact of genetic predisposition, and what advances in genome testing mean for early detection and prevention. (Source: Bloomberg)
Yahoo
06-07-2025
- Health
- Yahoo
Air Pollution 'Strongly Associated' With DNA Mutations Tied to Lung Cancer
Lung cancer cases are on the rise in non-smokers around the world, and air pollution could be an insidious, contributing factor. A genome study has now found that outdoor smog and soot are strongly associated with DNA mutations related to lung cancer – including known drivers seen in smokers, and new ones unique to non-smokers. The more pollution someone was exposed to, the more mutations scientists found in their lung tumors. The findings don't mean that air pollution is directly causing lung cancer, but they do contribute to evidence suggesting that possibility. Related: "We're seeing this problematic trend that never-smokers are increasingly getting lung cancer, but we haven't understood why," explains biomolecular scientist Ludmil Alexandrov from the University of California San Diego (UCSD). "Our research shows that air pollution is strongly associated with the same types of DNA mutations we typically associate with smoking." The extensive international analysis examined the cancer genomes of 871 individuals from four continents, all of whom had lung cancer despite never having smoked and who had not yet received cancer treatment. Those who lived in regions with high levels of air pollution were significantly more likely to have TP53 mutations, EGFR mutations, and shorter telomeres. Abnormal TP53 and EGFR genes are hallmarks of lung cancers, especially those driven by the SBS4 DNA mutation, and shorter telomeres are linked to accelerated aging. In the current study, non-smokers who lived in areas with higher air pollution were nearly four times more likely to exhibit SBS4 signatures as those who lived in regions with cleaner air. By contrast, exposure to secondhand smoke, which is a known cancer risk, showed only a slight increase in genetic mutations. "If there is a mutagenic effect of secondhand smoke, it may be too weak for our current tools to detect," says geneticist Tongwu Zhang from the US National Cancer Institute (NCI). Not so for air pollution or tobacco smoking: both were strongly linked to DNA mutations. Today in the United States, people who have never smoked or who have smoked fewer than 100 cigarettes in their lives make up about 10 to 20 percent of lung cancer cases. Scientists have long suspected that air pollution could be a contributing factor, but exactly how fine particulate matter in the air compares to tobacco smoking or secondhand smoke exposure remains unclear. Some studies suggest that breathing polluted air is on par with smoking a pack a day, and yet these conclusions are mostly based on observational analyses. The current study digs further by looking at some of the molecular mechanisms that may be at play. It compared the lung cancer genomes of the 871 non-smokers with tumors from 345 smokers, to find similarities and differences. The majority of non-smokers with lung cancer had adenocarcinomas (the most common type of lung cancer), and nearly 5 percent of those tumors showed the SBS4 mutational signature. In addition, 28 percent of non-smokers showed a new signature called SBS40a, which wasn't found in tobacco smokers. Strangely, the cause of this particular mutational driver was unknown, but doesn't seem to be environmental in nature. "We see it in a majority of cases in this study, but we don't yet know what's driving it," says Alexandrov. "This is something entirely different, and it opens up a whole new area of investigation." The current research relied only on regional air pollution levels, which means it can't say how much any one individual was directly exposed to fine particulate matter in the air. Participants who said they had never smoked may have also smoked more than reported. These limitations notwithstanding, the overall findings align with other evidence indicating that soot or smog may trigger tumor growth in a similar way to cigarette chemicals. "This is an urgent and growing global problem that we are working to understand regarding never-smokers," says epidemiologist Maria Teresa Landi from the NCI. The team now hopes to expand their study to include cancer genomes from a more diverse, global cohort. The study was published in Nature. FDA Issues Warning Over Dangerous 'Gas Station Heroin' Substance Mysterious Leprosy Pathogen Has Lurked in The Americas For 4,000 Years Massive Review Finds No 'Safe' Level of Processed Meat Consumption
The Guardian
02-07-2025
- Health
- The Guardian
Air pollution linked to lung cancer-driving DNA mutations, study finds
Air pollution has been linked to a swathe of lung cancer-driving DNA mutations, in a study of people diagnosed with the disease despite never having smoked tobacco. The findings from an investigation into cancer patients around the world helps explain why those who have never smoked make up a rising proportion of people developing the cancer, a trend the researchers called an 'urgent and growing global problem'. Prof Ludmil Alexandrov, a senior author on the study at the University of California in San Diego, said researchers had observed the 'problematic trend' but had not understood the cause. 'Our research shows that air pollution is strongly associated with the same types of DNA mutations we typically associate with smoking,' he said. The scientists analysed the entire genetic code of lung tumours removed from 871 never-smokers in Europe, North America, Africa and Asia as part of the Sherlock-Lung study. They found that the higher the levels of air pollution in a region, the more cancer-driving and cancer-promoting mutations were present in residents' tumours. Fine-particulate air pollution was in particular linked to mutations in the TP53 gene. These have previously been associated with tobacco smoking. People exposed to greater air pollution also had shorter telomeres, protective strands of DNA found at the ends of chromosomes, which are often compared with the caps on shoelaces. Premature shortening of telomeres is a sign of more rapid cell division, a hallmark of cancer. 'This is an urgent and growing global problem that we are working to understand,' said Dr Maria Teresa Landi, an epidemiologist on the study at the US National Cancer Institute in Maryland. With smoking in decline in many parts of the world, including the UK and the US, people who have never smoked are making up a larger proportion of lung cancer patients. Current estimates suggest that 10-25% of lung cancers are now diagnosed in this group. Almost all such cancers are a form known as adenocarcinoma. Lung cancer remains the leading cause of cancer-related death worldwide. About 2.5m new cases are diagnosed globally each year. More than a million of the deaths occur in China, where smoking, air pollution and other environmental contaminants are factors. Recent research found that the highest rates of adenocarcinoma attributable to air pollution were in east Asia. While cases in the UK were much lower, they still amounted to more than 1,100 new diagnoses a year, scientists found. The latest work, published in Nature, identified only a slight rise in cancer-causing mutations in people exposed to secondhand tobacco smoke. But the study highlighted a significant risk from certain Chinese herbal medicines that contain aristolochic acid. Signature mutations linked to the herbal medicines were seen almost exclusively in never-smokers from Taiwan. Another mysterious mutational signature was seen in people who had never smoked but not those who did, and was now the focus of 'intense investigation', Landi said.
The Guardian
02-07-2025
- Health
- The Guardian
Air pollution linked to lung cancer-driving DNA mutations, study finds
Air pollution has been linked to a swathe of lung cancer-driving DNA mutations, in a landmark study of people diagnosed with the disease despite never having smoked tobacco. The findings from an investigation into cancer patients around the world helps explain why never-smokers make up a rising proportion of people developing the cancer, a trend the researchers called an 'urgent and growing global problem'. Prof Ludmil Alexandrov, a senior author on the study at the University of California in San Diego, said researchers had observed the 'problematic trend' but had not understood the cause. 'Our research shows that air pollution is strongly associated with the same types of DNA mutations we typically associate with smoking,' he said. The scientists analysed the entire genetic code of lung tumours removed from 871 never-smokers in Europe, North America, Africa and Asia as part of the Sherlock-Lung study. They found that the higher the levels of air pollution in a region, the more cancer-driving and cancer-promoting mutations were present in residents' tumours. Fine-particulate air pollution was particularly linked to mutations in the TP53 gene. These have previously been associated with tobacco smoking. People exposed to greater air pollution also had shorter telomeres, protective strands of DNA found at the ends of chromosomes, which are often compared with the caps on shoelaces. Telomeres tend to shorten with age, so premature telomere shortening is interpreted as a sign of rapid ageing. 'This is an urgent and growing global problem that we are working to understand,' said Dr Maria Teresa Landi, an epidemiologist on the study at the US National Cancer Institute in Maryland. With smoking in decline in many parts of the world, including the UK and the US, never-smokers are making up a larger proportion of lung cancer patients. Current estimates suggest that 10-25% of lung cancers are now diagnosed in never-smokers. Almost all are a form of cancer known as adenocarcinoma. Lung cancer remains the leading cause of cancer-related death worldwide. About 2.5m new cases are diagnosed globally each year. More than a million of the deaths occur in China, where smoking, air pollution and other environmental contaminants are factors. Recent research found that the highest rates of adenocarcinoma attributable to air pollution were in east Asia. While cases in the UK were much lower, they still amounted to more than 1,100 new diagnoses a year, scientists found. The latest work, published in Nature, identified only a slight rise in cancer-causing mutations in people exposed to secondhand tobacco smoke. But the study highlighted a significant risk from certain Chinese herbal medicines that contain aristolochic acid. Signature mutations linked to the herbal medicines were seen almost exclusively in never-smokers from Taiwan. Another mysterious mutational signature was seen in never-smokers but not smokers. 'This is something entirely different,' Alexandrov said.
