Tag : Toxins

Washington: Chemical compounds in tobacco smoke alter the DNA of lung cells in ways that can lead to cancer in the longer term. Researchers at ETH Zurich have now been able to precisely localise such changes for the first time. Their results are clear: the pattern of DNA changes they determined in cell culture experiments is consistent with known mutations in lung cancer. While these results are not the first to show the link between cigarette smoking and lung cancer - this causal relationship has long been established - it is only now that scientists led by Shana Sturla, Professor of Toxicology at ETH Zurich, have been able to use their new method to map exactly which DNA building blocks are altered in the process. With this approach, it should one day also be possible to determine the effects of other toxins on cells - and doing so ought to be relatively easy using cell culture and molecular biological analyses. Up to now, such toxicological studies had to be carried out using laboratory animals. In their study, which has now been published in the journal ACS Central Science the researchers focused on a specific chemical compound: benzopyrene. This is produced when tobacco is burned. When the compound enters the human body, it is converted into very specific metabolites that have long been known for their toxicity. The scientists took these benzopyrene metabolites and added them to lung cells, which they cultured in in the lab for their studies. Changes as a precursor to mutations It has been known for some time that benzopyrene metabolites react with the DNA building block guanine (the G among the building blocks often abbreviated as A, C, T and G) and change it in a process known as alkylation. Although there are repair mecha ...