Researchers from the Norwegian Institute of Public Health and the German Institute of Human Nutrition Potsdam-Rehbruecke have found that mouse models used to estimate how carcinogenic some substances are to humans could be underestimating the danger.
Basically, a group of enzymes produced by humans in multiple places in the body are only produced in the liver of mice. This group of enzymes can make harmful substances less harmful but they can also make harmless substances carcinogenic. The team created “humanized mice” that had an expression more similar to humans and found that these mice had a higher incidence of tumors when fed a particular food mutagen than mice with normal expression of the enzyme. The paper has been accepted for publication by the journal Molecular Carcinogenesis and is available on their website.