The work of the group of Prof. Siegfried Knasmüller covers the area of genetic toxicology. The topics are widespread and comprise the contamination of environmental compartments (air, water, soils), with genotoxic carcinogens, the detection of dietary factors which protect against cancer and DNA damage, as well as studies concerning occupational exposures which cause DNA instability and cancer. Recent activities concern the effects of obesity on DNA stability and the investigation of adverse (DNA-damaging) properties of widely used synthetic drugs (cannabinoids, cathinones). A new project concerns the search for metabolically competent cell lines for mutagenicity testing.

Methods established in the Knasmüller group:

a) Bacterial mutagenicity tests;
b) Cytogenetic tests with plants;
c) Comet assays in vitro and with rodents, and humans;
d) Human biomonitoring protocols such as the MN assay with lymphocytes and exfoliated cells and chromosomal aberration assays;
e) Investigations concerning preneoplastic lesions in different organs e.g. ACF in the colon

Figures a-d: Examples for the detection of genotoxic carcinogens. (a) The Comet Assay is based on the measurement of DNA migration in an electric field and can be conducted with a number of different cell types and organisms. (b) Micronuclei are chromosomal fragments and can be detected in blood- and also in oral mucosa cells. The frequency is a parameter for increased cancer risks. (c) Bacterial tests are used in particular for routine compound testing but also for the investigation of water and air. The induction of revertant colonies in some Salmonella typhimurium strains serves for the measure of genotoxic activity of a test compound or of complex mixtures. (d) Shows an obese mouse used in studies concerning cancer risks caused by overweight.